pixman git update 18 July 2011

1 files changed, 1505 insertions, 1516 deletions

diff --git a/mesalib/src/mesa/swrast/s_span.c b/mesalib/src/mesa/swrast/s_span.c
index 7f88b6dd4..db102ac79 100644
--- a/mesalib/src/mesa/swrast/s_span.c
+++ b/mesalib/src/mesa/swrast/s_span.c
@@ -1,1516 +1,1505 @@
-/*

- * Mesa 3-D graphics library

- * Version:  7.5

- *

- * Copyright (C) 1999-2008  Brian Paul   All Rights Reserved.

- * Copyright (C) 2009  VMware, Inc.  All Rights Reserved.

- *

- * Permission is hereby granted, free of charge, to any person obtaining a

- * copy of this software and associated documentation files (the "Software"),

- * to deal in the Software without restriction, including without limitation

- * the rights to use, copy, modify, merge, publish, distribute, sublicense,

- * and/or sell copies of the Software, and to permit persons to whom the

- * Software is furnished to do so, subject to the following conditions:

- *

- * The above copyright notice and this permission notice shall be included

- * in all copies or substantial portions of the Software.

- *

- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS

- * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL

- * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN

- * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN

- * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

- */

-

-

-/**

- * \file swrast/s_span.c

- * \brief Span processing functions used by all rasterization functions.

- * This is where all the per-fragment tests are performed

- * \author Brian Paul

- */

-

-#include "main/glheader.h"

-#include "main/colormac.h"

-#include "main/macros.h"

-#include "main/imports.h"

-#include "main/image.h"

-

-#include "s_atifragshader.h"

-#include "s_alpha.h"

-#include "s_blend.h"

-#include "s_context.h"

-#include "s_depth.h"

-#include "s_fog.h"

-#include "s_logic.h"

-#include "s_masking.h"

-#include "s_fragprog.h"

-#include "s_span.h"

-#include "s_stencil.h"

-#include "s_texcombine.h"

-

-

-/**

- * Set default fragment attributes for the span using the

- * current raster values.  Used prior to glDraw/CopyPixels

- * and glBitmap.

- */

-void

-_swrast_span_default_attribs(struct gl_context *ctx, SWspan *span)

-{

-   GLchan r, g, b, a;

-   /* Z*/

-   {

-      const GLfloat depthMax = ctx->DrawBuffer->_DepthMaxF;

-      if (ctx->DrawBuffer->Visual.depthBits <= 16)

-         span->z = FloatToFixed(ctx->Current.RasterPos[2] * depthMax + 0.5F);

-      else {

-         GLfloat tmpf = ctx->Current.RasterPos[2] * depthMax; 

-         tmpf = MIN2(tmpf, depthMax);

-         span->z = (GLint)tmpf;

-      }

-      span->zStep = 0;

-      span->interpMask |= SPAN_Z;

-   }

-

-   /* W (for perspective correction) */

-   span->attrStart[FRAG_ATTRIB_WPOS][3] = 1.0;

-   span->attrStepX[FRAG_ATTRIB_WPOS][3] = 0.0;

-   span->attrStepY[FRAG_ATTRIB_WPOS][3] = 0.0;

-

-   /* primary color, or color index */

-   UNCLAMPED_FLOAT_TO_CHAN(r, ctx->Current.RasterColor[0]);

-   UNCLAMPED_FLOAT_TO_CHAN(g, ctx->Current.RasterColor[1]);

-   UNCLAMPED_FLOAT_TO_CHAN(b, ctx->Current.RasterColor[2]);

-   UNCLAMPED_FLOAT_TO_CHAN(a, ctx->Current.RasterColor[3]);

-#if CHAN_TYPE == GL_FLOAT

-   span->red = r;

-   span->green = g;

-   span->blue = b;

-   span->alpha = a;

-#else

-   span->red   = IntToFixed(r);

-   span->green = IntToFixed(g);

-   span->blue  = IntToFixed(b);

-   span->alpha = IntToFixed(a);

-#endif

-   span->redStep = 0;

-   span->greenStep = 0;

-   span->blueStep = 0;

-   span->alphaStep = 0;

-   span->interpMask |= SPAN_RGBA;

-

-   COPY_4V(span->attrStart[FRAG_ATTRIB_COL0], ctx->Current.RasterColor);

-   ASSIGN_4V(span->attrStepX[FRAG_ATTRIB_COL0], 0.0, 0.0, 0.0, 0.0);

-   ASSIGN_4V(span->attrStepY[FRAG_ATTRIB_COL0], 0.0, 0.0, 0.0, 0.0);

-

-   /* Secondary color */

-   if (ctx->Light.Enabled || ctx->Fog.ColorSumEnabled)

-   {

-      COPY_4V(span->attrStart[FRAG_ATTRIB_COL1], ctx->Current.RasterSecondaryColor);

-      ASSIGN_4V(span->attrStepX[FRAG_ATTRIB_COL1], 0.0, 0.0, 0.0, 0.0);

-      ASSIGN_4V(span->attrStepY[FRAG_ATTRIB_COL1], 0.0, 0.0, 0.0, 0.0);

-   }

-

-   /* fog */

-   {

-      const SWcontext *swrast = SWRAST_CONTEXT(ctx);

-      GLfloat fogVal; /* a coord or a blend factor */

-      if (swrast->_PreferPixelFog) {

-         /* fog blend factors will be computed from fog coordinates per pixel */

-         fogVal = ctx->Current.RasterDistance;

-      }

-      else {

-         /* fog blend factor should be computed from fogcoord now */

-         fogVal = _swrast_z_to_fogfactor(ctx, ctx->Current.RasterDistance);

-      }

-      span->attrStart[FRAG_ATTRIB_FOGC][0] = fogVal;

-      span->attrStepX[FRAG_ATTRIB_FOGC][0] = 0.0;

-      span->attrStepY[FRAG_ATTRIB_FOGC][0] = 0.0;

-   }

-

-   /* texcoords */

-   {

-      GLuint i;

-      for (i = 0; i < ctx->Const.MaxTextureCoordUnits; i++) {

-         const GLuint attr = FRAG_ATTRIB_TEX0 + i;

-         const GLfloat *tc = ctx->Current.RasterTexCoords[i];

-         if (ctx->FragmentProgram._Current || ctx->ATIFragmentShader._Enabled) {

-            COPY_4V(span->attrStart[attr], tc);

-         }

-         else if (tc[3] > 0.0F) {

-            /* use (s/q, t/q, r/q, 1) */

-            span->attrStart[attr][0] = tc[0] / tc[3];

-            span->attrStart[attr][1] = tc[1] / tc[3];

-            span->attrStart[attr][2] = tc[2] / tc[3];

-            span->attrStart[attr][3] = 1.0;

-         }

-         else {

-            ASSIGN_4V(span->attrStart[attr], 0.0F, 0.0F, 0.0F, 1.0F);

-         }

-         ASSIGN_4V(span->attrStepX[attr], 0.0F, 0.0F, 0.0F, 0.0F);

-         ASSIGN_4V(span->attrStepY[attr], 0.0F, 0.0F, 0.0F, 0.0F);

-      }

-   }

-}

-

-

-/**

- * Interpolate the active attributes (and'd with attrMask) to

- * fill in span->array->attribs[].

- * Perspective correction will be done.  The point/line/triangle function

- * should have computed attrStart/Step values for FRAG_ATTRIB_WPOS[3]!

- */

-static INLINE void

-interpolate_active_attribs(struct gl_context *ctx, SWspan *span, GLbitfield attrMask)

-{

-   const SWcontext *swrast = SWRAST_CONTEXT(ctx);

-

-   /*

-    * Don't overwrite existing array values, such as colors that may have

-    * been produced by glDraw/CopyPixels.

-    */

-   attrMask &= ~span->arrayAttribs;

-

-   ATTRIB_LOOP_BEGIN

-      if (attrMask & (1 << attr)) {

-         const GLfloat dwdx = span->attrStepX[FRAG_ATTRIB_WPOS][3];

-         GLfloat w = span->attrStart[FRAG_ATTRIB_WPOS][3];

-         const GLfloat dv0dx = span->attrStepX[attr][0];

-         const GLfloat dv1dx = span->attrStepX[attr][1];

-         const GLfloat dv2dx = span->attrStepX[attr][2];

-         const GLfloat dv3dx = span->attrStepX[attr][3];

-         GLfloat v0 = span->attrStart[attr][0] + span->leftClip * dv0dx;

-         GLfloat v1 = span->attrStart[attr][1] + span->leftClip * dv1dx;

-         GLfloat v2 = span->attrStart[attr][2] + span->leftClip * dv2dx;

-         GLfloat v3 = span->attrStart[attr][3] + span->leftClip * dv3dx;

-         GLuint k;

-         for (k = 0; k < span->end; k++) {

-            const GLfloat invW = 1.0f / w;

-            span->array->attribs[attr][k][0] = v0 * invW;

-            span->array->attribs[attr][k][1] = v1 * invW;

-            span->array->attribs[attr][k][2] = v2 * invW;

-            span->array->attribs[attr][k][3] = v3 * invW;

-            v0 += dv0dx;

-            v1 += dv1dx;

-            v2 += dv2dx;

-            v3 += dv3dx;

-            w += dwdx;

-         }

-         ASSERT((span->arrayAttribs & (1 << attr)) == 0);

-         span->arrayAttribs |= (1 << attr);

-      }

-   ATTRIB_LOOP_END

-}

-

-

-/**

- * Interpolate primary colors to fill in the span->array->rgba8 (or rgb16)

- * color array.

- */

-static INLINE void

-interpolate_int_colors(struct gl_context *ctx, SWspan *span)

-{

-   const GLuint n = span->end;

-   GLuint i;

-

-#if CHAN_BITS != 32

-   ASSERT(!(span->arrayMask & SPAN_RGBA));

-#endif

-

-   switch (span->array->ChanType) {

-#if CHAN_BITS != 32

-   case GL_UNSIGNED_BYTE:

-      {

-         GLubyte (*rgba)[4] = span->array->rgba8;

-         if (span->interpMask & SPAN_FLAT) {

-            GLubyte color[4];

-            color[RCOMP] = FixedToInt(span->red);

-            color[GCOMP] = FixedToInt(span->green);

-            color[BCOMP] = FixedToInt(span->blue);

-            color[ACOMP] = FixedToInt(span->alpha);

-            for (i = 0; i < n; i++) {

-               COPY_4UBV(rgba[i], color);

-            }

-         }

-         else {

-            GLfixed r = span->red;

-            GLfixed g = span->green;

-            GLfixed b = span->blue;

-            GLfixed a = span->alpha;

-            GLint dr = span->redStep;

-            GLint dg = span->greenStep;

-            GLint db = span->blueStep;

-            GLint da = span->alphaStep;

-            for (i = 0; i < n; i++) {

-               rgba[i][RCOMP] = FixedToChan(r);

-               rgba[i][GCOMP] = FixedToChan(g);

-               rgba[i][BCOMP] = FixedToChan(b);

-               rgba[i][ACOMP] = FixedToChan(a);

-               r += dr;

-               g += dg;

-               b += db;

-               a += da;

-            }

-         }

-      }

-      break;

-   case GL_UNSIGNED_SHORT:

-      {

-         GLushort (*rgba)[4] = span->array->rgba16;

-         if (span->interpMask & SPAN_FLAT) {

-            GLushort color[4];

-            color[RCOMP] = FixedToInt(span->red);

-            color[GCOMP] = FixedToInt(span->green);

-            color[BCOMP] = FixedToInt(span->blue);

-            color[ACOMP] = FixedToInt(span->alpha);

-            for (i = 0; i < n; i++) {

-               COPY_4V(rgba[i], color);

-            }

-         }

-         else {

-            GLushort (*rgba)[4] = span->array->rgba16;

-            GLfixed r, g, b, a;

-            GLint dr, dg, db, da;

-            r = span->red;

-            g = span->green;

-            b = span->blue;

-            a = span->alpha;

-            dr = span->redStep;

-            dg = span->greenStep;

-            db = span->blueStep;

-            da = span->alphaStep;

-            for (i = 0; i < n; i++) {

-               rgba[i][RCOMP] = FixedToChan(r);

-               rgba[i][GCOMP] = FixedToChan(g);

-               rgba[i][BCOMP] = FixedToChan(b);

-               rgba[i][ACOMP] = FixedToChan(a);

-               r += dr;

-               g += dg;

-               b += db;

-               a += da;

-            }

-         }

-      }

-      break;

-#endif

-   case GL_FLOAT:

-      interpolate_active_attribs(ctx, span, FRAG_BIT_COL0);

-      break;

-   default:

-      _mesa_problem(ctx, "bad datatype 0x%x in interpolate_int_colors",

-                    span->array->ChanType);

-   }

-   span->arrayMask |= SPAN_RGBA;

-}

-

-

-/**

- * Populate the FRAG_ATTRIB_COL0 array.

- */

-static INLINE void

-interpolate_float_colors(SWspan *span)

-{

-   GLfloat (*col0)[4] = span->array->attribs[FRAG_ATTRIB_COL0];

-   const GLuint n = span->end;

-   GLuint i;

-

-   assert(!(span->arrayAttribs & FRAG_BIT_COL0));

-

-   if (span->arrayMask & SPAN_RGBA) {

-      /* convert array of int colors */

-      for (i = 0; i < n; i++) {

-         col0[i][0] = UBYTE_TO_FLOAT(span->array->rgba8[i][0]);

-         col0[i][1] = UBYTE_TO_FLOAT(span->array->rgba8[i][1]);

-         col0[i][2] = UBYTE_TO_FLOAT(span->array->rgba8[i][2]);

-         col0[i][3] = UBYTE_TO_FLOAT(span->array->rgba8[i][3]);

-      }

-   }

-   else {

-      /* interpolate red/green/blue/alpha to get float colors */

-      ASSERT(span->interpMask & SPAN_RGBA);

-      if (span->interpMask & SPAN_FLAT) {

-         GLfloat r = FixedToFloat(span->red);

-         GLfloat g = FixedToFloat(span->green);

-         GLfloat b = FixedToFloat(span->blue);

-         GLfloat a = FixedToFloat(span->alpha);

-         for (i = 0; i < n; i++) {

-            ASSIGN_4V(col0[i], r, g, b, a);

-         }

-      }

-      else {

-         GLfloat r = FixedToFloat(span->red);

-         GLfloat g = FixedToFloat(span->green);

-         GLfloat b = FixedToFloat(span->blue);

-         GLfloat a = FixedToFloat(span->alpha);

-         GLfloat dr = FixedToFloat(span->redStep);

-         GLfloat dg = FixedToFloat(span->greenStep);

-         GLfloat db = FixedToFloat(span->blueStep);

-         GLfloat da = FixedToFloat(span->alphaStep);

-         for (i = 0; i < n; i++) {

-            col0[i][0] = r;

-            col0[i][1] = g;

-            col0[i][2] = b;

-            col0[i][3] = a;

-            r += dr;

-            g += dg;

-            b += db;

-            a += da;

-         }

-      }

-   }

-

-   span->arrayAttribs |= FRAG_BIT_COL0;

-   span->array->ChanType = GL_FLOAT;

-}

-

-

-

-/**

- * Fill in the span.zArray array from the span->z, zStep values.

