xserver and mesa git update 28-12-2010

1 files changed, 1245 insertions, 1245 deletions

diff --git a/mesalib/src/mesa/swrast/s_stencil.c b/mesalib/src/mesa/swrast/s_stencil.c
index aa74b21ee..999fe3c3f 100644
--- a/mesalib/src/mesa/swrast/s_stencil.c
+++ b/mesalib/src/mesa/swrast/s_stencil.c
@@ -1,1245 +1,1245 @@
-/*
- * Mesa 3-D graphics library
- * Version:  7.1
- *
- * Copyright (C) 1999-2007  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/context.h"
-#include "main/imports.h"
-
-#include "s_context.h"
-#include "s_depth.h"
-#include "s_stencil.h"
-#include "s_span.h"
-
-
-
-/* Stencil Logic:
-
-IF stencil test fails THEN
-   Apply fail-op to stencil value
-   Don't write the pixel (RGBA,Z)
-ELSE
-   IF doing depth test && depth test fails THEN
-      Apply zfail-op to stencil value
-      Write RGBA and Z to appropriate buffers
-   ELSE
-      Apply zpass-op to stencil value
-ENDIF
-
-*/
-
-
-/**
- * Apply the given stencil operator to the array of stencil values.
- * Don't touch stencil[i] if mask[i] is zero.
- * Input:  n - size of stencil array
- *         oper - the stencil buffer operator
- *         face - 0 or 1 for front or back face operation
- *         stencil - array of stencil values
- *         mask - array [n] of flag:  1=apply operator, 0=don't apply operator
- * Output:  stencil - modified values
- */
-static void
-apply_stencil_op( const GLcontext *ctx, GLenum oper, GLuint face,
-                  GLuint n, GLstencil stencil[], const GLubyte mask[] )
-{
-   const GLstencil ref = ctx->Stencil.Ref[face];
-   const GLstencil wrtmask = ctx->Stencil.WriteMask[face];
-   const GLstencil invmask = (GLstencil) (~wrtmask);
-   const GLstencil stencilMax = (1 << ctx->DrawBuffer->Visual.stencilBits) - 1;
-   GLuint i;
-
-   switch (oper) {
-      case GL_KEEP:
-         /* do nothing */
-         break;
-      case GL_ZERO:
-	 if (invmask==0) {
-	    for (i=0;i<n;i++) {
-	       if (mask[i]) {
-		  stencil[i] = 0;
-	       }
-	    }
-	 }
-	 else {
-	    for (i=0;i<n;i++) {
-	       if (mask[i]) {
-		  stencil[i] = (GLstencil) (stencil[i] & invmask);
-	       }
-	    }
-	 }
-	 break;
-      case GL_REPLACE:
-	 if (invmask==0) {
-	    for (i=0;i<n;i++) {
-	       if (mask[i]) {
-                  stencil[i] = ref;
-	       }
-	    }
-	 }
-	 else {
-	    for (i=0;i<n;i++) {
-	       if (mask[i]) {
-		  GLstencil s = stencil[i];
-		  stencil[i] = (GLstencil) ((invmask & s ) | (wrtmask & ref));
-	       }
-	    }
-	 }
-	 break;
-      case GL_INCR:
-	 if (invmask==0) {
-	    for (i=0;i<n;i++) {
-	       if (mask[i]) {
-		  GLstencil s = stencil[i];
-		  if (s < stencilMax) {
-		     stencil[i] = (GLstencil) (s+1);
-		  }
-	       }
-	    }
-	 }
-	 else {
-	    for (i=0;i<n;i++) {
-	       if (mask[i]) {
-		  /* VERIFY logic of adding 1 to a write-masked value */
-		  GLstencil s = stencil[i];
-		  if (s < stencilMax) {
-		     stencil[i] = (GLstencil) ((invmask & s) | (wrtmask & (s+1)));
-		  }
-	       }
-	    }
-	 }
-	 break;
-      case GL_DECR:
-	 if (invmask==0) {
-	    for (i=0;i<n;i++) {
-	       if (mask[i]) {
-		  GLstencil s = stencil[i];
-		  if (s>0) {
-		     stencil[i] = (GLstencil) (s-1);
-		  }
-	       }
-	    }
-	 }
-	 else {
-	    for (i=0;i<n;i++) {
-	       if (mask[i]) {
-		  /* VERIFY logic of subtracting 1 to a write-masked value */
-		  GLstencil s = stencil[i];
-		  if (s>0) {
-		     stencil[i] = (GLstencil) ((invmask & s) | (wrtmask & (s-1)));
-		  }
-	       }
-	    }
-	 }
-	 break;
-      case GL_INCR_WRAP_EXT:
-	 if (invmask==0) {
-	    for (i=0;i<n;i++) {
-	       if (mask[i]) {
-                  stencil[i]++;
-	       }
-	    }
-	 }
-	 else {
-	    for (i=0;i<n;i++) {
-	       if (mask[i]) {
-                  GLstencil s = stencil[i];
-                  stencil[i] = (GLstencil) ((invmask & s) | (wrtmask & (s+1)));
-	       }
-	    }
-	 }
-	 break;
-      case GL_DECR_WRAP_EXT:
-	 if (invmask==0) {
-	    for (i=0;i<n;i++) {
-	       if (mask[i]) {
-		  stencil[i]--;
-	       }
-	    }
-	 }
-	 else {
-	    for (i=0;i<n;i++) {
-	       if (mask[i]) {
-                  GLstencil s = stencil[i];
-                  stencil[i] = (GLstencil) ((invmask & s) | (wrtmask & (s-1)));
-	       }
-	    }
-	 }
-	 break;
-      case GL_INVERT:
-	 if (invmask==0) {
-	    for (i=0;i<n;i++) {
-	       if (mask[i]) {
-		  GLstencil s = stencil[i];
-		  stencil[i] = (GLstencil) ~s;
-	       }
-	    }
-	 }
-	 else {
-	    for (i=0;i<n;i++) {
-	       if (mask[i]) {
-		  GLstencil s = stencil[i];
-		  stencil[i] = (GLstencil) ((invmask & s) | (wrtmask & ~s));
-	       }
-	    }
-	 }
-	 break;
-      default:
-         _mesa_problem(ctx, "Bad stencil op in apply_stencil_op");
-   }
-}
-
-
-
-
-/**
- * Apply stencil test to an array of stencil values (before depth buffering).
- * Input:  face - 0 or 1 for front or back-face polygons
- *         n - number of pixels in the array
- *         stencil - array of [n] stencil values
- *         mask - array [n] of flag:  0=skip the pixel, 1=stencil the pixel
- * Output:  mask - pixels which fail the stencil test will have their
- *                 mask flag set to 0.
- *          stencil - updated stencil values (where the test passed)
- * Return:  GL_FALSE = all pixels failed, GL_TRUE = zero or more pixels passed.
- */
-static GLboolean
-do_stencil_test( GLcontext *ctx, GLuint face, GLuint n, GLstencil stencil[],
-                 GLubyte mask[] )
-{
-   GLubyte fail[MAX_WIDTH];
-   GLboolean allfail = GL_FALSE;
-   GLuint i;
-   const GLuint valueMask = ctx->Stencil.ValueMask[face];
-   const GLstencil r = (GLstencil) (ctx->Stencil.Ref[face] & valueMask);
-   GLstencil s;
-
-   ASSERT(n <= MAX_WIDTH);
-
-   /*
-    * Perform stencil test.  The results of this operation are stored
-    * in the fail[] array:
-    *   IF fail[i] is non-zero THEN
-    *       the stencil fail operator is to be applied
-    *   ELSE
-    *       the stencil fail operator is not to be applied
-    *   ENDIF
-    */
-   switch (ctx->Stencil.Function[face]) {
-      case GL_NEVER:
-         /* never pass; always fail */
-         for (i=0;i<n;i++) {
-	    if (mask[i]) {
-	       mask[i] = 0;
-	       fail[i] = 1;
-	    }
-	    else {
-	       fail[i] = 0;
-	    }
-	 }
-	 allfail = GL_TRUE;
-	 break;
-      case GL_LESS:
-	 for (i=0;i<n;i++) {
-	    if (mask[i]) {
-	       s = (GLstencil) (stencil[i] & valueMask);
-	       if (r < s) {
-		  /* passed */
-		  fail[i] = 0;
-	       }
-	       else {
-		  fail[i] = 1;
-		  mask[i] = 0;
-	       }
-	    }
-	    else {
-	       fail[i] = 0;
-	    }
-	 }
-	 break;
-      case GL_LEQUAL:
-	 for (i=0;i<n;i++) {
-	    if (mask[i]) {
-	       s = (GLstencil) (stencil[i] & valueMask);
-	       if (r <= s) {
-		  /* pass */
-		  fail[i] = 0;
-	       }
-	       else {
-		  fail[i] = 1;
-		  mask[i] = 0;
-	       }
-	    }
-	    else {
-	       fail[i] = 0;
-	    }
-	 }
-	 break;
-      case GL_GREATER:
-	 for (i=0;i<n;i++) {
-	    if (mask[i]) {
-	       s = (GLstencil) (stencil[i] & valueMask);
-	       if (r > s) {
-		  /* passed */
-		  fail[i] = 0;
-	       }
-	       else {
-		  fail[i] = 1;
-		  mask[i] = 0;
-	       }
-	    }
-	    else {
-	       fail[i] = 0;
-	    }
-	 }
-	 break;
-      case GL_GEQUAL:
-	 for (i=0;i<n;i++) {
-	    if (mask[i]) {
-	       s = (GLstencil) (stencil[i] & valueMask);
-	       if (r >= s) {
-		  /* passed */
-		  fail[i] = 0;
-	       }
-	       else {
-		  fail[i] = 1;
-		  mask[i] = 0;
-	       }
-	    }
-	    else {
-	       fail[i] = 0;
-	    }
-	 }
-	 break;
-      case GL_EQUAL:
-	 for (i=0;i<n;i++) {
-	    if (mask[i]) {
-	       s = (GLstencil) (stencil[i] & valueMask);
-	       if (r == s) {
-		  /* passed */
-		  fail[i] = 0;
-	       }
-	       else {
-		  fail[i] = 1;
-		  mask[i] = 0;
-	       }
-	    }
-	    else {
-	       fail[i] = 0;
-	    }
-	 }
-	 break;
-      case GL_NOTEQUAL:
-	 for (i=0;i<n;i++) {
-	    if (mask[i]) {
-	       s = (GLstencil) (stencil[i] & valueMask);
-	       if (r != s) {
-		  /* passed */
-		  fail[i] = 0;
-	       }
-	       else {
-		  fail[i] = 1;
-		  mask[i] = 0;
-	       }
-	    }
-	    else {
-	       fail[i] = 0;
-	    }
-	 }
-	 break;
-      case GL_ALWAYS:
-	 /* always pass */
-	 for (i=0;i<n;i++) {
-	    fail[i] = 0;
-	 }
-	 break;
-      default:
