Klaus's latest patches and some clean-up

12 files changed, 384 insertions, 173 deletions

diff --git a/src/mesa/swrast/s_alpha.c b/src/mesa/swrast/s_alpha.c
index c0d76fd9e1..7aa47f230f 100644
--- a/src/mesa/swrast/s_alpha.c
+++ b/src/mesa/swrast/s_alpha.c
@@ -1,10 +1,10 @@
-/* $Id: s_alpha.c,v 1.4 2001/03/12 00:48:41 gareth Exp $ */
+/* $Id: s_alpha.c,v 1.5 2002/01/21 18:12:34 brianp Exp $ */
 
 /*
  * Mesa 3-D graphics library
- * Version:  3.5
+ * Version:  4.1
  *
- * Copyright (C) 1999-2001  Brian Paul   All Rights Reserved.
+ * Copyright (C) 1999-2002  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"),
@@ -34,7 +34,84 @@
 #include "s_alpha.h"
 
 
+/*
+ * Apply the alpha test to a span of pixels.
+ * In:  rgba - array of pixels
+ * In/Out:  span -
+ * Return:  0 = all pixels in the span failed the alpha test.
+ *          1 = one or more pixels passed the alpha test.
+ */
+GLint
+_mesa_alpha_test( const GLcontext *ctx, struct sw_span *span,
+                  CONST GLchan rgba[][4])
+{
+   GLuint i;
+   const GLchan ref = ctx->Color.AlphaRef;
+   GLubyte *mask = span->mask;
+
+   ASSERT (span->filledMask == GL_TRUE);
+   ASSERT (span->filledAlpha == GL_TRUE);
+
+   SW_SPAN_SET_FLAG(span->testedAlpha);
+
+
+   /* switch cases ordered from most frequent to less frequent */
+   switch (ctx->Color.AlphaFunc) {
+      case GL_LESS:
+         for (i=span->start; i<span->end; i++) {
+	    mask[i] &= (rgba[i][ACOMP] < ref);
+	 }
+	 break;
+      case GL_LEQUAL:
+         for (i=span->start; i<span->end; i++)
+	    mask[i] &= (rgba[i][ACOMP] <= ref);
+	 break;
+      case GL_GEQUAL:
+         for (i=span->start; i<span->end; i++) {
+	    mask[i] &= (rgba[i][ACOMP] >= ref);
+	 }
+	 break;
+      case GL_GREATER:
+         for (i=span->start; i<span->end; i++) {
+	    mask[i] &= (rgba[i][ACOMP] > ref);
+	 }
+	 break;
+      case GL_NOTEQUAL:
+         for (i=span->start; i<span->end; i++) {
+	    mask[i] &= (rgba[i][ACOMP] != ref);
+	 }
+	 break;
+      case GL_EQUAL:
+         for (i=span->start; i<span->end; i++) {
+	    mask[i] &= (rgba[i][ACOMP] == ref);
+	 }
+	 break;
+      case GL_ALWAYS:
+	 /* do nothing */
+	 return 1;
+      case GL_NEVER:
+         /* caller should check for zero! */
+	 return 0;
+      default:
+	 _mesa_problem( ctx, "Invalid alpha test in gl_alpha_test" );
+         return 0;
+   }
+
+   while ((span->start <= span->end)  &&
+	  (mask[span->start] == 0))
+     span->start ++;
+
+   while ((span->end >= span->start)  &&
+	  (mask[span->end] == 0))
+     span->end --;
 
+   span->writeAll = GL_FALSE;
+
+   if (span->start >= span->end)
+     return 0;
+   else
+     return 1;
+}
 
 
 /*
@@ -46,11 +123,11 @@
  *          1 = one or more pixels passed the alpha test.
  */
 GLint
-_mesa_alpha_test( const GLcontext *ctx,
-                  GLuint n, CONST GLchan rgba[][4], GLubyte mask[] )
+_old_alpha_test( const GLcontext *ctx,
+		 GLuint n, CONST GLchan rgba[][4], GLubyte mask[] )
 {
    GLuint i;
-   GLchan ref = ctx->Color.AlphaRef;
+   const GLchan ref = ctx->Color.AlphaRef;
 
    /* switch cases ordered from most frequent to less frequent */
    switch (ctx->Color.AlphaFunc) {
diff --git a/src/mesa/swrast/s_alpha.h b/src/mesa/swrast/s_alpha.h
index 5338df58ae..ed60a9b552 100644
--- a/src/mesa/swrast/s_alpha.h
+++ b/src/mesa/swrast/s_alpha.h
@@ -1,4 +1,4 @@
-/* $Id: s_alpha.h,v 1.3 2001/03/12 00:48:41 gareth Exp $ */
+/* $Id: s_alpha.h,v 1.4 2002/01/21 18:12:34 brianp Exp $ */
 
 /*
  * Mesa 3-D graphics library
@@ -34,9 +34,14 @@
 
 
 extern GLint
-_mesa_alpha_test( const GLcontext *ctx, GLuint n,
-                  CONST GLchan rgba[][4], GLubyte mask[] );
+_old_alpha_test( const GLcontext *ctx, GLuint n,
+		 CONST GLchan rgba[][4], GLubyte mask[] );
+extern GLint
+_mesa_alpha_test( const GLcontext *ctx, struct sw_span *span,
+                  CONST GLchan rgba[][4]);
+
+#endif
+
 
 
 
-#endif
diff --git a/src/mesa/swrast/s_depth.c b/src/mesa/swrast/s_depth.c
index b892ffabb3..5a7fc4b4ed 100644
--- a/src/mesa/swrast/s_depth.c
+++ b/src/mesa/swrast/s_depth.c
@@ -1,10 +1,10 @@
-/* $Id: s_depth.c,v 1.10 2001/12/17 04:54:35 brianp Exp $ */
+/* $Id: s_depth.c,v 1.11 2002/01/21 18:12:34 brianp Exp $ */
 
 /*
  * Mesa 3-D graphics library
- * Version:  3.5
+ * Version:  4.1
  *
- * Copyright (C) 1999-2001  Brian Paul   All Rights Reserved.
+ * Copyright (C) 1999-2002  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"),
@@ -587,7 +587,7 @@ _mesa_depth_test_span( GLcontext *ctx, struct sw_span *span)
       ASSERT(swrast->Driver.WriteDepthSpan);
       (*swrast->Driver.WriteDepthSpan)(ctx, span->end, span->x, span->y, zbuffer, span->mask);
       if (passed < span->end)
-         span->write_all = GL_FALSE;
+         span->writeAll = GL_FALSE;
       return passed;
    }
    else {
@@ -602,7 +602,7 @@ _mesa_depth_test_span( GLcontext *ctx, struct sw_span *span)
          passed = depth_test_span32(ctx, span->end, span->x, span->y, zptr, span->depth, span->mask);
       }
       if (passed < span->end)
-         span->write_all = GL_FALSE;
+         span->writeAll = GL_FALSE;
       return passed;
    }
 }
diff --git a/src/mesa/swrast/s_fog.c b/src/mesa/swrast/s_fog.c
index 4441141bdd..5a8ac878cd 100644
--- a/src/mesa/swrast/s_fog.c
+++ b/src/mesa/swrast/s_fog.c
@@ -1,4 +1,4 @@
-/* $Id: s_fog.c,v 1.16 2001/12/18 04:06:46 brianp Exp $ */
+/* $Id: s_fog.c,v 1.17 2002/01/21 18:12:34 brianp Exp $ */
 