- */

-void

-_swrast_span_interpolate_z( const struct gl_context *ctx, SWspan *span )

-{

-   const GLuint n = span->end;

-   GLuint i;

-

-   ASSERT(!(span->arrayMask & SPAN_Z));

-

-   if (ctx->DrawBuffer->Visual.depthBits <= 16) {

-      GLfixed zval = span->z;

-      GLuint *z = span->array->z; 

-      for (i = 0; i < n; i++) {

-         z[i] = FixedToInt(zval);

-         zval += span->zStep;

-      }

-   }

-   else {

-      /* Deep Z buffer, no fixed->int shift */

-      GLuint zval = span->z;

-      GLuint *z = span->array->z;

-      for (i = 0; i < n; i++) {

-         z[i] = zval;

-         zval += span->zStep;

-      }

-   }

-   span->interpMask &= ~SPAN_Z;

-   span->arrayMask |= SPAN_Z;

-}

-

-

-/**

- * Compute mipmap LOD from partial derivatives.

- * This the ideal solution, as given in the OpenGL spec.

- */

-GLfloat

-_swrast_compute_lambda(GLfloat dsdx, GLfloat dsdy, GLfloat dtdx, GLfloat dtdy,

-                       GLfloat dqdx, GLfloat dqdy, GLfloat texW, GLfloat texH,

-                       GLfloat s, GLfloat t, GLfloat q, GLfloat invQ)

-{

-   GLfloat dudx = texW * ((s + dsdx) / (q + dqdx) - s * invQ);

-   GLfloat dvdx = texH * ((t + dtdx) / (q + dqdx) - t * invQ);

-   GLfloat dudy = texW * ((s + dsdy) / (q + dqdy) - s * invQ);

-   GLfloat dvdy = texH * ((t + dtdy) / (q + dqdy) - t * invQ);

-   GLfloat x = SQRTF(dudx * dudx + dvdx * dvdx);

-   GLfloat y = SQRTF(dudy * dudy + dvdy * dvdy);

-   GLfloat rho = MAX2(x, y);

-   GLfloat lambda = LOG2(rho);

-   return lambda;

-}

-

-

-/**

- * Compute mipmap LOD from partial derivatives.

- * This is a faster approximation than above function.

- */

-#if 0

-GLfloat

-_swrast_compute_lambda(GLfloat dsdx, GLfloat dsdy, GLfloat dtdx, GLfloat dtdy,

-                     GLfloat dqdx, GLfloat dqdy, GLfloat texW, GLfloat texH,

-                     GLfloat s, GLfloat t, GLfloat q, GLfloat invQ)

-{

-   GLfloat dsdx2 = (s + dsdx) / (q + dqdx) - s * invQ;

-   GLfloat dtdx2 = (t + dtdx) / (q + dqdx) - t * invQ;

-   GLfloat dsdy2 = (s + dsdy) / (q + dqdy) - s * invQ;

-   GLfloat dtdy2 = (t + dtdy) / (q + dqdy) - t * invQ;

-   GLfloat maxU, maxV, rho, lambda;

-   dsdx2 = FABSF(dsdx2);

-   dsdy2 = FABSF(dsdy2);

-   dtdx2 = FABSF(dtdx2);

-   dtdy2 = FABSF(dtdy2);

-   maxU = MAX2(dsdx2, dsdy2) * texW;

-   maxV = MAX2(dtdx2, dtdy2) * texH;

-   rho = MAX2(maxU, maxV);

-   lambda = LOG2(rho);

-   return lambda;

-}

-#endif

-

-

-/**

- * Fill in the span.array->attrib[FRAG_ATTRIB_TEXn] arrays from the

- * using the attrStart/Step values.

- *

- * This function only used during fixed-function fragment processing.

- *

- * Note: in the places where we divide by Q (or mult by invQ) we're

- * really doing two things: perspective correction and texcoord

- * projection.  Remember, for texcoord (s,t,r,q) we need to index

- * texels with (s/q, t/q, r/q).

- */

-static void

-interpolate_texcoords(struct gl_context *ctx, SWspan *span)

-{

-   const GLuint maxUnit

-      = (ctx->Texture._EnabledCoordUnits > 1) ? ctx->Const.MaxTextureUnits : 1;

-   GLuint u;

-

-   /* XXX CoordUnits vs. ImageUnits */

-   for (u = 0; u < maxUnit; u++) {

-      if (ctx->Texture._EnabledCoordUnits & (1 << u)) {

-         const GLuint attr = FRAG_ATTRIB_TEX0 + u;

-         const struct gl_texture_object *obj = ctx->Texture.Unit[u]._Current;

-         GLfloat texW, texH;

-         GLboolean needLambda;

-         GLfloat (*texcoord)[4] = span->array->attribs[attr];

-         GLfloat *lambda = span->array->lambda[u];

-         const GLfloat dsdx = span->attrStepX[attr][0];

-         const GLfloat dsdy = span->attrStepY[attr][0];

-         const GLfloat dtdx = span->attrStepX[attr][1];

-         const GLfloat dtdy = span->attrStepY[attr][1];

-         const GLfloat drdx = span->attrStepX[attr][2];

-         const GLfloat dqdx = span->attrStepX[attr][3];

-         const GLfloat dqdy = span->attrStepY[attr][3];

-         GLfloat s = span->attrStart[attr][0] + span->leftClip * dsdx;

-         GLfloat t = span->attrStart[attr][1] + span->leftClip * dtdx;

-         GLfloat r = span->attrStart[attr][2] + span->leftClip * drdx;

-         GLfloat q = span->attrStart[attr][3] + span->leftClip * dqdx;

-

-         if (obj) {

-            const struct gl_texture_image *img = obj->Image[0][obj->BaseLevel];

-            needLambda = (obj->Sampler.MinFilter != obj->Sampler.MagFilter)

-               || ctx->FragmentProgram._Current;

-            /* LOD is calculated directly in the ansiotropic filter, we can

-             * skip the normal lambda function as the result is ignored.

-             */

-            if (obj->Sampler.MaxAnisotropy > 1.0 &&

-                obj->Sampler.MinFilter == GL_LINEAR_MIPMAP_LINEAR) {

-               needLambda = GL_FALSE;

-            }

-            texW = img->WidthScale;

-            texH = img->HeightScale;

-         }

-         else {

-            /* using a fragment program */

-            texW = 1.0;

-            texH = 1.0;

-            needLambda = GL_FALSE;

-         }

-

-         if (needLambda) {

-            GLuint i;

-            if (ctx->FragmentProgram._Current

-                || ctx->ATIFragmentShader._Enabled) {

-               /* do perspective correction but don't divide s, t, r by q */

-               const GLfloat dwdx = span->attrStepX[FRAG_ATTRIB_WPOS][3];

-               GLfloat w = span->attrStart[FRAG_ATTRIB_WPOS][3] + span->leftClip * dwdx;

-               for (i = 0; i < span->end; i++) {

-                  const GLfloat invW = 1.0F / w;

-                  texcoord[i][0] = s * invW;

-                  texcoord[i][1] = t * invW;

-                  texcoord[i][2] = r * invW;

-                  texcoord[i][3] = q * invW;

-                  lambda[i] = _swrast_compute_lambda(dsdx, dsdy, dtdx, dtdy,

-                                                     dqdx, dqdy, texW, texH,

-                                                     s, t, q, invW);

-                  s += dsdx;

-                  t += dtdx;

-                  r += drdx;

-                  q += dqdx;

-                  w += dwdx;

-               }

-            }

-            else {

-               for (i = 0; i < span->end; i++) {

-                  const GLfloat invQ = (q == 0.0F) ? 1.0F : (1.0F / q);

-                  texcoord[i][0] = s * invQ;

-                  texcoord[i][1] = t * invQ;

-                  texcoord[i][2] = r * invQ;

-                  texcoord[i][3] = q;

-                  lambda[i] = _swrast_compute_lambda(dsdx, dsdy, dtdx, dtdy,

-                                                     dqdx, dqdy, texW, texH,

-                                                     s, t, q, invQ);

-                  s += dsdx;

-                  t += dtdx;

-                  r += drdx;

-                  q += dqdx;

-               }

-            }

-            span->arrayMask |= SPAN_LAMBDA;

-         }

-         else {

-            GLuint i;

-            if (ctx->FragmentProgram._Current ||

-                ctx->ATIFragmentShader._Enabled) {

-               /* do perspective correction but don't divide s, t, r by q */

-               const GLfloat dwdx = span->attrStepX[FRAG_ATTRIB_WPOS][3];

-               GLfloat w = span->attrStart[FRAG_ATTRIB_WPOS][3] + span->leftClip * dwdx;

-               for (i = 0; i < span->end; i++) {

-                  const GLfloat invW = 1.0F / w;

-                  texcoord[i][0] = s * invW;

-                  texcoord[i][1] = t * invW;

-                  texcoord[i][2] = r * invW;

-                  texcoord[i][3] = q * invW;

-                  lambda[i] = 0.0;

-                  s += dsdx;

-                  t += dtdx;

-                  r += drdx;

-                  q += dqdx;

-                  w += dwdx;

-               }

-            }

-            else if (dqdx == 0.0F) {

-               /* Ortho projection or polygon's parallel to window X axis */

-               const GLfloat invQ = (q == 0.0F) ? 1.0F : (1.0F / q);

-               for (i = 0; i < span->end; i++) {

-                  texcoord[i][0] = s * invQ;

-                  texcoord[i][1] = t * invQ;

-                  texcoord[i][2] = r * invQ;

-                  texcoord[i][3] = q;

-                  lambda[i] = 0.0;

-                  s += dsdx;

-                  t += dtdx;

-                  r += drdx;

-               }

-            }

-            else {

-               for (i = 0; i < span->end; i++) {

-                  const GLfloat invQ = (q == 0.0F) ? 1.0F : (1.0F / q);

-                  texcoord[i][0] = s * invQ;

-                  texcoord[i][1] = t * invQ;

-                  texcoord[i][2] = r * invQ;

-                  texcoord[i][3] = q;

-                  lambda[i] = 0.0;

-                  s += dsdx;

-                  t += dtdx;

-                  r += drdx;

-                  q += dqdx;

-               }

-            }

-         } /* lambda */

-      } /* if */

-   } /* for */

-}

-

-

-/**

- * Fill in the arrays->attribs[FRAG_ATTRIB_WPOS] array.

- */

-static INLINE void

-interpolate_wpos(struct gl_context *ctx, SWspan *span)

-{

-   GLfloat (*wpos)[4] = span->array->attribs[FRAG_ATTRIB_WPOS];

-   GLuint i;

-   const GLfloat zScale = 1.0F / ctx->DrawBuffer->_DepthMaxF;

-   GLfloat w, dw;

-

-   if (span->arrayMask & SPAN_XY) {

-      for (i = 0; i < span->end; i++) {

-         wpos[i][0] = (GLfloat) span->array->x[i];

-         wpos[i][1] = (GLfloat) span->array->y[i];

-      }

-   }

-   else {

-      for (i = 0; i < span->end; i++) {

-         wpos[i][0] = (GLfloat) span->x + i;

-         wpos[i][1] = (GLfloat) span->y;

-      }

-   }

-

-   dw = span->attrStepX[FRAG_ATTRIB_WPOS][3];

-   w = span->attrStart[FRAG_ATTRIB_WPOS][3] + span->leftClip * dw;

-   for (i = 0; i < span->end; i++) {

-      wpos[i][2] = (GLfloat) span->array->z[i] * zScale;

-      wpos[i][3] = w;

-      w += dw;

-   }

-}

-

-

-/**

- * Apply the current polygon stipple pattern to a span of pixels.

- */

-static INLINE void

-stipple_polygon_span(struct gl_context *ctx, SWspan *span)

-{

-   GLubyte *mask = span->array->mask;

-

-   ASSERT(ctx->Polygon.StippleFlag);

-

-   if (span->arrayMask & SPAN_XY) {

-      /* arrays of x/y pixel coords */

-      GLuint i;

-      for (i = 0; i < span->end; i++) {

-         const GLint col = span->array->x[i] % 32;

-         const GLint row = span->array->y[i] % 32;

-         const GLuint stipple = ctx->PolygonStipple[row];

-         if (((1 << col) & stipple) == 0) {

-            mask[i] = 0;

-         }

-      }

-   }

-   else {

-      /* horizontal span of pixels */

-      const GLuint highBit = 1 << 31;

-      const GLuint stipple = ctx->PolygonStipple[span->y % 32];

-      GLuint i, m = highBit >> (GLuint) (span->x % 32);

-      for (i = 0; i < span->end; i++) {

-         if ((m & stipple) == 0) {

-            mask[i] = 0;

-         }

-         m = m >> 1;

-         if (m == 0) {

-            m = highBit;

-         }

-      }

-   }

-   span->writeAll = GL_FALSE;

-}

-

-

-/**

- * Clip a pixel span to the current buffer/window boundaries:

- * DrawBuffer->_Xmin, _Xmax, _Ymin, _Ymax.  This will accomplish

- * window clipping and scissoring.