-         _mesa_problem(ctx, "Bad stencil func in gl_stencil_span");
-         return 0;
-   }
-
-   if (ctx->Stencil.FailFunc[face] != GL_KEEP) {
-      apply_stencil_op( ctx, ctx->Stencil.FailFunc[face], face, n, stencil, fail );
-   }
-
-   return !allfail;
-}
-
-
-/**
- * Compute the zpass/zfail masks by comparing the pre- and post-depth test
- * masks.
- */
-static INLINE void
-compute_pass_fail_masks(GLuint n, const GLubyte origMask[],
-                        const GLubyte newMask[],
-                        GLubyte passMask[], GLubyte failMask[])
-{
-   GLuint i;
-   for (i = 0; i < n; i++) {
-      ASSERT(newMask[i] == 0 || newMask[i] == 1);
-      passMask[i] = origMask[i] & newMask[i];
-      failMask[i] = origMask[i] & (newMask[i] ^ 1);
-   }
-}
-
-
-/**
- * Apply stencil and depth testing to the span of pixels.
- * Both software and hardware stencil buffers are acceptable.
- * Input:  n - number of pixels in the span
- *         x, y - location of leftmost pixel in span
- *         z - array [n] of z values
- *         mask - array [n] of flags  (1=test this pixel, 0=skip the pixel)
- * Output:  mask - array [n] of flags (1=stencil and depth test passed)
- * Return: GL_FALSE - all fragments failed the testing
- *         GL_TRUE - one or more fragments passed the testing
- *
- */
-static GLboolean
-stencil_and_ztest_span(GLcontext *ctx, SWspan *span, GLuint face)
-{
-   struct gl_framebuffer *fb = ctx->DrawBuffer;
-   struct gl_renderbuffer *rb = fb->_StencilBuffer;
-   GLstencil stencilRow[MAX_WIDTH];
-   GLstencil *stencil;
-   const GLuint n = span->end;
-   const GLint x = span->x;
-   const GLint y = span->y;
-   GLubyte *mask = span->array->mask;
-
-   ASSERT((span->arrayMask & SPAN_XY) == 0);
-   ASSERT(ctx->Stencil.Enabled);
-   ASSERT(n <= MAX_WIDTH);
-#ifdef DEBUG
-   if (ctx->Depth.Test) {
-      ASSERT(span->arrayMask & SPAN_Z);
-   }
-#endif
-
-   stencil = (GLstencil *) rb->GetPointer(ctx, rb, x, y);
-   if (!stencil) {
-      rb->GetRow(ctx, rb, n, x, y, stencilRow);
-      stencil = stencilRow;
-   }
-
-   /*
-    * Apply the stencil test to the fragments.
-    * failMask[i] is 1 if the stencil test failed.
-    */
-   if (do_stencil_test( ctx, face, n, stencil, mask ) == GL_FALSE) {
-      /* all fragments failed the stencil test, we're done. */
-      span->writeAll = GL_FALSE;
-      if (!rb->GetPointer(ctx, rb, 0, 0)) {
-         /* put updated stencil values into buffer */
-         rb->PutRow(ctx, rb, n, x, y, stencil, NULL);
-      }
-      return GL_FALSE;
-   }
-
-   /*
-    * Some fragments passed the stencil test, apply depth test to them
-    * and apply Zpass and Zfail stencil ops.
-    */
-   if (ctx->Depth.Test == GL_FALSE) {
-      /*
-       * No depth buffer, just apply zpass stencil function to active pixels.
-       */
-      apply_stencil_op( ctx, ctx->Stencil.ZPassFunc[face], face, n, stencil, mask );
-   }
-   else {
-      /*
-       * Perform depth buffering, then apply zpass or zfail stencil function.
-       */
-      GLubyte passMask[MAX_WIDTH], failMask[MAX_WIDTH], origMask[MAX_WIDTH];
-
-      /* save the current mask bits */
-      memcpy(origMask, mask, n * sizeof(GLubyte));
-
-      /* apply the depth test */
-      _swrast_depth_test_span(ctx, span);
-
-      compute_pass_fail_masks(n, origMask, mask, passMask, failMask);
-
-      /* apply the pass and fail operations */
-      if (ctx->Stencil.ZFailFunc[face] != GL_KEEP) {
-         apply_stencil_op( ctx, ctx->Stencil.ZFailFunc[face], face,
-                           n, stencil, failMask );
-      }
-      if (ctx->Stencil.ZPassFunc[face] != GL_KEEP) {
-         apply_stencil_op( ctx, ctx->Stencil.ZPassFunc[face], face,
-                           n, stencil, passMask );
-      }
-   }
-
-   /*
-    * Write updated stencil values back into hardware stencil buffer.
-    */
-   if (!rb->GetPointer(ctx, rb, 0, 0)) {
-      rb->PutRow(ctx, rb, n, x, y, stencil, NULL);
-   }
-   
-   span->writeAll = GL_FALSE;
-   
-   return GL_TRUE;  /* one or more fragments passed both tests */
-}
-
-
-
-/*
- * Return the address of a stencil buffer value given the window coords:
- */
-#define STENCIL_ADDRESS(X, Y)  (stencilStart + (Y) * stride + (X))
-
-
-
-/**
- * Apply the given stencil operator for each pixel in the array whose
- * mask flag is set.
- * \note  This is for software stencil buffers only.
- * Input:  n - number of pixels in the span
- *         x, y - array of [n] pixels
- *         operator - the stencil buffer operator
- *         mask - array [n] of flag:  1=apply operator, 0=don't apply operator
- */
-static void
-apply_stencil_op_to_pixels( GLcontext *ctx,
-                            GLuint n, const GLint x[], const GLint y[],
-                            GLenum oper, GLuint face, const GLubyte mask[] )
-{
-   struct gl_framebuffer *fb = ctx->DrawBuffer;
-   struct gl_renderbuffer *rb = fb->_StencilBuffer;
-   const GLstencil stencilMax = (1 << fb->Visual.stencilBits) - 1;
-   const GLstencil ref = ctx->Stencil.Ref[face];
-   const GLstencil wrtmask = ctx->Stencil.WriteMask[face];
-   const GLstencil invmask = (GLstencil) (~wrtmask);
-   GLuint i;
-   GLstencil *stencilStart = (GLubyte *) rb->Data;
-   const GLuint stride = rb->Width;
-
-   ASSERT(rb->GetPointer(ctx, rb, 0, 0));
-   ASSERT(sizeof(GLstencil) == 1);
-
-   switch (oper) {
-      case GL_KEEP:
-         /* do nothing */
-         break;
-      case GL_ZERO:
-	 if (invmask==0) {
-	    for (i=0;i<n;i++) {
-	       if (mask[i]) {
-                  GLstencil *sptr = STENCIL_ADDRESS( x[i], y[i] );
-                  *sptr = 0;
-	       }
-	    }
-	 }
-	 else {
-	    for (i=0;i<n;i++) {
-	       if (mask[i]) {
-                  GLstencil *sptr = STENCIL_ADDRESS( x[i], y[i] );
-		  *sptr = (GLstencil) (invmask & *sptr);
-	       }
-	    }
-	 }
-	 break;
-      case GL_REPLACE:
-	 if (invmask==0) {
-	    for (i=0;i<n;i++) {
-	       if (mask[i]) {
-                  GLstencil *sptr = STENCIL_ADDRESS( x[i], y[i] );
-                  *sptr = ref;
-	       }
-	    }
-	 }
-	 else {
-	    for (i=0;i<n;i++) {
-	       if (mask[i]) {
-                  GLstencil *sptr = STENCIL_ADDRESS( x[i], y[i] );
-		  *sptr = (GLstencil) ((invmask & *sptr ) | (wrtmask & ref));
-	       }
-	    }
-	 }
-	 break;
-      case GL_INCR:
-	 if (invmask==0) {
-	    for (i=0;i<n;i++) {
-	       if (mask[i]) {
-                  GLstencil *sptr = STENCIL_ADDRESS( x[i], y[i] );
-		  if (*sptr < stencilMax) {
-		     *sptr = (GLstencil) (*sptr + 1);
-		  }
-	       }
-	    }
-	 }
-	 else {
-	    for (i=0;i<n;i++) {
-	       if (mask[i]) {
-                  GLstencil *sptr = STENCIL_ADDRESS( x[i], y[i] );
-		  if (*sptr < stencilMax) {
-		     *sptr = (GLstencil) ((invmask & *sptr) | (wrtmask & (*sptr+1)));
-		  }
-	       }
-	    }
-	 }
-	 break;
-      case GL_DECR:
-	 if (invmask==0) {
-	    for (i=0;i<n;i++) {
-	       if (mask[i]) {
-                  GLstencil *sptr = STENCIL_ADDRESS( x[i], y[i] );
-		  if (*sptr>0) {
-		     *sptr = (GLstencil) (*sptr - 1);
-		  }
-	       }
-	    }
-	 }
-	 else {
-	    for (i=0;i<n;i++) {
-	       if (mask[i]) {
-                  GLstencil *sptr = STENCIL_ADDRESS( x[i], y[i] );
-		  if (*sptr>0) {
-		     *sptr = (GLstencil) ((invmask & *sptr) | (wrtmask & (*sptr-1)));
-		  }
-	       }
-	    }
-	 }
-	 break;
-      case GL_INCR_WRAP_EXT:
-	 if (invmask==0) {
-	    for (i=0;i<n;i++) {
-	       if (mask[i]) {
-                  GLstencil *sptr = STENCIL_ADDRESS( x[i], y[i] );
-                  *sptr = (GLstencil) (*sptr + 1);
-	       }
-	    }
-	 }
-	 else {
-	    for (i=0;i<n;i++) {
-	       if (mask[i]) {
-                  GLstencil *sptr = STENCIL_ADDRESS( x[i], y[i] );
-                  *sptr = (GLstencil) ((invmask & *sptr) | (wrtmask & (*sptr+1)));
-	       }
-	    }
-	 }
-	 break;
-      case GL_DECR_WRAP_EXT:
-	 if (invmask==0) {
-	    for (i=0;i<n;i++) {
-	       if (mask[i]) {
-                  GLstencil *sptr = STENCIL_ADDRESS( x[i], y[i] );
-                  *sptr = (GLstencil) (*sptr - 1);
-	       }
-	    }
-	 }
-	 else {
-	    for (i=0;i<n;i++) {
-	       if (mask[i]) {
-                  GLstencil *sptr = STENCIL_ADDRESS( x[i], y[i] );
-                  *sptr = (GLstencil) ((invmask & *sptr) | (wrtmask & (*sptr-1)));
-	       }
-	    }
