Clean-up and optimize alpha test code.

Major clean-up of pixel zoom code.

7 files changed, 463 insertions, 557 deletions

diff --git a/src/mesa/swrast/s_alpha.c b/src/mesa/swrast/s_alpha.c
index 7ee0f1b118..d44bdb63eb 100644
--- a/src/mesa/swrast/s_alpha.c
+++ b/src/mesa/swrast/s_alpha.c
@@ -1,4 +1,4 @@
-/* $Id: s_alpha.c,v 1.7 2002/01/28 00:07:33 brianp Exp $ */
+/* $Id: s_alpha.c,v 1.8 2002/01/31 00:27:43 brianp Exp $ */
 
 /*
  * Mesa 3-D graphics library
@@ -32,6 +32,7 @@
 #include "mmath.h"
 
 #include "s_alpha.h"
+#include "s_context.h"
 
 
 /*
@@ -42,67 +43,174 @@
  *          1 = one or more pixels passed the alpha test.
  */
 GLint
-_mesa_alpha_test( const GLcontext *ctx, struct sw_span *span,
-                  CONST GLchan rgba[][4])
+_mesa_alpha_test( const GLcontext *ctx, struct sw_span *span )
 {
-   GLuint i;
+   const GLchan (*rgba)[4] = (const GLchan (*)[4]) span->color.rgba;
    const GLchan ref = ctx->Color.AlphaRef;
+   const GLuint n = span->end;
    GLubyte *mask = span->mask;
+   GLuint i;
 
-   ASSERT(span->arrayMask & SPAN_RGBA);
-
-   /* 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;
+   if (span->arrayMask & SPAN_RGBA) {
+      /* Use the array values */
+      switch (ctx->Color.AlphaFunc) {
+         case GL_LESS:
+            for (i = 0; i < n; i++)
+               mask[i] &= (rgba[i][ACOMP] < ref);
+            break;
+         case GL_LEQUAL:
+            for (i = 0; i < n; i++)
+               mask[i] &= (rgba[i][ACOMP] <= ref);
+            break;
+         case GL_GEQUAL:
+            for (i = 0; i < n; i++)
+               mask[i] &= (rgba[i][ACOMP] >= ref);
+            break;
+         case GL_GREATER:
+            for (i = 0; i < n; i++)
+               mask[i] &= (rgba[i][ACOMP] > ref);
+            break;
+         case GL_NOTEQUAL:
+            for (i = 0; i < n; i++)
+               mask[i] &= (rgba[i][ACOMP] != ref);
+            break;
+         case GL_EQUAL:
+            for (i = 0; i < n; i++)
+               mask[i] &= (rgba[i][ACOMP] == ref);
+            break;
+         case GL_ALWAYS:
+            /* do nothing */
+            return 1;
+         case GL_NEVER:
+            /* caller should check for zero! */
+            span->writeAll = GL_FALSE;
+            return 0;
+         default:
+            _mesa_problem( ctx, "Invalid alpha test in _mesa_alpha_test" );
+            return 0;
+      }
+   }
+   else {
+      /* Use the interpolation values */
+#if CHAN_TYPE == GL_FLOAT
+      const GLfloat alphaStep = span->alphaStep;
+      GLfloat alpha = span->alpha;
+      ASSERT(span->interpMask & SPAN_RGBA);
+      switch (ctx->Color.AlphaFunc) {
+         case GL_LESS:
+            for (i = 0; i < n; i++) {
+               mask[i] &= (alpha < ref);
+               alpha += alphaStep;
+            }
+            break;
+         case GL_LEQUAL:
+            for (i = 0; i < n; i++) {
+               mask[i] &= (alpha <= ref);
+               alpha += alphaStep;
+            }
+            break;
+         case GL_GEQUAL:
+            for (i = 0; i < n; i++) {
+               mask[i] &= (alpha >= ref);
+               alpha += alphaStep;
+            }
+            break;
+         case GL_GREATER:
+            for (i = 0; i < n; i++) {
+               mask[i] &= (alpha > ref);
+               alpha += alphaStep;
+            }
+            break;
+         case GL_NOTEQUAL:
+            for (i = 0; i < n; i++) {
+               mask[i] &= (alpha != ref);
+               alpha += alphaStep;
+            }
+            break;
+         case GL_EQUAL:
+            for (i = 0; i < n; i++) {
+               mask[i] &= (alpha == ref);
+               alpha += alphaStep;
+            }
+            break;
+         case GL_ALWAYS:
+            /* do nothing */
+            return 1;
+         case GL_NEVER:
+            /* caller should check for zero! */
+            span->writeAll = GL_FALSE;
+            return 0;
+         default:
+            _mesa_problem( ctx, "Invalid alpha test in gl_alpha_test" );
+            return 0;
+      }
+#else
+      /* 8 or 16-bit channel interpolation */
+      const GLfixed alphaStep = span->alphaStep;
+      GLfixed alpha = span->alpha;
+      ASSERT(span->interpMask & SPAN_RGBA);
+      switch (ctx->Color.AlphaFunc) {
+         case GL_LESS:
+            for (i = 0; i < n; i++) {
+               mask[i] &= (FixedToChan(alpha) < ref);
+               alpha += alphaStep;
+            }
+            break;
+         case GL_LEQUAL:
+            for (i = 0; i < n; i++) {
+               mask[i] &= (FixedToChan(alpha) <= ref);
+               alpha += alphaStep;
+            }
+            break;
+         case GL_GEQUAL:
+            for (i = 0; i < n; i++) {
+               mask[i] &= (FixedToChan(alpha) >= ref);
+               alpha += alphaStep;
+            }
+            break;
+         case GL_GREATER:
+            for (i = 0; i < n; i++) {
+               mask[i] &= (FixedToChan(alpha) > ref);
+               alpha += alphaStep;
+            }
+            break;
+         case GL_NOTEQUAL:
+            for (i = 0; i < n; i++) {
+               mask[i] &= (FixedToChan(alpha) != ref);
+               alpha += alphaStep;
+            }
+            break;
+         case GL_EQUAL:
+            for (i = 0; i < n; i++) {
+               mask[i] &= (FixedToChan(alpha) == ref);
+               alpha += alphaStep;
+            }
+            break;
+         case GL_ALWAYS:
+            /* do nothing */
+            return 1;
+         case GL_NEVER:
+            /* caller should check for zero! */
+            span->writeAll = GL_FALSE;
+            return 0;
+         default:
+            _mesa_problem( ctx, "Invalid alpha test in gl_alpha_test" );
+            return 0;
+      }
+#endif /* CHAN_TYPE */
    }
 