 /*
  * Mesa 3-D graphics library
@@ -38,7 +38,7 @@
 
 
 
-/*
+/**
  * Used to convert current raster distance to a fog factor in [0,1].
  */
 GLfloat
@@ -70,7 +70,7 @@ _mesa_z_to_fogfactor(GLcontext *ctx, GLfloat z)
 
 
 
-/*
+/**
  * Apply fog to a span of RGBA pixels.
  * Input:  ctx  -
  *         span - where span->fog and span->fogStep have to be set.
@@ -102,7 +102,40 @@ _mesa_fog_rgba_pixels( const GLcontext *ctx, struct sw_span *span,
    }
 }
 
-/*
+
+/**
+ * Apply fog given in an array to RGBA pixels.
+ * Input:  ctx  -
+ *         span - 
+ *         fog  - array of fog factors in [0,1]
+ *         red, green, blue, alpha - pixel colors
+ * Output:  red, green, blue, alpha - fogged pixel colors
+ */
+void
+_mesa_fog_rgba_pixels_with_array( const GLcontext *ctx, struct sw_span *span,
+				  const GLfloat fog[], GLchan rgba[][4] )
+{
+   GLuint i;
+   GLchan rFog, gFog, bFog;
+
+   ASSERT(fog != NULL);
+   ASSERT(ctx->Fog.Enabled);
+   ASSERT(span->filledColor == GL_TRUE);
+
+   UNCLAMPED_FLOAT_TO_CHAN(rFog, ctx->Fog.Color[RCOMP]);
+   UNCLAMPED_FLOAT_TO_CHAN(gFog, ctx->Fog.Color[GCOMP]);
+   UNCLAMPED_FLOAT_TO_CHAN(bFog, ctx->Fog.Color[BCOMP]);
+
+   for (i = span->start; i < span->end; i++) {
+      const GLfloat f = fog[i];
+      const GLfloat g = 1.0F - f;
+      rgba[i][RCOMP] = (GLchan) (f * rgba[i][RCOMP] + g * rFog);
+      rgba[i][GCOMP] = (GLchan) (f * rgba[i][GCOMP] + g * gFog);
+      rgba[i][BCOMP] = (GLchan) (f * rgba[i][BCOMP] + g * bFog);
+   }
+}
+
+/**
  * Apply fog to an array of RGBA pixels.
  * Input:  n - number of pixels
  *         fog - array of fog factors in [0,1]
@@ -132,7 +165,7 @@ _old_fog_rgba_pixels( const GLcontext *ctx,
 }
 
 
-/*
+/**
  * Apply fog to a span of color index pixels.
  * Input:  ctx  -
  *         span - where span->fog and span->fogStep have to be set.
@@ -158,7 +191,33 @@ _mesa_fog_ci_pixels( const GLcontext *ctx, struct sw_span *span,
    }
 }
 
-/*
+
+/**
+ * Apply fog given in an array to a span of color index pixels.
+ * Input:  ctx  -
+ *         span - 
+ *         fog  - array of fog factors in [0,1]
+ *         index - pixel color indexes
+ * Output:  index - fogged pixel color indexes
+ */
+void
+_mesa_fog_ci_pixels_with_array( const GLcontext *ctx, struct sw_span *span,
+				const GLfloat fog[], GLuint index[] )
+{
+   GLuint idx = (GLuint) ctx->Fog.Index;
+   GLuint i;
+
+   ASSERT(fog != NULL);
+   ASSERT(ctx->Fog.Enabled);
+   ASSERT(span->filledColor == GL_TRUE);
+
+   for (i = span->start; i < span->end; i++) {
+      const GLfloat f = CLAMP(fog[i], 0.0F, 1.0F);
+      index[i] = (GLuint) ((GLfloat) index[i] + (1.0F - f) * idx);
+   }
+}
+
+/**
  * Apply fog to an array of color index pixels.
  * Input:  n - number of pixels
  *         fog - array of fog factors in [0,1]
@@ -180,7 +239,7 @@ _old_fog_ci_pixels( const GLcontext *ctx,
 
 
 
-/*
+/**
  * Calculate fog factors (in [0,1]) from window z values
  * Input:  n - number of pixels
  *         z - array of integer depth values
@@ -321,7 +380,7 @@ compute_fog_factors_from_z( const GLcontext *ctx,
 }
 
 
-/*
+/**
  * Apply fog to a span of RGBA pixels.
  * Input:  ctx  -
  *         span - where span->depth has to be filled.
@@ -341,10 +400,11 @@ _mesa_depth_fog_rgba_pixels(const GLcontext *ctx, struct sw_span *span,
    ASSERT(span->filledColor == GL_TRUE);
 
    compute_fog_factors_from_z(ctx, span->end, span->depth, fogFact );
-   _old_fog_rgba_pixels( ctx, span->end, fogFact, rgba );
+   _mesa_fog_rgba_pixels_with_array( ctx, span, fogFact, rgba );
 }
 
-/*
+
+/**
  * Apply fog to an array of RGBA pixels.
  * Input:  n - number of pixels
  *         z - array of integer depth values
@@ -362,7 +422,7 @@ _old_depth_fog_rgba_pixels( const GLcontext *ctx,
 }
 
 
-/*
+/**
  * Apply fog to a span of color index pixels.
  * Input:  ctx  -
  *         span - where span->depth has to be filled.
@@ -382,11 +442,11 @@ _mesa_depth_fog_ci_pixels( const GLcontext *ctx, struct sw_span *span,
    ASSERT(span->filledColor == GL_TRUE);
 
    compute_fog_factors_from_z(ctx, span->end, span->depth, fogFact );
-   _old_fog_ci_pixels( ctx, span->end, fogFact, index );
+   _mesa_fog_ci_pixels_with_array( ctx, span, fogFact, index );
 }
 
 
-/*
+/**
  * Apply fog to an array of color index pixels.
  * Input:  n - number of pixels
  *         z - array of integer depth values
diff --git a/src/mesa/swrast/s_fog.h b/src/mesa/swrast/s_fog.h
index 8db6495d01..10f1b923b3 100644
--- a/src/mesa/swrast/s_fog.h
+++ b/src/mesa/swrast/s_fog.h
@@ -1,4 +1,4 @@
-/* $Id: s_fog.h,v 1.6 2001/12/17 04:54:35 brianp Exp $ */
+/* $Id: s_fog.h,v 1.7 2002/01/21 18:12:34 brianp Exp $ */
 
 /*
  * Mesa 3-D graphics library
@@ -44,11 +44,18 @@ _old_fog_rgba_pixels( const GLcontext *ctx,
 extern void
 _mesa_fog_rgba_pixels( const GLcontext *ctx, struct sw_span *span,
 		       GLchan rgba[][4]);
+extern void
+_mesa_fog_rgba_pixels_with_array( const GLcontext *ctx, struct sw_span *span,
+				  const GLfloat fog[], GLchan rgba[][4] );
+
 
 extern void
 _mesa_fog_ci_pixels( const GLcontext *ctx, struct sw_span *span,
 		     GLuint indx[]);
 extern void
+_mesa_fog_ci_pixels_with_array( const GLcontext *ctx, struct sw_span *span,
+				const GLfloat fog[], GLuint index[] );
+extern void
 _old_fog_ci_pixels( const GLcontext *ctx,
 		    GLuint n, const GLfloat fog[],
 		    GLuint indx[] );
diff --git a/src/mesa/swrast/s_span.c b/src/mesa/swrast/s_span.c
index c00dd9f6b2..fce8d33c97 100644
--- a/src/mesa/swrast/s_span.c
+++ b/src/mesa/swrast/s_span.c
@@ -1,4 +1,4 @@
-/* $Id: s_span.c,v 1.22 2002/01/16 16:00:03 brianp Exp $ */
+/* $Id: s_span.c,v 1.23 2002/01/21 18:12:34 brianp Exp $ */
 