-	 }
-	 break;
-      case GL_INVERT:
-	 if (invmask==0) {
-	    for (i=0;i<n;i++) {
-	       if (mask[i]) {
-                  GLstencil *sptr = STENCIL_ADDRESS( x[i], y[i] );
-                  *sptr = (GLstencil) (~*sptr);
-	       }
-	    }
-	 }
-	 else {
-	    for (i=0;i<n;i++) {
-	       if (mask[i]) {
-                  GLstencil *sptr = STENCIL_ADDRESS( x[i], y[i] );
-                  *sptr = (GLstencil) ((invmask & *sptr) | (wrtmask & ~*sptr));
-	       }
-	    }
-	 }
-	 break;
-      default:
-         _mesa_problem(ctx, "Bad stencilop in apply_stencil_op_to_pixels");
-   }
-}
-
-
-
-/**
- * Apply stencil test to an array of pixels before depth buffering.
- *
- * \note Used for software stencil buffer only.
- * Input:  n - number of pixels in the span
- *         x, y - array of [n] pixels to stencil
- *         mask - array [n] of flag:  0=skip the pixel, 1=stencil the pixel
- * Output:  mask - pixels which fail the stencil test will have their
- *                 mask flag set to 0.
- * \return  GL_FALSE = all pixels failed, GL_TRUE = zero or more pixels passed.
- */
-static GLboolean
-stencil_test_pixels( GLcontext *ctx, GLuint face, GLuint n,
-                     const GLint x[], const GLint y[], GLubyte mask[] )
-{
-   const struct gl_framebuffer *fb = ctx->DrawBuffer;
-   struct gl_renderbuffer *rb = fb->_StencilBuffer;
-   GLubyte fail[MAX_WIDTH];
-   GLstencil r, s;
-   GLuint i;
-   GLboolean allfail = GL_FALSE;
-   const GLuint valueMask = ctx->Stencil.ValueMask[face];
-   const GLstencil *stencilStart = (GLstencil *) rb->Data;
-   const GLuint stride = rb->Width;
-
-   ASSERT(rb->GetPointer(ctx, rb, 0, 0));
-   ASSERT(sizeof(GLstencil) == 1);
-
-   /*
-    * Perform stencil test.  The results of this operation are stored
-    * in the fail[] array:
-    *   IF fail[i] is non-zero THEN
-    *       the stencil fail operator is to be applied
-    *   ELSE
-    *       the stencil fail operator is not to be applied
-    *   ENDIF
-    */
-
-   switch (ctx->Stencil.Function[face]) {
-      case GL_NEVER:
-         /* always fail */
-         for (i=0;i<n;i++) {
-	    if (mask[i]) {
-	       mask[i] = 0;
-	       fail[i] = 1;
-	    }
-	    else {
-	       fail[i] = 0;
-	    }
-	 }
-	 allfail = GL_TRUE;
-	 break;
-      case GL_LESS:
-	 r = (GLstencil) (ctx->Stencil.Ref[face] & valueMask);
-	 for (i=0;i<n;i++) {
-	    if (mask[i]) {
-               const GLstencil *sptr = STENCIL_ADDRESS(x[i],y[i]);
-	       s = (GLstencil) (*sptr & valueMask);
-	       if (r < s) {
-		  /* passed */
-		  fail[i] = 0;
-	       }
-	       else {
-		  fail[i] = 1;
-		  mask[i] = 0;
-	       }
-	    }
-	    else {
-	       fail[i] = 0;
-	    }
-	 }
-	 break;
-      case GL_LEQUAL:
-	 r = (GLstencil) (ctx->Stencil.Ref[face] & valueMask);
-	 for (i=0;i<n;i++) {
-	    if (mask[i]) {
-               const GLstencil *sptr = STENCIL_ADDRESS(x[i],y[i]);
-	       s = (GLstencil) (*sptr & valueMask);
-	       if (r <= s) {
-		  /* pass */
-		  fail[i] = 0;
-	       }
-	       else {
-		  fail[i] = 1;
-		  mask[i] = 0;
-	       }
-	    }
-	    else {
-	       fail[i] = 0;
-	    }
-	 }
-	 break;
-      case GL_GREATER:
-	 r = (GLstencil) (ctx->Stencil.Ref[face] & valueMask);
-	 for (i=0;i<n;i++) {
-	    if (mask[i]) {
-               const GLstencil *sptr = STENCIL_ADDRESS(x[i],y[i]);
-	       s = (GLstencil) (*sptr & valueMask);
-	       if (r > s) {
-		  /* passed */
-		  fail[i] = 0;
-	       }
-	       else {
-		  fail[i] = 1;
-		  mask[i] = 0;
-	       }
-	    }
-	    else {
-	       fail[i] = 0;
-	    }
-	 }
-	 break;
-      case GL_GEQUAL:
-	 r = (GLstencil) (ctx->Stencil.Ref[face] & valueMask);
-	 for (i=0;i<n;i++) {
-	    if (mask[i]) {
-               const GLstencil *sptr = STENCIL_ADDRESS(x[i],y[i]);
-	       s = (GLstencil) (*sptr & valueMask);
-	       if (r >= s) {
-		  /* passed */
-		  fail[i] = 0;
-	       }
-	       else {
-		  fail[i] = 1;
-		  mask[i] = 0;
-	       }
-	    }
-	    else {
-	       fail[i] = 0;
-	    }
-	 }
-	 break;
-      case GL_EQUAL:
-	 r = (GLstencil) (ctx->Stencil.Ref[face] & valueMask);
-	 for (i=0;i<n;i++) {
-	    if (mask[i]) {
-               const GLstencil *sptr = STENCIL_ADDRESS(x[i],y[i]);
-	       s = (GLstencil) (*sptr & valueMask);
-	       if (r == s) {
-		  /* passed */
-		  fail[i] = 0;
-	       }
-	       else {
-		  fail[i] = 1;
-		  mask[i] = 0;
-	       }
-	    }
-	    else {
-	       fail[i] = 0;
-	    }
-	 }
-	 break;
-      case GL_NOTEQUAL:
-	 r = (GLstencil) (ctx->Stencil.Ref[face] & valueMask);
-	 for (i=0;i<n;i++) {
-	    if (mask[i]) {
-               const GLstencil *sptr = STENCIL_ADDRESS(x[i],y[i]);
-	       s = (GLstencil) (*sptr & valueMask);
-	       if (r != s) {
-		  /* passed */
-		  fail[i] = 0;
-	       }
-	       else {
-		  fail[i] = 1;
-		  mask[i] = 0;
-	       }
-	    }
-	    else {
-	       fail[i] = 0;
-	    }
-	 }
-	 break;
-      case GL_ALWAYS:
-	 /* always pass */
-	 for (i=0;i<n;i++) {
-	    fail[i] = 0;
-	 }
-	 break;
-      default:
-         _mesa_problem(ctx, "Bad stencil func in gl_stencil_pixels");
-         return 0;
-   }
-
-   if (ctx->Stencil.FailFunc[face] != GL_KEEP) {
-      apply_stencil_op_to_pixels( ctx, n, x, y, ctx->Stencil.FailFunc[face],
-                                  face, fail );
-   }
-
-   return !allfail;
-}
-
-
-
-
-/**
- * Apply stencil and depth testing to an array of pixels.
- * This is used both for software and hardware stencil buffers.
- *
- * The comments in this function are a bit sparse but the code is
- * almost identical to stencil_and_ztest_span(), which is well
- * commented.
- *
- * Input:  n - number of pixels in the array
- *         x, y - array of [n] pixel positions
- *         z - array [n] of z values
- *         mask - array [n] of flags  (1=test this pixel, 0=skip the pixel)
- * Output: mask - array [n] of flags (1=stencil and depth test passed)
- * Return: GL_FALSE - all fragments failed the testing
- *         GL_TRUE - one or more fragments passed the testing
- */
-static GLboolean
-stencil_and_ztest_pixels( GLcontext *ctx, SWspan *span, GLuint face )
-{
-   GLubyte passMask[MAX_WIDTH], failMask[MAX_WIDTH], origMask[MAX_WIDTH];
-   struct gl_framebuffer *fb = ctx->DrawBuffer;
-   struct gl_renderbuffer *rb = fb->_StencilBuffer;
-   const GLuint n = span->end;
-   const GLint *x = span->array->x;
-   const GLint *y = span->array->y;
-   GLubyte *mask = span->array->mask;
-
-   ASSERT(span->arrayMask & SPAN_XY);
-   ASSERT(ctx->Stencil.Enabled);
-   ASSERT(n <= MAX_WIDTH);
-
-   if (!rb->GetPointer(ctx, rb, 0, 0)) {
-      /* No direct access */
-      GLstencil stencil[MAX_WIDTH];
-
-      ASSERT(rb->DataType == GL_UNSIGNED_BYTE);
-      _swrast_get_values(ctx, rb, n, x, y, stencil, sizeof(GLubyte));
-
-      memcpy(origMask, mask, n * sizeof(GLubyte));          
-
-      (void) do_stencil_test(ctx, face, n, stencil, mask);
-
-      if (ctx->Depth.Test == GL_FALSE) {
-         apply_stencil_op(ctx, ctx->Stencil.ZPassFunc[face], face,
-                          n, stencil, mask);
-      }
-      else {
-         GLubyte tmpMask[MAX_WIDTH]; 
-         memcpy(tmpMask, mask, n * sizeof(GLubyte));
-
-         _swrast_depth_test_span(ctx, span);
-
-         compute_pass_fail_masks(n, tmpMask, mask, passMask, failMask);
-
-         if (ctx->Stencil.ZFailFunc[face] != GL_KEEP) {
-            apply_stencil_op(ctx, ctx->Stencil.ZFailFunc[face], face,
-                             n, stencil, failMask);
-         }
-         if (ctx->Stencil.ZPassFunc[face] != GL_KEEP) {
-            apply_stencil_op(ctx, ctx->Stencil.ZPassFunc[face], face,
-                             n, stencil, passMask);
-         }
-      }
-
-      /* Write updated stencil values into hardware stencil buffer */
-      rb->PutValues(ctx, rb, n, x, y, stencil, origMask);
-
-      return GL_TRUE;
-   }
-   else {
-      /* Direct access to stencil buffer */
-
-      if (stencil_test_pixels(ctx, face, n, x, y, mask) == GL_FALSE) {
-         /* all fragments failed the stencil test, we're done. */
-         return GL_FALSE;
-      }
-
-      if (ctx->Depth.Test==GL_FALSE) {
-         apply_stencil_op_to_pixels(ctx, n, x, y,
-                                    ctx->Stencil.ZPassFunc[face], face, mask);
-      }
-      else {
