Implemented GL_SGIX_shadow and GL_SGIX_shadow_texture.

Added some const keywords in the s/w texturing code.

11 files changed, 169 insertions, 98 deletions

diff --git a/src/mesa/main/attrib.c b/src/mesa/main/attrib.c
index 205c14b0241..746ca7332b4 100644
--- a/src/mesa/main/attrib.c
+++ b/src/mesa/main/attrib.c
@@ -1,4 +1,4 @@
-/* $Id: attrib.c,v 1.43 2001/01/29 22:15:44 brianp Exp $ */
+/* $Id: attrib.c,v 1.44 2001/02/20 16:42:25 brianp Exp $ */
 
 /*
  * Mesa 3-D graphics library
@@ -101,6 +101,9 @@ copy_texobj_state( struct gl_texture_object *dest,
    dest->MaxLod = src->MaxLod;
    dest->BaseLevel = src->BaseLevel;
    dest->MaxLevel = src->MaxLevel;
+   dest->CompareFlag = src->CompareFlag;
+   dest->CompareOperator = src->CompareOperator;
+   dest->ShadowAmbient = src->ShadowAmbient;
    dest->_MaxLevel = src->_MaxLevel;
    dest->_MaxLambda = src->_MaxLambda;
    dest->Palette = src->Palette;
diff --git a/src/mesa/main/extensions.c b/src/mesa/main/extensions.c
index c68d751d322..a0b562378ef 100644
--- a/src/mesa/main/extensions.c
+++ b/src/mesa/main/extensions.c
@@ -1,4 +1,4 @@
-/* $Id: extensions.c,v 1.47 2001/02/17 18:41:01 brianp Exp $ */
+/* $Id: extensions.c,v 1.48 2001/02/20 16:42:25 brianp Exp $ */
 
 /*
  * Mesa 3-D graphics library
@@ -105,6 +105,7 @@ static struct {
    { ON,  "GL_SGIS_texture_edge_clamp",       F(SGIS_texture_edge_clamp) },
    { OFF, "GL_SGIX_depth_texture",            F(SGIX_depth_texture) },
    { OFF, "GL_SGIX_shadow",                   F(SGIX_shadow) },
+   { OFF, "GL_SGIX_shadow_ambient",           F(SGIX_shadow_ambient) },
    { ON,  "GL_SGIX_pixel_texture",            F(SGIX_pixel_texture) },
    { OFF, "GL_3DFX_texture_compression_FXT1", F(_3DFX_texture_compression_FXT1) }
 };
@@ -127,7 +128,8 @@ _mesa_enable_sw_extensions(GLcontext *ctx)
    gl_extensions_enable(ctx, "GL_NV_blend_square");
    gl_extensions_enable(ctx, "GL_MESA_sprite_point");
    gl_extensions_enable(ctx, "GL_SGIX_depth_texture");
-   /*gl_extensions_enable(ctx, "GL_SGIX_shadow"); not finished */
+   gl_extensions_enable(ctx, "GL_SGIX_shadow");
+   gl_extensions_enable(ctx, "GL_SGIX_shadow_ambient");
 }
 
 
diff --git a/src/mesa/main/mtypes.h b/src/mesa/main/mtypes.h
index b890fa0dbd0..93e76e57294 100644
--- a/src/mesa/main/mtypes.h
+++ b/src/mesa/main/mtypes.h
@@ -1,4 +1,4 @@
-/* $Id: mtypes.h,v 1.20 2001/02/17 18:41:01 brianp Exp $ */
+/* $Id: mtypes.h,v 1.21 2001/02/20 16:42:25 brianp Exp $ */
 
 /*
  * Mesa 3-D graphics library
@@ -834,6 +834,7 @@ struct gl_texture_object {
    GLint MaxLevel;		/* max mipmap level, OpenGL 1.2 */
    GLboolean CompareFlag;	/* GL_SGIX_shadow */
    GLenum CompareOperator;	/* GL_SGIX_shadow */
+   GLchan ShadowAmbient;	/* GL_SGIX_shadow_ambient */
    GLint _MaxLevel;		/* actual max mipmap level (q in the spec) */
    GLfloat _MaxLambda;		/* = _MaxLevel - BaseLevel (q - b in spec) */
    struct gl_texture_image *Image[MAX_TEXTURE_LEVELS];
@@ -1230,6 +1231,7 @@ struct gl_extensions {
    GLboolean SGIX_depth_texture;
    GLboolean SGIX_pixel_texture;
    GLboolean SGIX_shadow;
+   GLboolean SGIX_shadow_ambient;
    GLboolean _3DFX_texture_compression_FXT1;
 };
 