 #if 0
    /* XXXX This causes conformance failures!!!! */
    while ((span->start <= span->end)  &&
-	  (mask[span->start] == 0))
+          (mask[span->start] == 0))
      span->start ++;
 
    while ((span->end >= span->start)  &&
-	  (mask[span->end] == 0))
+          (mask[span->end] == 0))
      span->end --;
 #endif
+
    span->writeAll = GL_FALSE;
 
    if (span->start >= span->end)
@@ -122,7 +230,7 @@ _mesa_alpha_test( const GLcontext *ctx, struct sw_span *span,
  */
 GLint
 _old_alpha_test( const GLcontext *ctx,
-		 GLuint n, CONST GLchan rgba[][4], GLubyte mask[] )
+                 GLuint n, CONST GLchan rgba[][4], GLubyte mask[] )
 {
    GLuint i;
    const GLchan ref = ctx->Color.AlphaRef;
diff --git a/src/mesa/swrast/s_alpha.h b/src/mesa/swrast/s_alpha.h
index ed60a9b552..29eae7dca3 100644
--- a/src/mesa/swrast/s_alpha.h
+++ b/src/mesa/swrast/s_alpha.h
@@ -1,10 +1,10 @@
-/* $Id: s_alpha.h,v 1.4 2002/01/21 18:12:34 brianp Exp $ */
+/* $Id: s_alpha.h,v 1.5 2002/01/31 00:27:43 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"),
@@ -36,9 +36,9 @@
 extern GLint
 _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]);
+_mesa_alpha_test( const GLcontext *ctx, struct sw_span *span );
 