-         memcpy(origMask, mask, n * sizeof(GLubyte));
-
-         _swrast_depth_test_span(ctx, span);
-
-         compute_pass_fail_masks(n, origMask, mask, passMask, failMask);
-
-         if (ctx->Stencil.ZFailFunc[face] != GL_KEEP) {
-            apply_stencil_op_to_pixels(ctx, n, x, y,
-                                       ctx->Stencil.ZFailFunc[face],
-                                       face, failMask);
-         }
-         if (ctx->Stencil.ZPassFunc[face] != GL_KEEP) {
-            apply_stencil_op_to_pixels(ctx, n, x, y,
-                                       ctx->Stencil.ZPassFunc[face],
-                                       face, passMask);
-         }
-      }
-
-      return GL_TRUE;  /* one or more fragments passed both tests */
-   }
-}
-
-
-/**
- * /return GL_TRUE = one or more fragments passed,
- * GL_FALSE = all fragments failed.
- */
-GLboolean
-_swrast_stencil_and_ztest_span(GLcontext *ctx, SWspan *span)
-{
-   const GLuint face = (span->facing == 0) ? 0 : ctx->Stencil._BackFace;
-
-   if (span->arrayMask & SPAN_XY)
-      return stencil_and_ztest_pixels(ctx, span, face);
-   else
-      return stencil_and_ztest_span(ctx, span, face);
-}
-
-
-#if 0
-GLuint
-clip_span(GLuint bufferWidth, GLuint bufferHeight,
-          GLint x, GLint y, GLuint *count)
-{
-   GLuint n = *count;
-   GLuint skipPixels = 0;
-
-   if (y < 0 || y >= bufferHeight || x + n <= 0 || x >= bufferWidth) {
-      /* totally out of bounds */
-      n = 0;
-   }
-   else {
-      /* left clip */
-      if (x < 0) {
-         skipPixels = -x;
-         x = 0;
-         n -= skipPixels;
-      }
-      /* right clip */
-      if (x + n > bufferWidth) {
-         GLint dx = x + n - bufferWidth;
-         n -= dx;
-      }
-   }
-
-   *count = n;
-
-   return skipPixels;
-}
-#endif
-
-
-/**
- * Return a span of stencil values from the stencil buffer.
- * Used for glRead/CopyPixels
- * Input:  n - how many pixels
- *         x,y - location of first pixel
- * Output:  stencil - the array of stencil values
- */
-void
-_swrast_read_stencil_span(GLcontext *ctx, struct gl_renderbuffer *rb,
-                          GLint n, GLint x, GLint y, GLstencil stencil[])
-{
-   if (y < 0 || y >= (GLint) rb->Height ||
-       x + n <= 0 || x >= (GLint) rb->Width) {
-      /* span is completely outside framebuffer */
-      return; /* undefined values OK */
-   }
-
-   if (x < 0) {
-      GLint dx = -x;
-      x = 0;
-      n -= dx;
-      stencil += dx;
-   }
-   if (x + n > (GLint) rb->Width) {
-      GLint dx = x + n - rb->Width;
-      n -= dx;
-   }
-   if (n <= 0) {
-      return;
-   }
-
-   rb->GetRow(ctx, rb, n, x, y, stencil);
-}
-
-
-
-/**
- * Write a span of stencil values to the stencil buffer.  This function
- * applies the stencil write mask when needed.
- * Used for glDraw/CopyPixels
- * Input:  n - how many pixels
- *         x, y - location of first pixel
- *         stencil - the array of stencil values
- */
-void
-_swrast_write_stencil_span(GLcontext *ctx, GLint n, GLint x, GLint y,
-                           const GLstencil stencil[] )
-{
-   struct gl_framebuffer *fb = ctx->DrawBuffer;
-   struct gl_renderbuffer *rb = fb->_StencilBuffer;
-   const GLuint stencilMax = (1 << fb->Visual.stencilBits) - 1;
-   const GLuint stencilMask = ctx->Stencil.WriteMask[0];
-
-   if (y < 0 || y >= (GLint) rb->Height ||
-       x + n <= 0 || x >= (GLint) rb->Width) {
-      /* span is completely outside framebuffer */
-      return; /* undefined values OK */
-   }
-   if (x < 0) {
-      GLint dx = -x;
-      x = 0;
-      n -= dx;
-      stencil += dx;
-   }
-   if (x + n > (GLint) rb->Width) {
-      GLint dx = x + n - rb->Width;
-      n -= dx;
-   }
-   if (n <= 0) {
-      return;
-   }
-
-   if ((stencilMask & stencilMax) != stencilMax) {
-      /* need to apply writemask */
-      GLstencil destVals[MAX_WIDTH], newVals[MAX_WIDTH];
-      GLint i;
-      rb->GetRow(ctx, rb, n, x, y, destVals);
-      for (i = 0; i < n; i++) {
-         newVals[i]
-            = (stencil[i] & stencilMask) | (destVals[i] & ~stencilMask);
-      }
-      rb->PutRow(ctx, rb, n, x, y, newVals, NULL);
-   }
-   else {
-      rb->PutRow(ctx, rb, n, x, y, stencil, NULL);
-   }
-}
-
-
-
-/**
- * Clear the stencil buffer.
- */
-void
-_swrast_clear_stencil_buffer( GLcontext *ctx, struct gl_renderbuffer *rb )
-{
-   const GLubyte stencilBits = ctx->DrawBuffer->Visual.stencilBits;
-   const GLuint mask = ctx->Stencil.WriteMask[0];
-   const GLuint invMask = ~mask;
-   const GLuint clearVal = (ctx->Stencil.Clear & mask);
-   const GLuint stencilMax = (1 << stencilBits) - 1;
-   GLint x, y, width, height;
-
-   if (!rb || mask == 0)
-      return;
-
-   ASSERT(rb->DataType == GL_UNSIGNED_BYTE ||
-          rb->DataType == GL_UNSIGNED_SHORT);
-
-   ASSERT(rb->_BaseFormat == GL_STENCIL_INDEX);
-
-   /* compute region to clear */
-   x = ctx->DrawBuffer->_Xmin;
-   y = ctx->DrawBuffer->_Ymin;
-   width  = ctx->DrawBuffer->_Xmax - ctx->DrawBuffer->_Xmin;
-   height = ctx->DrawBuffer->_Ymax - ctx->DrawBuffer->_Ymin;
-
-   if (rb->GetPointer(ctx, rb, 0, 0)) {
-      /* Direct buffer access */
-      if ((mask & stencilMax) != stencilMax) {
-         /* need to mask the clear */
-         if (rb->DataType == GL_UNSIGNED_BYTE) {
-            GLint i, j;
-            for (i = 0; i < height; i++) {
-               GLubyte *stencil = (GLubyte*) rb->GetPointer(ctx, rb, x, y + i);
-               for (j = 0; j < width; j++) {
-                  stencil[j] = (stencil[j] & invMask) | clearVal;
-               }
-            }
-         }
-         else {
-            GLint i, j;
-            for (i = 0; i < height; i++) {
-               GLushort *stencil = (GLushort*) rb->GetPointer(ctx, rb, x, y + i);
-               for (j = 0; j < width; j++) {
-                  stencil[j] = (stencil[j] & invMask) | clearVal;
-               }
-            }
-         }
-      }
-      else {
-         /* no bit masking */
-         if (width == (GLint) rb->Width && rb->DataType == GL_UNSIGNED_BYTE) {
-            /* optimized case */
-            /* Note: bottom-to-top raster assumed! */
-            GLubyte *stencil = (GLubyte *) rb->GetPointer(ctx, rb, x, y);
-            GLuint len = width * height * sizeof(GLubyte);
-            memset(stencil, clearVal, len);
-         }
-         else {
-            /* general case */
-            GLint i;
-            for (i = 0; i < height; i++) {
-               GLvoid *stencil = rb->GetPointer(ctx, rb, x, y + i);
-               if (rb->DataType == GL_UNSIGNED_BYTE) {
-                  memset(stencil, clearVal, width);
-               }
-               else {
-                  _mesa_memset16((short unsigned int*) stencil, clearVal, width);
-               }
-            }
-         }
-      }
-   }
-   else {
-      /* no direct access */
-      if ((mask & stencilMax) != stencilMax) {
-         /* need to mask the clear */
-         if (rb->DataType == GL_UNSIGNED_BYTE) {
-            GLint i, j;
-            for (i = 0; i < height; i++) {
-               GLubyte stencil[MAX_WIDTH];
-               rb->GetRow(ctx, rb, width, x, y + i, stencil);
-               for (j = 0; j < width; j++) {
-                  stencil[j] = (stencil[j] & invMask) | clearVal;
-               }
-               rb->PutRow(ctx, rb, width, x, y + i, stencil, NULL);
-            }
-         }
-         else {
-            GLint i, j;
-            for (i = 0; i < height; i++) {
-               GLushort stencil[MAX_WIDTH];
-               rb->GetRow(ctx, rb, width, x, y + i, stencil);
-               for (j = 0; j < width; j++) {
-                  stencil[j] = (stencil[j] & invMask) | clearVal;
-               }
-               rb->PutRow(ctx, rb, width, x, y + i, stencil, NULL);
-            }
-         }
-      }
-      else {
-         /* no bit masking */
-         const GLubyte clear8 = (GLubyte) clearVal;
-         const GLushort clear16 = (GLushort) clearVal;
-         const void *clear;
-         GLint i;
-         if (rb->DataType == GL_UNSIGNED_BYTE) {
-            clear = &clear8;
-         }
-         else {
-            clear = &clear16;
-         }
-         for (i = 0; i < height; i++) {
-            rb->PutMonoRow(ctx, rb, width, x, y + i, clear, NULL);
-         }
-      }
-   }
-}
+/*