diff --git a/src/mesa/main/state.c b/src/mesa/main/state.c
index 533fa687242..badf180ce88 100644
--- a/src/mesa/main/state.c
+++ b/src/mesa/main/state.c
@@ -1,4 +1,4 @@
-/* $Id: state.c,v 1.58 2001/02/16 00:35:35 keithw Exp $ */
+/* $Id: state.c,v 1.59 2001/02/20 16:42:25 brianp Exp $ */
 
 /*
  * Mesa 3-D graphics library
@@ -993,6 +993,11 @@ void gl_update_state( GLcontext *ctx )
    ASSERT(ctx->Driver.TexSubImage1D);
    ASSERT(ctx->Driver.TexSubImage2D);
    ASSERT(ctx->Driver.TexSubImage3D);
+   ASSERT(ctx->Driver.CopyTexImage1D);
+   ASSERT(ctx->Driver.CopyTexImage2D);
+   ASSERT(ctx->Driver.CopyTexSubImage1D);
+   ASSERT(ctx->Driver.CopyTexSubImage2D);
+   ASSERT(ctx->Driver.CopyTexSubImage3D);
    if (ctx->Extensions.ARB_texture_compression) {
       ASSERT(ctx->Driver.CompressedTexImage1D);
       ASSERT(ctx->Driver.CompressedTexImage2D);
diff --git a/src/mesa/main/texobj.c b/src/mesa/main/texobj.c
index 95427855fba..b227a96192c 100644
--- a/src/mesa/main/texobj.c
+++ b/src/mesa/main/texobj.c
@@ -1,4 +1,4 @@
-/* $Id: texobj.c,v 1.39 2001/02/17 18:41:01 brianp Exp $ */
+/* $Id: texobj.c,v 1.40 2001/02/20 16:42:25 brianp Exp $ */
 
 /*
  * Mesa 3-D graphics library
@@ -81,6 +81,7 @@ _mesa_alloc_texture_object( struct gl_shared_state *shared,
       obj->MaxLevel = 1000;
       obj->CompareFlag = GL_FALSE;
       obj->CompareOperator = GL_TEXTURE_LEQUAL_R_SGIX;
+      obj->ShadowAmbient = 0;
       _mesa_init_colortable(&obj->Palette);
 
       /* insert into linked list */
diff --git a/src/mesa/main/texstate.c b/src/mesa/main/texstate.c
index f55cb5452a0..607f3b77dcf 100644
--- a/src/mesa/main/texstate.c
+++ b/src/mesa/main/texstate.c
@@ -1,4 +1,4 @@
-/* $Id: texstate.c,v 1.32 2001/02/17 18:41:01 brianp Exp $ */
+/* $Id: texstate.c,v 1.33 2001/02/20 16:42:25 brianp Exp $ */
 