 /*
  * Mesa 3-D graphics library
@@ -105,7 +105,7 @@ stipple_polygon_span( GLcontext *ctx, struct sw_span *span)
          m = highbit;
       }
    }
-   span->write_all = GL_FALSE;
+   span->writeAll = GL_FALSE;
 }
 
 
@@ -179,7 +179,7 @@ clip_span( GLcontext *ctx, struct sw_span *span)
       }
       else {
          /* partially off left side */
-	 span->write_all = GL_FALSE;
+	 span->writeAll = GL_FALSE;
          BZERO(span->mask, -x * sizeof(GLubyte));
 	 return GL_TRUE;
       }
@@ -488,7 +488,7 @@ _old_write_rgba_span( GLcontext *ctx, GLuint n, GLint x, GLint y,
 
    /* Do the alpha test */
    if (ctx->Color.AlphaEnabled) {
-      if (_mesa_alpha_test( ctx, n, (const GLchan (*)[4]) rgba, mask ) == 0) {
+      if (_old_alpha_test( ctx, n, (const GLchan (*)[4]) rgba, mask ) == 0) {
 	 return;
       }
       write_all = GL_FALSE;
@@ -575,7 +575,7 @@ _old_write_rgba_span( GLcontext *ctx, GLuint n, GLint x, GLint y,
  */
 void
 _mesa_write_index_span( GLcontext *ctx,	struct sw_span *span,
-			GLenum primitive )
+			const GLfloat fog[MAX_WIDTH], GLenum primitive)
 {
    const GLuint modBits = FOG_BIT | BLEND_BIT | MASKING_BIT | LOGIC_OP_BIT;
    GLuint indexBackup[MAX_WIDTH];
@@ -659,8 +659,9 @@ _mesa_write_index_span( GLcontext *ctx,	struct sw_span *span,
    }
 
    if (ctx->Fog.Enabled) {
-     /* Is this the right 'if' ?? */
-     if ((span->activeMask & SPAN_FOG)  &&  !swrast->_PreferPixelFog)
+     if (fog != NULL  &&  !swrast->_PreferPixelFog)
+       _mesa_fog_ci_pixels_with_array( ctx, span, fog, index);
+     else if ((span->activeMask & SPAN_FOG)  &&  !swrast->_PreferPixelFog)
        _mesa_fog_ci_pixels( ctx, span, index);
      else
        _mesa_depth_fog_ci_pixels( ctx, span, index);
@@ -791,7 +792,6 @@ _mesa_write_monoindex_span( GLcontext *ctx, struct sw_span *span,
       }
 
       if (ctx->Fog.Enabled) {
-	 /* Is this the right 'if' ?? */
 	 if ((span->activeMask & SPAN_FOG)  &&  !swrast->_PreferPixelFog)
  	    _mesa_fog_ci_pixels( ctx, span, indexes );
  	 else
@@ -853,7 +853,7 @@ _mesa_write_monoindex_span( GLcontext *ctx, struct sw_span *span,
  */
 void
 _mesa_write_rgba_span( GLcontext *ctx, struct sw_span *span,
-                       GLenum primitive )
+		       const GLfloat fog[MAX_WIDTH], GLenum primitive)
 {
    const GLuint modBits = FOG_BIT | BLEND_BIT | MASKING_BIT |
                           LOGIC_OP_BIT | TEXTURE_BIT;
@@ -898,10 +898,9 @@ _mesa_write_rgba_span( GLcontext *ctx, struct sw_span *span,
 
    /* Do the alpha test */
    if (ctx->Color.AlphaEnabled) {
-      if (_mesa_alpha_test( ctx, span->end, (const GLchan (*)[4]) rgba, span->mask ) == 0) {
+      if (_mesa_alpha_test( ctx, span, (const GLchan (*)[4]) rgba) == 0) {
 	 return;
       }
-      span->write_all = GL_FALSE;
    }
 
    /* I have to think where to put this!! */
@@ -943,8 +942,9 @@ _mesa_write_rgba_span( GLcontext *ctx, struct sw_span *span,
 
    /* Per-pixel fog */
    if (ctx->Fog.Enabled) {
-      /* Is this the right 'if' ?? */
-      if ((span->activeMask & SPAN_FOG)  &&  !swrast->_PreferPixelFog)
+      if (fog != NULL  &&  !swrast->_PreferPixelFog)
+	 _mesa_fog_rgba_pixels_with_array( ctx, span, fog, rgba);
+      else if ((span->activeMask & SPAN_FOG)  &&  !swrast->_PreferPixelFog)
          _mesa_fog_rgba_pixels( ctx, span, rgba );
       else
          _mesa_depth_fog_rgba_pixels( ctx, span, rgba );
@@ -986,12 +986,12 @@ _mesa_write_rgba_span( GLcontext *ctx, struct sw_span *span,
       /* write pixels */
       (*swrast->Driver.WriteRGBASpan)( ctx, span->end, span->x, span->y,
                                  (const GLchan (*)[4]) rgba,
-                                 span->write_all ? ((const GLubyte *) NULL) : span->mask );
+                                 span->writeAll ? ((const GLubyte *) NULL) : span->mask );
 
       if (swrast->_RasterMask & ALPHABUF_BIT) {
          _mesa_write_alpha_span( ctx, span->end, span->x, span->y,
                                  (const GLchan (*)[4]) rgba,
-                                 span->write_all ? ((const GLubyte *) NULL) : span->mask );
+                                 span->writeAll ? ((const GLubyte *) NULL) : span->mask );
       }
    }
 }
@@ -1036,13 +1036,13 @@ _mesa_write_monocolor_span( GLcontext *ctx, struct sw_span *span,
 
    /* Do the alpha test */
    if (ctx->Color.AlphaEnabled) {
+      SW_SPAN_SET_FLAG(span->filledAlpha);
       for (i = 0; i < span->end; i++) {
          rgba[i][ACOMP] = color[ACOMP];
       }
-      if (_mesa_alpha_test( ctx, span->end, (const GLchan (*)[4])rgba, span->mask ) == 0) {
+      if (_mesa_alpha_test( ctx, span, (const GLchan (*)[4])rgba) == 0) {
 	 return;
       }
-      span->write_all = GL_FALSE;
    }
 
    /* I have to think where to put this!! */
@@ -1103,8 +1103,7 @@ _mesa_write_monocolor_span( GLcontext *ctx, struct sw_span *span,
 
