Implemented GL_EXT_depth_bounds_test.

3 files changed, 125 insertions, 10 deletions

diff --git a/src/mesa/swrast/s_depth.c b/src/mesa/swrast/s_depth.c
index 109585748de..fc242be2aab 100644
--- a/src/mesa/swrast/s_depth.c
+++ b/src/mesa/swrast/s_depth.c
@@ -1,10 +1,8 @@
-/* $Id: s_depth.c,v 1.26 2003/03/25 02:23:45 brianp Exp $ */
-
 /*
  * Mesa 3-D graphics library
- * Version:  4.1
+ * Version:  5.1
  *
- * Copyright (C) 1999-2002  Brian Paul   All Rights Reserved.
+ * Copyright (C) 1999-2003  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"),
@@ -1364,6 +1362,103 @@ _swrast_depth_test_span( GLcontext *ctx, struct sw_span *span)
 }
 
 
+/**
+ * GL_EXT_depth_bounds_test extension.
+ * Discard fragments depending on whether the corresponding Z-buffer
+ * values are outside the depth bounds test range.
+ * Note: we test the Z buffer values, not the fragment Z values!
+ * \return GL_TRUE if any fragments pass, GL_FALSE if no fragments pass
+ */
+GLboolean
+_swrast_depth_bounds_test( GLcontext *ctx, struct sw_span *span )
+{
+   SWcontext *swrast = SWRAST_CONTEXT(ctx);
+   GLdepth zMin = (GLdepth) (ctx->Depth.BoundsMin * ctx->DepthMaxF + 0.5F);
+   GLdepth zMax = (GLdepth) (ctx->Depth.BoundsMax * ctx->DepthMaxF + 0.5F);
+   GLubyte *mask = span->array->mask;
+   GLuint i;
+   GLboolean anyPass = GL_FALSE;
+
+   if (swrast->Driver.ReadDepthPixels) {
+      /* read depth values from hardware Z buffer */
+      GLdepth zbuffer[MAX_WIDTH];
+      ASSERT(span->end <= MAX_WIDTH);
+      if (span->arrayMask & SPAN_XY)
+         (*swrast->Driver.ReadDepthPixels)(ctx, span->end, span->array->x,
+                                           span->array->y, zbuffer);
+      else
+         (*swrast->Driver.ReadDepthSpan)(ctx, span->end, span->x, span->y,
+                                         zbuffer);
+      for (i = 0; i < span->end; i++) {
+         if (mask[i]) {
+            if (zbuffer[i] < zMin || zbuffer[i] > zMax)
+               mask[i] = GL_FALSE;
+            else
+               anyPass = GL_TRUE;
+         }
+      }
+   }
+   else {
+      /* software Z buffer */
+      if (span->arrayMask & SPAN_XY) {
+         if (ctx->Visual.depthBits <= 16) {
+            /* 16 bits / Z */
+            for (i = 0; i < span->end; i++) {
+               if (mask[i]) {
+                  const GLushort *zPtr = Z_ADDRESS16(ctx, span->array->x[i],
+                                                     span->array->y[i]);
+                  if (*zPtr < zMin || *zPtr > zMax)
+                     mask[i] = GL_FALSE;
+                  else
+                     anyPass = GL_TRUE;
+               }
+            }
+         }
+         else {
+            /* 32 bits / Z */
+            for (i = 0; i < span->end; i++) {
+               if (mask[i]) {
+                  const GLuint *zPtr = Z_ADDRESS32(ctx, span->array->x[i],
+                                                   span->array->y[i]);
+                  if (*zPtr < zMin || *zPtr > zMax)
+                     mask[i] = GL_FALSE;
+                  else
+                     anyPass = GL_TRUE;
+               }
+            }
+         }
+      }
+      else {
+         if (ctx->Visual.depthBits <= 16) {
+            /* 16 bits / Z */
+            const GLushort *zPtr = Z_ADDRESS16(ctx, span->x, span->y);
+            for (i = 0; i < span->end; i++) {
+               if (mask[i]) {
+                  if (zPtr[i] < zMin || zPtr[i] > zMax)
+                     mask[i] = GL_FALSE;
+                  else
+                     anyPass = GL_TRUE;
+               }
+            }
+         }
+         else {
+            /* 32 bits / Z */
+            const GLuint *zPtr = Z_ADDRESS32(ctx, span->x, span->y);
+            for (i = 0; i < span->end; i++) {
+               if (mask[i]) {
+                  if (zPtr[i] < zMin || zPtr[i] > zMax)
+                     mask[i] = GL_FALSE;
+                  else
+                     anyPass = GL_TRUE;
+               }
+            }
+         }
+      }
+   }
+   return anyPass;
+}
+
+
 
