Synchronised line endinge with release branch

1 files changed, 598 insertions, 598 deletions

diff --git a/mesalib/src/mesa/swrast/s_accum.c b/mesalib/src/mesa/swrast/s_accum.c
index 2889d908b..0ec907d79 100644
--- a/mesalib/src/mesa/swrast/s_accum.c
+++ b/mesalib/src/mesa/swrast/s_accum.c
@@ -1,598 +1,598 @@
-/*

- * Mesa 3-D graphics library

- * Version:  6.5.2

- *

- * Copyright (C) 1999-2006  Brian Paul   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.

- */

-

-

-#include "main/glheader.h"

-#include "main/condrender.h"

-#include "main/context.h"

-#include "main/macros.h"

-#include "main/imports.h"

-

-#include "s_accum.h"

-#include "s_context.h"

-#include "s_masking.h"

-#include "s_span.h"

-

-

-/* XXX this would have to change for accum buffers with more or less

- * than 16 bits per color channel.

- */

-#define ACCUM_SCALE16 32767.0F

-

-

-/*

- * Accumulation buffer notes

- *

- * Normally, accumulation buffer values are GLshorts with values in

- * [-32767, 32767] which represent floating point colors in [-1, 1],

- * as defined by the OpenGL specification.

- *

- * We optimize for the common case used for full-scene antialiasing:

- *    // start with accum buffer cleared to zero

- *    glAccum(GL_LOAD, w);   // or GL_ACCUM the first image

- *    glAccum(GL_ACCUM, w);

- *    ...

- *    glAccum(GL_ACCUM, w);

- *    glAccum(GL_RETURN, 1.0);

- * That is, we start with an empty accumulation buffer and accumulate

- * n images, each with weight w = 1/n.

- * In this scenario, we can simply store unscaled integer values in

- * the accum buffer instead of scaled integers.  We'll also keep track

- * of the w value so when we do GL_RETURN we simply divide the accumulated

- * values by n (n=1/w).

- * This lets us avoid _many_ int->float->int conversions.

- */

-

-

-#if CHAN_BITS == 8

-/* enable the optimization */

-#define USE_OPTIMIZED_ACCUM  1

-#else

-#define USE_OPTIMIZED_ACCUM  0

-#endif

-

-

-/**

- * This is called when we fall out of optimized/unscaled accum buffer mode.

- * That is, we convert each unscaled accum buffer value into a scaled value

- * representing the range[-1, 1].

- */

-static void

-rescale_accum( struct gl_context *ctx )

-{

-   SWcontext *swrast = SWRAST_CONTEXT(ctx);

-   struct gl_renderbuffer *rb

-      = ctx->DrawBuffer->Attachment[BUFFER_ACCUM].Renderbuffer;

-   const GLfloat s = swrast->_IntegerAccumScaler * (32767.0F / CHAN_MAXF);

-

-   assert(rb);

-   assert(rb->_BaseFormat == GL_RGBA);

-   /* add other types in future? */

-   assert(rb->DataType == GL_SHORT || rb->DataType == GL_UNSIGNED_SHORT);

-   assert(swrast->_IntegerAccumMode);

-

-   if (rb->GetPointer(ctx, rb, 0, 0)) {

-      /* directly-addressable memory */

-      GLuint y;

-      for (y = 0; y < rb->Height; y++) {

-         GLuint i;

-         GLshort *acc = (GLshort *) rb->GetPointer(ctx, rb, 0, y);

-         for (i = 0; i < 4 * rb->Width; i++) {

-            acc[i] = (GLshort) (acc[i] * s);

-         }

-      }

-   }

-   else {

-      /* use get/put row funcs */

-      GLuint y;

-      for (y = 0; y < rb->Height; y++) {

-         GLshort accRow[MAX_WIDTH * 4];

-         GLuint i;

-         rb->GetRow(ctx, rb, rb->Width, 0, y, accRow);

-         for (i = 0; i < 4 * rb->Width; i++) {

-            accRow[i] = (GLshort) (accRow[i] * s);

-         }

-         rb->PutRow(ctx, rb, rb->Width, 0, y, accRow, NULL);

-      }

-   }

-

-   swrast->_IntegerAccumMode = GL_FALSE;

-}

-

-

-

-/**

- * Clear the accumulation Buffer.

- */

-void

-_swrast_clear_accum_buffer( struct gl_context *ctx, struct gl_renderbuffer *rb )

-{

-   SWcontext *swrast = SWRAST_CONTEXT(ctx);

-   GLuint x, y, width, height;

-

-   /* No accumulation buffer! Not an error. */

-   if (!rb || !rb->Data)

-      return;

-

-   assert(rb->_BaseFormat == GL_RGBA);

-   /* add other types in future? */

-   assert(rb->DataType == GL_SHORT || rb->DataType == GL_UNSIGNED_SHORT);

-

-   /* bounds, with scissor */

-   x = ctx->DrawBuffer->_Xmin;

-   y = ctx->DrawBuffer->_Ymin;

-   width = ctx->DrawBuffer->_Xmax - ctx->DrawBuffer->_Xmin;

-   height = ctx->DrawBuffer->_Ymax - ctx->DrawBuffer->_Ymin;

-

-   if (rb->DataType == GL_SHORT || rb->DataType == GL_UNSIGNED_SHORT) {

-      const GLfloat accScale = 32767.0;

-      GLshort clearVal[4];

-      GLuint i;

-

-      clearVal[0] = (GLshort) (ctx->Accum.ClearColor[0] * accScale);

-      clearVal[1] = (GLshort) (ctx->Accum.ClearColor[1] * accScale);

-      clearVal[2] = (GLshort) (ctx->Accum.ClearColor[2] * accScale);

-      clearVal[3] = (GLshort) (ctx->Accum.ClearColor[3] * accScale);

-

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

-         rb->PutMonoRow(ctx, rb, width, x, y + i, clearVal, NULL);