       /* Per-pixel fog */
       if (ctx->Fog.Enabled) {
-	/* Is this the right 'if' ?? */
-	if ((span->activeMask & SPAN_FOG)  &&  !swrast->_PreferPixelFog)
+	 if ((span->activeMask & SPAN_FOG)  &&  !swrast->_PreferPixelFog)
 	    _mesa_fog_rgba_pixels( ctx, span, rgba );
 	 else
 	    _mesa_depth_fog_rgba_pixels( ctx, span, rgba );
@@ -1144,11 +1143,11 @@ _mesa_write_monocolor_span( GLcontext *ctx, struct sw_span *span,
          /* write pixels */
          (*swrast->Driver.WriteRGBASpan)( ctx, span->end, span->x, span->y,
                                 (const GLchan (*)[4]) rgba,
-                                 span->write_all ? ((const GLubyte *) NULL) : span->mask );
+                                 span->writeAll ? ((const GLubyte *) NULL) : span->mask );
          if (swrast->_RasterMask & ALPHABUF_BIT) {
             _mesa_write_alpha_span( ctx, span->end, span->x, span->y,
                                  (const GLchan (*)[4]) rgba,
-                                 span->write_all ? ((const GLubyte *) NULL) : span->mask );
+                                 span->writeAll ? ((const GLubyte *) NULL) : span->mask );
          }
       }
    }
@@ -1170,8 +1169,9 @@ _mesa_write_monocolor_span( GLcontext *ctx, struct sw_span *span,
       else {
          (*swrast->Driver.WriteMonoRGBASpan)( ctx, span->end, span->x, span->y, color, span->mask );
          if (swrast->_RasterMask & ALPHABUF_BIT) {
-            _mesa_write_mono_alpha_span( ctx, span->end, span->x, span->y, (GLchan) color[ACOMP],
-                                 span->write_all ? ((const GLubyte *) NULL) : span->mask );
+            _mesa_write_mono_alpha_span( ctx, span->end, span->x, span->y,
+                                         (GLchan) color[ACOMP],
+                                 span->writeAll ? ((const GLubyte *) NULL) : span->mask );
          }
       }
    }
@@ -1219,7 +1219,7 @@ add_colors(CONST struct sw_span *span, GLchan rgba[][4])
  */
 void
 _mesa_write_texture_span( GLcontext *ctx, struct sw_span *span,
-			  const GLfloat fog[], GLenum primitive )
+			  const GLfloat fog[MAX_WIDTH], GLenum primitive )
 {
    const GLuint colorMask = *((GLuint *) ctx->Color.ColorMask);
    GLchan rgbaBackup[MAX_WIDTH][4];
@@ -1265,10 +1265,9 @@ _mesa_write_texture_span( GLcontext *ctx, struct sw_span *span,
       _swrast_texture_fragments( ctx, 0, span, rgba );
 
       /* Do the alpha test */
-      if (_mesa_alpha_test( ctx, span->end, (const GLchan (*)[4]) rgba, span->mask ) == 0) {
+      if (_mesa_alpha_test( ctx, span, (const GLchan (*)[4]) rgba ) == 0) {
          return;
       }
-      span->write_all = GL_FALSE;
    }
 
    if (ctx->Stencil.Enabled) {
@@ -1301,9 +1300,10 @@ _mesa_write_texture_span( GLcontext *ctx, struct sw_span *span,
    
    /* Per-pixel fog */
    if (ctx->Fog.Enabled) {
-      /* Is this the right 'if' ?? */
-      if ((span->activeMask & SPAN_FOG)  &&  !swrast->_PreferPixelFog)
-	 _old_fog_rgba_pixels( ctx, span->end, fog, rgba );
+      if (fog != NULL && !swrast->_PreferPixelFog)
+	 _mesa_fog_rgba_pixels_with_array( ctx, span, fog, rgba);
+      else if ((span->activeMask & SPAN_FOG)  &&  !swrast->_PreferPixelFog)
+	 _mesa_fog_rgba_pixels( ctx, span, rgba );
       else
 	 _mesa_depth_fog_rgba_pixels(ctx, span, rgba);
    }
@@ -1337,14 +1337,15 @@ _mesa_write_texture_span( GLcontext *ctx, struct sw_span *span,
          _mesa_mask_rgba_span( ctx, span->end, span->x, span->y, rgba );
       }
 
-      (*swrast->Driver.WriteRGBASpan)( ctx, span->end, span->x, span->y, (const GLchan (*)[4])rgba,
-				    span->write_all ? NULL : span->mask );
+      (*swrast->Driver.WriteRGBASpan)( ctx, span->end, span->x, span->y,
+                                       (const GLchan (*)[4]) rgba,
+                                       span->writeAll ? NULL : span->mask );
       if (swrast->_RasterMask & ALPHABUF_BIT) {
-         _mesa_write_alpha_span( ctx, span->end, span->x, span->y, (const GLchan (*)[4]) rgba,
-                                 span->write_all ? NULL : span->mask );
+         _mesa_write_alpha_span( ctx, span->end, span->x, span->y,
+                                 (const GLchan (*)[4]) rgba,
+                                 span->writeAll ? NULL : span->mask );
       }
    }
-
 }
 
 
@@ -1391,10 +1392,9 @@ masked_texture_span( GLcontext *ctx, struct sw_span *span)
    /* Texture with alpha test */
    if (ctx->Color.AlphaEnabled) {
       /* Do the alpha test */
-      if (_mesa_alpha_test( ctx, span->end, (const GLchan (*)[4]) rgba, span->mask ) == 0) {
+      if (_mesa_alpha_test( ctx, span, (const GLchan (*)[4]) rgba ) == 0) {
          return;
       }
-      span->write_all = GL_FALSE;
       
       /* Depth test usually in 'rasterize_span' but if alpha test
          needed, we have to wait for that test before depth test can
@@ -1459,11 +1459,13 @@ masked_texture_span( GLcontext *ctx, struct sw_span *span)
          _mesa_mask_rgba_span( ctx, span->end, span->x, span->y, rgba );
       }
 
-      (*swrast->Driver.WriteRGBASpan)( ctx, span->end, span->x, span->y, (const GLchan (*)[4])rgba,
-				    span->write_all ? NULL : span->mask );
+      (*swrast->Driver.WriteRGBASpan)( ctx, span->end, span->x, span->y,
+                                       (const GLchan (*)[4]) rgba,
+				       span->writeAll ? NULL : span->mask );
       if (swrast->_RasterMask & ALPHABUF_BIT) {
-         _mesa_write_alpha_span( ctx, span->end, span->x, span->y, (const GLchan (*)[4]) rgba,
-                                 span->write_all ? NULL : span->mask );
+         _mesa_write_alpha_span( ctx, span->end, span->x, span->y,
+                                 (const GLchan (*)[4]) rgba,
+                                 span->writeAll ? NULL : span->mask );
       }
    }
 }
@@ -1500,10 +1502,10 @@ masked_multitexture_span( GLcontext *ctx, struct sw_span *span)
    /* Texture with alpha test */
    if (ctx->Color.AlphaEnabled) {
       /* Do the alpha test */
-      if (_mesa_alpha_test( ctx, span->end, (const GLchan (*)[4])rgba, span->mask ) == 0) {
+      if (_mesa_alpha_test( ctx, span, (const GLchan (*)[4])rgba ) == 0) {
          return;
       }
-      span->write_all = GL_FALSE;
+
       /* Depth test usually in 'rasterize_span' but if alpha test
          needed, we have to wait for that test before depth test can
          be done. */
@@ -1550,7 +1552,8 @@ masked_multitexture_span( GLcontext *ctx, struct sw_span *span)
 #endif
 
    if (swrast->_RasterMask & MULTI_DRAW_BIT) {
-      multi_write_rgba_span( ctx, span->end, span->x, span->y, (const GLchan (*)[4]) rgba, span->mask );
+      multi_write_rgba_span( ctx, span->end, span->x, span->y,
+                             (const GLchan (*)[4]) rgba, span->mask );
    }
    else {
       /* normal: write to exactly one buffer */
@@ -1570,11 +1573,13 @@ masked_multitexture_span( GLcontext *ctx, struct sw_span *span)
          _mesa_mask_rgba_span( ctx, span->end, span->x, span->y, rgba );
       }
 