 /**********************************************************************/
 /*****                      Read Depth Buffer                     *****/
diff --git a/src/mesa/swrast/s_depth.h b/src/mesa/swrast/s_depth.h
index 9cc8e94524a..b972a84c56f 100644
--- a/src/mesa/swrast/s_depth.h
+++ b/src/mesa/swrast/s_depth.h
@@ -1,10 +1,8 @@
-/* $Id: s_depth.h,v 1.8 2003/03/25 02:23:45 brianp Exp $ */
-
 /*
  * Mesa 3-D graphics library
- * Version:  4.1
+ * Version:  5.1
  *
- * Copyright (C) 1999-2002  Brian Paul   All Rights Reserved.
+ * Copyright (C) 1999-2003  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"),
@@ -37,11 +35,13 @@ extern GLvoid *
 _swrast_zbuffer_address(GLcontext *ctx, GLint x, GLint y);
 
 
-
 extern GLuint
 _swrast_depth_test_span( GLcontext *ctx, struct sw_span *span);
 
 
+extern GLboolean
+_swrast_depth_bounds_test( GLcontext *ctx, struct sw_span *span );
+
 
 extern void
 _swrast_read_depth_span( GLcontext *ctx,
diff --git a/src/mesa/swrast/s_span.c b/src/mesa/swrast/s_span.c
index 231e549c5ae..cce69b8c439 100644
--- a/src/mesa/swrast/s_span.c
+++ b/src/mesa/swrast/s_span.c
@@ -792,6 +792,13 @@ _swrast_write_index_span( GLcontext *ctx, struct sw_span *span)
       }
    }
 
+   /* Depth bounds test */
+   if (ctx->Depth.BoundsTest && ctx->Visual.depthBits > 0) {
+      if (!_swrast_depth_bounds_test(ctx, span)) {
+         return;
+      }
+   }
+
 #ifdef DEBUG
    if (span->arrayMask & SPAN_XY) {
       GLuint i;
@@ -962,6 +969,13 @@ _swrast_write_rgba_span( GLcontext *ctx, struct sw_span *span)
       }
    }
 
+   /* Depth bounds test */
+   if (ctx->Depth.BoundsTest && ctx->Visual.depthBits > 0) {
+      if (!_swrast_depth_bounds_test(ctx, span)) {
+         return;
+      }
+   }
+
 #ifdef DEBUG
    if (span->arrayMask & SPAN_XY) {
       GLuint i;
@@ -1168,6 +1182,7 @@ _swrast_write_texture_span( GLcontext *ctx, struct sw_span *span)
 {
    const GLuint colorMask = *((GLuint *) ctx->Color.ColorMask);
    SWcontext *swrast = SWRAST_CONTEXT(ctx);
+   const GLuint origInterpMask = span->interpMask;
    const GLuint origArrayMask = span->arrayMask;
 
    ASSERT(span->primitive == GL_POINT  ||  span->primitive == GL_LINE ||
@@ -1253,6 +1268,7 @@ _swrast_write_texture_span( GLcontext *ctx, struct sw_span *span)
 
       if (ctx->Stencil.Enabled) {
          if (!_swrast_stencil_and_ztest_span(ctx, span)) {
+            span->interpMask = origInterpMask;
             span->arrayMask = origArrayMask;
             return;
          }
@@ -1262,6 +1278,7 @@ _swrast_write_texture_span( GLcontext *ctx, struct sw_span *span)
          ASSERT(span->arrayMask & SPAN_Z);
          /* regular depth testing */
          if (!_swrast_depth_test_span(ctx, span)) {
+            span->interpMask = origInterpMask;
             span->arrayMask = origArrayMask;
             return;
          }
@@ -1275,6 +1292,7 @@ _swrast_write_texture_span( GLcontext *ctx, struct sw_span *span)
     * the occlusion test.
     */
    if (colorMask == 0x0) {
+      span->interpMask = origInterpMask;
       span->arrayMask = origArrayMask;
       return;
    }
@@ -1336,11 +1354,12 @@ _swrast_write_texture_span( GLcontext *ctx, struct sw_span *span)
          _swrast_blend_span(ctx, span, span->array->rgba);
       }
 
+      /* Color component masking */
       if (colorMask != 0xffffffff) {
          _swrast_mask_rgba_span(ctx, span, span->array->rgba);
       }
 
- 
+      /* write pixels */
       if (span->arrayMask & SPAN_XY) {
          /* array of pixel coords */
          (*swrast->Driver.WriteRGBAPixels)(ctx, span->end, span->array->x,
@@ -1365,6 +1384,7 @@ _swrast_write_texture_span( GLcontext *ctx, struct sw_span *span)
       }
    }
 
+   span->interpMask = origInterpMask;
    span->arrayMask = origArrayMask;
 }