-      }

-   }

-   else {

-      /* someday support other sizes */

-   }

-

-   /* update optimized accum state vars */

-   if (ctx->Accum.ClearColor[0] == 0.0 && ctx->Accum.ClearColor[1] == 0.0 &&

-       ctx->Accum.ClearColor[2] == 0.0 && ctx->Accum.ClearColor[3] == 0.0) {

-#if USE_OPTIMIZED_ACCUM

-      swrast->_IntegerAccumMode = GL_TRUE;

-#else

-      swrast->_IntegerAccumMode = GL_FALSE;

-#endif

-      swrast->_IntegerAccumScaler = 0.0;  /* denotes empty accum buffer */

-   }

-   else {

-      swrast->_IntegerAccumMode = GL_FALSE;

-   }

-}

-

-

-static void

-accum_add(struct gl_context *ctx, GLfloat value,

-          GLint xpos, GLint ypos, GLint width, GLint height )

-{

-   SWcontext *swrast = SWRAST_CONTEXT(ctx);

-   struct gl_renderbuffer *rb

-      = ctx->DrawBuffer->Attachment[BUFFER_ACCUM].Renderbuffer;

-

-   assert(rb);

-

-   /* Leave optimized accum buffer mode */

-   if (swrast->_IntegerAccumMode)

-      rescale_accum(ctx);

-

-   if (rb->DataType == GL_SHORT || rb->DataType == GL_UNSIGNED_SHORT) {

-      const GLshort incr = (GLshort) (value * ACCUM_SCALE16);

-      if (rb->GetPointer(ctx, rb, 0, 0)) {

-         GLint i, j;

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

-            GLshort *acc = (GLshort *) rb->GetPointer(ctx, rb, xpos, ypos + i);

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

-               acc[j] += incr;

-            }

-         }

-      }

-      else {

-         GLint i, j;

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

-            GLshort accRow[4 * MAX_WIDTH];

-            rb->GetRow(ctx, rb, width, xpos, ypos + i, accRow);

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

-               accRow[j] += incr;

-            }

-            rb->PutRow(ctx, rb, width, xpos, ypos + i, accRow, NULL);

-         }

-      }

-   }

-   else {

-      /* other types someday */

-   }

-}

-

-

-static void

-accum_mult(struct gl_context *ctx, GLfloat mult,

-           GLint xpos, GLint ypos, GLint width, GLint height )

-{

-   SWcontext *swrast = SWRAST_CONTEXT(ctx);

-   struct gl_renderbuffer *rb

-      = ctx->DrawBuffer->Attachment[BUFFER_ACCUM].Renderbuffer;

-

-   assert(rb);

-

-   /* Leave optimized accum buffer mode */

-   if (swrast->_IntegerAccumMode)

-      rescale_accum(ctx);

-

-   if (rb->DataType == GL_SHORT || rb->DataType == GL_UNSIGNED_SHORT) {

-      if (rb->GetPointer(ctx, rb, 0, 0)) {

-         GLint i, j;

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

-            GLshort *acc = (GLshort *) rb->GetPointer(ctx, rb, xpos, ypos + i);

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

-               acc[j] = (GLshort) (acc[j] * mult);

-            }

-         }

-      }

-      else {

-         GLint i, j;

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

-            GLshort accRow[4 * MAX_WIDTH];

-            rb->GetRow(ctx, rb, width, xpos, ypos + i, accRow);

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

-               accRow[j] = (GLshort) (accRow[j] * mult);

-            }

-            rb->PutRow(ctx, rb, width, xpos, ypos + i, accRow, NULL);

-         }

-      }

-   }

-   else {

-      /* other types someday */

-   }

-}

-

-

-

-static void

-accum_accum(struct gl_context *ctx, GLfloat value,

-            GLint xpos, GLint ypos, GLint width, GLint height )

-{

-   SWcontext *swrast = SWRAST_CONTEXT(ctx);

-   struct gl_renderbuffer *rb

-      = ctx->DrawBuffer->Attachment[BUFFER_ACCUM].Renderbuffer;

-   const GLboolean directAccess = (rb->GetPointer(ctx, rb, 0, 0) != NULL);

-

-   assert(rb);

-

-   if (!ctx->ReadBuffer->_ColorReadBuffer) {

-      /* no read buffer - OK */

-      return;

-   }

-

-   /* May have to leave optimized accum buffer mode */

-   if (swrast->_IntegerAccumScaler == 0.0 && value > 0.0 && value <= 1.0)

-      swrast->_IntegerAccumScaler = value;

-   if (swrast->_IntegerAccumMode && value != swrast->_IntegerAccumScaler)

-      rescale_accum(ctx);

-

-   if (rb->DataType == GL_SHORT || rb->DataType == GL_UNSIGNED_SHORT) {

-      const GLfloat scale = value * ACCUM_SCALE16 / CHAN_MAXF;

-      GLshort accumRow[4 * MAX_WIDTH];

-      GLchan rgba[MAX_WIDTH][4];

-      GLint i;

-

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

-         GLshort *acc;

-         if (directAccess) {

-            acc = (GLshort *) rb->GetPointer(ctx, rb, xpos, ypos + i);

-         }

-         else {

-            rb->GetRow(ctx, rb, width, xpos, ypos + i, accumRow);

-            acc = accumRow;

-         }

-

-         /* read colors from color buffer */

-         _swrast_read_rgba_span(ctx, ctx->ReadBuffer->_ColorReadBuffer, width,

-                                xpos, ypos + i, CHAN_TYPE, rgba);

-

-         /* do accumulation */

-         if (swrast->_IntegerAccumMode) {

-            /* simply add integer color values into accum buffer */

-            GLint j;

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

-               acc[j * 4 + 0] += rgba[j][RCOMP];

-               acc[j * 4 + 1] += rgba[j][GCOMP];