- * Return:   GL_TRUE   some pixels still visible

- *           GL_FALSE  nothing visible

- */

-static INLINE GLuint

-clip_span( struct gl_context *ctx, SWspan *span )

-{

-   const GLint xmin = ctx->DrawBuffer->_Xmin;

-   const GLint xmax = ctx->DrawBuffer->_Xmax;

-   const GLint ymin = ctx->DrawBuffer->_Ymin;

-   const GLint ymax = ctx->DrawBuffer->_Ymax;

-

-   span->leftClip = 0;

-

-   if (span->arrayMask & SPAN_XY) {

-      /* arrays of x/y pixel coords */

-      const GLint *x = span->array->x;

-      const GLint *y = span->array->y;

-      const GLint n = span->end;

-      GLubyte *mask = span->array->mask;

-      GLint i;

-      if (span->arrayMask & SPAN_MASK) {

-         /* note: using & intead of && to reduce branches */

-         for (i = 0; i < n; i++) {

-            mask[i] &= (x[i] >= xmin) & (x[i] < xmax)

-                     & (y[i] >= ymin) & (y[i] < ymax);

-         }

-      }

-      else {

-         /* note: using & intead of && to reduce branches */

-         for (i = 0; i < n; i++) {

-            mask[i] = (x[i] >= xmin) & (x[i] < xmax)

-                    & (y[i] >= ymin) & (y[i] < ymax);

-         }

-      }

-      return GL_TRUE;  /* some pixels visible */

-   }

-   else {

-      /* horizontal span of pixels */

-      const GLint x = span->x;

-      const GLint y = span->y;

-      GLint n = span->end;

-

-      /* Trivial rejection tests */

-      if (y < ymin || y >= ymax || x + n <= xmin || x >= xmax) {

-         span->end = 0;

-         return GL_FALSE;  /* all pixels clipped */

-      }

-

-      /* Clip to right */

-      if (x + n > xmax) {

-         ASSERT(x < xmax);

-         n = span->end = xmax - x;

-      }

-

-      /* Clip to the left */

-      if (x < xmin) {

-         const GLint leftClip = xmin - x;

-         GLuint i;

-

-         ASSERT(leftClip > 0);

-         ASSERT(x + n > xmin);

-

-         /* Clip 'leftClip' pixels from the left side.

-          * The span->leftClip field will be applied when we interpolate

-          * fragment attributes.

-          * For arrays of values, shift them left.

-          */

-         for (i = 0; i < FRAG_ATTRIB_MAX; i++) {

-            if (span->interpMask & (1 << i)) {

-               GLuint j;

-               for (j = 0; j < 4; j++) {

-                  span->attrStart[i][j] += leftClip * span->attrStepX[i][j];

-               }

-            }

-         }

-

-         span->red += leftClip * span->redStep;

-         span->green += leftClip * span->greenStep;

-         span->blue += leftClip * span->blueStep;

-         span->alpha += leftClip * span->alphaStep;

-         span->index += leftClip * span->indexStep;

-         span->z += leftClip * span->zStep;

-         span->intTex[0] += leftClip * span->intTexStep[0];

-         span->intTex[1] += leftClip * span->intTexStep[1];

-

-#define SHIFT_ARRAY(ARRAY, SHIFT, LEN) \

-         memcpy(ARRAY, ARRAY + (SHIFT), (LEN) * sizeof(ARRAY[0]))

-

-         for (i = 0; i < FRAG_ATTRIB_MAX; i++) {

-            if (span->arrayAttribs & (1 << i)) {

-               /* shift array elements left by 'leftClip' */

-               SHIFT_ARRAY(span->array->attribs[i], leftClip, n - leftClip);

-            }

-         }

-

-         SHIFT_ARRAY(span->array->mask, leftClip, n - leftClip);

-         SHIFT_ARRAY(span->array->rgba8, leftClip, n - leftClip);

-         SHIFT_ARRAY(span->array->rgba16, leftClip, n - leftClip);

-         SHIFT_ARRAY(span->array->x, leftClip, n - leftClip);

-         SHIFT_ARRAY(span->array->y, leftClip, n - leftClip);

-         SHIFT_ARRAY(span->array->z, leftClip, n - leftClip);

-         SHIFT_ARRAY(span->array->index, leftClip, n - leftClip);

-         for (i = 0; i < MAX_TEXTURE_COORD_UNITS; i++) {

-            SHIFT_ARRAY(span->array->lambda[i], leftClip, n - leftClip);

-         }

-         SHIFT_ARRAY(span->array->coverage, leftClip, n - leftClip);

-

-#undef SHIFT_ARRAY

-

-         span->leftClip = leftClip;

-         span->x = xmin;

-         span->end -= leftClip;

-         span->writeAll = GL_FALSE;

-      }

-

-      ASSERT(span->x >= xmin);

-      ASSERT(span->x + span->end <= xmax);

-      ASSERT(span->y >= ymin);

-      ASSERT(span->y < ymax);

-

-      return GL_TRUE;  /* some pixels visible */

-   }

-}

-

-

-/**

- * Add specular colors to primary colors.

- * Only called during fixed-function operation.

- * Result is float color array (FRAG_ATTRIB_COL0).

- */

-static INLINE void

-add_specular(struct gl_context *ctx, SWspan *span)

-{

-   const SWcontext *swrast = SWRAST_CONTEXT(ctx);

-   const GLubyte *mask = span->array->mask;

-   GLfloat (*col0)[4] = span->array->attribs[FRAG_ATTRIB_COL0];

-   GLfloat (*col1)[4] = span->array->attribs[FRAG_ATTRIB_COL1];

-   GLuint i;

-

-   ASSERT(!ctx->FragmentProgram._Current);

-   ASSERT(span->arrayMask & SPAN_RGBA);

-   ASSERT(swrast->_ActiveAttribMask & FRAG_BIT_COL1);

-   (void) swrast; /* silence warning */

-

-   if (span->array->ChanType == GL_FLOAT) {

-      if ((span->arrayAttribs & FRAG_BIT_COL0) == 0) {

-         interpolate_active_attribs(ctx, span, FRAG_BIT_COL0);

-      }

-   }

-   else {

-      /* need float colors */

-      if ((span->arrayAttribs & FRAG_BIT_COL0) == 0) {

-         interpolate_float_colors(span);

-      }

-   }

-

-   if ((span->arrayAttribs & FRAG_BIT_COL1) == 0) {

-      /* XXX could avoid this and interpolate COL1 in the loop below */

-      interpolate_active_attribs(ctx, span, FRAG_BIT_COL1);

-   }

-

-   ASSERT(span->arrayAttribs & FRAG_BIT_COL0);

-   ASSERT(span->arrayAttribs & FRAG_BIT_COL1);

-

-   for (i = 0; i < span->end; i++) {

-      if (mask[i]) {

-         col0[i][0] += col1[i][0];

-         col0[i][1] += col1[i][1];

-         col0[i][2] += col1[i][2];

-      }

-   }

-

-   span->array->ChanType = GL_FLOAT;

-}

-

-

-/**

- * Apply antialiasing coverage value to alpha values.

- */

-static INLINE void

-apply_aa_coverage(SWspan *span)

-{

-   const GLfloat *coverage = span->array->coverage;

-   GLuint i;

-   if (span->array->ChanType == GL_UNSIGNED_BYTE) {

-      GLubyte (*rgba)[4] = span->array->rgba8;

-      for (i = 0; i < span->end; i++) {

-         const GLfloat a = rgba[i][ACOMP] * coverage[i];

-         rgba[i][ACOMP] = (GLubyte) CLAMP(a, 0.0, 255.0);

-         ASSERT(coverage[i] >= 0.0);

-         ASSERT(coverage[i] <= 1.0);

-      }

-   }

-   else if (span->array->ChanType == GL_UNSIGNED_SHORT) {

-      GLushort (*rgba)[4] = span->array->rgba16;

-      for (i = 0; i < span->end; i++) {

-         const GLfloat a = rgba[i][ACOMP] * coverage[i];

-         rgba[i][ACOMP] = (GLushort) CLAMP(a, 0.0, 65535.0);

-      }

-   }

-   else {

-      GLfloat (*rgba)[4] = span->array->attribs[FRAG_ATTRIB_COL0];

-      for (i = 0; i < span->end; i++) {

-         rgba[i][ACOMP] = rgba[i][ACOMP] * coverage[i];

-         /* clamp later */

-      }

-   }

-}

-

-

-/**

- * Clamp span's float colors to [0,1]

- */

-static INLINE void

-clamp_colors(SWspan *span)

-{

-   GLfloat (*rgba)[4] = span->array->attribs[FRAG_ATTRIB_COL0];

-   GLuint i;

-   ASSERT(span->array->ChanType == GL_FLOAT);

-   for (i = 0; i < span->end; i++) {

-      rgba[i][RCOMP] = CLAMP(rgba[i][RCOMP], 0.0F, 1.0F);

-      rgba[i][GCOMP] = CLAMP(rgba[i][GCOMP], 0.0F, 1.0F);

-      rgba[i][BCOMP] = CLAMP(rgba[i][BCOMP], 0.0F, 1.0F);

-      rgba[i][ACOMP] = CLAMP(rgba[i][ACOMP], 0.0F, 1.0F);

-   }

-}

-

-

-/**

- * Convert the span's color arrays to the given type.

- * The only way 'output' can be greater than zero is when we have a fragment

- * program that writes to gl_FragData[1] or higher.

- * \param output  which fragment program color output is being processed

- */

-static INLINE void

-convert_color_type(SWspan *span, GLenum newType, GLuint output)

-{

-   GLvoid *src, *dst;

-

-   if (output > 0 || span->array->ChanType == GL_FLOAT) {

-      src = span->array->attribs[FRAG_ATTRIB_COL0 + output];

-      span->array->ChanType = GL_FLOAT;

-   }

-   else if (span->array->ChanType == GL_UNSIGNED_BYTE) {

-      src = span->array->rgba8;

-   }

-   else {

-      ASSERT(span->array->ChanType == GL_UNSIGNED_SHORT);

-      src = span->array->rgba16;

-   }

-

-   if (newType == GL_UNSIGNED_BYTE) {

-      dst = span->array->rgba8;

-   }

-   else if (newType == GL_UNSIGNED_SHORT) {

-      dst = span->array->rgba16;

-   }

-   else {

-      dst = span->array->attribs[FRAG_ATTRIB_COL0];

-   }

-

-   _mesa_convert_colors(span->array->ChanType, src,

-                        newType, dst,

-                        span->end, span->array->mask);

-

-   span->array->ChanType = newType;

-   span->array->rgba = dst;

-}

-

-

-

-/**

- * Apply fragment shader, fragment program or normal texturing to span.

- */

-static INLINE void

-shade_texture_span(struct gl_context *ctx, SWspan *span)

-{

-   GLbitfield inputsRead;

-

-   /* Determine which fragment attributes are actually needed */

-   if (ctx->FragmentProgram._Current) {

-      inputsRead = ctx->FragmentProgram._Current->Base.InputsRead;

-   }

-   else {

-      /* XXX we could be a bit smarter about this */

-      inputsRead = ~0;

-   }

-

-   if (ctx->FragmentProgram._Current ||

-       ctx->ATIFragmentShader._Enabled) {

-      /* programmable shading */

-      if (span->primitive == GL_BITMAP && span->array->ChanType != GL_FLOAT) {

-         convert_color_type(span, GL_FLOAT, 0);

-      }

-      else {

-         span->array->rgba = (void *) span->array->attribs[FRAG_ATTRIB_COL0];

-      }

-

-      if (span->primitive != GL_POINT ||

-	  (span->interpMask & SPAN_RGBA) ||

-	  ctx->Point.PointSprite) {

-         /* for single-pixel points, we populated the arrays already */

-         interpolate_active_attribs(ctx, span, ~0);

-      }

-      span->array->ChanType = GL_FLOAT;

-

-      if (!(span->arrayMask & SPAN_Z))

-         _swrast_span_interpolate_z (ctx, span);

-

-#if 0

-      if (inputsRead & FRAG_BIT_WPOS)

-#else

-      /* XXX always interpolate wpos so that DDX/DDY work */

-#endif

-         interpolate_wpos(ctx, span);

-

-      /* Run fragment program/shader now */

-      if (ctx->FragmentProgram._Current) {

-         _swrast_exec_fragment_program(ctx, span);

-      }

-      else {

-         ASSERT(ctx->ATIFragmentShader._Enabled);

-         _swrast_exec_fragment_shader(ctx, span);

-      }

-   }

-   else if (ctx->Texture._EnabledCoordUnits) {

-      /* conventional texturing */

-

-#if CHAN_BITS == 32

-      if ((span->arrayAttribs & FRAG_BIT_COL0) == 0) {

-         interpolate_int_colors(ctx, span);

-      }

-#else

-      if (!(span->arrayMask & SPAN_RGBA))

-         interpolate_int_colors(ctx, span);

-#endif

-      if ((span->arrayAttribs & FRAG_BITS_TEX_ANY) == 0x0)

-         interpolate_texcoords(ctx, span);

-

-      _swrast_texture_span(ctx, span);

-   }

-}

-

-

-

-/**

- * Apply all the per-fragment operations to a span.

- * This now includes texturing (_swrast_write_texture_span() is history).

- * This function may modify any of the array values in the span.

- * span->interpMask and span->arrayMask may be changed but will be restored

- * to their original values before returning.

- */

-void

-_swrast_write_rgba_span( struct gl_context *ctx, SWspan *span)

-{

-   const SWcontext *swrast = SWRAST_CONTEXT(ctx);

-   const GLuint *colorMask = (GLuint *) ctx->Color.ColorMask;

-   const GLbitfield origInterpMask = span->interpMask;

-   const GLbitfield origArrayMask = span->arrayMask;

-   const GLbitfield origArrayAttribs = span->arrayAttribs;

-   const GLenum origChanType = span->array->ChanType;

-   void * const origRgba = span->array->rgba;

-   const GLboolean shader = (ctx->FragmentProgram._Current

-                             || ctx->ATIFragmentShader._Enabled);

-   const GLboolean shaderOrTexture = shader || ctx->Texture._EnabledCoordUnits;

-   struct gl_framebuffer *fb = ctx->DrawBuffer;

-

-   /*

-   printf("%s()  interp 0x%x  array 0x%x\n", __FUNCTION__,

-          span->interpMask, span->arrayMask);

-   */

-

-   ASSERT(span->primitive == GL_POINT ||

-          span->primitive == GL_LINE ||

-	  span->primitive == GL_POLYGON ||

-          span->primitive == GL_BITMAP);

-

-   /* Fragment write masks */

-   if (span->arrayMask & SPAN_MASK) {

-      /* mask was initialized by caller, probably glBitmap */

-      span->writeAll = GL_FALSE;

-   }

-   else {

-      memset(span->array->mask, 1, span->end);

-      span->writeAll = GL_TRUE;

-   }

-

-   /* Clip to window/scissor box */

-   if (!clip_span(ctx, span)) {

-      return;

-   }

-

-   ASSERT(span->end <= MAX_WIDTH);

-

-   /* Depth bounds test */

-   if (ctx->Depth.BoundsTest && fb->Visual.depthBits > 0) {

-      if (!_swrast_depth_bounds_test(ctx, span)) {

-         return;

-      }

-   }

-

-#ifdef DEBUG

-   /* Make sure all fragments are within window bounds */

-   if (span->arrayMask & SPAN_XY) {

-      /* array of pixel locations */

-      GLuint i;

-      for (i = 0; i < span->end; i++) {

-         if (span->array->mask[i]) {

-            assert(span->array->x[i] >= fb->_Xmin);

-            assert(span->array->x[i] < fb->_Xmax);

-            assert(span->array->y[i] >= fb->_Ymin);

-            assert(span->array->y[i] < fb->_Ymax);

-         }

-      }

-   }

-#endif

-

-   /* Polygon Stippling */

-   if (ctx->Polygon.StippleFlag && span->primitive == GL_POLYGON) {

-      stipple_polygon_span(ctx, span);

-   }

-

-   /* This is the normal place to compute the fragment color/Z

-    * from texturing or shading.