-      (*swrast->Driver.WriteRGBASpan)( ctx, span->end, span->x, span->y, (const GLchan (*)[4])rgba,
-                                    span->write_all ? NULL : span->mask );
+      (*swrast->Driver.WriteRGBASpan)( ctx, span->end, span->x, span->y,
+                                       (const GLchan (*)[4])rgba,
+                                       span->writeAll ? NULL : span->mask );
       if (swrast->_RasterMask & ALPHABUF_BIT) {
-         _mesa_write_alpha_span( ctx, span->end, span->x, span->y, (const GLchan (*)[4])rgba,
-                                 span->write_all ? NULL : span->mask );
+         _mesa_write_alpha_span( ctx, span->end, span->x, span->y,
+                                 (const GLchan (*)[4])rgba,
+                                 span->writeAll ? NULL : span->mask );
       }
    }
 }
@@ -1655,8 +1660,8 @@ _mesa_rasterize_span(GLcontext *ctx, struct sw_span *span)
    }
 
    if (span->activeMask & SPAN_RGBA) {
-      ASSERT(span->filledColor == GL_FALSE);
       SW_SPAN_SET_FLAG(span->filledColor);
+      SW_SPAN_SET_FLAG(span->filledAlpha);
       if (span->activeMask & SPAN_FLAT) {
          GLuint i;
          GLchan color[4];
@@ -1696,7 +1701,7 @@ _mesa_rasterize_span(GLcontext *ctx, struct sw_span *span)
    }
 
    if (span->activeMask & SPAN_SPEC) {
-     SW_SPAN_SET_FLAG(span->filledSpecular);
+      SW_SPAN_SET_FLAG(span->filledSpecular);
       if (span->activeMask & SPAN_FLAT) {
          const GLchan r = FixedToChan(span->specRed);
          const GLchan g = FixedToChan(span->specGreen);
@@ -1993,7 +1998,7 @@ _old_write_texture_span( GLcontext *ctx, GLuint n, GLint x, GLint y,
                                  (CONST GLchan (*)[4]) rgba, rgba );
 
       /* Do the alpha test */
-      if (_mesa_alpha_test( ctx, n, (const GLchan (*)[4]) rgba, mask ) == 0) {
+      if (_old_alpha_test( ctx, n, (const GLchan (*)[4]) rgba, mask ) == 0) {
          return;
       }
       write_all = GL_FALSE;
@@ -2149,7 +2154,7 @@ _old_write_multitexture_span( GLcontext *ctx, GLuint n, GLint x, GLint y,
                                     (CONST GLchan (*)[4]) rgbaIn, rgba );
 
       /* Do the alpha test */
-      if (_mesa_alpha_test( ctx, n, (const GLchan (*)[4])rgba, mask ) == 0) {
+      if (_old_alpha_test( ctx, n, (const GLchan (*)[4])rgba, mask ) == 0) {
          return;
       }
       write_all = GL_FALSE;
diff --git a/src/mesa/swrast/s_span.h b/src/mesa/swrast/s_span.h
index 326d02415a..ce67c6c761 100644
--- a/src/mesa/swrast/s_span.h
+++ b/src/mesa/swrast/s_span.h
@@ -1,4 +1,4 @@
-/* $Id: s_span.h,v 1.10 2002/01/16 16:00:04 brianp Exp $ */
+/* $Id: s_span.h,v 1.11 2002/01/21 18:12:34 brianp Exp $ */
 
 /*
  * Mesa 3-D graphics library
@@ -47,7 +47,7 @@ _old_write_rgba_span( GLcontext *ctx, GLuint n, GLint x, GLint y,
 
 void
 _mesa_write_index_span( GLcontext *ctx,	struct sw_span *span,
-			GLenum primitive);
+			const GLfloat fog[MAX_WIDTH], GLenum primitive);
 
 extern void
 _mesa_write_monoindex_span( GLcontext *ctx, struct sw_span *span,
@@ -55,7 +55,7 @@ _mesa_write_monoindex_span( GLcontext *ctx, struct sw_span *span,
 
 extern void
 _mesa_write_rgba_span( GLcontext *ctx, struct sw_span *span,
-                       GLenum primitive );
+		       const GLfloat fog[MAX_WIDTH], GLenum primitive);
 
 extern void
 _mesa_write_monocolor_span( GLcontext *ctx, struct sw_span *span,
@@ -63,7 +63,7 @@ _mesa_write_monocolor_span( GLcontext *ctx, struct sw_span *span,
 
 extern void
 _mesa_write_texture_span( GLcontext *ctx, struct sw_span *span,
-			  const GLfloat fog[], GLenum primitive );
+			  const GLfloat fog[MAX_WIDTH], GLenum primitive );
 
 
 extern void
diff --git a/src/mesa/swrast/s_stencil.c b/src/mesa/swrast/s_stencil.c
index a28721bbc1..6e69fc8d70 100644
--- a/src/mesa/swrast/s_stencil.c
+++ b/src/mesa/swrast/s_stencil.c
@@ -1,4 +1,4 @@
-/* $Id: s_stencil.c,v 1.14 2002/01/08 14:56:51 brianp Exp $ */
+/* $Id: s_stencil.c,v 1.15 2002/01/21 18:12:34 brianp Exp $ */
 
 /*
  * Mesa 3-D graphics library
@@ -586,7 +586,7 @@ _mesa_stencil_and_ztest_span(GLcontext *ctx, struct sw_span *span)
 					span->y, stencil, span->mask );
    }
    
-   span->write_all = GL_FALSE;
+   span->writeAll = GL_FALSE;
    
    return result;
 }
diff --git a/src/mesa/swrast/s_triangle.c b/src/mesa/swrast/s_triangle.c
index f4c1643d6b..06d1c31308 100644
--- a/src/mesa/swrast/s_triangle.c
+++ b/src/mesa/swrast/s_triangle.c
@@ -1,4 +1,4 @@
-/* $Id: s_triangle.c,v 1.47 2002/01/16 16:00:04 brianp Exp $ */
+/* $Id: s_triangle.c,v 1.48 2002/01/21 18:12:34 brianp Exp $ */
 
 /*
  * Mesa 3-D graphics library
@@ -107,7 +107,7 @@ static void smooth_ci_triangle( GLcontext *ctx,
       span.color.index[i] = FixedToInt(span.index);			\
       span.index += span.indexStep;					\
    }									\
-   _mesa_write_index_span(ctx, &span, GL_POLYGON);
+   _mesa_write_index_span(ctx, &span, NULL, GL_POLYGON);
 