-               acc[j * 4 + 2] += rgba[j][BCOMP];

-               acc[j * 4 + 3] += rgba[j][ACOMP];

-            }

-         }

-         else {

-            /* scaled integer (or float) accum buffer */

-            GLint j;

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

-               acc[j * 4 + 0] += (GLshort) ((GLfloat) rgba[j][RCOMP] * scale);

-               acc[j * 4 + 1] += (GLshort) ((GLfloat) rgba[j][GCOMP] * scale);

-               acc[j * 4 + 2] += (GLshort) ((GLfloat) rgba[j][BCOMP] * scale);

-               acc[j * 4 + 3] += (GLshort) ((GLfloat) rgba[j][ACOMP] * scale);

-            }

-         }

-

-         if (!directAccess) {

-            rb->PutRow(ctx, rb, width, xpos, ypos + i, accumRow, NULL);

-         }

-      }

-   }

-   else {

-      /* other types someday */

-   }

-}

-

-

-

-static void

-accum_load(struct gl_context *ctx, GLfloat value,

-           GLint xpos, GLint ypos, GLint width, GLint height )

-{

-   SWcontext *swrast = SWRAST_CONTEXT(ctx);

-   struct gl_renderbuffer *rb

-      = ctx->DrawBuffer->Attachment[BUFFER_ACCUM].Renderbuffer;

-   const GLboolean directAccess = (rb->GetPointer(ctx, rb, 0, 0) != NULL);

-

-   assert(rb);

-

-   if (!ctx->ReadBuffer->_ColorReadBuffer) {

-      /* no read buffer - OK */

-      return;

-   }

-

-   /* This is a change to go into optimized accum buffer mode */

-   if (value > 0.0 && value <= 1.0) {

-#if USE_OPTIMIZED_ACCUM

-      swrast->_IntegerAccumMode = GL_TRUE;

-#else

-      swrast->_IntegerAccumMode = GL_FALSE;

-#endif

-      swrast->_IntegerAccumScaler = value;

-   }

-   else {

-      swrast->_IntegerAccumMode = GL_FALSE;

-      swrast->_IntegerAccumScaler = 0.0;

-   }

-

-   if (rb->DataType == GL_SHORT || rb->DataType == GL_UNSIGNED_SHORT) {

-      const GLfloat scale = value * ACCUM_SCALE16 / CHAN_MAXF;

-      GLshort accumRow[4 * MAX_WIDTH];

-      GLchan rgba[MAX_WIDTH][4];

-      GLint i;

-

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

-         GLshort *acc;

-         if (directAccess) {

-            acc = (GLshort *) rb->GetPointer(ctx, rb, xpos, ypos + i);

-         }

-         else {

-            rb->GetRow(ctx, rb, width, xpos, ypos + i, accumRow);

-            acc = accumRow;

-         }

-

-         /* read colors from color buffer */

-         _swrast_read_rgba_span(ctx, ctx->ReadBuffer->_ColorReadBuffer, width,

-                                xpos, ypos + i, CHAN_TYPE, rgba);

-

-         /* do load */

-         if (swrast->_IntegerAccumMode) {

-            /* just copy values in */

-            GLint j;

-            assert(swrast->_IntegerAccumScaler > 0.0);

-            assert(swrast->_IntegerAccumScaler <= 1.0);

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

-               acc[j * 4 + 0] = rgba[j][RCOMP];

-               acc[j * 4 + 1] = rgba[j][GCOMP];

-               acc[j * 4 + 2] = rgba[j][BCOMP];

-               acc[j * 4 + 3] = rgba[j][ACOMP];

-            }

-         }

-         else {

-            /* scaled integer (or float) accum buffer */

-            GLint j;

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

-               acc[j * 4 + 0] = (GLshort) ((GLfloat) rgba[j][RCOMP] * scale);

-               acc[j * 4 + 1] = (GLshort) ((GLfloat) rgba[j][GCOMP] * scale);

-               acc[j * 4 + 2] = (GLshort) ((GLfloat) rgba[j][BCOMP] * scale);

-               acc[j * 4 + 3] = (GLshort) ((GLfloat) rgba[j][ACOMP] * scale);

-            }

-         }

-

-         if (!directAccess) {

-            rb->PutRow(ctx, rb, width, xpos, ypos + i, accumRow, NULL);

-         }

-      }

-   }

-}

-

-

-static void

-accum_return(struct gl_context *ctx, GLfloat value,

-             GLint xpos, GLint ypos, GLint width, GLint height )

-{

-   SWcontext *swrast = SWRAST_CONTEXT(ctx);

-   struct gl_framebuffer *fb = ctx->DrawBuffer;

-   struct gl_renderbuffer *accumRb = fb->Attachment[BUFFER_ACCUM].Renderbuffer;

-   const GLboolean directAccess

-      = (accumRb->GetPointer(ctx, accumRb, 0, 0) != NULL);

-

-   static GLchan multTable[32768];

-   static GLfloat prevMult = 0.0;

-   const GLfloat mult = swrast->_IntegerAccumScaler;

-   const GLint max = MIN2((GLint) (256 / mult), 32767);

-

-   /* May have to leave optimized accum buffer mode */

-   if (swrast->_IntegerAccumMode && value != 1.0)

-      rescale_accum(ctx);

-

-   if (swrast->_IntegerAccumMode && swrast->_IntegerAccumScaler > 0) {

-      /* build lookup table to avoid many floating point multiplies */

-      GLint j;

-      assert(swrast->_IntegerAccumScaler <= 1.0);

-      if (mult != prevMult) {

-         for (j = 0; j < max; j++)

-            multTable[j] = IROUND((GLfloat) j * mult);

-         prevMult = mult;

-      }

-   }

-

-   if (accumRb->DataType == GL_SHORT ||

-       accumRb->DataType == GL_UNSIGNED_SHORT) {

-      const GLfloat scale = value * CHAN_MAXF / ACCUM_SCALE16;