-    */

-   if (shaderOrTexture && !swrast->_DeferredTexture) {

-      shade_texture_span(ctx, span);

-   }

-

-   /* Do the alpha test */

-   if (ctx->Color.AlphaEnabled) {

-      if (!_swrast_alpha_test(ctx, span)) {

-         /* all fragments failed test */

-         goto end;

-      }

-   }

-

-   /* Stencil and Z testing */

-   if (ctx->Stencil._Enabled || ctx->Depth.Test) {

-      if (!(span->arrayMask & SPAN_Z))

-         _swrast_span_interpolate_z(ctx, span);

-

-      if (ctx->Transform.DepthClamp)

-	 _swrast_depth_clamp_span(ctx, span);

-

-      if (ctx->Stencil._Enabled) {

-         /* Combined Z/stencil tests */

-         if (!_swrast_stencil_and_ztest_span(ctx, span)) {

-            /* all fragments failed test */

-            goto end;

-         }

-      }

-      else if (fb->Visual.depthBits > 0) {

-         /* Just regular depth testing */

-         ASSERT(ctx->Depth.Test);

-         ASSERT(span->arrayMask & SPAN_Z);

-         if (!_swrast_depth_test_span(ctx, span)) {

-            /* all fragments failed test */

-            goto end;

-         }

-      }

-   }

-

-   if (ctx->Query.CurrentOcclusionObject) {

-      /* update count of 'passed' fragments */

-      struct gl_query_object *q = ctx->Query.CurrentOcclusionObject;

-      GLuint i;

-      for (i = 0; i < span->end; i++)

-         q->Result += span->array->mask[i];

-   }

-

-   /* We had to wait until now to check for glColorMask(0,0,0,0) because of

-    * the occlusion test.

-    */

-   if (fb->_NumColorDrawBuffers == 1 && colorMask[0] == 0x0) {

-      /* no colors to write */

-      goto end;

-   }

-

-   /* If we were able to defer fragment color computation to now, there's

-    * a good chance that many fragments will have already been killed by

-    * Z/stencil testing.

-    */

-   if (shaderOrTexture && swrast->_DeferredTexture) {

-      shade_texture_span(ctx, span);

-   }

-

-#if CHAN_BITS == 32

-   if ((span->arrayAttribs & FRAG_BIT_COL0) == 0) {

-      interpolate_active_attribs(ctx, span, FRAG_BIT_COL0);

-   }

-#else

-   if ((span->arrayMask & SPAN_RGBA) == 0) {

-      interpolate_int_colors(ctx, span);

-   }

-#endif

-

-   ASSERT(span->arrayMask & SPAN_RGBA);

-

-   if (span->primitive == GL_BITMAP || !swrast->SpecularVertexAdd) {

-      /* Add primary and specular (diffuse + specular) colors */

-      if (!shader) {

-         if (ctx->Fog.ColorSumEnabled ||

-             (ctx->Light.Enabled &&

-              ctx->Light.Model.ColorControl == GL_SEPARATE_SPECULAR_COLOR)) {

-            add_specular(ctx, span);

-         }

-      }

-   }

-

-   /* Fog */

-   if (swrast->_FogEnabled) {

-      _swrast_fog_rgba_span(ctx, span);

-   }

-

-   /* Antialias coverage application */

-   if (span->arrayMask & SPAN_COVERAGE) {

-      apply_aa_coverage(span);

-   }

-

-   /* Clamp color/alpha values over the range [0.0, 1.0] before storage */

-   if (ctx->Color.ClampFragmentColor == GL_TRUE &&

-       span->array->ChanType == GL_FLOAT) {

-      clamp_colors(span);

-   }

-

-   /*

-    * Write to renderbuffers.

-    * Depending on glDrawBuffer() state and the which color outputs are

-    * written by the fragment shader, we may either replicate one color to

-    * all renderbuffers or write a different color to each renderbuffer.

-    * multiFragOutputs=TRUE for the later case.

-    */

-   {

-      const GLuint numBuffers = fb->_NumColorDrawBuffers;

-      const struct gl_fragment_program *fp = ctx->FragmentProgram._Current;

-      const GLboolean multiFragOutputs = 

-         (fp && fp->Base.OutputsWritten >= (1 << FRAG_RESULT_DATA0));

-      GLuint buf;

-

-      for (buf = 0; buf < numBuffers; buf++) {

-         struct gl_renderbuffer *rb = fb->_ColorDrawBuffers[buf];

-

-         /* color[fragOutput] will be written to buffer[buf] */

-

-         if (rb) {

-            GLchan rgbaSave[MAX_WIDTH][4];

-            const GLuint fragOutput = multiFragOutputs ? buf : 0;

-

-            /* set span->array->rgba to colors for render buffer's datatype */

-            if (rb->DataType != span->array->ChanType || fragOutput > 0) {

-               convert_color_type(span, rb->DataType, fragOutput);

-            }

-            else {

-               if (rb->DataType == GL_UNSIGNED_BYTE) {

-                  span->array->rgba = span->array->rgba8;

-               }

-               else if (rb->DataType == GL_UNSIGNED_SHORT) {

-                  span->array->rgba = (void *) span->array->rgba16;

-               }

-               else {

-                  span->array->rgba = (void *)

-                     span->array->attribs[FRAG_ATTRIB_COL0];

-               }

-            }

-

-            if (!multiFragOutputs && numBuffers > 1) {

-               /* save colors for second, third renderbuffer writes */

-               memcpy(rgbaSave, span->array->rgba,

-                      4 * span->end * sizeof(GLchan));

-            }

-

-            ASSERT(rb->_BaseFormat == GL_RGBA || rb->_BaseFormat == GL_RGB ||

-		   rb->_BaseFormat == GL_ALPHA);

-

-            if (ctx->Color._LogicOpEnabled) {

-               _swrast_logicop_rgba_span(ctx, rb, span);

-            }

-            else if ((ctx->Color.BlendEnabled >> buf) & 1) {

-               _swrast_blend_span(ctx, rb, span);

-            }

-

-            if (colorMask[buf] != 0xffffffff) {

-               _swrast_mask_rgba_span(ctx, rb, span, buf);

-            }

-

-            if (span->arrayMask & SPAN_XY) {

-               /* array of pixel coords */

-               ASSERT(rb->PutValues);

-               rb->PutValues(ctx, rb, span->end,

-                             span->array->x, span->array->y,

-                             span->array->rgba, span->array->mask);

-            }

-            else {

-               /* horizontal run of pixels */

-               ASSERT(rb->PutRow);

-               rb->PutRow(ctx, rb, span->end, span->x, span->y,

-                          span->array->rgba,

-                          span->writeAll ? NULL: span->array->mask);

-            }

-

-            if (!multiFragOutputs && numBuffers > 1) {

-               /* restore original span values */

-               memcpy(span->array->rgba, rgbaSave,

-                      4 * span->end * sizeof(GLchan));

-            }

-

-         } /* if rb */

-      } /* for buf */

-   }

-

-end:

-   /* restore these values before returning */

-   span->interpMask = origInterpMask;

-   span->arrayMask = origArrayMask;

-   span->arrayAttribs = origArrayAttribs;

-   span->array->ChanType = origChanType;

-   span->array->rgba = origRgba;

-}

-

-

-/**

- * Read RGBA pixels from a renderbuffer.  Clipping will be done to prevent

- * reading ouside the buffer's boundaries.

- * \param dstType  datatype for returned colors

- * \param rgba  the returned colors

- */

-void

-_swrast_read_rgba_span( struct gl_context *ctx, struct gl_renderbuffer *rb,

-                        GLuint n, GLint x, GLint y, GLenum dstType,

-                        GLvoid *rgba)

-{

-   const GLint bufWidth = (GLint) rb->Width;

-   const GLint bufHeight = (GLint) rb->Height;

-

-   if (y < 0 || y >= bufHeight || x + (GLint) n < 0 || x >= bufWidth) {

-      /* completely above, below, or right */

-      /* XXX maybe leave rgba values undefined? */

-      memset(rgba, 0, 4 * n * sizeof(GLchan));

-   }

-   else {

-      GLint skip, length;

-      if (x < 0) {

-         /* left edge clipping */

-         skip = -x;

-         length = (GLint) n - skip;

-         if (length < 0) {

-            /* completely left of window */

-            return;

-         }

-         if (length > bufWidth) {

-            length = bufWidth;

-         }

-      }

-      else if ((GLint) (x + n) > bufWidth) {

-         /* right edge clipping */

-         skip = 0;

-         length = bufWidth - x;

-         if (length < 0) {

-            /* completely to right of window */

-            return;

-         }

-      }

-      else {

-         /* no clipping */

-         skip = 0;

-         length = (GLint) n;

-      }

-

-      ASSERT(rb);

-      ASSERT(rb->GetRow);

-      ASSERT(rb->_BaseFormat == GL_RGBA ||

-	     rb->_BaseFormat == GL_RGB ||

-	     rb->_BaseFormat == GL_RG ||

-	     rb->_BaseFormat == GL_RED ||

-	     rb->_BaseFormat == GL_LUMINANCE ||

-	     rb->_BaseFormat == GL_INTENSITY ||

-	     rb->_BaseFormat == GL_LUMINANCE_ALPHA ||

-	     rb->_BaseFormat == GL_ALPHA);

-

-      if (rb->DataType == dstType) {

-         rb->GetRow(ctx, rb, length, x + skip, y,

-                    (GLubyte *) rgba + skip * RGBA_PIXEL_SIZE(rb->DataType));

-      }

-      else {

-         GLuint temp[MAX_WIDTH * 4];

-         rb->GetRow(ctx, rb, length, x + skip, y, temp);

-         _mesa_convert_colors(rb->DataType, temp,

-                   dstType, (GLubyte *) rgba + skip * RGBA_PIXEL_SIZE(dstType),

-                   length, NULL);

-      }

-   }

-}

-

-

-/**

- * Wrapper for gl_renderbuffer::GetValues() which does clipping to avoid

- * reading values outside the buffer bounds.

- * We can use this for reading any format/type of renderbuffer.

- * \param valueSize is the size in bytes of each value (pixel) put into the

- *                  values array.

- */

-void

-_swrast_get_values(struct gl_context *ctx, struct gl_renderbuffer *rb,

-                   GLuint count, const GLint x[], const GLint y[],

-                   void *values, GLuint valueSize)

-{

-   GLuint i, inCount = 0, inStart = 0;

-

-   for (i = 0; i < count; i++) {

-      if (x[i] >= 0 && y[i] >= 0 &&

-	  x[i] < (GLint) rb->Width && y[i] < (GLint) rb->Height) {

-         /* inside */

-         if (inCount == 0)

-            inStart = i;

-         inCount++;

-      }

-      else {

-         if (inCount > 0) {

-            /* read [inStart, inStart + inCount) */

-            rb->GetValues(ctx, rb, inCount, x + inStart, y + inStart,

-                          (GLubyte *) values + inStart * valueSize);

-            inCount = 0;

-         }

-      }

-   }

-   if (inCount > 0) {

-      /* read last values */

-      rb->GetValues(ctx, rb, inCount, x + inStart, y + inStart,

-                    (GLubyte *) values + inStart * valueSize);

-   }

-}

-

-

-/**

- * Wrapper for gl_renderbuffer::PutRow() which does clipping.

- * \param valueSize  size of each value (pixel) in bytes

- */

-void

-_swrast_put_row(struct gl_context *ctx, struct gl_renderbuffer *rb,

-                GLuint count, GLint x, GLint y,

-                const GLvoid *values, GLuint valueSize)

-{

-   GLint skip = 0;

-

-   if (y < 0 || y >= (GLint) rb->Height)

-      return; /* above or below */

-

-   if (x + (GLint) count <= 0 || x >= (GLint) rb->Width)

-      return; /* entirely left or right */

-

-   if ((GLint) (x + count) > (GLint) rb->Width) {

-      /* right clip */

-      GLint clip = x + count - rb->Width;

-      count -= clip;

-   }

-

-   if (x < 0) {

-      /* left clip */

-      skip = -x;

-      x = 0;

-      count -= skip;

-   }

-

-   rb->PutRow(ctx, rb, count, x, y,

-              (const GLubyte *) values + skip * valueSize, NULL);

-}

-

-

-/**

- * Wrapper for gl_renderbuffer::GetRow() which does clipping.

- * \param valueSize  size of each value (pixel) in bytes

- */

-void

-_swrast_get_row(struct gl_context *ctx, struct gl_renderbuffer *rb,

-                GLuint count, GLint x, GLint y,

-                GLvoid *values, GLuint valueSize)

-{

-   GLint skip = 0;

-

-   if (y < 0 || y >= (GLint) rb->Height)

-      return; /* above or below */

-

-   if (x + (GLint) count <= 0 || x >= (GLint) rb->Width)

-      return; /* entirely left or right */

-

-   if (x + count > rb->Width) {

-      /* right clip */

-      GLint clip = x + count - rb->Width;

-      count -= clip;

-   }

-

-   if (x < 0) {

-      /* left clip */

-      skip = -x;

-      x = 0;

-      count -= skip;

-   }

-

-   rb->GetRow(ctx, rb, count, x, y, (GLubyte *) values + skip * valueSize);

-}

-

-

-/**

- * Get RGBA pixels from the given renderbuffer.

- * Used by blending, logicop and masking functions.

- * \return pointer to the colors we read.