 #endif
 
diff --git a/src/mesa/swrast/s_copypix.c b/src/mesa/swrast/s_copypix.c
index 7d2bca38f4..296b193e10 100644
--- a/src/mesa/swrast/s_copypix.c
+++ b/src/mesa/swrast/s_copypix.c
@@ -1,4 +1,4 @@
-/* $Id: s_copypix.c,v 1.31 2002/01/28 04:25:56 brianp Exp $ */
+/* $Id: s_copypix.c,v 1.32 2002/01/31 00:27:43 brianp Exp $ */
 
 /*
  * Mesa 3-D graphics library
@@ -272,10 +272,12 @@ copy_conv_rgba_pixels(GLcontext *ctx, GLint srcx, GLint srcy,
 		       (const GLchan (*)[4])span.color.rgba, NULL );
       }
       else if (zoom) {
-         _mesa_write_zoomed_rgba_span( ctx, width, destx, dy, span.zArray,
-                                       span.fogArray,
-                                       (const GLchan (*)[4])span.color.rgba,
-                                       desty);
+         span.x = destx;
+         span.y = dy;
+         span.end = width;
+         _mesa_write_zoomed_rgba_span(ctx, &span, 
+                                     (CONST GLchan (*)[4])span.color.rgba,
+                                     desty);
       }
       else {
          span.x = destx;
@@ -511,10 +513,12 @@ copy_rgba_pixels(GLcontext *ctx, GLint srcx, GLint srcy,
 				       (const GLchan (*)[4])span.color.rgba, NULL );
       }
       else if (zoom) {
-         _mesa_write_zoomed_rgba_span( ctx, width, destx, dy, span.zArray,
-                                       span.fogArray,
-                                       (const GLchan (*)[4]) span.color.rgba,
-                                       desty);
+         span.x = destx;
+         span.y = dy;
+         span.end = width;
+         _mesa_write_zoomed_rgba_span(ctx, &span,
+                                     (CONST GLchan (*)[4]) span.color.rgba,
+                                     desty);
       }
       else {
          span.x = destx;
@@ -629,17 +633,13 @@ static void copy_ci_pixels( GLcontext *ctx,
          _mesa_map_ci( ctx, width, span.color.index );
       }
 
-      if (zoom) {
-         _mesa_write_zoomed_index_span(ctx, width, destx, dy,
-                                       span.zArray, span.fogArray,
-                                       span.color.index, desty );
-      }
-      else {
-         span.x = destx;
-         span.y = dy;
-         span.end = width;
+      span.x = destx;
+      span.y = dy;
+      span.end = width;
+      if (zoom)
+         _mesa_write_zoomed_index_span(ctx, &span, desty);
+      else
          _mesa_write_index_span(ctx, &span, GL_BITMAP);
-      }
    }
 
    /* Restore pixel source to be the draw buffer (for blending, etc) */
@@ -729,32 +729,22 @@ static void copy_depth_pixels( GLcontext *ctx, GLint srcx, GLint srcy,
          span.zArray[i] = (GLdepth) (CLAMP(d, 0.0F, 1.0F) * ctx->DepthMax);
       }
 
+      span.x = destx;
+      span.y = dy;
+      span.end = width;
       if (ctx->Visual.rgbMode) {
-         if (zoom) {
-            _mesa_write_zoomed_rgba_span( ctx, width, destx, dy, span.zArray,
-                                          span.fogArray,
+         if (zoom)
+            _mesa_write_zoomed_rgba_span( ctx, &span, 
                                           (const GLchan (*)[4])span.color.rgba,
                                           desty );
-         }
-         else {
-            span.x = destx;
-            span.y = dy;
-            span.end = width;
+         else
             _mesa_write_rgba_span(ctx, &span, GL_BITMAP);
-         }
       }
       else {
-         if (zoom) {
-            _mesa_write_zoomed_index_span( ctx, width, destx, dy,
-                                           span.zArray, span.fogArray,
-                                           span.color.index, desty );
-         }
-         else {
-            span.x = destx;
-            span.y = dy;
-            span.end = width;
+         if (zoom)
+            _mesa_write_zoomed_index_span( ctx, &span, desty );
+         else
             _mesa_write_index_span(ctx, &span, GL_BITMAP);
-         }
       }
    }
 