+ * Mesa 3-D graphics library

+ * Version:  7.1

+ *

+ * Copyright (C) 1999-2007  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/context.h"

+#include "main/imports.h"

+

+#include "s_context.h"

+#include "s_depth.h"

+#include "s_stencil.h"

+#include "s_span.h"

+

+

+

+/* Stencil Logic:

+

+IF stencil test fails THEN

+   Apply fail-op to stencil value

+   Don't write the pixel (RGBA,Z)

+ELSE

+   IF doing depth test && depth test fails THEN

+      Apply zfail-op to stencil value

+      Write RGBA and Z to appropriate buffers

+   ELSE

+      Apply zpass-op to stencil value

+ENDIF

+

+*/

+

+

+/**

+ * Apply the given stencil operator to the array of stencil values.

+ * Don't touch stencil[i] if mask[i] is zero.

+ * Input:  n - size of stencil array

+ *         oper - the stencil buffer operator

+ *         face - 0 or 1 for front or back face operation

+ *         stencil - array of stencil values

+ *         mask - array [n] of flag:  1=apply operator, 0=don't apply operator

+ * Output:  stencil - modified values

+ */

+static void

+apply_stencil_op( const struct gl_context *ctx, GLenum oper, GLuint face,

+                  GLuint n, GLstencil stencil[], const GLubyte mask[] )

+{

+   const GLstencil ref = ctx->Stencil.Ref[face];

+   const GLstencil wrtmask = ctx->Stencil.WriteMask[face];

+   const GLstencil invmask = (GLstencil) (~wrtmask);

+   const GLstencil stencilMax = (1 << ctx->DrawBuffer->Visual.stencilBits) - 1;

+   GLuint i;

+

+   switch (oper) {

+      case GL_KEEP:

+         /* do nothing */

+         break;

+      case GL_ZERO:

+	 if (invmask==0) {

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

+	       if (mask[i]) {

+		  stencil[i] = 0;

+	       }

+	    }

+	 }

+	 else {

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

+	       if (mask[i]) {

+		  stencil[i] = (GLstencil) (stencil[i] & invmask);

+	       }

+	    }

+	 }

+	 break;

+      case GL_REPLACE:

+	 if (invmask==0) {

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

+	       if (mask[i]) {

+                  stencil[i] = ref;

+	       }

+	    }

+	 }

+	 else {

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

+	       if (mask[i]) {

+		  GLstencil s = stencil[i];

+		  stencil[i] = (GLstencil) ((invmask & s ) | (wrtmask & ref));

+	       }

+	    }

+	 }

+	 break;

+      case GL_INCR:

+	 if (invmask==0) {

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

+	       if (mask[i]) {

+		  GLstencil s = stencil[i];

+		  if (s < stencilMax) {

+		     stencil[i] = (GLstencil) (s+1);

+		  }

+	       }

+	    }

+	 }

+	 else {

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

+	       if (mask[i]) {

+		  /* VERIFY logic of adding 1 to a write-masked value */

+		  GLstencil s = stencil[i];

+		  if (s < stencilMax) {

+		     stencil[i] = (GLstencil) ((invmask & s) | (wrtmask & (s+1)));

+		  }

+	       }

+	    }

+	 }

+	 break;

+      case GL_DECR:

+	 if (invmask==0) {

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

+	       if (mask[i]) {

+		  GLstencil s = stencil[i];

+		  if (s>0) {

+		     stencil[i] = (GLstencil) (s-1);

+		  }

+	       }

+	    }

+	 }

+	 else {

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

+	       if (mask[i]) {

+		  /* VERIFY logic of subtracting 1 to a write-masked value */

+		  GLstencil s = stencil[i];

+		  if (s>0) {

+		     stencil[i] = (GLstencil) ((invmask & s) | (wrtmask & (s-1)));

+		  }

+	       }

+	    }

+	 }

+	 break;

+      case GL_INCR_WRAP_EXT:

+	 if (invmask==0) {

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

+	       if (mask[i]) {

+                  stencil[i]++;

+	       }

+	    }

+	 }

+	 else {

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

+	       if (mask[i]) {

+                  GLstencil s = stencil[i];

+                  stencil[i] = (GLstencil) ((invmask & s) | (wrtmask & (s+1)));

+	       }

+	    }

+	 }

+	 break;

+      case GL_DECR_WRAP_EXT:

+	 if (invmask==0) {

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

+	       if (mask[i]) {

+		  stencil[i]--;

+	       }

+	    }

+	 }

+	 else {

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

+	       if (mask[i]) {

+                  GLstencil s = stencil[i];

+                  stencil[i] = (GLstencil) ((invmask & s) | (wrtmask & (s-1)));

+	       }

+	    }

+	 }

+	 break;

+      case GL_INVERT:

+	 if (invmask==0) {

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

+	       if (mask[i]) {

+		  GLstencil s = stencil[i];

+		  stencil[i] = (GLstencil) ~s;

+	       }

+	    }

+	 }

+	 else {

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

+	       if (mask[i]) {

+		  GLstencil s = stencil[i];

+		  stencil[i] = (GLstencil) ((invmask & s) | (wrtmask & ~s));

+	       }

+	    }

+	 }

+	 break;

+      default:

+         _mesa_problem(ctx, "Bad stencil op in apply_stencil_op");

+   }

+}

+

+

+

+

+/**

+ * Apply stencil test to an array of stencil values (before depth buffering).

+ * Input:  face - 0 or 1 for front or back-face polygons

+ *         n - number of pixels in the array

+ *         stencil - array of [n] stencil values

+ *         mask - array [n] of flag:  0=skip the pixel, 1=stencil the pixel

+ * Output:  mask - pixels which fail the stencil test will have their

+ *                 mask flag set to 0.

+ *          stencil - updated stencil values (where the test passed)

+ * Return:  GL_FALSE = all pixels failed, GL_TRUE = zero or more pixels passed.

+ */

+static GLboolean

+do_stencil_test( struct gl_context *ctx, GLuint face, GLuint n, GLstencil stencil[],

+                 GLubyte mask[] )

+{

+   GLubyte fail[MAX_WIDTH];

+   GLboolean allfail = GL_FALSE;

+   GLuint i;

+   const GLuint valueMask = ctx->Stencil.ValueMask[face];

+   const GLstencil r = (GLstencil) (ctx->Stencil.Ref[face] & valueMask);

+   GLstencil s;

+

+   ASSERT(n <= MAX_WIDTH);

+

+   /*

+    * Perform stencil test.  The results of this operation are stored

+    * in the fail[] array:

+    *   IF fail[i] is non-zero THEN

+    *       the stencil fail operator is to be applied

+    *   ELSE

+    *       the stencil fail operator is not to be applied

+    *   ENDIF

+    */

+   switch (ctx->Stencil.Function[face]) {

+      case GL_NEVER:

+         /* never pass; always fail */

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

+	    if (mask[i]) {

+	       mask[i] = 0;

+	       fail[i] = 1;

+	    }

+	    else {

+	       fail[i] = 0;

+	    }

+	 }

+	 allfail = GL_TRUE;

+	 break;

+      case GL_LESS:

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

+	    if (mask[i]) {

+	       s = (GLstencil) (stencil[i] & valueMask);

+	       if (r < s) {

+		  /* passed */

+		  fail[i] = 0;

+	       }

+	       else {

+		  fail[i] = 1;

+		  mask[i] = 0;

+	       }

+	    }

+	    else {

+	       fail[i] = 0;

+	    }

+	 }

+	 break;

+      case GL_LEQUAL:

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

+	    if (mask[i]) {

+	       s = (GLstencil) (stencil[i] & valueMask);

+	       if (r <= s) {

+		  /* pass */

+		  fail[i] = 0;

+	       }

+	       else {

+		  fail[i] = 1;

+		  mask[i] = 0;

+	       }

+	    }

+	    else {

+	       fail[i] = 0;

+	    }

+	 }

+	 break;

+      case GL_GREATER:

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

+	    if (mask[i]) {

+	       s = (GLstencil) (stencil[i] & valueMask);

+	       if (r > s) {

+		  /* passed */

+		  fail[i] = 0;

+	       }

+	       else {

+		  fail[i] = 1;

+		  mask[i] = 0;

+	       }

+	    }

+	    else {

+	       fail[i] = 0;