 /*
  * Mesa 3-D graphics library
@@ -784,7 +784,7 @@ _mesa_TexParameterfv( GLenum target, GLenum pname, const GLfloat *params )
             GLenum op = (GLenum) params[0];
             if (op == GL_TEXTURE_LEQUAL_R_SGIX ||
                 op == GL_TEXTURE_GEQUAL_R_SGIX) {
-               texObj->CompareFlag = (GLenum) op;
+               texObj->CompareOperator = op;
             }
             else {
                gl_error(ctx, GL_INVALID_ENUM, "glTexParameter(param)");
@@ -795,6 +795,15 @@ _mesa_TexParameterfv( GLenum target, GLenum pname, const GLfloat *params )
             return;
          }
          break;
+      case GL_SHADOW_AMBIENT_SGIX:
+         if (ctx->Extensions.SGIX_shadow_ambient) {
+            UNCLAMPED_FLOAT_TO_CHAN(texObj->ShadowAmbient, params[0]);
+         }
+         else {
+            gl_error(ctx, GL_INVALID_ENUM, "glTexParameter(pname)");
+            return;
+         }
+         break;
       default:
          gl_error( ctx, GL_INVALID_ENUM, "glTexParameter(pname)" );
          return;
@@ -1064,6 +1073,15 @@ _mesa_GetTexParameterfv( GLenum target, GLenum pname, GLfloat *params )
             return;
          }
          break;
+      case GL_SHADOW_AMBIENT_SGIX:
+         if (ctx->Extensions.SGIX_shadow_ambient) {
+            *params = CHAN_TO_FLOAT(obj->ShadowAmbient);
+         }
+         else {
+            gl_error(ctx, GL_INVALID_ENUM, "glGetTexParameterfv(pname)");
+            return;
+         }
+         break;
       default:
          gl_error( ctx, GL_INVALID_ENUM, "glGetTexParameterfv(pname)" );
    }
@@ -1156,6 +1174,16 @@ _mesa_GetTexParameteriv( GLenum target, GLenum pname, GLint *params )
             return;
          }
          break;
+      case GL_SHADOW_AMBIENT_SGIX:
+         if (ctx->Extensions.SGIX_shadow_ambient) {
+            /* XXX range? */
+            *params = CHAN_TO_FLOAT(obj->ShadowAmbient);
+         }
+         else {
+            gl_error(ctx, GL_INVALID_ENUM, "glGetTexParameteriv(pname)");
+            return;
+         }
+         break;
       default:
          gl_error( ctx, GL_INVALID_ENUM, "glGetTexParameteriv(pname)" );
    }
diff --git a/src/mesa/swrast/s_copypix.c b/src/mesa/swrast/s_copypix.c
index 401955d00ae..4c4d0003178 100644
--- a/src/mesa/swrast/s_copypix.c
+++ b/src/mesa/swrast/s_copypix.c
@@ -1,4 +1,4 @@
-/* $Id: s_copypix.c,v 1.10 2001/01/23 23:39:37 brianp Exp $ */
+/* $Id: s_copypix.c,v 1.11 2001/02/20 16:42:26 brianp Exp $ */
 
 /*
  * Mesa 3-D graphics library
@@ -248,7 +248,8 @@ copy_conv_rgba_pixels(GLcontext *ctx, GLint srcx, GLint srcy,
             _mesa_pixeltexgen(ctx, width, (const GLchan (*)[4]) rgba,
                               s, t, r, q);
             _swrast_texture_fragments(ctx, unit, width, s, t, r, NULL,
-                                      primary_rgba, rgba);
+                                      (CONST GLchan (*)[4]) primary_rgba,
+                                      rgba);
          }
       }
 
@@ -494,7 +495,8 @@ copy_rgba_pixels(GLcontext *ctx, GLint srcx, GLint srcy,
             _mesa_pixeltexgen(ctx, width, (const GLchan (*)[4]) rgba,
                               s, t, r, q);
             _swrast_texture_fragments(ctx, unit, width, s, t, r, NULL,
-                                      primary_rgba, rgba);
+                                      (CONST GLchan (*)[4]) primary_rgba,
+                                      rgba);
          }
       }
 
diff --git a/src/mesa/swrast/s_drawpix.c b/src/mesa/swrast/s_drawpix.c
index 24339f61bbc..94d8d873a2a 100644
--- a/src/mesa/swrast/s_drawpix.c
+++ b/src/mesa/swrast/s_drawpix.c
@@ -1,4 +1,4 @@
-/* $Id: s_drawpix.c,v 1.9 2001/02/17 18:41:01 brianp Exp $ */
+/* $Id: s_drawpix.c,v 1.10 2001/02/20 16:42:26 brianp Exp $ */
 
 /*
  * Mesa 3-D graphics library
@@ -821,7 +821,8 @@ draw_rgba_pixels( GLcontext *ctx, GLint x, GLint y,
                   _mesa_pixeltexgen(ctx, width, (const GLchan (*)[4]) rgba,
                                     s, t, r, q);
                   _swrast_texture_fragments(ctx, unit, width, s, t, r, NULL,
-                                            primary_rgba, rgba);
+                                            (CONST GLchan (*)[4]) primary_rgba,
+                                            rgba);
                }
             }
          }
diff --git a/src/mesa/swrast/s_span.c b/src/mesa/swrast/s_span.c
index c2d946b35fb..cb62a8a10bf 100644
--- a/src/mesa/swrast/s_span.c
+++ b/src/mesa/swrast/s_span.c
@@ -1,4 +1,4 @@
-/* $Id: s_span.c,v 1.8 2001/02/15 22:59:01 brianp Exp $ */
+/* $Id: s_span.c,v 1.9 2001/02/20 16:42:26 brianp Exp $ */
 