diff --git a/src/mesa/swrast/s_drawpix.c b/src/mesa/swrast/s_drawpix.c
index 94dea3d510..5ce9469aac 100644
--- a/src/mesa/swrast/s_drawpix.c
+++ b/src/mesa/swrast/s_drawpix.c
@@ -1,4 +1,4 @@
-/* $Id: s_drawpix.c,v 1.27 2002/01/28 00:07:33 brianp Exp $ */
+/* $Id: s_drawpix.c,v 1.28 2002/01/31 00:27:43 brianp Exp $ */
 
 /*
  * Mesa 3-D graphics library
@@ -103,13 +103,20 @@ fast_draw_pixels(GLcontext *ctx, GLint x, GLint y,
 {
    SWcontext *swrast = SWRAST_CONTEXT(ctx);
    const struct gl_pixelstore_attrib *unpack = &ctx->Unpack;
-   GLchan rgb[MAX_WIDTH][3];
-   GLchan rgba[MAX_WIDTH][4];
+   struct sw_span span;
+
+   INIT_SPAN(span);
+   span.arrayMask |= SPAN_RGBA;
 
    if (!ctx->Current.RasterPosValid) {
       return GL_TRUE;      /* no-op */
    }
 
+   if (ctx->Depth.Test)
+      _mesa_span_default_z(ctx, &span);
+   if (ctx->Fog.Enabled)
+      _mesa_span_default_fog(ctx, &span);
+
    if ((SWRAST_CONTEXT(ctx)->_RasterMask&(~(SCISSOR_BIT|WINCLIP_BIT)))==0
        && ctx->Texture._ReallyEnabled == 0
        && unpack->Alignment == 1
@@ -232,8 +239,11 @@ fast_draw_pixels(GLcontext *ctx, GLint x, GLint y,
                /* with zooming */
                GLint row;
                for (row=0; row<drawHeight; row++) {
-                  _mesa_write_zoomed_rgba_span(ctx, drawWidth, destX, destY,
-                                  zSpan, 0, (CONST GLchan (*)[4]) src, zoomY0);
+                  span.x = destX;
+                  span.y = destY;
+                  span.end = drawWidth;
+                  _mesa_write_zoomed_rgba_span(ctx, &span,
+                                            (CONST GLchan (*)[4]) src, zoomY0);
                   src += rowLength * 4;
                   destY++;
                }
@@ -269,8 +279,11 @@ fast_draw_pixels(GLcontext *ctx, GLint x, GLint y,
                /* with zooming */
                GLint row;
                for (row=0; row<drawHeight; row++) {
-                  _mesa_write_zoomed_rgb_span(ctx, drawWidth, destX, destY,
-                                  zSpan, 0, (CONST GLchan (*)[3]) src, zoomY0);
+                  span.x = destX;
+                  span.y = destY;
+                  span.end = drawWidth;
+                  _mesa_write_zoomed_rgb_span(ctx, &span, 
+                                            (CONST GLchan (*)[3]) src, zoomY0);
                   src += rowLength * 3;
                   destY++;
                }
@@ -290,12 +303,12 @@ fast_draw_pixels(GLcontext *ctx, GLint x, GLint y,
                for (row=0; row<drawHeight; row++) {
                   GLint i;
 		  for (i=0;i<drawWidth;i++) {
-                     rgb[i][0] = src[i];
-                     rgb[i][1] = src[i];
-                     rgb[i][2] = src[i];
+                     span.color.rgb[i][0] = src[i];
+                     span.color.rgb[i][1] = src[i];
+                     span.color.rgb[i][2] = src[i];
 		  }
                   (*swrast->Driver.WriteRGBSpan)(ctx, drawWidth, destX, destY,
-                                              (CONST GLchan (*)[3]) rgb, NULL);
+                                   (CONST GLchan (*)[3]) span.color.rgb, NULL);
                   src += rowLength;
                   destY++;
                }
@@ -307,13 +320,13 @@ fast_draw_pixels(GLcontext *ctx, GLint x, GLint y,
                for (row=0; row<drawHeight; row++) {
                   GLint i;
                   for (i=0;i<drawWidth;i++) {
-                     rgb[i][0] = src[i];
-                     rgb[i][1] = src[i];
-                     rgb[i][2] = src[i];
+                     span.color.rgb[i][0] = src[i];
+                     span.color.rgb[i][1] = src[i];