+	    }

+	 }

+	 break;

+      case GL_GEQUAL:

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

+	    if (mask[i]) {

+	       s = (GLstencil) (stencil[i] & valueMask);

+	       if (r >= s) {

+		  /* passed */

+		  fail[i] = 0;

+	       }

+	       else {

+		  fail[i] = 1;

+		  mask[i] = 0;

+	       }

+	    }

+	    else {

+	       fail[i] = 0;

+	    }

+	 }

+	 break;

+      case GL_EQUAL:

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

+	    if (mask[i]) {

+	       s = (GLstencil) (stencil[i] & valueMask);

+	       if (r == s) {

+		  /* passed */

+		  fail[i] = 0;

+	       }

+	       else {

+		  fail[i] = 1;

+		  mask[i] = 0;

+	       }

+	    }

+	    else {

+	       fail[i] = 0;

+	    }

+	 }

+	 break;

+      case GL_NOTEQUAL:

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

+	    if (mask[i]) {

+	       s = (GLstencil) (stencil[i] & valueMask);

+	       if (r != s) {

+		  /* passed */

+		  fail[i] = 0;

+	       }

+	       else {

+		  fail[i] = 1;

+		  mask[i] = 0;

+	       }

+	    }

+	    else {

+	       fail[i] = 0;

+	    }

+	 }

+	 break;

+      case GL_ALWAYS:

+	 /* always pass */

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

+	    fail[i] = 0;

+	 }

+	 break;

+      default:

+         _mesa_problem(ctx, "Bad stencil func in gl_stencil_span");

+         return 0;

+   }

+

+   if (ctx->Stencil.FailFunc[face] != GL_KEEP) {

+      apply_stencil_op( ctx, ctx->Stencil.FailFunc[face], face, n, stencil, fail );

+   }

+

+   return !allfail;

+}

+

+

+/**

+ * Compute the zpass/zfail masks by comparing the pre- and post-depth test

+ * masks.

+ */

+static INLINE void

+compute_pass_fail_masks(GLuint n, const GLubyte origMask[],

+                        const GLubyte newMask[],

+                        GLubyte passMask[], GLubyte failMask[])

+{

+   GLuint i;

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

+      ASSERT(newMask[i] == 0 || newMask[i] == 1);

+      passMask[i] = origMask[i] & newMask[i];

+      failMask[i] = origMask[i] & (newMask[i] ^ 1);

+   }

+}

+

+

+/**

+ * Apply stencil and depth testing to the span of pixels.

+ * Both software and hardware stencil buffers are acceptable.

+ * Input:  n - number of pixels in the span

+ *         x, y - location of leftmost pixel in span

+ *         z - array [n] of z values

+ *         mask - array [n] of flags  (1=test this pixel, 0=skip the pixel)

+ * Output:  mask - array [n] of flags (1=stencil and depth test passed)

+ * Return: GL_FALSE - all fragments failed the testing

+ *         GL_TRUE - one or more fragments passed the testing

+ *

+ */

+static GLboolean

+stencil_and_ztest_span(struct gl_context *ctx, SWspan *span, GLuint face)

+{

+   struct gl_framebuffer *fb = ctx->DrawBuffer;

+   struct gl_renderbuffer *rb = fb->_StencilBuffer;

+   GLstencil stencilRow[MAX_WIDTH];

+   GLstencil *stencil;

+   const GLuint n = span->end;

+   const GLint x = span->x;

+   const GLint y = span->y;

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

+

+   ASSERT((span->arrayMask & SPAN_XY) == 0);

+   ASSERT(ctx->Stencil.Enabled);

+   ASSERT(n <= MAX_WIDTH);

+#ifdef DEBUG

+   if (ctx->Depth.Test) {

+      ASSERT(span->arrayMask & SPAN_Z);

+   }

+#endif

+

+   stencil = (GLstencil *) rb->GetPointer(ctx, rb, x, y);

+   if (!stencil) {

+      rb->GetRow(ctx, rb, n, x, y, stencilRow);

+      stencil = stencilRow;

+   }

+

+   /*

+    * Apply the stencil test to the fragments.

+    * failMask[i] is 1 if the stencil test failed.

+    */

+   if (do_stencil_test( ctx, face, n, stencil, mask ) == GL_FALSE) {

+      /* all fragments failed the stencil test, we're done. */

+      span->writeAll = GL_FALSE;

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

+         /* put updated stencil values into buffer */

+         rb->PutRow(ctx, rb, n, x, y, stencil, NULL);

+      }

+      return GL_FALSE;

+   }

+

+   /*

+    * Some fragments passed the stencil test, apply depth test to them

+    * and apply Zpass and Zfail stencil ops.

+    */

+   if (ctx->Depth.Test == GL_FALSE) {

+      /*

+       * No depth buffer, just apply zpass stencil function to active pixels.

+       */

+      apply_stencil_op( ctx, ctx->Stencil.ZPassFunc[face], face, n, stencil, mask );

+   }

+   else {

+      /*

+       * Perform depth buffering, then apply zpass or zfail stencil function.

+       */

+      GLubyte passMask[MAX_WIDTH], failMask[MAX_WIDTH], origMask[MAX_WIDTH];

+

+      /* save the current mask bits */

+      memcpy(origMask, mask, n * sizeof(GLubyte));

+

+      /* apply the depth test */

+      _swrast_depth_test_span(ctx, span);

+

+      compute_pass_fail_masks(n, origMask, mask, passMask, failMask);

+

+      /* apply the pass and fail operations */

+      if (ctx->Stencil.ZFailFunc[face] != GL_KEEP) {

+         apply_stencil_op( ctx, ctx->Stencil.ZFailFunc[face], face,

+                           n, stencil, failMask );

+      }

+      if (ctx->Stencil.ZPassFunc[face] != GL_KEEP) {

+         apply_stencil_op( ctx, ctx->Stencil.ZPassFunc[face], face,

+                           n, stencil, passMask );

+      }

+   }

+

+   /*

+    * Write updated stencil values back into hardware stencil buffer.

+    */

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

+      rb->PutRow(ctx, rb, n, x, y, stencil, NULL);

+   }

+   

+   span->writeAll = GL_FALSE;

+   

+   return GL_TRUE;  /* one or more fragments passed both tests */

+}

+

+

+

+/*

+ * Return the address of a stencil buffer value given the window coords:

+ */

+#define STENCIL_ADDRESS(X, Y)  (stencilStart + (Y) * stride + (X))

+

+

+

+/**

+ * Apply the given stencil operator for each pixel in the array whose

+ * mask flag is set.

+ * \note  This is for software stencil buffers only.

+ * Input:  n - number of pixels in the span

+ *         x, y - array of [n] pixels

+ *         operator - the stencil buffer operator

+ *         mask - array [n] of flag:  1=apply operator, 0=don't apply operator

+ */

+static void

+apply_stencil_op_to_pixels( struct gl_context *ctx,

+                            GLuint n, const GLint x[], const GLint y[],

+                            GLenum oper, GLuint face, const GLubyte mask[] )

+{

+   struct gl_framebuffer *fb = ctx->DrawBuffer;

+   struct gl_renderbuffer *rb = fb->_StencilBuffer;

+   const GLstencil stencilMax = (1 << fb->Visual.stencilBits) - 1;

+   const GLstencil ref = ctx->Stencil.Ref[face];

+   const GLstencil wrtmask = ctx->Stencil.WriteMask[face];

+   const GLstencil invmask = (GLstencil) (~wrtmask);

+   GLuint i;

+   GLstencil *stencilStart = (GLubyte *) rb->Data;

+   const GLuint stride = rb->Width;

+

+   ASSERT(rb->GetPointer(ctx, rb, 0, 0));

+   ASSERT(sizeof(GLstencil) == 1);

+

+   switch (oper) {

+      case GL_KEEP:

+         /* do nothing */

+         break;

+      case GL_ZERO:

+	 if (invmask==0) {

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

+	       if (mask[i]) {

+                  GLstencil *sptr = STENCIL_ADDRESS( x[i], y[i] );

+                  *sptr = 0;

+	       }

+	    }

+	 }

+	 else {

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

+	       if (mask[i]) {

+                  GLstencil *sptr = STENCIL_ADDRESS( x[i], y[i] );

+		  *sptr = (GLstencil) (invmask & *sptr);

+	       }

+	    }

+	 }

+	 break;

+      case GL_REPLACE:

+	 if (invmask==0) {

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

+	       if (mask[i]) {

+                  GLstencil *sptr = STENCIL_ADDRESS( x[i], y[i] );

+                  *sptr = ref;

+	       }

+	    }

+	 }

+	 else {

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

+	       if (mask[i]) {

+                  GLstencil *sptr = STENCIL_ADDRESS( x[i], y[i] );

+		  *sptr = (GLstencil) ((invmask & *sptr ) | (wrtmask & ref));

+	       }

+	    }

+	 }

+	 break;

+      case GL_INCR:

+	 if (invmask==0) {

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

+	       if (mask[i]) {

+                  GLstencil *sptr = STENCIL_ADDRESS( x[i], y[i] );

+		  if (*sptr < stencilMax) {

+		     *sptr = (GLstencil) (*sptr + 1);

+		  }

+	       }

+	    }

+	 }

+	 else {

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

+	       if (mask[i]) {

+                  GLstencil *sptr = STENCIL_ADDRESS( x[i], y[i] );

+		  if (*sptr < stencilMax) {

+		     *sptr = (GLstencil) ((invmask & *sptr) | (wrtmask & (*sptr+1)));

+		  }

+	       }

+	    }

+	 }

+	 break;

+      case GL_DECR:

+	 if (invmask==0) {

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

+	       if (mask[i]) {

+                  GLstencil *sptr = STENCIL_ADDRESS( x[i], y[i] );

+		  if (*sptr>0) {

+		     *sptr = (GLstencil) (*sptr - 1);

+		  }

+	       }

+	    }

+	 }

+	 else {

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

+	       if (mask[i]) {

+                  GLstencil *sptr = STENCIL_ADDRESS( x[i], y[i] );