- */

-void *

-_swrast_get_dest_rgba(struct gl_context *ctx, struct gl_renderbuffer *rb,

-                      SWspan *span)

-{

-   const GLuint pixelSize = RGBA_PIXEL_SIZE(span->array->ChanType);

-   void *rbPixels;

-

-   /* Point rbPixels to a temporary space */

-   rbPixels = span->array->attribs[FRAG_ATTRIB_MAX - 1];

-

-   /* Get destination values from renderbuffer */

-   if (span->arrayMask & SPAN_XY) {

-      _swrast_get_values(ctx, rb, span->end, span->array->x, span->array->y,

-                         rbPixels, pixelSize);

-   }

-   else {

-      _swrast_get_row(ctx, rb, span->end, span->x, span->y,

-                      rbPixels, pixelSize);

-   }

-

-   return rbPixels;

-}

+/*
+ * Mesa 3-D graphics library
+ * Version:  7.5
+ *
+ * Copyright (C) 1999-2008  Brian Paul   All Rights Reserved.
+ * Copyright (C) 2009  VMware, Inc.  All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+ * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+
+/**
+ * \file swrast/s_span.c
+ * \brief Span processing functions used by all rasterization functions.
+ * This is where all the per-fragment tests are performed
+ * \author Brian Paul
+ */
+
+#include "main/glheader.h"
+#include "main/colormac.h"
+#include "main/macros.h"
+#include "main/imports.h"
+#include "main/image.h"
+
+#include "s_atifragshader.h"
+#include "s_alpha.h"
+#include "s_blend.h"
+#include "s_context.h"
+#include "s_depth.h"
+#include "s_fog.h"
+#include "s_logic.h"
+#include "s_masking.h"
+#include "s_fragprog.h"
+#include "s_span.h"
+#include "s_stencil.h"
+#include "s_texcombine.h"
+
+
+/**
+ * Set default fragment attributes for the span using the
+ * current raster values.  Used prior to glDraw/CopyPixels
+ * and glBitmap.
+ */
+void
+_swrast_span_default_attribs(struct gl_context *ctx, SWspan *span)
+{
+   GLchan r, g, b, a;
+   /* Z*/
+   {
+      const GLfloat depthMax = ctx->DrawBuffer->_DepthMaxF;
+      if (ctx->DrawBuffer->Visual.depthBits <= 16)
+         span->z = FloatToFixed(ctx->Current.RasterPos[2] * depthMax + 0.5F);
+      else {
+         GLfloat tmpf = ctx->Current.RasterPos[2] * depthMax; 
+         tmpf = MIN2(tmpf, depthMax);
+         span->z = (GLint)tmpf;
+      }
+      span->zStep = 0;
+      span->interpMask |= SPAN_Z;
+   }
+
+   /* W (for perspective correction) */
+   span->attrStart[FRAG_ATTRIB_WPOS][3] = 1.0;
+   span->attrStepX[FRAG_ATTRIB_WPOS][3] = 0.0;
+   span->attrStepY[FRAG_ATTRIB_WPOS][3] = 0.0;
+
+   /* primary color, or color index */
+   UNCLAMPED_FLOAT_TO_CHAN(r, ctx->Current.RasterColor[0]);
+   UNCLAMPED_FLOAT_TO_CHAN(g, ctx->Current.RasterColor[1]);
+   UNCLAMPED_FLOAT_TO_CHAN(b, ctx->Current.RasterColor[2]);
+   UNCLAMPED_FLOAT_TO_CHAN(a, ctx->Current.RasterColor[3]);
+#if CHAN_TYPE == GL_FLOAT
+   span->red = r;
+   span->green = g;
+   span->blue = b;
+   span->alpha = a;
+#else
+   span->red   = IntToFixed(r);
+   span->green = IntToFixed(g);
+   span->blue  = IntToFixed(b);
+   span->alpha = IntToFixed(a);
+#endif
+   span->redStep = 0;
+   span->greenStep = 0;
+   span->blueStep = 0;
+   span->alphaStep = 0;
+   span->interpMask |= SPAN_RGBA;
+
+   COPY_4V(span->attrStart[FRAG_ATTRIB_COL0], ctx->Current.RasterColor);
+   ASSIGN_4V(span->attrStepX[FRAG_ATTRIB_COL0], 0.0, 0.0, 0.0, 0.0);
+   ASSIGN_4V(span->attrStepY[FRAG_ATTRIB_COL0], 0.0, 0.0, 0.0, 0.0);
+
+   /* Secondary color */
+   if (ctx->Light.Enabled || ctx->Fog.ColorSumEnabled)
+   {
+      COPY_4V(span->attrStart[FRAG_ATTRIB_COL1], ctx->Current.RasterSecondaryColor);
+      ASSIGN_4V(span->attrStepX[FRAG_ATTRIB_COL1], 0.0, 0.0, 0.0, 0.0);
+      ASSIGN_4V(span->attrStepY[FRAG_ATTRIB_COL1], 0.0, 0.0, 0.0, 0.0);
+   }
+
+   /* fog */
+   {
+      const SWcontext *swrast = SWRAST_CONTEXT(ctx);
+      GLfloat fogVal; /* a coord or a blend factor */
+      if (swrast->_PreferPixelFog) {
+         /* fog blend factors will be computed from fog coordinates per pixel */
+         fogVal = ctx->Current.RasterDistance;
+      }
+      else {
+         /* fog blend factor should be computed from fogcoord now */
+         fogVal = _swrast_z_to_fogfactor(ctx, ctx->Current.RasterDistance);
+      }
+      span->attrStart[FRAG_ATTRIB_FOGC][0] = fogVal;
+      span->attrStepX[FRAG_ATTRIB_FOGC][0] = 0.0;
+      span->attrStepY[FRAG_ATTRIB_FOGC][0] = 0.0;
+   }
+
+   /* texcoords */
+   {
+      GLuint i;
+      for (i = 0; i < ctx->Const.MaxTextureCoordUnits; i++) {
+         const GLuint attr = FRAG_ATTRIB_TEX0 + i;
+         const GLfloat *tc = ctx->Current.RasterTexCoords[i];
+         if (ctx->FragmentProgram._Current || ctx->ATIFragmentShader._Enabled) {
+            COPY_4V(span->attrStart[attr], tc);
+         }
+         else if (tc[3] > 0.0F) {
+            /* use (s/q, t/q, r/q, 1) */
+            span->attrStart[attr][0] = tc[0] / tc[3];
+            span->attrStart[attr][1] = tc[1] / tc[3];
+            span->attrStart[attr][2] = tc[2] / tc[3];
+            span->attrStart[attr][3] = 1.0;
+         }
+         else {
+            ASSIGN_4V(span->attrStart[attr], 0.0F, 0.0F, 0.0F, 1.0F);
+         }
+         ASSIGN_4V(span->attrStepX[attr], 0.0F, 0.0F, 0.0F, 0.0F);
+         ASSIGN_4V(span->attrStepY[attr], 0.0F, 0.0F, 0.0F, 0.0F);
+      }
+   }
+}
+
+
+/**
+ * Interpolate the active attributes (and'd with attrMask) to
+ * fill in span->array->attribs[].
+ * Perspective correction will be done.  The point/line/triangle function
+ * should have computed attrStart/Step values for FRAG_ATTRIB_WPOS[3]!
+ */
+static INLINE void
+interpolate_active_attribs(struct gl_context *ctx, SWspan *span, GLbitfield attrMask)
+{
+   const SWcontext *swrast = SWRAST_CONTEXT(ctx);
+
+   /*
+    * Don't overwrite existing array values, such as colors that may have
+    * been produced by glDraw/CopyPixels.
+    */
+   attrMask &= ~span->arrayAttribs;
+
+   ATTRIB_LOOP_BEGIN
+      if (attrMask & (1 << attr)) {
+         const GLfloat dwdx = span->attrStepX[FRAG_ATTRIB_WPOS][3];
+         GLfloat w = span->attrStart[FRAG_ATTRIB_WPOS][3];
+         const GLfloat dv0dx = span->attrStepX[attr][0];
+         const GLfloat dv1dx = span->attrStepX[attr][1];
+         const GLfloat dv2dx = span->attrStepX[attr][2];
+         const GLfloat dv3dx = span->attrStepX[attr][3];
+         GLfloat v0 = span->attrStart[attr][0] + span->leftClip * dv0dx;
+         GLfloat v1 = span->attrStart[attr][1] + span->leftClip * dv1dx;
+         GLfloat v2 = span->attrStart[attr][2] + span->leftClip * dv2dx;
+         GLfloat v3 = span->attrStart[attr][3] + span->leftClip * dv3dx;
+         GLuint k;
+         for (k = 0; k < span->end; k++) {
+            const GLfloat invW = 1.0f / w;
+            span->array->attribs[attr][k][0] = v0 * invW;
+            span->array->attribs[attr][k][1] = v1 * invW;
+            span->array->attribs[attr][k][2] = v2 * invW;
+            span->array->attribs[attr][k][3] = v3 * invW;
+            v0 += dv0dx;
+            v1 += dv1dx;
+            v2 += dv2dx;
+            v3 += dv3dx;
+            w += dwdx;
+         }
+         ASSERT((span->arrayAttribs & (1 << attr)) == 0);
+         span->arrayAttribs |= (1 << attr);
+      }
+   ATTRIB_LOOP_END
+}
+
+
+/**
+ * Interpolate primary colors to fill in the span->array->rgba8 (or rgb16)
+ * color array.
+ */
+static INLINE void
+interpolate_int_colors(struct gl_context *ctx, SWspan *span)
+{
+   const GLuint n = span->end;
+   GLuint i;
+
+#if CHAN_BITS != 32
+   ASSERT(!(span->arrayMask & SPAN_RGBA));
+#endif
+
+   switch (span->array->ChanType) {
+#if CHAN_BITS != 32
+   case GL_UNSIGNED_BYTE:
+      {
+         GLubyte (*rgba)[4] = span->array->rgba8;
+         if (span->interpMask & SPAN_FLAT) {
+            GLubyte color[4];
+            color[RCOMP] = FixedToInt(span->red);
+            color[GCOMP] = FixedToInt(span->green);
+            color[BCOMP] = FixedToInt(span->blue);
+            color[ACOMP] = FixedToInt(span->alpha);
+            for (i = 0; i < n; i++) {
+               COPY_4UBV(rgba[i], color);
+            }
+         }
+         else {
+            GLfixed r = span->red;
+            GLfixed g = span->green;
+            GLfixed b = span->blue;
+            GLfixed a = span->alpha;
+            GLint dr = span->redStep;
+            GLint dg = span->greenStep;
+            GLint db = span->blueStep;
+            GLint da = span->alphaStep;
+            for (i = 0; i < n; i++) {
+               rgba[i][RCOMP] = FixedToChan(r);
+               rgba[i][GCOMP] = FixedToChan(g);
+               rgba[i][BCOMP] = FixedToChan(b);
+               rgba[i][ACOMP] = FixedToChan(a);
+               r += dr;
+               g += dg;
+               b += db;
+               a += da;
+            }
+         }
+      }
+      break;
+   case GL_UNSIGNED_SHORT:
+      {
+         GLushort (*rgba)[4] = span->array->rgba16;
+         if (span->interpMask & SPAN_FLAT) {
+            GLushort color[4];
+            color[RCOMP] = FixedToInt(span->red);
+            color[GCOMP] = FixedToInt(span->green);
+            color[BCOMP] = FixedToInt(span->blue);
+            color[ACOMP] = FixedToInt(span->alpha);
+            for (i = 0; i < n; i++) {
+               COPY_4V(rgba[i], color);
+            }
+         }
+         else {
+            GLushort (*rgba)[4] = span->array->rgba16;
+            GLfixed r, g, b, a;
+            GLint dr, dg, db, da;
+            r = span->red;
+            g = span->green;
+            b = span->blue;
+            a = span->alpha;
+            dr = span->redStep;
+            dg = span->greenStep;
+            db = span->blueStep;
+            da = span->alphaStep;
+            for (i = 0; i < n; i++) {
+               rgba[i][RCOMP] = FixedToChan(r);
+               rgba[i][GCOMP] = FixedToChan(g);
+               rgba[i][BCOMP] = FixedToChan(b);
+               rgba[i][ACOMP] = FixedToChan(a);
+               r += dr;
+               g += dg;
+               b += db;
+               a += da;
+            }
+         }
+      }
+      break;
+#endif
+   case GL_FLOAT:
+      interpolate_active_attribs(ctx, span, FRAG_BIT_COL0);
+      break;
+   default:
+      _mesa_problem(ctx, "bad datatype 0x%x in interpolate_int_colors",
+                    span->array->ChanType);
+   }
+   span->arrayMask |= SPAN_RGBA;
+}
+
+
+/**
+ * Populate the FRAG_ATTRIB_COL0 array.
+ */
+static INLINE void
+interpolate_float_colors(SWspan *span)
+{
+   GLfloat (*col0)[4] = span->array->attribs[FRAG_ATTRIB_COL0];
+   const GLuint n = span->end;
+   GLuint i;
+
+   assert(!(span->arrayAttribs & FRAG_BIT_COL0));
+
+   if (span->arrayMask & SPAN_RGBA) {
+      /* convert array of int colors */
+      for (i = 0; i < n; i++) {
+         col0[i][0] = UBYTE_TO_FLOAT(span->array->rgba8[i][0]);
+         col0[i][1] = UBYTE_TO_FLOAT(span->array->rgba8[i][1]);
+         col0[i][2] = UBYTE_TO_FLOAT(span->array->rgba8[i][2]);
+         col0[i][3] = UBYTE_TO_FLOAT(span->array->rgba8[i][3]);
+      }
+   }
+   else {
+      /* interpolate red/green/blue/alpha to get float colors */
+      ASSERT(span->interpMask & SPAN_RGBA);
+      if (span->interpMask & SPAN_FLAT) {
+         GLfloat r = FixedToFloat(span->red);
+         GLfloat g = FixedToFloat(span->green);
+         GLfloat b = FixedToFloat(span->blue);
+         GLfloat a = FixedToFloat(span->alpha);
+         for (i = 0; i < n; i++) {
+            ASSIGN_4V(col0[i], r, g, b, a);
+         }
+      }
+      else {
+         GLfloat r = FixedToFloat(span->red);
+         GLfloat g = FixedToFloat(span->green);
+         GLfloat b = FixedToFloat(span->blue);
+         GLfloat a = FixedToFloat(span->alpha);
+         GLfloat dr = FixedToFloat(span->redStep);
+         GLfloat dg = FixedToFloat(span->greenStep);
+         GLfloat db = FixedToFloat(span->blueStep);
+         GLfloat da = FixedToFloat(span->alphaStep);
+         for (i = 0; i < n; i++) {
+            col0[i][0] = r;
+            col0[i][1] = g;
+            col0[i][2] = b;
+            col0[i][3] = a;
+            r += dr;
+            g += dg;
+            b += db;
+            a += da;
+         }
+      }
+   }
+
+   span->arrayAttribs |= FRAG_BIT_COL0;
+   span->array->ChanType = GL_FLOAT;
+}
+
+
+
+/**
+ * Fill in the span.zArray array from the span->z, zStep values.