+                     span.color.rgb[i][2] = src[i];
                   }
                   destY--;
                   (*swrast->Driver.WriteRGBSpan)(ctx, drawWidth, destX, destY,
-                                              (CONST GLchan (*)[3]) rgb, NULL);
+                                              (CONST GLchan (*)[3]) span.color.rgb, NULL);
                   src += rowLength;
                }
             }
@@ -324,12 +337,15 @@ fast_draw_pixels(GLcontext *ctx, GLint x, GLint y,
                for (row=0; row<drawHeight; row++) {
                   GLint i;
 		  for (i=0;i<drawWidth;i++) {
-                     rgb[i][0] = src[i];
-                     rgb[i][1] = src[i];
-                     rgb[i][2] = src[i];
+                     span.color.rgb[i][0] = src[i];
+                     span.color.rgb[i][1] = src[i];
+                     span.color.rgb[i][2] = src[i];
 		  }
-                  _mesa_write_zoomed_rgb_span(ctx, drawWidth, destX, destY,
-                                  zSpan, 0, (CONST GLchan (*)[3]) rgb, zoomY0);
+                  span.x = destX;
+                  span.y = destY;
+                  span.end = drawWidth;
+                  _mesa_write_zoomed_rgb_span(ctx, &span,
+                                 (CONST GLchan (*)[3]) span.color.rgb, zoomY0);
                   src += rowLength;
                   destY++;
                }
@@ -350,13 +366,13 @@ fast_draw_pixels(GLcontext *ctx, GLint x, GLint y,
                   GLint i;
                   GLchan *ptr = src;
 		  for (i=0;i<drawWidth;i++) {
-                     rgba[i][0] = *ptr;
-                     rgba[i][1] = *ptr;
-                     rgba[i][2] = *ptr++;
-                     rgba[i][3] = *ptr++;
+                     span.color.rgba[i][0] = *ptr;
+                     span.color.rgba[i][1] = *ptr;
+                     span.color.rgba[i][2] = *ptr++;
+                     span.color.rgba[i][3] = *ptr++;
 		  }
                   (*swrast->Driver.WriteRGBASpan)(ctx, drawWidth, destX, destY,
-                                             (CONST GLchan (*)[4]) rgba, NULL);
+                                             (CONST GLchan (*)[4]) span.color.rgba, NULL);
                   src += rowLength*2;
                   destY++;
                }
@@ -369,14 +385,14 @@ fast_draw_pixels(GLcontext *ctx, GLint x, GLint y,
                   GLint i;
                   GLchan *ptr = src;
                   for (i=0;i<drawWidth;i++) {
-                     rgba[i][0] = *ptr;
-                     rgba[i][1] = *ptr;
-                     rgba[i][2] = *ptr++;
-                     rgba[i][3] = *ptr++;
+                     span.color.rgba[i][0] = *ptr;
+                     span.color.rgba[i][1] = *ptr;
+                     span.color.rgba[i][2] = *ptr++;
+                     span.color.rgba[i][3] = *ptr++;
                   }
                   destY--;
                   (*swrast->Driver.WriteRGBASpan)(ctx, drawWidth, destX, destY,
-                                             (CONST GLchan (*)[4]) rgba, NULL);
+                                             (CONST GLchan (*)[4]) span.color.rgba, NULL);
                   src += rowLength*2;
                }
             }
@@ -388,13 +404,16 @@ fast_draw_pixels(GLcontext *ctx, GLint x, GLint y,
                   GLchan *ptr = src;
                   GLint i;
 		  for (i=0;i<drawWidth;i++) {
-                     rgba[i][0] = *ptr;
-                     rgba[i][1] = *ptr;
-                     rgba[i][2] = *ptr++;
-                     rgba[i][3] = *ptr++;
+                     span.color.rgba[i][0] = *ptr;
+                     span.color.rgba[i][1] = *ptr;