+		  if (*sptr>0) {

+		     *sptr = (GLstencil) ((invmask & *sptr) | (wrtmask & (*sptr-1)));

+		  }

+	       }

+	    }

+	 }

+	 break;

+      case GL_INCR_WRAP_EXT:

+	 if (invmask==0) {

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

+	       if (mask[i]) {

+                  GLstencil *sptr = STENCIL_ADDRESS( x[i], y[i] );

+                  *sptr = (GLstencil) (*sptr + 1);

+	       }

+	    }

+	 }

+	 else {

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

+	       if (mask[i]) {

+                  GLstencil *sptr = STENCIL_ADDRESS( x[i], y[i] );

+                  *sptr = (GLstencil) ((invmask & *sptr) | (wrtmask & (*sptr+1)));

+	       }

+	    }

+	 }

+	 break;

+      case GL_DECR_WRAP_EXT:

+	 if (invmask==0) {

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

+	       if (mask[i]) {

+                  GLstencil *sptr = STENCIL_ADDRESS( x[i], y[i] );

+                  *sptr = (GLstencil) (*sptr - 1);

+	       }

+	    }

+	 }

+	 else {

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

+	       if (mask[i]) {

+                  GLstencil *sptr = STENCIL_ADDRESS( x[i], y[i] );

+                  *sptr = (GLstencil) ((invmask & *sptr) | (wrtmask & (*sptr-1)));

+	       }

+	    }

+	 }

+	 break;

+      case GL_INVERT:

+	 if (invmask==0) {

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

+	       if (mask[i]) {

+                  GLstencil *sptr = STENCIL_ADDRESS( x[i], y[i] );

+                  *sptr = (GLstencil) (~*sptr);

+	       }

+	    }

+	 }

+	 else {

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

+	       if (mask[i]) {

+                  GLstencil *sptr = STENCIL_ADDRESS( x[i], y[i] );

+                  *sptr = (GLstencil) ((invmask & *sptr) | (wrtmask & ~*sptr));

+	       }

+	    }

+	 }

+	 break;

+      default:

+         _mesa_problem(ctx, "Bad stencilop in apply_stencil_op_to_pixels");

+   }

+}

+

+

+

+/**

+ * Apply stencil test to an array of pixels before depth buffering.

+ *

+ * \note Used for software stencil buffer only.

+ * Input:  n - number of pixels in the span

+ *         x, y - array of [n] pixels to stencil

+ *         mask - array [n] of flag:  0=skip the pixel, 1=stencil the pixel

+ * Output:  mask - pixels which fail the stencil test will have their

+ *                 mask flag set to 0.

+ * \return  GL_FALSE = all pixels failed, GL_TRUE = zero or more pixels passed.

+ */

+static GLboolean

+stencil_test_pixels( struct gl_context *ctx, GLuint face, GLuint n,

+                     const GLint x[], const GLint y[], GLubyte mask[] )

+{

+   const struct gl_framebuffer *fb = ctx->DrawBuffer;

+   struct gl_renderbuffer *rb = fb->_StencilBuffer;

+   GLubyte fail[MAX_WIDTH];

+   GLstencil r, s;

+   GLuint i;

+   GLboolean allfail = GL_FALSE;

+   const GLuint valueMask = ctx->Stencil.ValueMask[face];

+   const GLstencil *stencilStart = (GLstencil *) rb->Data;

+   const GLuint stride = rb->Width;

+

+   ASSERT(rb->GetPointer(ctx, rb, 0, 0));

+   ASSERT(sizeof(GLstencil) == 1);

+

+   /*

+    * Perform stencil test.  The results of this operation are stored

+    * in the fail[] array:

+    *   IF fail[i] is non-zero THEN

+    *       the stencil fail operator is to be applied

+    *   ELSE

+    *       the stencil fail operator is not to be applied

+    *   ENDIF

+    */

+

+   switch (ctx->Stencil.Function[face]) {

+      case GL_NEVER:

+         /* always fail */

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

+	    if (mask[i]) {

+	       mask[i] = 0;

+	       fail[i] = 1;

+	    }

+	    else {

+	       fail[i] = 0;

+	    }

+	 }

+	 allfail = GL_TRUE;

+	 break;

+      case GL_LESS:

+	 r = (GLstencil) (ctx->Stencil.Ref[face] & valueMask);

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

+	    if (mask[i]) {

+               const GLstencil *sptr = STENCIL_ADDRESS(x[i],y[i]);

+	       s = (GLstencil) (*sptr & valueMask);

+	       if (r < s) {

+		  /* passed */

+		  fail[i] = 0;

+	       }

+	       else {

+		  fail[i] = 1;

+		  mask[i] = 0;

+	       }

+	    }

+	    else {

+	       fail[i] = 0;

+	    }

+	 }

+	 break;

+      case GL_LEQUAL:

+	 r = (GLstencil) (ctx->Stencil.Ref[face] & valueMask);

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

+	    if (mask[i]) {

+               const GLstencil *sptr = STENCIL_ADDRESS(x[i],y[i]);

+	       s = (GLstencil) (*sptr & valueMask);

+	       if (r <= s) {

+		  /* pass */

+		  fail[i] = 0;

+	       }

+	       else {

+		  fail[i] = 1;

+		  mask[i] = 0;

+	       }

+	    }

+	    else {

+	       fail[i] = 0;

+	    }

+	 }

+	 break;

+      case GL_GREATER:

+	 r = (GLstencil) (ctx->Stencil.Ref[face] & valueMask);

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

+	    if (mask[i]) {

+               const GLstencil *sptr = STENCIL_ADDRESS(x[i],y[i]);

+	       s = (GLstencil) (*sptr & valueMask);

+	       if (r > s) {

+		  /* passed */

+		  fail[i] = 0;

+	       }

+	       else {

+		  fail[i] = 1;

+		  mask[i] = 0;

+	       }

+	    }

+	    else {

+	       fail[i] = 0;

+	    }

+	 }

+	 break;

+      case GL_GEQUAL:

+	 r = (GLstencil) (ctx->Stencil.Ref[face] & valueMask);

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

+	    if (mask[i]) {

+               const GLstencil *sptr = STENCIL_ADDRESS(x[i],y[i]);

+	       s = (GLstencil) (*sptr & valueMask);

+	       if (r >= s) {

+		  /* passed */

+		  fail[i] = 0;

+	       }

+	       else {

+		  fail[i] = 1;

+		  mask[i] = 0;

+	       }

+	    }

+	    else {

+	       fail[i] = 0;

+	    }

+	 }

+	 break;

+      case GL_EQUAL:

+	 r = (GLstencil) (ctx->Stencil.Ref[face] & valueMask);

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

+	    if (mask[i]) {

+               const GLstencil *sptr = STENCIL_ADDRESS(x[i],y[i]);

+	       s = (GLstencil) (*sptr & valueMask);

+	       if (r == s) {

+		  /* passed */

+		  fail[i] = 0;

+	       }

+	       else {

+		  fail[i] = 1;

+		  mask[i] = 0;

+	       }

+	    }

+	    else {

+	       fail[i] = 0;

+	    }

+	 }

+	 break;

+      case GL_NOTEQUAL:

+	 r = (GLstencil) (ctx->Stencil.Ref[face] & valueMask);

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

+	    if (mask[i]) {

+               const GLstencil *sptr = STENCIL_ADDRESS(x[i],y[i]);

+	       s = (GLstencil) (*sptr & valueMask);

+	       if (r != s) {

+		  /* passed */

+		  fail[i] = 0;

+	       }

+	       else {

+		  fail[i] = 1;

+		  mask[i] = 0;

+	       }

+	    }

+	    else {

+	       fail[i] = 0;

+	    }

+	 }

+	 break;

+      case GL_ALWAYS:

+	 /* always pass */

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

+	    fail[i] = 0;

+	 }

+	 break;

+      default:

+         _mesa_problem(ctx, "Bad stencil func in gl_stencil_pixels");

+         return 0;

+   }

+

+   if (ctx->Stencil.FailFunc[face] != GL_KEEP) {

+      apply_stencil_op_to_pixels( ctx, n, x, y, ctx->Stencil.FailFunc[face],

+                                  face, fail );

+   }

+

+   return !allfail;

+}

+

+

+

+

+/**

+ * Apply stencil and depth testing to an array of pixels.

+ * This is used both for software and hardware stencil buffers.

+ *

+ * The comments in this function are a bit sparse but the code is

+ * almost identical to stencil_and_ztest_span(), which is well

+ * commented.

+ *

+ * Input:  n - number of pixels in the array

+ *         x, y - array of [n] pixel positions

+ *         z - array [n] of z values

+ *         mask - array [n] of flags  (1=test this pixel, 0=skip the pixel)

+ * Output: mask - array [n] of flags (1=stencil and depth test passed)

+ * Return: GL_FALSE - all fragments failed the testing

+ *         GL_TRUE - one or more fragments passed the testing

+ */

+static GLboolean

+stencil_and_ztest_pixels( struct gl_context *ctx, SWspan *span, GLuint face )

+{

+   GLubyte passMask[MAX_WIDTH], failMask[MAX_WIDTH], origMask[MAX_WIDTH];

+   struct gl_framebuffer *fb = ctx->DrawBuffer;

+   struct gl_renderbuffer *rb = fb->_StencilBuffer;

+   const GLuint n = span->end;

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

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

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

+

+   ASSERT(span->arrayMask & SPAN_XY);

+   ASSERT(ctx->Stencil.Enabled);

+   ASSERT(n <= MAX_WIDTH);

+

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

+      /* No direct access */

+      GLstencil stencil[MAX_WIDTH];

+

+      ASSERT(rb->DataType == GL_UNSIGNED_BYTE);

+      _swrast_get_values(ctx, rb, n, x, y, stencil, sizeof(GLubyte));

+

+      memcpy(origMask, mask, n * sizeof(GLubyte));          

+

+      (void) do_stencil_test(ctx, face, n, stencil, mask);

+

+      if (ctx->Depth.Test == GL_FALSE) {

+         apply_stencil_op(ctx, ctx->Stencil.ZPassFunc[face], face,

+                          n, stencil, mask);