+ */
+void
+_swrast_span_interpolate_z( const struct gl_context *ctx, SWspan *span )
+{
+   const GLuint n = span->end;
+   GLuint i;
+
+   ASSERT(!(span->arrayMask & SPAN_Z));
+
+   if (ctx->DrawBuffer->Visual.depthBits <= 16) {
+      GLfixed zval = span->z;
+      GLuint *z = span->array->z; 
+      for (i = 0; i < n; i++) {
+         z[i] = FixedToInt(zval);
+         zval += span->zStep;
+      }
+   }
+   else {
+      /* Deep Z buffer, no fixed->int shift */
+      GLuint zval = span->z;
+      GLuint *z = span->array->z;
+      for (i = 0; i < n; i++) {
+         z[i] = zval;
+         zval += span->zStep;
+      }
+   }
+   span->interpMask &= ~SPAN_Z;
+   span->arrayMask |= SPAN_Z;
+}
+
+
+/**
+ * Compute mipmap LOD from partial derivatives.
+ * This the ideal solution, as given in the OpenGL spec.
+ */
+GLfloat
+_swrast_compute_lambda(GLfloat dsdx, GLfloat dsdy, GLfloat dtdx, GLfloat dtdy,
+                       GLfloat dqdx, GLfloat dqdy, GLfloat texW, GLfloat texH,
+                       GLfloat s, GLfloat t, GLfloat q, GLfloat invQ)
+{
+   GLfloat dudx = texW * ((s + dsdx) / (q + dqdx) - s * invQ);
+   GLfloat dvdx = texH * ((t + dtdx) / (q + dqdx) - t * invQ);
+   GLfloat dudy = texW * ((s + dsdy) / (q + dqdy) - s * invQ);
+   GLfloat dvdy = texH * ((t + dtdy) / (q + dqdy) - t * invQ);
+   GLfloat x = SQRTF(dudx * dudx + dvdx * dvdx);
+   GLfloat y = SQRTF(dudy * dudy + dvdy * dvdy);
+   GLfloat rho = MAX2(x, y);
+   GLfloat lambda = LOG2(rho);
+   return lambda;
+}
+
+
+/**
+ * Compute mipmap LOD from partial derivatives.
+ * This is a faster approximation than above function.
+ */
+#if 0
+GLfloat
+_swrast_compute_lambda(GLfloat dsdx, GLfloat dsdy, GLfloat dtdx, GLfloat dtdy,
+                     GLfloat dqdx, GLfloat dqdy, GLfloat texW, GLfloat texH,
+                     GLfloat s, GLfloat t, GLfloat q, GLfloat invQ)
+{
+   GLfloat dsdx2 = (s + dsdx) / (q + dqdx) - s * invQ;
+   GLfloat dtdx2 = (t + dtdx) / (q + dqdx) - t * invQ;
+   GLfloat dsdy2 = (s + dsdy) / (q + dqdy) - s * invQ;
+   GLfloat dtdy2 = (t + dtdy) / (q + dqdy) - t * invQ;
+   GLfloat maxU, maxV, rho, lambda;
+   dsdx2 = FABSF(dsdx2);
+   dsdy2 = FABSF(dsdy2);
+   dtdx2 = FABSF(dtdx2);
+   dtdy2 = FABSF(dtdy2);
+   maxU = MAX2(dsdx2, dsdy2) * texW;
+   maxV = MAX2(dtdx2, dtdy2) * texH;
+   rho = MAX2(maxU, maxV);
+   lambda = LOG2(rho);
+   return lambda;
+}
+#endif
+
+
+/**
+ * Fill in the span.array->attrib[FRAG_ATTRIB_TEXn] arrays from the
+ * using the attrStart/Step values.
+ *
+ * This function only used during fixed-function fragment processing.
+ *
+ * Note: in the places where we divide by Q (or mult by invQ) we're
+ * really doing two things: perspective correction and texcoord
+ * projection.  Remember, for texcoord (s,t,r,q) we need to index
+ * texels with (s/q, t/q, r/q).
+ */
+static void
+interpolate_texcoords(struct gl_context *ctx, SWspan *span)
+{
+   const GLuint maxUnit
+      = (ctx->Texture._EnabledCoordUnits > 1) ? ctx->Const.MaxTextureUnits : 1;
+   GLuint u;
+
+   /* XXX CoordUnits vs. ImageUnits */
+   for (u = 0; u < maxUnit; u++) {
+      if (ctx->Texture._EnabledCoordUnits & (1 << u)) {
+         const GLuint attr = FRAG_ATTRIB_TEX0 + u;
+         const struct gl_texture_object *obj = ctx->Texture.Unit[u]._Current;
+         GLfloat texW, texH;
+         GLboolean needLambda;
+         GLfloat (*texcoord)[4] = span->array->attribs[attr];
+         GLfloat *lambda = span->array->lambda[u];
+         const GLfloat dsdx = span->attrStepX[attr][0];
+         const GLfloat dsdy = span->attrStepY[attr][0];
+         const GLfloat dtdx = span->attrStepX[attr][1];
+         const GLfloat dtdy = span->attrStepY[attr][1];
+         const GLfloat drdx = span->attrStepX[attr][2];
+         const GLfloat dqdx = span->attrStepX[attr][3];
+         const GLfloat dqdy = span->attrStepY[attr][3];
+         GLfloat s = span->attrStart[attr][0] + span->leftClip * dsdx;
+         GLfloat t = span->attrStart[attr][1] + span->leftClip * dtdx;
+         GLfloat r = span->attrStart[attr][2] + span->leftClip * drdx;
+         GLfloat q = span->attrStart[attr][3] + span->leftClip * dqdx;
+
+         if (obj) {
+            const struct gl_texture_image *img = obj->Image[0][obj->BaseLevel];
+            needLambda = (obj->Sampler.MinFilter != obj->Sampler.MagFilter)
+               || ctx->FragmentProgram._Current;
+            /* LOD is calculated directly in the ansiotropic filter, we can
+             * skip the normal lambda function as the result is ignored.
+             */
+            if (obj->Sampler.MaxAnisotropy > 1.0 &&
+                obj->Sampler.MinFilter == GL_LINEAR_MIPMAP_LINEAR) {
+               needLambda = GL_FALSE;
+            }
+            texW = img->WidthScale;
+            texH = img->HeightScale;
+         }
+         else {
+            /* using a fragment program */
+            texW = 1.0;
+            texH = 1.0;
+            needLambda = GL_FALSE;
+         }
+
+         if (needLambda) {
+            GLuint i;
+            if (ctx->FragmentProgram._Current
+                || ctx->ATIFragmentShader._Enabled) {
+               /* do perspective correction but don't divide s, t, r by q */
+               const GLfloat dwdx = span->attrStepX[FRAG_ATTRIB_WPOS][3];
+               GLfloat w = span->attrStart[FRAG_ATTRIB_WPOS][3] + span->leftClip * dwdx;
+               for (i = 0; i < span->end; i++) {
+                  const GLfloat invW = 1.0F / w;
+                  texcoord[i][0] = s * invW;
+                  texcoord[i][1] = t * invW;
+                  texcoord[i][2] = r * invW;
+                  texcoord[i][3] = q * invW;
+                  lambda[i] = _swrast_compute_lambda(dsdx, dsdy, dtdx, dtdy,
+                                                     dqdx, dqdy, texW, texH,
+                                                     s, t, q, invW);
+                  s += dsdx;
+                  t += dtdx;
+                  r += drdx;
+                  q += dqdx;
+                  w += dwdx;
+               }
+            }
+            else {
+               for (i = 0; i < span->end; i++) {
+                  const GLfloat invQ = (q == 0.0F) ? 1.0F : (1.0F / q);
+                  texcoord[i][0] = s * invQ;
+                  texcoord[i][1] = t * invQ;
+                  texcoord[i][2] = r * invQ;
+                  texcoord[i][3] = q;
+                  lambda[i] = _swrast_compute_lambda(dsdx, dsdy, dtdx, dtdy,
+                                                     dqdx, dqdy, texW, texH,
+                                                     s, t, q, invQ);
+                  s += dsdx;
+                  t += dtdx;
+                  r += drdx;
+                  q += dqdx;
+               }
+            }
+            span->arrayMask |= SPAN_LAMBDA;
+         }
+         else {
+            GLuint i;
+            if (ctx->FragmentProgram._Current ||
+                ctx->ATIFragmentShader._Enabled) {
+               /* do perspective correction but don't divide s, t, r by q */
+               const GLfloat dwdx = span->attrStepX[FRAG_ATTRIB_WPOS][3];
+               GLfloat w = span->attrStart[FRAG_ATTRIB_WPOS][3] + span->leftClip * dwdx;
+               for (i = 0; i < span->end; i++) {
+                  const GLfloat invW = 1.0F / w;
+                  texcoord[i][0] = s * invW;
+                  texcoord[i][1] = t * invW;
+                  texcoord[i][2] = r * invW;
+                  texcoord[i][3] = q * invW;
+                  lambda[i] = 0.0;
+                  s += dsdx;
+                  t += dtdx;
+                  r += drdx;
+                  q += dqdx;
+                  w += dwdx;
+               }
+            }
+            else if (dqdx == 0.0F) {
+               /* Ortho projection or polygon's parallel to window X axis */
+               const GLfloat invQ = (q == 0.0F) ? 1.0F : (1.0F / q);
+               for (i = 0; i < span->end; i++) {
+                  texcoord[i][0] = s * invQ;
+                  texcoord[i][1] = t * invQ;
+                  texcoord[i][2] = r * invQ;
+                  texcoord[i][3] = q;
+                  lambda[i] = 0.0;
+                  s += dsdx;
+                  t += dtdx;
+                  r += drdx;
+               }
+            }
+            else {
+               for (i = 0; i < span->end; i++) {
+                  const GLfloat invQ = (q == 0.0F) ? 1.0F : (1.0F / q);
+                  texcoord[i][0] = s * invQ;
+                  texcoord[i][1] = t * invQ;
+                  texcoord[i][2] = r * invQ;
+                  texcoord[i][3] = q;
+                  lambda[i] = 0.0;
+                  s += dsdx;
+                  t += dtdx;
+                  r += drdx;
+                  q += dqdx;
+               }
+            }
+         } /* lambda */
+      } /* if */
+   } /* for */
+}
+
+
+/**
+ * Fill in the arrays->attribs[FRAG_ATTRIB_WPOS] array.
+ */
+static INLINE void
+interpolate_wpos(struct gl_context *ctx, SWspan *span)
+{
+   GLfloat (*wpos)[4] = span->array->attribs[FRAG_ATTRIB_WPOS];
+   GLuint i;
+   const GLfloat zScale = 1.0F / ctx->DrawBuffer->_DepthMaxF;
+   GLfloat w, dw;
+
+   if (span->arrayMask & SPAN_XY) {
+      for (i = 0; i < span->end; i++) {
+         wpos[i][0] = (GLfloat) span->array->x[i];
+         wpos[i][1] = (GLfloat) span->array->y[i];
+      }
+   }
+   else {
+      for (i = 0; i < span->end; i++) {
+         wpos[i][0] = (GLfloat) span->x + i;
+         wpos[i][1] = (GLfloat) span->y;
+      }
+   }
+
+   dw = span->attrStepX[FRAG_ATTRIB_WPOS][3];
+   w = span->attrStart[FRAG_ATTRIB_WPOS][3] + span->leftClip * dw;
+   for (i = 0; i < span->end; i++) {
+      wpos[i][2] = (GLfloat) span->array->z[i] * zScale;
+      wpos[i][3] = w;
+      w += dw;
+   }
+}
+
+
+/**
+ * Apply the current polygon stipple pattern to a span of pixels.
+ */
+static INLINE void
+stipple_polygon_span(struct gl_context *ctx, SWspan *span)
+{
+   GLubyte *mask = span->array->mask;
+
+   ASSERT(ctx->Polygon.StippleFlag);
+
+   if (span->arrayMask & SPAN_XY) {
+      /* arrays of x/y pixel coords */
+      GLuint i;
+      for (i = 0; i < span->end; i++) {
+         const GLint col = span->array->x[i] % 32;
+         const GLint row = span->array->y[i] % 32;
+         const GLuint stipple = ctx->PolygonStipple[row];
+         if (((1 << col) & stipple) == 0) {
+            mask[i] = 0;
+         }
+      }
+   }
+   else {
+      /* horizontal span of pixels */
+      const GLuint highBit = 1 << 31;
+      const GLuint stipple = ctx->PolygonStipple[span->y % 32];
+      GLuint i, m = highBit >> (GLuint) (span->x % 32);
+      for (i = 0; i < span->end; i++) {
+         if ((m & stipple) == 0) {
+            mask[i] = 0;
+         }
+         m = m >> 1;
+         if (m == 0) {
+            m = highBit;
+         }
+      }
+   }
+   span->writeAll = GL_FALSE;
+}
+
+
+/**
+ * Clip a pixel span to the current buffer/window boundaries:
+ * DrawBuffer->_Xmin, _Xmax, _Ymin, _Ymax.  This will accomplish
+ * window clipping and scissoring.
+ * Return:   GL_TRUE   some pixels still visible
+ *           GL_FALSE  nothing visible
+ */
+static INLINE GLuint
+clip_span( struct gl_context *ctx, SWspan *span )
+{
+   const GLint xmin = ctx->DrawBuffer->_Xmin;
+   const GLint xmax = ctx->DrawBuffer->_Xmax;
+   const GLint ymin = ctx->DrawBuffer->_Ymin;
+   const GLint ymax = ctx->DrawBuffer->_Ymax;
+
+   span->leftClip = 0;
+
+   if (span->arrayMask & SPAN_XY) {
+      /* arrays of x/y pixel coords */
+      const GLint *x = span->array->x;
+      const GLint *y = span->array->y;
+      const GLint n = span->end;
+      GLubyte *mask = span->array->mask;
+      GLint i;
+      if (span->arrayMask & SPAN_MASK) {
+         /* note: using & intead of && to reduce branches */
+         for (i = 0; i < n; i++) {
+            mask[i] &= (x[i] >= xmin) & (x[i] < xmax)
+                     & (y[i] >= ymin) & (y[i] < ymax);
+         }
+      }
+      else {
+         /* note: using & intead of && to reduce branches */
+         for (i = 0; i < n; i++) {
+            mask[i] = (x[i] >= xmin) & (x[i] < xmax)
+                    & (y[i] >= ymin) & (y[i] < ymax);
+         }
+      }