+                     span.color.rgba[i][2] = *ptr++;
+                     span.color.rgba[i][3] = *ptr++;
 		  }
-                  _mesa_write_zoomed_rgba_span(ctx, drawWidth, destX, destY,
-                                 zSpan, 0, (CONST GLchan (*)[4]) rgba, zoomY0);
+                  span.x = destX;
+                  span.y = destY;
+                  span.end = drawWidth;
+                  _mesa_write_zoomed_rgba_span(ctx, &span,
+                               (CONST GLchan (*)[4]) span.color.rgba, zoomY0);
                   src += rowLength*2;
                   destY++;
                }
@@ -411,10 +430,9 @@ fast_draw_pixels(GLcontext *ctx, GLint x, GLint y,
                GLint row;
                for (row=0; row<drawHeight; row++) {
                   ASSERT(drawWidth < MAX_WIDTH);
-                  _mesa_map_ci8_to_rgba(ctx, drawWidth, src, rgba);
+                  _mesa_map_ci8_to_rgba(ctx, drawWidth, src, span.color.rgba);
                   (*swrast->Driver.WriteRGBASpan)(ctx, drawWidth, destX, destY,
-                                               (const GLchan (*)[4]) rgba,
-					       NULL);
+                                  (const GLchan (*)[4]) span.color.rgba, NULL);
                   src += rowLength;
                   destY++;
                }
@@ -425,11 +443,10 @@ fast_draw_pixels(GLcontext *ctx, GLint x, GLint y,
                GLint row;
                for (row=0; row<drawHeight; row++) {
                   ASSERT(drawWidth < MAX_WIDTH);
-                  _mesa_map_ci8_to_rgba(ctx, drawWidth, src, rgba);
+                  _mesa_map_ci8_to_rgba(ctx, drawWidth, src, span.color.rgba);
                   destY--;
                   (*swrast->Driver.WriteRGBASpan)(ctx, drawWidth, destX, destY,
-                                               (CONST GLchan (*)[4]) rgba,
-                                               NULL);
+                                 (CONST GLchan (*)[4]) span.color.rgba, NULL);
                   src += rowLength;
                }
                return GL_TRUE;
@@ -439,9 +456,12 @@ fast_draw_pixels(GLcontext *ctx, GLint x, GLint y,
                GLint row;
                for (row=0; row<drawHeight; row++) {
                   ASSERT(drawWidth < MAX_WIDTH);
-                  _mesa_map_ci8_to_rgba(ctx, drawWidth, src, rgba);
-                  _mesa_write_zoomed_rgba_span(ctx, drawWidth, destX, destY,
-                                 zSpan, 0, (CONST GLchan (*)[4]) rgba, zoomY0);
+                  _mesa_map_ci8_to_rgba(ctx, drawWidth, src, span.color.rgba);
+                  span.x = destX;
+                  span.y = destY;
+                  span.end = drawWidth;
+                  _mesa_write_zoomed_rgba_span(ctx, &span,
+                               (CONST GLchan (*)[4]) span.color.rgba, zoomY0);
                   src += rowLength;
                   destY++;
                }
@@ -510,17 +530,13 @@ draw_index_pixels( GLcontext *ctx, GLint x, GLint y,
                               span.color.index,
                               type, source, &ctx->Unpack,
                               ctx->_ImageTransferState);
-      if (zoom) {
-         _mesa_write_zoomed_index_span(ctx, drawWidth, x, y,
-                                       span.zArray, span.fogArray,
-                                       span.color.index, desty);
-      }
-      else {
-         span.x = x;
-         span.y = y;
-         span.end = drawWidth;
+      span.x = x;
+      span.y = y;
+      span.end = drawWidth;
+      if (zoom)
+         _mesa_write_zoomed_index_span(ctx, &span, desty);
+      else
          _mesa_write_index_span(ctx, &span, GL_BITMAP);
-      }
    }
 }
 