 /*
  * Mesa 3-D graphics library
@@ -817,7 +817,8 @@ void gl_write_texture_span( GLcontext *ctx,
       /* Texturing without alpha is done after depth-testing which
          gives a potential speed-up. */
       ASSERT(ctx->Texture._ReallyEnabled);
-      _swrast_texture_fragments( ctx, 0, n, s, t, u, lambda, rgba, rgba );
+      _swrast_texture_fragments( ctx, 0, n, s, t, u, lambda,
+                                 (CONST GLchan (*)[4]) rgba, rgba );
      
       /* Do the alpha test */
       if (_mesa_alpha_test( ctx, n, (const GLchan (*)[4]) rgba, mask ) == 0) {
@@ -850,7 +851,8 @@ void gl_write_texture_span( GLcontext *ctx,
    /* Texture without alpha test */
    if (! ctx->Color.AlphaEnabled) {
       ASSERT(ctx->Texture._ReallyEnabled);
-      _swrast_texture_fragments( ctx, 0, n, s, t, u, lambda, rgba, rgba );
+      _swrast_texture_fragments( ctx, 0, n, s, t, u, lambda,
+                                 (CONST GLchan (*)[4]) rgba, rgba );
    }
 
    /* Add base and specular colors */
@@ -965,8 +967,8 @@ gl_write_multitexture_span( GLcontext *ctx,
        */
       ASSERT(ctx->Texture._ReallyEnabled);
       for (i = 0; i < texUnits; i++)
-         _swrast_texture_fragments( ctx, i, n, s[i], t[i], u[i],
-                                    lambda[i], rgbaIn, rgba );
+         _swrast_texture_fragments( ctx, i, n, s[i], t[i], u[i], lambda[i],
+                                    (CONST GLchan (*)[4]) rgbaIn, rgba );
      
       /* Do the alpha test */
       if (_mesa_alpha_test( ctx, n, (const GLchan (*)[4])rgba, mask ) == 0) {
@@ -1000,8 +1002,8 @@ gl_write_multitexture_span( GLcontext *ctx,
    if (! ctx->Color.AlphaEnabled) {
       ASSERT(ctx->Texture._ReallyEnabled);
       for (i = 0; i < texUnits; i++)
-         _swrast_texture_fragments( ctx, i, n, s[i], t[i], u[i],
-                                    lambda[i], rgbaIn, rgba );
+         _swrast_texture_fragments( ctx, i, n, s[i], t[i], u[i], lambda[i],
+                                    (CONST GLchan (*)[4]) rgbaIn, rgba );
    }
 
    /* Add base and specular colors */
diff --git a/src/mesa/swrast/s_texture.c b/src/mesa/swrast/s_texture.c
index 2a7d3db460e..62439af94c5 100644
--- a/src/mesa/swrast/s_texture.c
+++ b/src/mesa/swrast/s_texture.c
@@ -1,4 +1,4 @@
-/* $Id: s_texture.c,v 1.11 2001/02/17 18:41:01 brianp Exp $ */
+/* $Id: s_texture.c,v 1.12 2001/02/20 16:42:26 brianp Exp $ */
 
 /*
  * Mesa 3-D graphics library
@@ -1667,16 +1667,16 @@ _swrast_choose_texture_sample_func( GLcontext *ctx, GLuint texUnit,
 #define S_PROD(A,B) ( (GLint)(A) * ((GLint)(B)+1) )
 