-      GLuint buffer;

-      GLint i;

-

-      /* XXX maybe transpose the 'i' and 'buffer' loops??? */

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

-         GLshort accumRow[4 * MAX_WIDTH];

-         GLshort *acc;

-         SWspan span;

-

-         /* init color span */

-         INIT_SPAN(span, GL_BITMAP);

-         span.end = width;

-         span.arrayMask = SPAN_RGBA;

-         span.x = xpos;

-         span.y = ypos + i;

-

-         if (directAccess) {

-            acc = (GLshort *) accumRb->GetPointer(ctx, accumRb, xpos, ypos +i);

-         }

-         else {

-            accumRb->GetRow(ctx, accumRb, width, xpos, ypos + i, accumRow);

-            acc = accumRow;

-         }

-

-         /* get the colors to return */

-         if (swrast->_IntegerAccumMode) {

-            GLint j;

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

-               ASSERT(acc[j * 4 + 0] < max);

-               ASSERT(acc[j * 4 + 1] < max);

-               ASSERT(acc[j * 4 + 2] < max);

-               ASSERT(acc[j * 4 + 3] < max);

-               span.array->rgba[j][RCOMP] = multTable[acc[j * 4 + 0]];

-               span.array->rgba[j][GCOMP] = multTable[acc[j * 4 + 1]];

-               span.array->rgba[j][BCOMP] = multTable[acc[j * 4 + 2]];

-               span.array->rgba[j][ACOMP] = multTable[acc[j * 4 + 3]];

-            }

-         }

-         else {

-            /* scaled integer (or float) accum buffer */

-            GLint j;

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

-#if CHAN_BITS==32

-               GLchan r = acc[j * 4 + 0] * scale;

-               GLchan g = acc[j * 4 + 1] * scale;

-               GLchan b = acc[j * 4 + 2] * scale;

-               GLchan a = acc[j * 4 + 3] * scale;

-#else

-               GLint r = IROUND( (GLfloat) (acc[j * 4 + 0]) * scale );

-               GLint g = IROUND( (GLfloat) (acc[j * 4 + 1]) * scale );

-               GLint b = IROUND( (GLfloat) (acc[j * 4 + 2]) * scale );

-               GLint a = IROUND( (GLfloat) (acc[j * 4 + 3]) * scale );

-#endif

-               span.array->rgba[j][RCOMP] = CLAMP( r, 0, CHAN_MAX );

-               span.array->rgba[j][GCOMP] = CLAMP( g, 0, CHAN_MAX );

-               span.array->rgba[j][BCOMP] = CLAMP( b, 0, CHAN_MAX );

-               span.array->rgba[j][ACOMP] = CLAMP( a, 0, CHAN_MAX );

-            }

-         }

-

-         /* store colors */

-         for (buffer = 0; buffer < fb->_NumColorDrawBuffers; buffer++) {

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

-            const GLboolean masking = (!ctx->Color.ColorMask[buffer][RCOMP] ||

-                                       !ctx->Color.ColorMask[buffer][GCOMP] ||

-                                       !ctx->Color.ColorMask[buffer][BCOMP] ||

-                                       !ctx->Color.ColorMask[buffer][ACOMP]);

-            if (masking) {

-               _swrast_mask_rgba_span(ctx, rb, &span, buffer);

-            }

-            rb->PutRow(ctx, rb, width, xpos, ypos + i, span.array->rgba, NULL);

-         }

-      }

-   }

-   else {

-      /* other types someday */

-   }

-}

-

-

-

-/**

- * Software fallback for glAccum.

- */

-void

-_swrast_Accum(struct gl_context *ctx, GLenum op, GLfloat value)

-{

-   SWcontext *swrast = SWRAST_CONTEXT(ctx);

-   GLint xpos, ypos, width, height;

-

-   if (swrast->NewState)

-      _swrast_validate_derived( ctx );

-

-   if (!ctx->DrawBuffer->Attachment[BUFFER_ACCUM].Renderbuffer) {

-      _mesa_warning(ctx, "Calling glAccum() without an accumulation buffer");

-      return;

-   }

-

-   if (!_mesa_check_conditional_render(ctx))

-      return;

-

-   swrast_render_start(ctx);

-

-   /* Compute region after calling swrast_render_start() so that we know the

-    * drawbuffer's size/bounds are up to date.

-    */

-   xpos = ctx->DrawBuffer->_Xmin;

-   ypos = ctx->DrawBuffer->_Ymin;

-   width =  ctx->DrawBuffer->_Xmax - ctx->DrawBuffer->_Xmin;

-   height = ctx->DrawBuffer->_Ymax - ctx->DrawBuffer->_Ymin;

-

-   switch (op) {

-      case GL_ADD:

-         if (value != 0.0F) {

-            accum_add(ctx, value, xpos, ypos, width, height);

-	 }

-	 break;

-      case GL_MULT:

-         if (value != 1.0F) {

-            accum_mult(ctx, value, xpos, ypos, width, height);

-	 }

-	 break;

-      case GL_ACCUM:

-         if (value != 0.0F) {

-            accum_accum(ctx, value, xpos, ypos, width, height);

-         }

-	 break;

-      case GL_LOAD:

-         accum_load(ctx, value, xpos, ypos, width, height);

-	 break;

-      case GL_RETURN:

-         accum_return(ctx, value, xpos, ypos, width, height);

-	 break;

-      default:

-         _mesa_problem(ctx, "invalid mode in _swrast_Accum()");

-         break;

-   }

-

-   swrast_render_finish(ctx);