+      }

+      else {

+         GLubyte tmpMask[MAX_WIDTH]; 

+         memcpy(tmpMask, mask, n * sizeof(GLubyte));

+

+         _swrast_depth_test_span(ctx, span);

+

+         compute_pass_fail_masks(n, tmpMask, mask, passMask, failMask);

+

+         if (ctx->Stencil.ZFailFunc[face] != GL_KEEP) {

+            apply_stencil_op(ctx, ctx->Stencil.ZFailFunc[face], face,

+                             n, stencil, failMask);

+         }

+         if (ctx->Stencil.ZPassFunc[face] != GL_KEEP) {

+            apply_stencil_op(ctx, ctx->Stencil.ZPassFunc[face], face,

+                             n, stencil, passMask);

+         }

+      }

+

+      /* Write updated stencil values into hardware stencil buffer */

+      rb->PutValues(ctx, rb, n, x, y, stencil, origMask);

+

+      return GL_TRUE;

+   }

+   else {

+      /* Direct access to stencil buffer */

+

+      if (stencil_test_pixels(ctx, face, n, x, y, mask) == GL_FALSE) {

+         /* all fragments failed the stencil test, we're done. */

+         return GL_FALSE;

+      }

+

+      if (ctx->Depth.Test==GL_FALSE) {

+         apply_stencil_op_to_pixels(ctx, n, x, y,

+                                    ctx->Stencil.ZPassFunc[face], face, mask);

+      }

+      else {

+         memcpy(origMask, mask, n * sizeof(GLubyte));

+

+         _swrast_depth_test_span(ctx, span);

+

+         compute_pass_fail_masks(n, origMask, mask, passMask, failMask);

+

+         if (ctx->Stencil.ZFailFunc[face] != GL_KEEP) {

+            apply_stencil_op_to_pixels(ctx, n, x, y,

+                                       ctx->Stencil.ZFailFunc[face],

+                                       face, failMask);

+         }

+         if (ctx->Stencil.ZPassFunc[face] != GL_KEEP) {

+            apply_stencil_op_to_pixels(ctx, n, x, y,

+                                       ctx->Stencil.ZPassFunc[face],

+                                       face, passMask);

+         }

+      }

+

+      return GL_TRUE;  /* one or more fragments passed both tests */

+   }

+}

+

+

+/**

+ * /return GL_TRUE = one or more fragments passed,

+ * GL_FALSE = all fragments failed.

+ */

+GLboolean

+_swrast_stencil_and_ztest_span(struct gl_context *ctx, SWspan *span)

+{

+   const GLuint face = (span->facing == 0) ? 0 : ctx->Stencil._BackFace;

+

+   if (span->arrayMask & SPAN_XY)

+      return stencil_and_ztest_pixels(ctx, span, face);

+   else

+      return stencil_and_ztest_span(ctx, span, face);

+}

+

+

+#if 0

+GLuint

+clip_span(GLuint bufferWidth, GLuint bufferHeight,

+          GLint x, GLint y, GLuint *count)

+{

+   GLuint n = *count;

+   GLuint skipPixels = 0;

+

+   if (y < 0 || y >= bufferHeight || x + n <= 0 || x >= bufferWidth) {

+      /* totally out of bounds */

+      n = 0;

+   }

+   else {

+      /* left clip */

+      if (x < 0) {

+         skipPixels = -x;

+         x = 0;

+         n -= skipPixels;

+      }

+      /* right clip */

+      if (x + n > bufferWidth) {

+         GLint dx = x + n - bufferWidth;

+         n -= dx;

+      }

+   }

+

+   *count = n;

+

+   return skipPixels;

+}

+#endif

+

+

+/**

+ * Return a span of stencil values from the stencil buffer.

+ * Used for glRead/CopyPixels

+ * Input:  n - how many pixels

+ *         x,y - location of first pixel

+ * Output:  stencil - the array of stencil values

+ */

+void

+_swrast_read_stencil_span(struct gl_context *ctx, struct gl_renderbuffer *rb,

+                          GLint n, GLint x, GLint y, GLstencil stencil[])

+{

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

+       x + n <= 0 || x >= (GLint) rb->Width) {

+      /* span is completely outside framebuffer */

+      return; /* undefined values OK */

+   }

+

+   if (x < 0) {

+      GLint dx = -x;

+      x = 0;

+      n -= dx;

+      stencil += dx;

+   }

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

+      GLint dx = x + n - rb->Width;

+      n -= dx;

+   }

+   if (n <= 0) {

+      return;

+   }

+

+   rb->GetRow(ctx, rb, n, x, y, stencil);

+}

+

+

+

+/**

+ * Write a span of stencil values to the stencil buffer.  This function

+ * applies the stencil write mask when needed.

+ * Used for glDraw/CopyPixels

+ * Input:  n - how many pixels

+ *         x, y - location of first pixel

+ *         stencil - the array of stencil values

+ */

+void

+_swrast_write_stencil_span(struct gl_context *ctx, GLint n, GLint x, GLint y,

+                           const GLstencil stencil[] )

+{

+   struct gl_framebuffer *fb = ctx->DrawBuffer;

+   struct gl_renderbuffer *rb = fb->_StencilBuffer;

+   const GLuint stencilMax = (1 << fb->Visual.stencilBits) - 1;

+   const GLuint stencilMask = ctx->Stencil.WriteMask[0];

+

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

+       x + n <= 0 || x >= (GLint) rb->Width) {

+      /* span is completely outside framebuffer */

+      return; /* undefined values OK */

+   }

+   if (x < 0) {

+      GLint dx = -x;

+      x = 0;

+      n -= dx;

+      stencil += dx;

+   }

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

+      GLint dx = x + n - rb->Width;

+      n -= dx;

+   }

+   if (n <= 0) {

+      return;

+   }

+

+   if ((stencilMask & stencilMax) != stencilMax) {

+      /* need to apply writemask */

+      GLstencil destVals[MAX_WIDTH], newVals[MAX_WIDTH];

+      GLint i;

+      rb->GetRow(ctx, rb, n, x, y, destVals);

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

+         newVals[i]

+            = (stencil[i] & stencilMask) | (destVals[i] & ~stencilMask);

+      }

+      rb->PutRow(ctx, rb, n, x, y, newVals, NULL);

+   }

+   else {

+      rb->PutRow(ctx, rb, n, x, y, stencil, NULL);

+   }

+}

+

+

+

+/**

+ * Clear the stencil buffer.

+ */

+void

+_swrast_clear_stencil_buffer( struct gl_context *ctx, struct gl_renderbuffer *rb )

+{

+   const GLubyte stencilBits = ctx->DrawBuffer->Visual.stencilBits;

+   const GLuint mask = ctx->Stencil.WriteMask[0];

+   const GLuint invMask = ~mask;

+   const GLuint clearVal = (ctx->Stencil.Clear & mask);

+   const GLuint stencilMax = (1 << stencilBits) - 1;

+   GLint x, y, width, height;

+

+   if (!rb || mask == 0)

+      return;

+

+   ASSERT(rb->DataType == GL_UNSIGNED_BYTE ||

+          rb->DataType == GL_UNSIGNED_SHORT);

+

+   ASSERT(rb->_BaseFormat == GL_STENCIL_INDEX);

+

+   /* compute region to clear */

+   x = ctx->DrawBuffer->_Xmin;

+   y = ctx->DrawBuffer->_Ymin;

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

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

+

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

+      /* Direct buffer access */

+      if ((mask & stencilMax) != stencilMax) {

+         /* need to mask the clear */

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

+            GLint i, j;

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

+               GLubyte *stencil = (GLubyte*) rb->GetPointer(ctx, rb, x, y + i);

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

+                  stencil[j] = (stencil[j] & invMask) | clearVal;

+               }

+            }

+         }

+         else {

+            GLint i, j;

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

+               GLushort *stencil = (GLushort*) rb->GetPointer(ctx, rb, x, y + i);

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

+                  stencil[j] = (stencil[j] & invMask) | clearVal;

+               }

+            }

+         }

+      }

+      else {

+         /* no bit masking */

+         if (width == (GLint) rb->Width && rb->DataType == GL_UNSIGNED_BYTE) {

+            /* optimized case */

+            /* Note: bottom-to-top raster assumed! */

+            GLubyte *stencil = (GLubyte *) rb->GetPointer(ctx, rb, x, y);

+            GLuint len = width * height * sizeof(GLubyte);

+            memset(stencil, clearVal, len);

+         }

+         else {

+            /* general case */

+            GLint i;

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

+               GLvoid *stencil = rb->GetPointer(ctx, rb, x, y + i);

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

+                  memset(stencil, clearVal, width);

+               }

+               else {

+                  _mesa_memset16((short unsigned int*) stencil, clearVal, width);

+               }

+            }

+         }

+      }

+   }

+   else {

+      /* no direct access */

+      if ((mask & stencilMax) != stencilMax) {

+         /* need to mask the clear */

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

+            GLint i, j;

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

+               GLubyte stencil[MAX_WIDTH];

+               rb->GetRow(ctx, rb, width, x, y + i, stencil);

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

+                  stencil[j] = (stencil[j] & invMask) | clearVal;

+               }

+               rb->PutRow(ctx, rb, width, x, y + i, stencil, NULL);

+            }

+         }

+         else {

+            GLint i, j;

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

+               GLushort stencil[MAX_WIDTH];

+               rb->GetRow(ctx, rb, width, x, y + i, stencil);

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

+                  stencil[j] = (stencil[j] & invMask) | clearVal;

+               }

+               rb->PutRow(ctx, rb, width, x, y + i, stencil, NULL);

+            }

+         }

+      }

+      else {

+         /* no bit masking */

+         const GLubyte clear8 = (GLubyte) clearVal;

+         const GLushort clear16 = (GLushort) clearVal;

+         const void *clear;

+         GLint i;

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

+            clear = &clear8;

+         }

+         else {

+            clear = &clear16;

+         }

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

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

+         }

+      }

+   }

+}