 static INLINE void
-_mesa_texture_combine(const GLcontext *ctx,
-                      const struct gl_texture_unit *textureUnit,
-                      GLuint n,
-                      GLchan (*primary_rgba)[4],
-                      GLchan (*texel)[4],
-                      GLchan (*rgba)[4])
+texture_combine(const GLcontext *ctx,
+                const struct gl_texture_unit *textureUnit,
+                GLuint n,
+                CONST GLchan (*primary_rgba)[4],
+                CONST GLchan (*texel)[4],
+                GLchan (*rgba)[4])
 {
    GLchan ccolor [3][3*MAX_WIDTH][4];
-   GLchan (*argRGB [3])[4];
-   GLchan (*argA [3])[4];
+   const GLchan (*argRGB [3])[4];
+   const GLchan (*argA [3])[4];
    GLuint i, j;
    const GLuint RGBshift = textureUnit->CombineScaleShiftRGB;
    const GLuint Ashift   = textureUnit->CombineScaleShiftA;
@@ -1692,7 +1692,7 @@ _mesa_texture_combine(const GLcontext *ctx,
             argA[j] = primary_rgba;
             break;
          case GL_PREVIOUS_EXT:
-            argA[j] = rgba;
+            argA[j] = (const GLchan (*)[4]) rgba;
             break;
          case GL_CONSTANT_EXT:
             {
@@ -1700,7 +1700,7 @@ _mesa_texture_combine(const GLcontext *ctx,
                UNCLAMPED_FLOAT_TO_CHAN(alpha, textureUnit->EnvColor[3]);
                for (i = 0; i < n; i++)
                   c[i][ACOMP] = alpha;
-               argA[j] = ccolor[j];
+               argA[j] = (const GLchan (*)[4]) ccolor[j];
             }
             break;
          default:
@@ -1715,7 +1715,7 @@ _mesa_texture_combine(const GLcontext *ctx,
             argRGB[j] = primary_rgba;
             break;
          case GL_PREVIOUS_EXT:
-            argRGB[j] = rgba;
+            argRGB[j] = (const GLchan (*)[4]) rgba;
             break;
          case GL_CONSTANT_EXT:
             {
@@ -1729,7 +1729,7 @@ _mesa_texture_combine(const GLcontext *ctx,
                   c[i][GCOMP] = green;
                   c[i][BCOMP] = blue;
                }
-               argRGB[j] = ccolor[j];
+               argRGB[j] = (const GLchan (*)[4]) ccolor[j];
             }
             break;
          default:
@@ -1737,10 +1737,10 @@ _mesa_texture_combine(const GLcontext *ctx,
       }
 
       if (textureUnit->CombineOperandRGB[j] != GL_SRC_COLOR) {
-         GLchan (*src)[4] = argRGB[j];
+         const GLchan (*src)[4] = argRGB[j];
          GLchan (*dst)[4] = ccolor[j];
 
-         argRGB[j] = ccolor[j];
+         argRGB[j] = (const GLchan (*)[4]) ccolor[j];
 
          if (textureUnit->CombineOperandRGB[j] == GL_ONE_MINUS_SRC_COLOR) {
             for (i = 0; i < n; i++) {
@@ -1750,7 +1750,7 @@ _mesa_texture_combine(const GLcontext *ctx,
             }
          }
          else if (textureUnit->CombineOperandRGB[j] == GL_SRC_ALPHA) {
-            src = argA[j];
+            src = (const GLchan (*)[4]) argA[j];
             for (i = 0; i < n; i++) {
                dst[i][RCOMP] = src[i][ACOMP];
                dst[i][GCOMP] = src[i][ACOMP];
@@ -1758,7 +1758,7 @@ _mesa_texture_combine(const GLcontext *ctx,
             }
          }
          else {                      /*  GL_ONE_MINUS_SRC_ALPHA  */
-            src = argA[j];
+            src = (const GLchan (*)[4]) argA[j];
             for (i = 0; i < n; i++) {
                dst[i][RCOMP] = CHAN_MAX - src[i][ACOMP];
                dst[i][GCOMP] = CHAN_MAX - src[i][ACOMP];
@@ -1768,9 +1768,9 @@ _mesa_texture_combine(const GLcontext *ctx,
       }
 
       if (textureUnit->CombineOperandA[j] == GL_ONE_MINUS_SRC_ALPHA) {
-         GLchan (*src)[4] = argA[j];
+         const GLchan (*src)[4] = argA[j];
          GLchan (*dst)[4] = ccolor[j];
-         argA[j] = ccolor[j];
+         argA[j] = (const GLchan (*)[4]) ccolor[j];
          for (i = 0; i < n; i++) {
             dst[i][ACOMP] = CHAN_MAX - src[i][ACOMP];
          }
@@ -1994,7 +1994,7 @@ _mesa_texture_combine(const GLcontext *ctx,
  * Input:  textureUnit - pointer to texture unit to apply
  *         format - base internal texture format
  *         n - number of fragments
- *         primary_rgba - primary colors (may be rgba for single texture)
+ *         primary_rgba - primary colors (may alias rgba for single texture)
  *         texels - array of texel colors
  * InOut:  rgba - incoming fragment colors modified by texel colors
  *                according to the texture environment mode.
@@ -2003,7 +2003,7 @@ static void
 apply_texture( const GLcontext *ctx,
                const struct gl_texture_unit *texUnit,
                GLuint n,
-               GLchan primary_rgba[][4], GLchan texel[][4],
+               CONST GLchan primary_rgba[][4], CONST GLchan texel[][4],
                GLchan rgba[][4] )
 {
    GLint baseLevel;
@@ -2019,7 +2019,7 @@ apply_texture( const GLcontext *ctx,
 
    format = texUnit->_Current->Image[baseLevel]->Format;
 