-}

+/*
+ * Mesa 3-D graphics library
+ * Version:  6.5.2
+ *
+ * Copyright (C) 1999-2006  Brian Paul   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.
+ */
+
+
+#include "main/glheader.h"
+#include "main/condrender.h"
+#include "main/context.h"
+#include "main/macros.h"
+#include "main/imports.h"
+
+#include "s_accum.h"
+#include "s_context.h"
+#include "s_masking.h"
+#include "s_span.h"
+
+
+/* XXX this would have to change for accum buffers with more or less
+ * than 16 bits per color channel.
+ */
+#define ACCUM_SCALE16 32767.0F
+
+
+/*
+ * Accumulation buffer notes
+ *
+ * Normally, accumulation buffer values are GLshorts with values in
+ * [-32767, 32767] which represent floating point colors in [-1, 1],
+ * as defined by the OpenGL specification.
+ *
+ * We optimize for the common case used for full-scene antialiasing:
+ *    // start with accum buffer cleared to zero
+ *    glAccum(GL_LOAD, w);   // or GL_ACCUM the first image
+ *    glAccum(GL_ACCUM, w);
+ *    ...
+ *    glAccum(GL_ACCUM, w);
+ *    glAccum(GL_RETURN, 1.0);
+ * That is, we start with an empty accumulation buffer and accumulate
+ * n images, each with weight w = 1/n.
+ * In this scenario, we can simply store unscaled integer values in
+ * the accum buffer instead of scaled integers.  We'll also keep track
+ * of the w value so when we do GL_RETURN we simply divide the accumulated
+ * values by n (n=1/w).
+ * This lets us avoid _many_ int->float->int conversions.
+ */
+
+
+#if CHAN_BITS == 8
+/* enable the optimization */
+#define USE_OPTIMIZED_ACCUM  1
+#else
+#define USE_OPTIMIZED_ACCUM  0
+#endif
+
+
+/**
+ * This is called when we fall out of optimized/unscaled accum buffer mode.
+ * That is, we convert each unscaled accum buffer value into a scaled value
+ * representing the range[-1, 1].
+ */
+static void
+rescale_accum( struct gl_context *ctx )
+{
+   SWcontext *swrast = SWRAST_CONTEXT(ctx);
+   struct gl_renderbuffer *rb
+      = ctx->DrawBuffer->Attachment[BUFFER_ACCUM].Renderbuffer;
+   const GLfloat s = swrast->_IntegerAccumScaler * (32767.0F / CHAN_MAXF);
+
+   assert(rb);
+   assert(rb->_BaseFormat == GL_RGBA);
+   /* add other types in future? */
+   assert(rb->DataType == GL_SHORT || rb->DataType == GL_UNSIGNED_SHORT);
+   assert(swrast->_IntegerAccumMode);
+
+   if (rb->GetPointer(ctx, rb, 0, 0)) {
+      /* directly-addressable memory */
+      GLuint y;
+      for (y = 0; y < rb->Height; y++) {
+         GLuint i;
+         GLshort *acc = (GLshort *) rb->GetPointer(ctx, rb, 0, y);
+         for (i = 0; i < 4 * rb->Width; i++) {
+            acc[i] = (GLshort) (acc[i] * s);
+         }
+      }
+   }
+   else {
+      /* use get/put row funcs */
+      GLuint y;
+      for (y = 0; y < rb->Height; y++) {
+         GLshort accRow[MAX_WIDTH * 4];
+         GLuint i;
+         rb->GetRow(ctx, rb, rb->Width, 0, y, accRow);
+         for (i = 0; i < 4 * rb->Width; i++) {
+            accRow[i] = (GLshort) (accRow[i] * s);
+         }
+         rb->PutRow(ctx, rb, rb->Width, 0, y, accRow, NULL);
+      }
+   }
+
+   swrast->_IntegerAccumMode = GL_FALSE;
+}
+
+
+
+/**
+ * Clear the accumulation Buffer.
+ */
+void
+_swrast_clear_accum_buffer( struct gl_context *ctx, struct gl_renderbuffer *rb )
+{
+   SWcontext *swrast = SWRAST_CONTEXT(ctx);
+   GLuint x, y, width, height;
+
+   /* No accumulation buffer! Not an error. */
+   if (!rb || !rb->Data)
+      return;
+
+   assert(rb->_BaseFormat == GL_RGBA);
+   /* add other types in future? */
+   assert(rb->DataType == GL_SHORT || rb->DataType == GL_UNSIGNED_SHORT);
+
+   /* bounds, with scissor */
+   x = ctx->DrawBuffer->_Xmin;
+   y = ctx->DrawBuffer->_Ymin;
+   width = ctx->DrawBuffer->_Xmax - ctx->DrawBuffer->_Xmin;
+   height = ctx->DrawBuffer->_Ymax - ctx->DrawBuffer->_Ymin;
+
+   if (rb->DataType == GL_SHORT || rb->DataType == GL_UNSIGNED_SHORT) {
+      const GLfloat accScale = 32767.0;
+      GLshort clearVal[4];
+      GLuint i;
+
+      clearVal[0] = (GLshort) (ctx->Accum.ClearColor[0] * accScale);
+      clearVal[1] = (GLshort) (ctx->Accum.ClearColor[1] * accScale);
+      clearVal[2] = (GLshort) (ctx->Accum.ClearColor[2] * accScale);
+      clearVal[3] = (GLshort) (ctx->Accum.ClearColor[3] * accScale);
+
+      for (i = 0; i < height; i++) {
+         rb->PutMonoRow(ctx, rb, width, x, y + i, clearVal, NULL);
+      }
+   }
+   else {
+      /* someday support other sizes */
+   }
+
+   /* update optimized accum state vars */
+   if (ctx->Accum.ClearColor[0] == 0.0 && ctx->Accum.ClearColor[1] == 0.0 &&
+       ctx->Accum.ClearColor[2] == 0.0 && ctx->Accum.ClearColor[3] == 0.0) {
+#if USE_OPTIMIZED_ACCUM
+      swrast->_IntegerAccumMode = GL_TRUE;