+      return GL_TRUE;  /* some pixels visible */
+   }
+   else {
+      /* horizontal span of pixels */
+      const GLint x = span->x;
+      const GLint y = span->y;
+      GLint n = span->end;
+
+      /* Trivial rejection tests */
+      if (y < ymin || y >= ymax || x + n <= xmin || x >= xmax) {
+         span->end = 0;
+         return GL_FALSE;  /* all pixels clipped */
+      }
+
+      /* Clip to right */
+      if (x + n > xmax) {
+         ASSERT(x < xmax);
+         n = span->end = xmax - x;
+      }
+
+      /* Clip to the left */
+      if (x < xmin) {
+         const GLint leftClip = xmin - x;
+         GLuint i;
+
+         ASSERT(leftClip > 0);
+         ASSERT(x + n > xmin);
+
+         /* Clip 'leftClip' pixels from the left side.
+          * The span->leftClip field will be applied when we interpolate
+          * fragment attributes.
+          * For arrays of values, shift them left.
+          */
+         for (i = 0; i < FRAG_ATTRIB_MAX; i++) {
+            if (span->interpMask & (1 << i)) {
+               GLuint j;
+               for (j = 0; j < 4; j++) {
+                  span->attrStart[i][j] += leftClip * span->attrStepX[i][j];
+               }
+            }
+         }
+
+         span->red += leftClip * span->redStep;
+         span->green += leftClip * span->greenStep;
+         span->blue += leftClip * span->blueStep;
+         span->alpha += leftClip * span->alphaStep;
+         span->index += leftClip * span->indexStep;
+         span->z += leftClip * span->zStep;
+         span->intTex[0] += leftClip * span->intTexStep[0];
+         span->intTex[1] += leftClip * span->intTexStep[1];
+
+#define SHIFT_ARRAY(ARRAY, SHIFT, LEN) \
+         memcpy(ARRAY, ARRAY + (SHIFT), (LEN) * sizeof(ARRAY[0]))
+
+         for (i = 0; i < FRAG_ATTRIB_MAX; i++) {
+            if (span->arrayAttribs & (1 << i)) {
+               /* shift array elements left by 'leftClip' */
+               SHIFT_ARRAY(span->array->attribs[i], leftClip, n - leftClip);
+            }
+         }
+
+         SHIFT_ARRAY(span->array->mask, leftClip, n - leftClip);
+         SHIFT_ARRAY(span->array->rgba8, leftClip, n - leftClip);
+         SHIFT_ARRAY(span->array->rgba16, leftClip, n - leftClip);
+         SHIFT_ARRAY(span->array->x, leftClip, n - leftClip);
+         SHIFT_ARRAY(span->array->y, leftClip, n - leftClip);
+         SHIFT_ARRAY(span->array->z, leftClip, n - leftClip);
+         SHIFT_ARRAY(span->array->index, leftClip, n - leftClip);
+         for (i = 0; i < MAX_TEXTURE_COORD_UNITS; i++) {
+            SHIFT_ARRAY(span->array->lambda[i], leftClip, n - leftClip);
+         }
+         SHIFT_ARRAY(span->array->coverage, leftClip, n - leftClip);
+
+#undef SHIFT_ARRAY
+
+         span->leftClip = leftClip;
+         span->x = xmin;
+         span->end -= leftClip;
+         span->writeAll = GL_FALSE;
+      }
+
+      ASSERT(span->x >= xmin);
+      ASSERT(span->x + span->end <= xmax);
+      ASSERT(span->y >= ymin);
+      ASSERT(span->y < ymax);
+
+      return GL_TRUE;  /* some pixels visible */
+   }
+}
+
+
+/**
+ * Add specular colors to primary colors.
+ * Only called during fixed-function operation.
+ * Result is float color array (FRAG_ATTRIB_COL0).
+ */
+static INLINE void
+add_specular(struct gl_context *ctx, SWspan *span)
+{
+   const SWcontext *swrast = SWRAST_CONTEXT(ctx);
+   const GLubyte *mask = span->array->mask;
+   GLfloat (*col0)[4] = span->array->attribs[FRAG_ATTRIB_COL0];
+   GLfloat (*col1)[4] = span->array->attribs[FRAG_ATTRIB_COL1];
+   GLuint i;
+
+   ASSERT(!ctx->FragmentProgram._Current);
+   ASSERT(span->arrayMask & SPAN_RGBA);
+   ASSERT(swrast->_ActiveAttribMask & FRAG_BIT_COL1);
+   (void) swrast; /* silence warning */
+
+   if (span->array->ChanType == GL_FLOAT) {
+      if ((span->arrayAttribs & FRAG_BIT_COL0) == 0) {
+         interpolate_active_attribs(ctx, span, FRAG_BIT_COL0);
+      }
+   }
+   else {
+      /* need float colors */
+      if ((span->arrayAttribs & FRAG_BIT_COL0) == 0) {
+         interpolate_float_colors(span);
+      }
+   }
+
+   if ((span->arrayAttribs & FRAG_BIT_COL1) == 0) {
+      /* XXX could avoid this and interpolate COL1 in the loop below */
+      interpolate_active_attribs(ctx, span, FRAG_BIT_COL1);
+   }
+
+   ASSERT(span->arrayAttribs & FRAG_BIT_COL0);
+   ASSERT(span->arrayAttribs & FRAG_BIT_COL1);
+
+   for (i = 0; i < span->end; i++) {
+      if (mask[i]) {
+         col0[i][0] += col1[i][0];
+         col0[i][1] += col1[i][1];
+         col0[i][2] += col1[i][2];
+      }
+   }
+
+   span->array->ChanType = GL_FLOAT;
+}
+
+
+/**
+ * Apply antialiasing coverage value to alpha values.
+ */
+static INLINE void
+apply_aa_coverage(SWspan *span)
+{
+   const GLfloat *coverage = span->array->coverage;
+   GLuint i;
+   if (span->array->ChanType == GL_UNSIGNED_BYTE) {
+      GLubyte (*rgba)[4] = span->array->rgba8;
+      for (i = 0; i < span->end; i++) {
+         const GLfloat a = rgba[i][ACOMP] * coverage[i];
+         rgba[i][ACOMP] = (GLubyte) CLAMP(a, 0.0, 255.0);
+         ASSERT(coverage[i] >= 0.0);
+         ASSERT(coverage[i] <= 1.0);
+      }
+   }
+   else if (span->array->ChanType == GL_UNSIGNED_SHORT) {
+      GLushort (*rgba)[4] = span->array->rgba16;
+      for (i = 0; i < span->end; i++) {
+         const GLfloat a = rgba[i][ACOMP] * coverage[i];
+         rgba[i][ACOMP] = (GLushort) CLAMP(a, 0.0, 65535.0);
+      }
+   }
+   else {
+      GLfloat (*rgba)[4] = span->array->attribs[FRAG_ATTRIB_COL0];
+      for (i = 0; i < span->end; i++) {
+         rgba[i][ACOMP] = rgba[i][ACOMP] * coverage[i];
+         /* clamp later */
+      }
+   }
+}
+
+
+/**
+ * Clamp span's float colors to [0,1]
+ */
+static INLINE void
+clamp_colors(SWspan *span)
+{
+   GLfloat (*rgba)[4] = span->array->attribs[FRAG_ATTRIB_COL0];
+   GLuint i;
+   ASSERT(span->array->ChanType == GL_FLOAT);
+   for (i = 0; i < span->end; i++) {
+      rgba[i][RCOMP] = CLAMP(rgba[i][RCOMP], 0.0F, 1.0F);
+      rgba[i][GCOMP] = CLAMP(rgba[i][GCOMP], 0.0F, 1.0F);
+      rgba[i][BCOMP] = CLAMP(rgba[i][BCOMP], 0.0F, 1.0F);
+      rgba[i][ACOMP] = CLAMP(rgba[i][ACOMP], 0.0F, 1.0F);
+   }
+}
+
+
+/**
+ * Convert the span's color arrays to the given type.
+ * The only way 'output' can be greater than zero is when we have a fragment
+ * program that writes to gl_FragData[1] or higher.
+ * \param output  which fragment program color output is being processed
+ */
+static INLINE void
+convert_color_type(SWspan *span, GLenum newType, GLuint output)
+{
+   GLvoid *src, *dst;
+
+   if (output > 0 || span->array->ChanType == GL_FLOAT) {
+      src = span->array->attribs[FRAG_ATTRIB_COL0 + output];
+      span->array->ChanType = GL_FLOAT;
+   }
+   else if (span->array->ChanType == GL_UNSIGNED_BYTE) {
+      src = span->array->rgba8;
+   }
+   else {
+      ASSERT(span->array->ChanType == GL_UNSIGNED_SHORT);
+      src = span->array->rgba16;
+   }
+
+   if (newType == GL_UNSIGNED_BYTE) {
+      dst = span->array->rgba8;
+   }
+   else if (newType == GL_UNSIGNED_SHORT) {
+      dst = span->array->rgba16;
+   }
+   else {
+      dst = span->array->attribs[FRAG_ATTRIB_COL0];
+   }
+
+   _mesa_convert_colors(span->array->ChanType, src,
+                        newType, dst,
+                        span->end, span->array->mask);
+
+   span->array->ChanType = newType;
+   span->array->rgba = dst;
+}
+
+
+
+/**
+ * Apply fragment shader, fragment program or normal texturing to span.
+ */
+static INLINE void
+shade_texture_span(struct gl_context *ctx, SWspan *span)
+{
+   if (ctx->FragmentProgram._Current ||
+       ctx->ATIFragmentShader._Enabled) {
+      /* programmable shading */
+      if (span->primitive == GL_BITMAP && span->array->ChanType != GL_FLOAT) {
+         convert_color_type(span, GL_FLOAT, 0);
+      }
+      else {
+         span->array->rgba = (void *) span->array->attribs[FRAG_ATTRIB_COL0];
+      }
+
+      if (span->primitive != GL_POINT ||
+	  (span->interpMask & SPAN_RGBA) ||
+	  ctx->Point.PointSprite) {
+         /* for single-pixel points, we populated the arrays already */
+         interpolate_active_attribs(ctx, span, ~0);
+      }
+      span->array->ChanType = GL_FLOAT;
+
+      if (!(span->arrayMask & SPAN_Z))
+         _swrast_span_interpolate_z (ctx, span);
+
+#if 0
+      if (inputsRead & FRAG_BIT_WPOS)
+#else
+      /* XXX always interpolate wpos so that DDX/DDY work */
+#endif
+         interpolate_wpos(ctx, span);
+
+      /* Run fragment program/shader now */
+      if (ctx->FragmentProgram._Current) {
+         _swrast_exec_fragment_program(ctx, span);
+      }
+      else {
+         ASSERT(ctx->ATIFragmentShader._Enabled);
+         _swrast_exec_fragment_shader(ctx, span);
+      }
+   }
+   else if (ctx->Texture._EnabledCoordUnits) {
+      /* conventional texturing */
+
+#if CHAN_BITS == 32
+      if ((span->arrayAttribs & FRAG_BIT_COL0) == 0) {
+         interpolate_int_colors(ctx, span);
+      }
+#else
+      if (!(span->arrayMask & SPAN_RGBA))
+         interpolate_int_colors(ctx, span);
+#endif
+      if ((span->arrayAttribs & FRAG_BITS_TEX_ANY) == 0x0)
+         interpolate_texcoords(ctx, span);
+
+      _swrast_texture_span(ctx, span);
+   }
+}
+
+
+
+/**
+ * Apply all the per-fragment operations to a span.
+ * This now includes texturing (_swrast_write_texture_span() is history).
+ * This function may modify any of the array values in the span.
+ * span->interpMask and span->arrayMask may be changed but will be restored
+ * to their original values before returning.
+ */
+void
+_swrast_write_rgba_span( struct gl_context *ctx, SWspan *span)
+{
+   const SWcontext *swrast = SWRAST_CONTEXT(ctx);
+   const GLuint *colorMask = (GLuint *) ctx->Color.ColorMask;
+   const GLbitfield origInterpMask = span->interpMask;
+   const GLbitfield origArrayMask = span->arrayMask;
+   const GLbitfield origArrayAttribs = span->arrayAttribs;
+   const GLenum origChanType = span->array->ChanType;
+   void * const origRgba = span->array->rgba;
+   const GLboolean shader = (ctx->FragmentProgram._Current
+                             || ctx->ATIFragmentShader._Enabled);
+   const GLboolean shaderOrTexture = shader || ctx->Texture._EnabledCoordUnits;
+   struct gl_framebuffer *fb = ctx->DrawBuffer;
+
+   /*
+   printf("%s()  interp 0x%x  array 0x%x\n", __FUNCTION__,
+          span->interpMask, span->arrayMask);
+   */
+
+   ASSERT(span->primitive == GL_POINT ||
+          span->primitive == GL_LINE ||
+	  span->primitive == GL_POLYGON ||
+          span->primitive == GL_BITMAP);
+
+   /* Fragment write masks */
+   if (span->arrayMask & SPAN_MASK) {
+      /* mask was initialized by caller, probably glBitmap */
+      span->writeAll = GL_FALSE;
+   }
+   else {
+      memset(span->array->mask, 1, span->end);
+      span->writeAll = GL_TRUE;
+   }
+
+   /* Clip to window/scissor box */
+   if (!clip_span(ctx, span)) {
+      return;
+   }
+
+   ASSERT(span->end <= MAX_WIDTH);
+
+   /* Depth bounds test */
+   if (ctx->Depth.BoundsTest && fb->Visual.depthBits > 0) {
+      if (!_swrast_depth_bounds_test(ctx, span)) {
+         return;
+      }
+   }
+
+#ifdef DEBUG
+   /* Make sure all fragments are within window bounds */
+   if (span->arrayMask & SPAN_XY) {
+      /* array of pixel locations */
+      GLuint i;
+      for (i = 0; i < span->end; i++) {
+         if (span->array->mask[i]) {
+            assert(span->array->x[i] >= fb->_Xmin);
+            assert(span->array->x[i] < fb->_Xmax);
+            assert(span->array->y[i] >= fb->_Ymin);
+            assert(span->array->y[i] < fb->_Ymax);
+         }
+      }
+   }
+#endif
+
+   /* Polygon Stippling */
+   if (ctx->Polygon.StippleFlag && span->primitive == GL_POLYGON) {
+      stipple_polygon_span(ctx, span);
+   }
+
+   /* This is the normal place to compute the fragment color/Z
+    * from texturing or shading.
+    */
+   if (shaderOrTexture && !swrast->_DeferredTexture) {
+      shade_texture_span(ctx, span);
+   }
+
+   /* Do the alpha test */
+   if (ctx->Color.AlphaEnabled) {
+      if (!_swrast_alpha_test(ctx, span)) {
+         /* all fragments failed test */
+         goto end;
+      }
+   }
+
+   /* Stencil and Z testing */
+   if (ctx->Stencil._Enabled || ctx->Depth.Test) {