 #include "s_tritemp.h"
 }
@@ -155,6 +155,7 @@ static void smooth_rgba_triangle( GLcontext *ctx,
 #define RENDER_SPAN( span )					\
    GLuint i;				        	        \
    SW_SPAN_SET_FLAG(span.filledColor);			        \
+   SW_SPAN_SET_FLAG(span.filledAlpha);			        \
    for (i = 0; i < span.end; i++) {				\
       span.color.rgba[i][RCOMP] = FixedToChan(span.red);	\
       span.color.rgba[i][GCOMP] = FixedToChan(span.green);	\
@@ -165,7 +166,7 @@ static void smooth_rgba_triangle( GLcontext *ctx,
       span.blue += span.blueStep;				\
       span.alpha += span.alphaStep;				\
    }								\
-   _mesa_write_rgba_span(ctx, &span, GL_POLYGON);
+   _mesa_write_rgba_span(ctx, &span, NULL, GL_POLYGON);
 
 #include "s_tritemp.h"
 
@@ -192,7 +193,7 @@ static void simple_textured_triangle( GLcontext *ctx,
 #define SETUP_CODE							\
    SWcontext *swrast = SWRAST_CONTEXT(ctx);                             \
    struct gl_texture_object *obj = ctx->Texture.Unit[0].Current2D;	\
-   GLint b = obj->BaseLevel;						\
+   const GLint b = obj->BaseLevel;					\
    const GLfloat twidth = (GLfloat) obj->Image[b]->Width;		\
    const GLfloat theight = (GLfloat) obj->Image[b]->Height;		\
    const GLint twidth_log2 = obj->Image[b]->WidthLog2;			\
@@ -221,7 +222,8 @@ static void simple_textured_triangle( GLcontext *ctx,
       span.intTex[1] += span.intTexStep[1];				\
    }									\
    (*swrast->Driver.WriteRGBSpan)(ctx, span.end, span.x, span.y,	\
-                                  (CONST GLchan (*)[3]) span.color.rgb, NULL );
+                                  (CONST GLchan (*)[3]) span.color.rgb,	\
+                                  NULL );
 
 #include "s_tritemp.h"
 }
@@ -248,13 +250,13 @@ static void simple_z_textured_triangle( GLcontext *ctx,
 #define SETUP_CODE							\
    SWcontext *swrast = SWRAST_CONTEXT(ctx);                             \
    struct gl_texture_object *obj = ctx->Texture.Unit[0].Current2D;	\
-   GLint b = obj->BaseLevel;						\
-   GLfloat twidth = (GLfloat) obj->Image[b]->Width;			\
-   GLfloat theight = (GLfloat) obj->Image[b]->Height;			\
-   GLint twidth_log2 = obj->Image[b]->WidthLog2;			\
+   const GLint b = obj->BaseLevel;					\
+   const GLfloat twidth = (GLfloat) obj->Image[b]->Width;		\
+   const GLfloat theight = (GLfloat) obj->Image[b]->Height;		\
+   const GLint twidth_log2 = obj->Image[b]->WidthLog2;			\
    const GLchan *texture = (const GLchan *) obj->Image[b]->Data;	\
-   GLint smask = obj->Image[b]->Width - 1;				\
-   GLint tmask = obj->Image[b]->Height - 1;				\
+   const GLint smask = obj->Image[b]->Width - 1;			\
+   const GLint tmask = obj->Image[b]->Height - 1;			\
    if (!texture) {							\
       /* this shouldn't happen */					\
       return;								\
@@ -286,7 +288,8 @@ static void simple_z_textured_triangle( GLcontext *ctx,
       span.z += span.zStep;						\
    }									\
    (*swrast->Driver.WriteRGBSpan)(ctx, span.end, span.x, span.y,	\
-                                  (CONST GLchan (*)[3]) span.color.rgb, span.mask );
+                                  (CONST GLchan (*)[3]) span.color.rgb,	\
+                                  span.mask );
 
 #include "s_tritemp.h"
 }
@@ -552,7 +555,7 @@ affine_span(GLcontext *ctx, struct sw_span *span,
       }
       break;
    }
-   _mesa_write_rgba_span(ctx, span, GL_POLYGON);
+   _mesa_write_rgba_span(ctx, span, NULL, GL_POLYGON);
 
 #undef SPAN_NEAREST
 #undef SPAN_LINEAR
@@ -581,9 +584,9 @@ static void affine_textured_triangle( GLcontext *ctx,
    struct affine_info info;						\
    struct gl_texture_unit *unit = ctx->Texture.Unit+0;			\
    struct gl_texture_object *obj = unit->Current2D;			\
-   GLint b = obj->BaseLevel;						\
-   GLfloat twidth = (GLfloat) obj->Image[b]->Width;			\
-   GLfloat theight = (GLfloat) obj->Image[b]->Height;			\
+   const GLint b = obj->BaseLevel;					\
+   const GLfloat twidth = (GLfloat) obj->Image[b]->Width;		\
+   const GLfloat theight = (GLfloat) obj->Image[b]->Height;		\
    info.texture = (const GLchan *) obj->Image[b]->Data;			\
    info.twidth_log2 = obj->Image[b]->WidthLog2;				\
    info.smask = obj->Image[b]->Width - 1;				\
@@ -824,7 +827,7 @@ fast_persp_span(GLcontext *ctx, struct sw_span *span,
       break;
    }
    
-   _mesa_write_rgba_span(ctx, span, GL_POLYGON);
+   _mesa_write_rgba_span(ctx, span, NULL, GL_POLYGON);
 
 
 #undef SPAN_NEAREST
@@ -852,9 +855,9 @@ static void persp_textured_triangle( GLcontext *ctx,
 
 #define SETUP_CODE							\
    struct persp_info info;						\
-   struct gl_texture_unit *unit = ctx->Texture.Unit+0;			\
-   struct gl_texture_object *obj = unit->Current2D;			\
-   GLint b = obj->BaseLevel;						\
+   const struct gl_texture_unit *unit = ctx->Texture.Unit+0;		\
+   const struct gl_texture_object *obj = unit->Current2D;		\
+   const GLint b = obj->BaseLevel;					\
    info.texture = (const GLchan *) obj->Image[b]->Data;			\
    info.twidth_log2 = obj->Image[b]->WidthLog2;				\
    info.smask = obj->Image[b]->Width - 1;				\
@@ -932,22 +935,20 @@ static void general_textured_triangle( GLcontext *ctx,
    (void) fixedToDepthShift;
 
 #define RENDER_SPAN( span )						\
-   GLfloat fogSpan[MAX_WIDTH];						\
    GLuint i;								\
    SW_SPAN_SET_FLAG(span.filledColor);					\
+   SW_SPAN_SET_FLAG(span.filledAlpha);					\
    SW_SPAN_SET_FLAG(span.filledTex[0]);					\
    /* NOTE: we could just call rasterize_span() here instead */		\
    for (i = 0; i < span.end; i++) {					\
       GLdouble invQ = span.tex[0][3] ? (1.0 / span.tex[0][3]) : 1.0;	\
       span.depth[i] = FixedToDepth(span.z);				\
       span.z += span.zStep;						\
-      fogSpan[i] = span.fog;			          		\
-      span.fog += span.fogStep;					\
       span.color.rgba[i][RCOMP] = FixedToChan(span.red);		\
       span.color.rgba[i][GCOMP] = FixedToChan(span.green);		\
       span.color.rgba[i][BCOMP] = FixedToChan(span.blue);		\
       span.color.rgba[i][ACOMP] = FixedToChan(span.alpha);		\
-      span.red += span.redStep;					\
+      span.red += span.redStep;						\
       span.green += span.greenStep;					\
       span.blue += span.blueStep;					\
       span.alpha += span.alphaStep;					\
@@ -959,8 +960,7 @@ static void general_textured_triangle( GLcontext *ctx,
       span.tex[0][2] += span.texStep[0][2];				\
       span.tex[0][3] += span.texStep[0][3];				\
    }									\
-   _mesa_write_texture_span( ctx, &span, fogSpan,			\
-                             GL_POLYGON );
+   _mesa_write_texture_span( ctx, &span, NULL, GL_POLYGON );
 