+#else
+      swrast->_IntegerAccumMode = GL_FALSE;
+#endif
+      swrast->_IntegerAccumScaler = 0.0;  /* denotes empty accum buffer */
+   }
+   else {
+      swrast->_IntegerAccumMode = GL_FALSE;
+   }
+}
+
+
+static void
+accum_add(struct gl_context *ctx, GLfloat value,
+          GLint xpos, GLint ypos, GLint width, GLint height )
+{
+   SWcontext *swrast = SWRAST_CONTEXT(ctx);
+   struct gl_renderbuffer *rb
+      = ctx->DrawBuffer->Attachment[BUFFER_ACCUM].Renderbuffer;
+
+   assert(rb);
+
+   /* Leave optimized accum buffer mode */
+   if (swrast->_IntegerAccumMode)
+      rescale_accum(ctx);
+
+   if (rb->DataType == GL_SHORT || rb->DataType == GL_UNSIGNED_SHORT) {
+      const GLshort incr = (GLshort) (value * ACCUM_SCALE16);
+      if (rb->GetPointer(ctx, rb, 0, 0)) {
+         GLint i, j;
+         for (i = 0; i < height; i++) {
+            GLshort *acc = (GLshort *) rb->GetPointer(ctx, rb, xpos, ypos + i);
+            for (j = 0; j < 4 * width; j++) {
+               acc[j] += incr;
+            }
+         }
+      }
+      else {
+         GLint i, j;
+         for (i = 0; i < height; i++) {
+            GLshort accRow[4 * MAX_WIDTH];
+            rb->GetRow(ctx, rb, width, xpos, ypos + i, accRow);
+            for (j = 0; j < 4 * width; j++) {
+               accRow[j] += incr;
+            }
+            rb->PutRow(ctx, rb, width, xpos, ypos + i, accRow, NULL);
+         }
+      }
+   }
+   else {
+      /* other types someday */
+   }
+}
+
+
+static void
+accum_mult(struct gl_context *ctx, GLfloat mult,
+           GLint xpos, GLint ypos, GLint width, GLint height )
+{
+   SWcontext *swrast = SWRAST_CONTEXT(ctx);
+   struct gl_renderbuffer *rb
+      = ctx->DrawBuffer->Attachment[BUFFER_ACCUM].Renderbuffer;
+
+   assert(rb);
+
+   /* Leave optimized accum buffer mode */
+   if (swrast->_IntegerAccumMode)
+      rescale_accum(ctx);
+
+   if (rb->DataType == GL_SHORT || rb->DataType == GL_UNSIGNED_SHORT) {
+      if (rb->GetPointer(ctx, rb, 0, 0)) {
+         GLint i, j;
+         for (i = 0; i < height; i++) {
+            GLshort *acc = (GLshort *) rb->GetPointer(ctx, rb, xpos, ypos + i);
+            for (j = 0; j < 4 * width; j++) {
+               acc[j] = (GLshort) (acc[j] * mult);
+            }
+         }
+      }
+      else {
+         GLint i, j;
+         for (i = 0; i < height; i++) {
+            GLshort accRow[4 * MAX_WIDTH];
+            rb->GetRow(ctx, rb, width, xpos, ypos + i, accRow);
+            for (j = 0; j < 4 * width; j++) {
+               accRow[j] = (GLshort) (accRow[j] * mult);
+            }
+            rb->PutRow(ctx, rb, width, xpos, ypos + i, accRow, NULL);
+         }
+      }
+   }
+   else {
+      /* other types someday */
+   }
+}
+
+
+
+static void
+accum_accum(struct gl_context *ctx, GLfloat value,
+            GLint xpos, GLint ypos, GLint width, GLint height )
+{
+   SWcontext *swrast = SWRAST_CONTEXT(ctx);
+   struct gl_renderbuffer *rb
+      = ctx->DrawBuffer->Attachment[BUFFER_ACCUM].Renderbuffer;
+   const GLboolean directAccess = (rb->GetPointer(ctx, rb, 0, 0) != NULL);
+
+   assert(rb);
+
+   if (!ctx->ReadBuffer->_ColorReadBuffer) {
+      /* no read buffer - OK */
+      return;
+   }
+
+   /* May have to leave optimized accum buffer mode */
+   if (swrast->_IntegerAccumScaler == 0.0 && value > 0.0 && value <= 1.0)
+      swrast->_IntegerAccumScaler = value;
+   if (swrast->_IntegerAccumMode && value != swrast->_IntegerAccumScaler)
+      rescale_accum(ctx);
+
+   if (rb->DataType == GL_SHORT || rb->DataType == GL_UNSIGNED_SHORT) {
+      const GLfloat scale = value * ACCUM_SCALE16 / CHAN_MAXF;
+      GLshort accumRow[4 * MAX_WIDTH];
+      GLchan rgba[MAX_WIDTH][4];
+      GLint i;
+
+      for (i = 0; i < height; i++) {
+         GLshort *acc;
+         if (directAccess) {
+            acc = (GLshort *) rb->GetPointer(ctx, rb, xpos, ypos + i);
+         }
+         else {
+            rb->GetRow(ctx, rb, width, xpos, ypos + i, accumRow);
+            acc = accumRow;
+         }
+
+         /* read colors from color buffer */
+         _swrast_read_rgba_span(ctx, ctx->ReadBuffer->_ColorReadBuffer, width,
+                                xpos, ypos + i, CHAN_TYPE, rgba);
+
+         /* do accumulation */
+         if (swrast->_IntegerAccumMode) {
+            /* simply add integer color values into accum buffer */
+            GLint j;
+            for (j = 0; j < width; j++) {
+               acc[j * 4 + 0] += rgba[j][RCOMP];
+               acc[j * 4 + 1] += rgba[j][GCOMP];
+               acc[j * 4 + 2] += rgba[j][BCOMP];
+               acc[j * 4 + 3] += rgba[j][ACOMP];
+            }
+         }