+      if (!(span->arrayMask & SPAN_Z))
+         _swrast_span_interpolate_z(ctx, span);
+
+      if (ctx->Transform.DepthClamp)
+	 _swrast_depth_clamp_span(ctx, span);
+
+      if (ctx->Stencil._Enabled) {
+         /* Combined Z/stencil tests */
+         if (!_swrast_stencil_and_ztest_span(ctx, span)) {
+            /* all fragments failed test */
+            goto end;
+         }
+      }
+      else if (fb->Visual.depthBits > 0) {
+         /* Just regular depth testing */
+         ASSERT(ctx->Depth.Test);
+         ASSERT(span->arrayMask & SPAN_Z);
+         if (!_swrast_depth_test_span(ctx, span)) {
+            /* all fragments failed test */
+            goto end;
+         }
+      }
+   }
+
+   if (ctx->Query.CurrentOcclusionObject) {
+      /* update count of 'passed' fragments */
+      struct gl_query_object *q = ctx->Query.CurrentOcclusionObject;
+      GLuint i;
+      for (i = 0; i < span->end; i++)
+         q->Result += span->array->mask[i];
+   }
+
+   /* We had to wait until now to check for glColorMask(0,0,0,0) because of
+    * the occlusion test.
+    */
+   if (fb->_NumColorDrawBuffers == 1 && colorMask[0] == 0x0) {
+      /* no colors to write */
+      goto end;
+   }
+
+   /* If we were able to defer fragment color computation to now, there's
+    * a good chance that many fragments will have already been killed by
+    * Z/stencil testing.
+    */
+   if (shaderOrTexture && swrast->_DeferredTexture) {
+      shade_texture_span(ctx, span);
+   }
+
+#if CHAN_BITS == 32
+   if ((span->arrayAttribs & FRAG_BIT_COL0) == 0) {
+      interpolate_active_attribs(ctx, span, FRAG_BIT_COL0);
+   }
+#else
+   if ((span->arrayMask & SPAN_RGBA) == 0) {
+      interpolate_int_colors(ctx, span);
+   }
+#endif
+
+   ASSERT(span->arrayMask & SPAN_RGBA);
+
+   if (span->primitive == GL_BITMAP || !swrast->SpecularVertexAdd) {
+      /* Add primary and specular (diffuse + specular) colors */
+      if (!shader) {
+         if (ctx->Fog.ColorSumEnabled ||
+             (ctx->Light.Enabled &&
+              ctx->Light.Model.ColorControl == GL_SEPARATE_SPECULAR_COLOR)) {
+            add_specular(ctx, span);
+         }
+      }
+   }
+
+   /* Fog */
+   if (swrast->_FogEnabled) {
+      _swrast_fog_rgba_span(ctx, span);
+   }
+
+   /* Antialias coverage application */
+   if (span->arrayMask & SPAN_COVERAGE) {
+      apply_aa_coverage(span);
+   }
+
+   /* Clamp color/alpha values over the range [0.0, 1.0] before storage */
+   if (ctx->Color.ClampFragmentColor == GL_TRUE &&
+       span->array->ChanType == GL_FLOAT) {
+      clamp_colors(span);
+   }
+
+   /*
+    * Write to renderbuffers.
+    * Depending on glDrawBuffer() state and the which color outputs are
+    * written by the fragment shader, we may either replicate one color to
+    * all renderbuffers or write a different color to each renderbuffer.
+    * multiFragOutputs=TRUE for the later case.
+    */
+   {
+      const GLuint numBuffers = fb->_NumColorDrawBuffers;
+      const struct gl_fragment_program *fp = ctx->FragmentProgram._Current;
+      const GLboolean multiFragOutputs = 
+         (fp && fp->Base.OutputsWritten >= (1 << FRAG_RESULT_DATA0));
+      GLuint buf;
+
+      for (buf = 0; buf < numBuffers; buf++) {
+         struct gl_renderbuffer *rb = fb->_ColorDrawBuffers[buf];
+
+         /* color[fragOutput] will be written to buffer[buf] */
+
+         if (rb) {
+            GLchan rgbaSave[MAX_WIDTH][4];
+            const GLuint fragOutput = multiFragOutputs ? buf : 0;
+
+            /* set span->array->rgba to colors for render buffer's datatype */
+            if (rb->DataType != span->array->ChanType || fragOutput > 0) {
+               convert_color_type(span, rb->DataType, fragOutput);
+            }
+            else {
+               if (rb->DataType == GL_UNSIGNED_BYTE) {
+                  span->array->rgba = span->array->rgba8;
+               }
+               else if (rb->DataType == GL_UNSIGNED_SHORT) {
+                  span->array->rgba = (void *) span->array->rgba16;
+               }
+               else {
+                  span->array->rgba = (void *)
+                     span->array->attribs[FRAG_ATTRIB_COL0];
+               }
+            }
+
+            if (!multiFragOutputs && numBuffers > 1) {
+               /* save colors for second, third renderbuffer writes */
+               memcpy(rgbaSave, span->array->rgba,
+                      4 * span->end * sizeof(GLchan));
+            }
+
+            ASSERT(rb->_BaseFormat == GL_RGBA || rb->_BaseFormat == GL_RGB ||
+		   rb->_BaseFormat == GL_ALPHA);
+
+            if (ctx->Color._LogicOpEnabled) {
+               _swrast_logicop_rgba_span(ctx, rb, span);
+            }
+            else if ((ctx->Color.BlendEnabled >> buf) & 1) {
+               _swrast_blend_span(ctx, rb, span);
+            }
+
+            if (colorMask[buf] != 0xffffffff) {
+               _swrast_mask_rgba_span(ctx, rb, span, buf);
+            }
+
+            if (span->arrayMask & SPAN_XY) {
+               /* array of pixel coords */
+               ASSERT(rb->PutValues);
+               rb->PutValues(ctx, rb, span->end,
+                             span->array->x, span->array->y,
+                             span->array->rgba, span->array->mask);
+            }
+            else {
+               /* horizontal run of pixels */
+               ASSERT(rb->PutRow);
+               rb->PutRow(ctx, rb, span->end, span->x, span->y,
+                          span->array->rgba,
+                          span->writeAll ? NULL: span->array->mask);
+            }
+
+            if (!multiFragOutputs && numBuffers > 1) {
+               /* restore original span values */
+               memcpy(span->array->rgba, rgbaSave,
+                      4 * span->end * sizeof(GLchan));
+            }
+
+         } /* if rb */
+      } /* for buf */
+   }
+
+end:
+   /* restore these values before returning */
+   span->interpMask = origInterpMask;
+   span->arrayMask = origArrayMask;
+   span->arrayAttribs = origArrayAttribs;
+   span->array->ChanType = origChanType;
+   span->array->rgba = origRgba;
+}
+
+
+/**
+ * Read RGBA pixels from a renderbuffer.  Clipping will be done to prevent
+ * reading ouside the buffer's boundaries.
+ * \param dstType  datatype for returned colors
+ * \param rgba  the returned colors
+ */
+void
+_swrast_read_rgba_span( struct gl_context *ctx, struct gl_renderbuffer *rb,
+                        GLuint n, GLint x, GLint y, GLenum dstType,
+                        GLvoid *rgba)
+{
+   const GLint bufWidth = (GLint) rb->Width;
+   const GLint bufHeight = (GLint) rb->Height;
+
+   if (y < 0 || y >= bufHeight || x + (GLint) n < 0 || x >= bufWidth) {
+      /* completely above, below, or right */
+      /* XXX maybe leave rgba values undefined? */
+      memset(rgba, 0, 4 * n * sizeof(GLchan));
+   }
+   else {
+      GLint skip, length;
+      if (x < 0) {
+         /* left edge clipping */
+         skip = -x;
+         length = (GLint) n - skip;
+         if (length < 0) {
+            /* completely left of window */
+            return;
+         }
+         if (length > bufWidth) {
+            length = bufWidth;
+         }
+      }
+      else if ((GLint) (x + n) > bufWidth) {
+         /* right edge clipping */
+         skip = 0;
+         length = bufWidth - x;
+         if (length < 0) {
+            /* completely to right of window */
+            return;
+         }
+      }
+      else {
+         /* no clipping */
+         skip = 0;
+         length = (GLint) n;
+      }
+
+      ASSERT(rb);
+      ASSERT(rb->GetRow);
+      ASSERT(rb->_BaseFormat == GL_RGBA ||
+	     rb->_BaseFormat == GL_RGB ||
+	     rb->_BaseFormat == GL_RG ||
+	     rb->_BaseFormat == GL_RED ||
+	     rb->_BaseFormat == GL_LUMINANCE ||
+	     rb->_BaseFormat == GL_INTENSITY ||
+	     rb->_BaseFormat == GL_LUMINANCE_ALPHA ||
+	     rb->_BaseFormat == GL_ALPHA);
+
+      if (rb->DataType == dstType) {
+         rb->GetRow(ctx, rb, length, x + skip, y,
+                    (GLubyte *) rgba + skip * RGBA_PIXEL_SIZE(rb->DataType));
+      }
+      else {
+         GLuint temp[MAX_WIDTH * 4];
+         rb->GetRow(ctx, rb, length, x + skip, y, temp);
+         _mesa_convert_colors(rb->DataType, temp,
+                   dstType, (GLubyte *) rgba + skip * RGBA_PIXEL_SIZE(dstType),
+                   length, NULL);
+      }
+   }
+}
+
+
+/**
+ * Wrapper for gl_renderbuffer::GetValues() which does clipping to avoid
+ * reading values outside the buffer bounds.
+ * We can use this for reading any format/type of renderbuffer.
+ * \param valueSize is the size in bytes of each value (pixel) put into the
+ *                  values array.
+ */
+void
+_swrast_get_values(struct gl_context *ctx, struct gl_renderbuffer *rb,
+                   GLuint count, const GLint x[], const GLint y[],
+                   void *values, GLuint valueSize)
+{
+   GLuint i, inCount = 0, inStart = 0;
+
+   for (i = 0; i < count; i++) {
+      if (x[i] >= 0 && y[i] >= 0 &&
+	  x[i] < (GLint) rb->Width && y[i] < (GLint) rb->Height) {
+         /* inside */
+         if (inCount == 0)
+            inStart = i;
+         inCount++;
+      }
+      else {
+         if (inCount > 0) {
+            /* read [inStart, inStart + inCount) */
+            rb->GetValues(ctx, rb, inCount, x + inStart, y + inStart,
+                          (GLubyte *) values + inStart * valueSize);
+            inCount = 0;
+         }
+      }
+   }
+   if (inCount > 0) {
+      /* read last values */
+      rb->GetValues(ctx, rb, inCount, x + inStart, y + inStart,
+                    (GLubyte *) values + inStart * valueSize);
+   }
+}
+
+
+/**
+ * Wrapper for gl_renderbuffer::PutRow() which does clipping.
+ * \param valueSize  size of each value (pixel) in bytes
+ */
+void
+_swrast_put_row(struct gl_context *ctx, struct gl_renderbuffer *rb,
+                GLuint count, GLint x, GLint y,
+                const GLvoid *values, GLuint valueSize)
+{
+   GLint skip = 0;
+
+   if (y < 0 || y >= (GLint) rb->Height)
+      return; /* above or below */
+
+   if (x + (GLint) count <= 0 || x >= (GLint) rb->Width)
+      return; /* entirely left or right */
+
+   if ((GLint) (x + count) > (GLint) rb->Width) {
+      /* right clip */
+      GLint clip = x + count - rb->Width;
+      count -= clip;
+   }
+
+   if (x < 0) {
+      /* left clip */
+      skip = -x;
+      x = 0;
+      count -= skip;
+   }
+
+   rb->PutRow(ctx, rb, count, x, y,
+              (const GLubyte *) values + skip * valueSize, NULL);
+}
+
+
+/**
+ * Wrapper for gl_renderbuffer::GetRow() which does clipping.
+ * \param valueSize  size of each value (pixel) in bytes
+ */
+void
+_swrast_get_row(struct gl_context *ctx, struct gl_renderbuffer *rb,
+                GLuint count, GLint x, GLint y,
+                GLvoid *values, GLuint valueSize)
+{
+   GLint skip = 0;
+
+   if (y < 0 || y >= (GLint) rb->Height)
+      return; /* above or below */
+
+   if (x + (GLint) count <= 0 || x >= (GLint) rb->Width)
+      return; /* entirely left or right */
+
+   if (x + count > rb->Width) {
+      /* right clip */
+      GLint clip = x + count - rb->Width;
+      count -= clip;
+   }
+
+   if (x < 0) {
+      /* left clip */
+      skip = -x;
+      x = 0;
+      count -= skip;
+   }
+
+   rb->GetRow(ctx, rb, count, x, y, (GLubyte *) values + skip * valueSize);
+}
+
+
+/**
+ * Get RGBA pixels from the given renderbuffer.
+ * Used by blending, logicop and masking functions.
+ * \return pointer to the colors we read.
+ */
+void *
+_swrast_get_dest_rgba(struct gl_context *ctx, struct gl_renderbuffer *rb,
+                      SWspan *span)
+{
+   const GLuint pixelSize = RGBA_PIXEL_SIZE(span->array->ChanType);
+   void *rbPixels;
+
+   /* Point rbPixels to a temporary space */
+   rbPixels = span->array->attribs[FRAG_ATTRIB_MAX - 1];
+
+   /* Get destination values from renderbuffer */
+   if (span->arrayMask & SPAN_XY) {
+      _swrast_get_values(ctx, rb, span->end, span->array->x, span->array->y,
+                         rbPixels, pixelSize);
+   }
+   else {
+      _swrast_get_row(ctx, rb, span->end, span->x, span->y,
+                      rbPixels, pixelSize);
+   }
+
+   return rbPixels;
+}