-   if (format==GL_COLOR_INDEX) {
+   if (format==GL_COLOR_INDEX || format==GL_DEPTH_COMPONENT) {
       format = GL_RGBA;  /* XXXX a hack! */
    }
 
@@ -2328,50 +2328,8 @@ apply_texture( const GLcontext *ctx,
 	 }
 	 break;
 
-      case GL_COMBINE_EXT:    /*  GL_EXT_combine_ext; we modify texel array */
-         switch (format) {
-            case GL_ALPHA:
-               for (i=0;i<n;i++)
-                  texel[i][RCOMP] = texel[i][GCOMP] = texel[i][BCOMP] = 0;
-               break;
-            case GL_LUMINANCE:
-               for (i=0;i<n;i++) {
-                  /* Cv = Lt */
-                  GLchan Lt = texel[i][RCOMP];
-                  texel[i][GCOMP] = texel[i][BCOMP] = Lt;
-                  /* Av = 1 */
-                  texel[i][ACOMP] = CHAN_MAX;
-               }
-               break;
-            case GL_LUMINANCE_ALPHA:
-               for (i=0;i<n;i++) {
-                  GLchan Lt = texel[i][RCOMP];
-                  /* Cv = Lt */
-                  texel[i][GCOMP] = texel[i][BCOMP] = Lt;
-               }
-               break;
-            case GL_INTENSITY:
-               for (i=0;i<n;i++) {
-                  /* Cv = It */
-                  GLchan It = texel[i][RCOMP];
-                  texel[i][GCOMP] = texel[i][BCOMP] = It;
-                  /* Av = It */
-                  texel[i][ACOMP] = It;
-               }
-               break;
-            case GL_RGB:
-               for (i=0;i<n;i++) {
-                  /* Av = 1 */
-                  texel[i][ACOMP] = CHAN_MAX;
-               }
-               break;
-            case GL_RGBA:  /* do nothing. */
-               break;
-            default:
-               gl_problem(ctx, "Bad format in apply_texture (GL_COMBINE_EXT)");
-               return;
-         }
-         _mesa_texture_combine(ctx, texUnit, n, primary_rgba, texel, rgba);
+      case GL_COMBINE_EXT:
+         texture_combine(ctx, texUnit, n, primary_rgba, texel, rgba);
          break;
 
       default:
@@ -2383,13 +2341,73 @@ apply_texture( const GLcontext *ctx,
 
 
 /*
+ * Apply a shadow/depth texture to the array of colors.
+ * Input:  ctx - context
+ *         texUnit - the texture unit
+ *         n - number of colors
+ *         r - array [n] of texture R coordinates
+ * In/Out:  rgba - array [n] of colors.
+ */
+static void
+sample_depth_texture(const GLcontext *ctx,
+                     const struct gl_texture_unit *texUnit,
+                     GLuint n,
+                     const GLfloat s[], const GLfloat t[], const GLfloat r[],
+                     GLchan texel[][4])
+{
+   const struct gl_texture_object *texObj = texUnit->_Current;
+   const struct gl_texture_image *texImage = texObj->Image[0]; /* XXX hack */
+   const GLchan ambient = texObj->ShadowAmbient;
+   GLboolean lequal, gequal;
+   GLuint i;
+
+   if (texObj->CompareOperator == GL_TEXTURE_LEQUAL_R_SGIX) {
+      lequal = GL_TRUE;
+      gequal = GL_FALSE;
+   }
+   else {
+      lequal = GL_FALSE;
+      gequal = GL_TRUE;
+   }
+
+   assert(texObj->Dimensions == 2);
+   assert(texImage->Format == GL_DEPTH_COMPONENT);
+
+   for (i = 0; i < n; i++) {
+      const GLfloat *src;
+      GLfloat depthSample;
+      GLint col, row;
+      /* XXX this is a hack - implement proper sampling */
+      COMPUTE_NEAREST_TEXEL_LOCATION(texObj->WrapS, s[i], texImage->Width, col);
+      COMPUTE_NEAREST_TEXEL_LOCATION(texObj->WrapT, t[i], texImage->Height,row);
+      src = (const GLfloat *) texImage->Data + row * texImage->Width + col;
+      depthSample = *src;
+      if ((depthSample <= r[i] && lequal) ||
+          (depthSample >= r[i] && gequal)) {
+         texel[i][RCOMP] = ambient;
+         texel[i][GCOMP] = ambient;
+         texel[i][BCOMP] = ambient;
+         texel[i][ACOMP] = CHAN_MAX;
+      }
+      else {
+         texel[i][RCOMP] = CHAN_MAX;
+         texel[i][GCOMP] = CHAN_MAX;
+         texel[i][BCOMP] = CHAN_MAX;
+         texel[i][ACOMP] = CHAN_MAX;
+      }
+   }
+}
+
+
+
+/*
  * Apply a unit of texture mapping to the incoming fragments.
  */
 void
 _swrast_texture_fragments( GLcontext *ctx, GLuint texUnit, GLuint n,
                            const GLfloat s[], const GLfloat t[],
                            const GLfloat r[], GLfloat lambda[],
-                           GLchan primary_rgba[][4], GLchan rgba[][4] )
+                           CONST GLchan primary_rgba[][4], GLchan rgba[][4] )
 {
    const GLuint mask = TEXTURE0_ANY << (texUnit * 4);
 