+         else {
+            /* scaled integer (or float) accum buffer */
+            GLint j;
+            for (j = 0; j < width; j++) {
+               acc[j * 4 + 0] += (GLshort) ((GLfloat) rgba[j][RCOMP] * scale);
+               acc[j * 4 + 1] += (GLshort) ((GLfloat) rgba[j][GCOMP] * scale);
+               acc[j * 4 + 2] += (GLshort) ((GLfloat) rgba[j][BCOMP] * scale);
+               acc[j * 4 + 3] += (GLshort) ((GLfloat) rgba[j][ACOMP] * scale);
+            }
+         }
+
+         if (!directAccess) {
+            rb->PutRow(ctx, rb, width, xpos, ypos + i, accumRow, NULL);
+         }
+      }
+   }
+   else {
+      /* other types someday */
+   }
+}
+
+
+
+static void
+accum_load(struct gl_context *ctx, GLfloat value,
+           GLint xpos, GLint ypos, GLint width, GLint height )
+{
+   SWcontext *swrast = SWRAST_CONTEXT(ctx);
+   struct gl_renderbuffer *rb
+      = ctx->DrawBuffer->Attachment[BUFFER_ACCUM].Renderbuffer;
+   const GLboolean directAccess = (rb->GetPointer(ctx, rb, 0, 0) != NULL);
+
+   assert(rb);
+
+   if (!ctx->ReadBuffer->_ColorReadBuffer) {
+      /* no read buffer - OK */
+      return;
+   }
+
+   /* This is a change to go into optimized accum buffer mode */
+   if (value > 0.0 && value <= 1.0) {
+#if USE_OPTIMIZED_ACCUM
+      swrast->_IntegerAccumMode = GL_TRUE;
+#else
+      swrast->_IntegerAccumMode = GL_FALSE;
+#endif
+      swrast->_IntegerAccumScaler = value;
+   }
+   else {
+      swrast->_IntegerAccumMode = GL_FALSE;
+      swrast->_IntegerAccumScaler = 0.0;
+   }
+
+   if (rb->DataType == GL_SHORT || rb->DataType == GL_UNSIGNED_SHORT) {
+      const GLfloat scale = value * ACCUM_SCALE16 / CHAN_MAXF;
+      GLshort accumRow[4 * MAX_WIDTH];
+      GLchan rgba[MAX_WIDTH][4];
+      GLint i;
+
+      for (i = 0; i < height; i++) {
+         GLshort *acc;
+         if (directAccess) {
+            acc = (GLshort *) rb->GetPointer(ctx, rb, xpos, ypos + i);
+         }
+         else {
+            rb->GetRow(ctx, rb, width, xpos, ypos + i, accumRow);
+            acc = accumRow;
+         }
+
+         /* read colors from color buffer */
+         _swrast_read_rgba_span(ctx, ctx->ReadBuffer->_ColorReadBuffer, width,
+                                xpos, ypos + i, CHAN_TYPE, rgba);
+
+         /* do load */
+         if (swrast->_IntegerAccumMode) {
+            /* just copy values in */
+            GLint j;
+            assert(swrast->_IntegerAccumScaler > 0.0);
+            assert(swrast->_IntegerAccumScaler <= 1.0);
+            for (j = 0; j < width; j++) {
+               acc[j * 4 + 0] = rgba[j][RCOMP];
+               acc[j * 4 + 1] = rgba[j][GCOMP];
+               acc[j * 4 + 2] = rgba[j][BCOMP];
+               acc[j * 4 + 3] = rgba[j][ACOMP];
+            }
+         }
+         else {
+            /* scaled integer (or float) accum buffer */
+            GLint j;
+            for (j = 0; j < width; j++) {
+               acc[j * 4 + 0] = (GLshort) ((GLfloat) rgba[j][RCOMP] * scale);
+               acc[j * 4 + 1] = (GLshort) ((GLfloat) rgba[j][GCOMP] * scale);
+               acc[j * 4 + 2] = (GLshort) ((GLfloat) rgba[j][BCOMP] * scale);
+               acc[j * 4 + 3] = (GLshort) ((GLfloat) rgba[j][ACOMP] * scale);
+            }
+         }
+
+         if (!directAccess) {
+            rb->PutRow(ctx, rb, width, xpos, ypos + i, accumRow, NULL);
+         }
+      }
+   }
+}
+
+
+static void
+accum_return(struct gl_context *ctx, GLfloat value,
+             GLint xpos, GLint ypos, GLint width, GLint height )
+{
+   SWcontext *swrast = SWRAST_CONTEXT(ctx);
+   struct gl_framebuffer *fb = ctx->DrawBuffer;
+   struct gl_renderbuffer *accumRb = fb->Attachment[BUFFER_ACCUM].Renderbuffer;
+   const GLboolean directAccess
+      = (accumRb->GetPointer(ctx, accumRb, 0, 0) != NULL);
+
+   static GLchan multTable[32768];
+   static GLfloat prevMult = 0.0;
+   const GLfloat mult = swrast->_IntegerAccumScaler;
+   const GLint max = MIN2((GLint) (256 / mult), 32767);
+
+   /* May have to leave optimized accum buffer mode */
+   if (swrast->_IntegerAccumMode && value != 1.0)
+      rescale_accum(ctx);
+
+   if (swrast->_IntegerAccumMode && swrast->_IntegerAccumScaler > 0) {
+      /* build lookup table to avoid many floating point multiplies */
+      GLint j;
+      assert(swrast->_IntegerAccumScaler <= 1.0);
+      if (mult != prevMult) {
+         for (j = 0; j < max; j++)
+            multTable[j] = IROUND((GLfloat) j * mult);
+         prevMult = mult;
+      }
+   }
+
+   if (accumRb->DataType == GL_SHORT ||
+       accumRb->DataType == GL_UNSIGNED_SHORT) {
+      const GLfloat scale = value * CHAN_MAXF / ACCUM_SCALE16;
+      GLuint buffer;