 #include "s_tritemp.h"
 }
@@ -1124,7 +1124,7 @@ static void occlusion_zless_triangle( GLcontext *ctx,
 #define RENDER_SPAN( span )				\
    GLuint i;						\
    for (i = 0; i < span.end; i++) {			\
-      GLdepth z = FixedToDepth(span.z);		\
+      GLdepth z = FixedToDepth(span.z);			\
       if (z < zRow[i]) {				\
          ctx->OcclusionResult = GL_TRUE;		\
          return;					\
diff --git a/src/mesa/swrast/s_zoom.c b/src/mesa/swrast/s_zoom.c
index b331be1306..26567fa3c8 100644
--- a/src/mesa/swrast/s_zoom.c
+++ b/src/mesa/swrast/s_zoom.c
@@ -1,10 +1,10 @@
-/* $Id: s_zoom.c,v 1.7 2001/12/17 04:54:35 brianp Exp $ */
+/* $Id: s_zoom.c,v 1.8 2002/01/21 18:12:34 brianp Exp $ */
 
 /*
  * Mesa 3-D graphics library
- * Version:  3.5
+ * Version:  4.1
  *
- * Copyright (C) 1999-2001  Brian Paul   All Rights Reserved.
+ * Copyright (C) 1999-2002  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"),
@@ -26,6 +26,8 @@
 
 #include "glheader.h"
 #include "macros.h"
+#include "mem.h"
+#include "colormac.h"
 
 #include "s_context.h"
 #include "s_span.h"
@@ -33,6 +35,36 @@
 #include "s_zoom.h"
 
 
+#ifdef DEBUG
+
+#define SAVE_SPAN(span)    struct sw_span tmp_span = (span);
+
+#define RESTORE_SPAN(span)						\
+{									\
+   GLint i;								\
+   for (i=tmp_span.start; i<tmp_span.end; i++) {			\
+      if (tmp_span.color.rgba[i][RCOMP] !=				\
+          (span).color.rgba[i][RCOMP] ||	 			\
+          tmp_span.color.rgba[i][GCOMP] != 				\
+	  (span).color.rgba[i][GCOMP] || 				\
+	  tmp_span.color.rgba[i][BCOMP] != 				\
+	  (span).color.rgba[i][BCOMP]) {				\
+         fprintf(stderr, "glZoom: Color-span changed in subfunction.");	\
+      }									\
+      if (tmp_span.depth[i] != (span).depth[i]) {			\
+         fprintf(stderr, "glZoom: Depth-span changed in subfunction.");	\
+      }									\
+   }									\
+   (span) = tmp_span;							\
+}
+
+#else /* DEBUG not defined */
+
+#define SAVE_SPAN(span)    GLint start = (span).start, end = (span).end;
+#define RESTORE_SPAN(span) (span).start = start, (span).end = end;      \
+			   (span).writeAll = GL_TRUE;
+
+#endif /* DEBUG */
 
 /*
  * Write a span of pixels to the frame buffer while applying a pixel zoom.
@@ -49,25 +81,31 @@ _mesa_write_zoomed_rgba_span( GLcontext *ctx,
                               const GLfloat *fog,
                               CONST GLchan rgba[][4], GLint y0 )
 {
-   GLint m;
-   GLint r0, r1, row, r;
-   GLint i, j, skipcol;
-   GLchan zrgba[MAX_WIDTH][4];  /* zoomed pixel colors */
-   GLdepth zdepth[MAX_WIDTH];  /* zoomed depth values */
+   GLint r0, r1, row;
+   GLint i, j;
+   struct sw_span dstspan;
    GLfloat zfog[MAX_WIDTH];  /* zoomed fog values */
-   GLint maxwidth = MIN2( ctx->DrawBuffer->Width, MAX_WIDTH );
-   const GLuint *srcRGBA32 = (const GLuint *) rgba;
-   GLuint *dstRGBA32 = (GLuint *) zrgba;
+   const GLint maxwidth = MIN2( ctx->DrawBuffer->Width, MAX_WIDTH );
+
+   SW_SPAN_RESET (dstspan);
 
    /* compute width of output row */
-   m = (GLint) ABSF( n * ctx->Pixel.ZoomX );
-   if (m==0) {
+   dstspan.end = (GLint) ABSF( n * ctx->Pixel.ZoomX );
+   if (dstspan.end == 0) {
       return;
    }
+   /*here ok or better latter? like it was before */
+   else if (dstspan.end > maxwidth) {
+     dstspan.end = maxwidth;
+   }
+
    if (ctx->Pixel.ZoomX<0.0) {
       /* adjust x coordinate for left/right mirroring */
-      x = x - m;
+      dstspan.x = x - dstspan.end;
    }
+   else
+     dstspan.x = x;
+
 
    /* compute which rows to draw */
    row = y-y0;
@@ -93,47 +131,53 @@ _mesa_write_zoomed_rgba_span( GLcontext *ctx,
    }
 
    /* check if left edge is outside window */
-   skipcol = 0;
-   if (x<0) {
-      skipcol = -x;
-      m += x;
+   if (dstspan.x < 0) {
+      dstspan.start = -x;
    }
+
    /* make sure span isn't too long or short */
-   if (m>maxwidth) {
+   /*   if (m>maxwidth) {
       m = maxwidth;
-   }
-   else if (m<=0) {
+      }*/
+
+   if (dstspan.end <= dstspan.start) {
       return;
    }
 
-   ASSERT( m <= MAX_WIDTH );
+   ASSERT( dstspan.end <= MAX_WIDTH );
 
    /* zoom the span horizontally */
    if (ctx->Pixel.ZoomX==-1.0F) {
+      SW_SPAN_SET_FLAG(dstspan.filledColor);
+      SW_SPAN_SET_FLAG(dstspan.filledAlpha);
+      SW_SPAN_SET_FLAG(dstspan.filledDepth);
       /* n==m */
-      for (j=0;j<m;j++) {
-         i = n - (j+skipcol) - 1;
-         dstRGBA32[j] = srcRGBA32[i];
-         zdepth[j] = z[i];
+      for (j=dstspan.start; j<dstspan.end; j++) {
+         i = n - j - 1;
+	 COPY_CHAN4(dstspan.color.rgba[j], rgba[i]);
+         dstspan.depth[j] = z[i];
       }
       if (fog && ctx->Fog.Enabled) {
-	 for (j=0;j<m;j++) {
-	    i = n - (j+skipcol) - 1;
+	 for (j=dstspan.start; j<dstspan.end; j++) {
+	    i = n - j - 1;
 	    zfog[j] = fog[i];
 	 }
       }
    }
    else {
-      GLfloat xscale = 1.0F / ctx->Pixel.ZoomX;
-      for (j=0;j<m;j++) {
-         i = (GLint) ((j+skipcol) * xscale);
+      const GLfloat xscale = 1.0F / ctx->Pixel.ZoomX;
+      SW_SPAN_SET_FLAG(dstspan.filledColor);
+      SW_SPAN_SET_FLAG(dstspan.filledAlpha);
+      SW_SPAN_SET_FLAG(dstspan.filledDepth);
+      for (j=dstspan.start; j<dstspan.end; j++) {
+         i = (GLint) (j * xscale);
          if (i<0)  i = n + i - 1;
-         dstRGBA32[j] = srcRGBA32[i];
-         zdepth[j] = z[i];
+	 COPY_CHAN4(dstspan.color.rgba[j], rgba[i]);
+         dstspan.depth[j] = z[i];
       }
       if (fog && ctx->Fog.Enabled) {
-	 for (j=0;j<m;j++) {
-	    i = (GLint) ((j+skipcol) * xscale);
+	 for (j=dstspan.start; j<dstspan.end; j++) {
+	    i = (GLint) (j * xscale);
 	    if (i<0)  i = n + i - 1;
 	    zfog[j] = fog[i];
 	 }
@@ -141,9 +185,13 @@ _mesa_write_zoomed_rgba_span( GLcontext *ctx,
    }
 