@@ -2410,8 +2428,8 @@ _swrast_texture_fragments( GLcontext *ctx, GLuint texUnit, GLuint n,
          if (textureUnit->_Current->MinLod != -1000.0
              || textureUnit->_Current->MaxLod != 1000.0) {
             /* apply LOD clamping to lambda */
-            GLfloat min = textureUnit->_Current->MinLod;
-            GLfloat max = textureUnit->_Current->MaxLod;
+            const GLfloat min = textureUnit->_Current->MinLod;
+            const GLfloat max = textureUnit->_Current->MaxLod;
             GLuint i;
             for (i=0;i<n;i++) {
                GLfloat l = lambda[i];
@@ -2420,12 +2438,19 @@ _swrast_texture_fragments( GLcontext *ctx, GLuint texUnit, GLuint n,
          }
 
          /* Sample the texture. */
-         SWRAST_CONTEXT(ctx)->TextureSample[texUnit]( ctx, texUnit,
-						      textureUnit->_Current,
-						      n, s, t, r,
-						      lambda, texel );
-
-         apply_texture( ctx, textureUnit, n, primary_rgba, texel, rgba );
+         if (textureUnit->_Current->CompareFlag) {
+            /* depth texture */
+            sample_depth_texture(ctx, textureUnit, n, s, t, r, texel);
+         }
+         else {
+            /* color texture */
+            SWRAST_CONTEXT(ctx)->TextureSample[texUnit]( ctx, texUnit,
+                                                         textureUnit->_Current,
+                                                         n, s, t, r,
+                                                         lambda, texel );
+         }
+         apply_texture( ctx, textureUnit, n, primary_rgba,
+                        (const GLchan (*)[4]) texel, rgba );
       }
    }
 }
diff --git a/src/mesa/swrast/s_texture.h b/src/mesa/swrast/s_texture.h
index 9a64928b5d4..821e8199d5b 100644
--- a/src/mesa/swrast/s_texture.h
+++ b/src/mesa/swrast/s_texture.h
@@ -1,10 +1,10 @@
-/* $Id: s_texture.h,v 1.4 2001/01/05 21:28:31 brianp Exp $ */
+/* $Id: s_texture.h,v 1.5 2001/02/20 16:42:26 brianp Exp $ */
 
 /*
  * Mesa 3-D graphics library
  * Version:  3.5
  *
- * Copyright (C) 1999-2000  Brian Paul   All Rights Reserved.
+ * Copyright (C) 1999-2001  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"),
@@ -43,7 +43,7 @@ extern void
 _swrast_texture_fragments( GLcontext *ctx, GLuint texSet, GLuint n,
                            const GLfloat s[], const GLfloat t[],
                            const GLfloat r[], GLfloat lambda[],
-                           GLchan primary_rgba[][4], GLchan rgba[][4] );
+                           CONST GLchan primary_rgba[][4], GLchan rgba[][4] );
 
 
 #endif