+      GLint i;
+
+      /* XXX maybe transpose the 'i' and 'buffer' loops??? */
+      for (i = 0; i < height; i++) {
+         GLshort accumRow[4 * MAX_WIDTH];
+         GLshort *acc;
+         SWspan span;
+
+         /* init color span */
+         INIT_SPAN(span, GL_BITMAP);
+         span.end = width;
+         span.arrayMask = SPAN_RGBA;
+         span.x = xpos;
+         span.y = ypos + i;
+
+         if (directAccess) {
+            acc = (GLshort *) accumRb->GetPointer(ctx, accumRb, xpos, ypos +i);
+         }
+         else {
+            accumRb->GetRow(ctx, accumRb, width, xpos, ypos + i, accumRow);
+            acc = accumRow;
+         }
+
+         /* get the colors to return */
+         if (swrast->_IntegerAccumMode) {
+            GLint j;
+            for (j = 0; j < width; j++) {
+               ASSERT(acc[j * 4 + 0] < max);
+               ASSERT(acc[j * 4 + 1] < max);
+               ASSERT(acc[j * 4 + 2] < max);
+               ASSERT(acc[j * 4 + 3] < max);
+               span.array->rgba[j][RCOMP] = multTable[acc[j * 4 + 0]];
+               span.array->rgba[j][GCOMP] = multTable[acc[j * 4 + 1]];
+               span.array->rgba[j][BCOMP] = multTable[acc[j * 4 + 2]];
+               span.array->rgba[j][ACOMP] = multTable[acc[j * 4 + 3]];
+            }
+         }
+         else {
+            /* scaled integer (or float) accum buffer */
+            GLint j;
+            for (j = 0; j < width; j++) {
+#if CHAN_BITS==32
+               GLchan r = acc[j * 4 + 0] * scale;
+               GLchan g = acc[j * 4 + 1] * scale;
+               GLchan b = acc[j * 4 + 2] * scale;
+               GLchan a = acc[j * 4 + 3] * scale;
+#else
+               GLint r = IROUND( (GLfloat) (acc[j * 4 + 0]) * scale );
+               GLint g = IROUND( (GLfloat) (acc[j * 4 + 1]) * scale );
+               GLint b = IROUND( (GLfloat) (acc[j * 4 + 2]) * scale );
+               GLint a = IROUND( (GLfloat) (acc[j * 4 + 3]) * scale );
+#endif
+               span.array->rgba[j][RCOMP] = CLAMP( r, 0, CHAN_MAX );
+               span.array->rgba[j][GCOMP] = CLAMP( g, 0, CHAN_MAX );
+               span.array->rgba[j][BCOMP] = CLAMP( b, 0, CHAN_MAX );
+               span.array->rgba[j][ACOMP] = CLAMP( a, 0, CHAN_MAX );
+            }
+         }
+
+         /* store colors */
+         for (buffer = 0; buffer < fb->_NumColorDrawBuffers; buffer++) {
+            struct gl_renderbuffer *rb = fb->_ColorDrawBuffers[buffer];
+            const GLboolean masking = (!ctx->Color.ColorMask[buffer][RCOMP] ||
+                                       !ctx->Color.ColorMask[buffer][GCOMP] ||
+                                       !ctx->Color.ColorMask[buffer][BCOMP] ||
+                                       !ctx->Color.ColorMask[buffer][ACOMP]);
+            if (masking) {
+               _swrast_mask_rgba_span(ctx, rb, &span, buffer);
+            }
+            rb->PutRow(ctx, rb, width, xpos, ypos + i, span.array->rgba, NULL);
+         }
+      }
+   }
+   else {
+      /* other types someday */
+   }
+}
+
+
+
+/**
+ * Software fallback for glAccum.
+ */
+void
+_swrast_Accum(struct gl_context *ctx, GLenum op, GLfloat value)
+{
+   SWcontext *swrast = SWRAST_CONTEXT(ctx);
+   GLint xpos, ypos, width, height;
+
+   if (swrast->NewState)
+      _swrast_validate_derived( ctx );
+
+   if (!ctx->DrawBuffer->Attachment[BUFFER_ACCUM].Renderbuffer) {
+      _mesa_warning(ctx, "Calling glAccum() without an accumulation buffer");
+      return;
+   }
+
+   if (!_mesa_check_conditional_render(ctx))
+      return;
+
+   swrast_render_start(ctx);
+
+   /* Compute region after calling swrast_render_start() so that we know the
+    * drawbuffer's size/bounds are up to date.
+    */
+   xpos = ctx->DrawBuffer->_Xmin;
+   ypos = ctx->DrawBuffer->_Ymin;
+   width =  ctx->DrawBuffer->_Xmax - ctx->DrawBuffer->_Xmin;
+   height = ctx->DrawBuffer->_Ymax - ctx->DrawBuffer->_Ymin;
+
+   switch (op) {
+      case GL_ADD:
+         if (value != 0.0F) {
+            accum_add(ctx, value, xpos, ypos, width, height);
+	 }
+	 break;
+      case GL_MULT:
+         if (value != 1.0F) {
+            accum_mult(ctx, value, xpos, ypos, width, height);
+	 }
+	 break;
+      case GL_ACCUM:
+         if (value != 0.0F) {
+            accum_accum(ctx, value, xpos, ypos, width, height);
+         }
+	 break;
+      case GL_LOAD:
+         accum_load(ctx, value, xpos, ypos, width, height);
+	 break;
+      case GL_RETURN:
+         accum_return(ctx, value, xpos, ypos, width, height);
+	 break;
+      default:
+         _mesa_problem(ctx, "invalid mode in _swrast_Accum()");
+         break;
+   }
+
+   swrast_render_finish(ctx);
+}