    /* write the span */
-   for (r=r0; r<r1; r++) {
-      _old_write_rgba_span( ctx, m, x+skipcol, r, zdepth,
-			  (fog ? zfog : 0), zrgba, NULL, GL_BITMAP );
+   for (dstspan.y = r0; dstspan.y < r1; dstspan.y++) {
+      SAVE_SPAN(dstspan);
+      _mesa_write_rgba_span(ctx, &dstspan, (fog ? zfog : NULL), GL_BITMAP);
+      RESTORE_SPAN(dstspan);
+      /* problem here: "dstspan" can change inside
+	 "_mesa_write_rgba_span". Best solution: make copy "tmpspan"
+	 and give to function, but too slow */
    }
 }
 
diff --git a/src/mesa/swrast/s_zoom.h b/src/mesa/swrast/s_zoom.h
index 940970d7ab..2891d305e7 100644
--- a/src/mesa/swrast/s_zoom.h
+++ b/src/mesa/swrast/s_zoom.h
@@ -1,10 +1,10 @@
-/* $Id: s_zoom.h,v 1.5 2001/05/03 22:13:32 brianp Exp $ */
+/* $Id: s_zoom.h,v 1.6 2002/01/21 18:12:34 brianp Exp $ */
 
 /*
  * Mesa 3-D graphics library
- * Version:  3.5
+ * Version:  4.1
  *
- * Copyright (C) 1999-2001  Brian Paul   All Rights Reserved.
+ * Copyright (C) 1999-2002  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"),
@@ -30,7 +30,7 @@
 
 
 #include "mtypes.h"
-
+#include "swrast.h"
 
 extern void
 _mesa_write_zoomed_rgba_span( GLcontext *ctx,
diff --git a/src/mesa/swrast/swrast.h b/src/mesa/swrast/swrast.h
index edc78b19b3..5ee58bfcf1 100644
--- a/src/mesa/swrast/swrast.h
+++ b/src/mesa/swrast/swrast.h
@@ -1,4 +1,4 @@
-/* $Id: swrast.h,v 1.14 2002/01/10 16:54:29 brianp Exp $ */
+/* $Id: swrast.h,v 1.15 2002/01/21 18:12:34 brianp Exp $ */
 
 /*
  * Mesa 3-D graphics library
@@ -33,7 +33,6 @@
 #include "mtypes.h"
 
 
-
 /* The software rasterizer now uses this format for vertices.  Thus a
  * 'RasterSetup' stage or other translation is required between the
  * tnl module and the swrast rasterization functions.  This serves to
@@ -98,9 +97,15 @@ typedef struct {
 
 struct sw_span {
    GLint x, y;
-   GLuint start, end;  /* start=first pixel in span, end=last pixel in span*/
-                       /* only end is used until now.(end was before called count) */
+
+   /* only need to process pixels between start <= i < end */
+   GLuint start, end;
+
+   /* This flag indicates that only a part of the span is visible */
+   GLboolean writeAll;
+
    GLuint activeMask;  /* OR of the SPAN_* flags */
+
 #if CHAN_TYPE == GL_FLOAT
    GLfloat red, redStep;
    GLfloat green, greenStep;
@@ -127,29 +132,33 @@ struct sw_span {
    GLfloat rho[MAX_TEXTURE_UNITS];
    GLfloat texWidth[MAX_TEXTURE_UNITS], texHeight[MAX_TEXTURE_UNITS];
 
-   GLboolean write_all;   /* This flag indicates that only a part of */
-                          /*the span is visible. */
-#ifdef DEBUG
-   GLboolean filledDepth, filledMask, filledAlpha;
-   GLboolean filledColor, filledSpecular;
-   GLboolean filledLambda[MAX_TEXTURE_UNITS], filledTex[MAX_TEXTURE_UNITS];
-   GLboolean testedDepth, testedAlpha;
-#endif
-   /* The interpolated fragment values */
+   /**
+    * Arrays of fragment values.  These will either be computed from the
+    * x/xStep values above or loadd from glDrawPixels, etc.
+    */
    GLdepth depth[MAX_WIDTH];
    union {
       GLchan rgb[MAX_WIDTH][3];
       GLchan rgba[MAX_WIDTH][4];
       GLuint index[MAX_WIDTH];
    } color;
-   GLchan specular[MAX_WIDTH][4];
-   GLint   itexcoords[MAX_WIDTH][2];                       /* s, t    */
-   GLfloat texcoords[MAX_TEXTURE_UNITS][MAX_WIDTH][4];     /* s, t, r */
+   GLchan  specular[MAX_WIDTH][4];
+   GLint   itexcoords[MAX_WIDTH][2];           /* Integer texture (s, t) */
+   /* Texture (s,t,r).  4th component only used for pixel texture */
+   GLfloat texcoords[MAX_TEXTURE_UNITS][MAX_WIDTH][4];
    GLfloat lambda[MAX_TEXTURE_UNITS][MAX_WIDTH];
    GLfloat coverage[MAX_WIDTH];
    GLubyte mask[MAX_WIDTH];
+
+#ifdef DEBUG
+   GLboolean filledDepth, filledMask, filledAlpha;
+   GLboolean filledColor, filledSpecular;
+   GLboolean filledLambda[MAX_TEXTURE_UNITS], filledTex[MAX_TEXTURE_UNITS];
+   GLboolean testedDepth, testedAlpha;
+#endif
 };
 
+
 #ifdef DEBUG
 #define SW_SPAN_SET_FLAG(flag) {ASSERT((flag) == GL_FALSE);(flag) = GL_TRUE;}
 #define SW_SPAN_RESET(span) {                                        \
@@ -160,10 +169,10 @@ struct sw_span {
 		MAX_TEXTURE_UNITS*sizeof(GLboolean));                \
          MEMSET((span).filledLambda, GL_FALSE,                       \
 		MAX_TEXTURE_UNITS*sizeof(GLboolean));                \
-         (span).start = 0; (span).write_all = GL_TRUE;}
+         (span).start = 0; (span).writeAll = GL_TRUE;}
 #else
 #define SW_SPAN_SET_FLAG(flag) ;
-#define SW_SPAN_RESET(span) {(span).start = 0;(span).write_all = GL_TRUE;}
+#define SW_SPAN_RESET(span) {(span).start = 0;(span).writeAll = GL_TRUE;}
 #endif
 
 struct swrast_device_driver;