@@ -674,30 +690,21 @@ draw_depth_pixels( GLcontext *ctx, GLint x, GLint y,
             }
          }
 
+         span.x = x;
+         span.y = y;
+         span.end = drawWidth;
          if (ctx->Visual.rgbMode) {
-            if (zoom) {
-               _mesa_write_zoomed_rgba_span(ctx, width, x, y, span.zArray, 0,
-                                (const GLchan (*)[4]) span.color.rgba, desty);
-            }
-            else {
-               span.x = x;
-               span.y = y;
-               span.end = drawWidth;
+            if (zoom)
+               _mesa_write_zoomed_rgba_span(ctx, &span,
+                                 (const GLchan (*)[4]) span.color.rgba, desty);
+            else
                _mesa_write_rgba_span(ctx, &span, GL_BITMAP);
-            }
          }
          else {
-            if (zoom) {
-               _mesa_write_zoomed_index_span(ctx, drawWidth, x, y,
-                                             span.zArray, 0,
-                                             span.color.index, GL_BITMAP);
-            }
-            else {
-               span.x = x;
-               span.y = y;
-               span.end = drawWidth;
+            if (zoom)
+               _mesa_write_zoomed_index_span(ctx, &span, desty);
+            else
                _mesa_write_index_span(ctx, &span, GL_BITMAP);
-            }
          }
       }
    }
@@ -826,17 +833,10 @@ draw_rgba_pixels( GLcontext *ctx, GLint x, GLint y,
       for (row = 0; row < height; row++, y++) {
          const GLvoid *source = _mesa_image_address(unpack,
                   pixels, width, height, format, type, 0, row, 0);
-         /*         printf("Unpack f=0x%x t=0x%x\n", format, type);*/
          _mesa_unpack_chan_color_span(ctx, width, GL_RGBA,
                                       (GLchan *) span.color.rgba,
                                       format, type, source, unpack,
                                       transferOps);
-         if (0){
-            int k;
-            for (k = 0; k < width; k++)
-               printf("%02x ", span.color.rgba[k][3]);
-            printf("\n");
-         }
 
          if ((ctx->Pixel.MinMaxEnabled && ctx->MinMax.Sink) ||
              (ctx->Pixel.HistogramEnabled && ctx->Histogram.Sink))
@@ -852,8 +852,10 @@ draw_rgba_pixels( GLcontext *ctx, GLint x, GLint y,
                                  (CONST GLchan (*)[4]) span.color.rgba, NULL);
          }
          else if (zoom) {
-            _mesa_write_zoomed_rgba_span(ctx, width, x, y, span.zArray,
-                                span.fogArray,
+            span.x = x;
+            span.y = y;
+            span.end = width;
+            _mesa_write_zoomed_rgba_span(ctx, &span,
                                 (CONST GLchan (*)[4]) span.color.rgba, desty);
          }
          else {
diff --git a/src/mesa/swrast/s_span.c b/src/mesa/swrast/s_span.c
index f709494a7e..4266f085e2 100644
--- a/src/mesa/swrast/s_span.c
+++ b/src/mesa/swrast/s_span.c
@@ -1,4 +1,4 @@
-/* $Id: s_span.c,v 1.27 2002/01/28 04:25:56 brianp Exp $ */
+/* $Id: s_span.c,v 1.28 2002/01/31 00:27:43 brianp Exp $ */
 
 /*
  * Mesa 3-D graphics library
@@ -720,6 +720,7 @@ _mesa_write_rgba_span( GLcontext *ctx, struct sw_span *span,
    GLboolean monoColor;
 
    ASSERT((span->interpMask & span->arrayMask) == 0);
+   ASSERT((span->interpMask | span->arrayMask) & SPAN_RGBA);
 
    MEMSET(span->mask, 1, span->end);
    span->writeAll = GL_TRUE;
@@ -748,17 +749,9 @@ _mesa_write_rgba_span( GLcontext *ctx, struct sw_span *span,
       stipple_polygon_span(ctx, span);
    }
 
-   /* Now we may need to interpolate the colors */
-   if ((span->interpMask & SPAN_RGBA) && (span->arrayMask & SPAN_RGBA) == 0) {
-      interpolate_colors(ctx, span);
-      /* clear the bit - this allows the WriteMonoCISpan optimization below */
-      span->interpMask &= ~SPAN_RGBA;
-   }
-
    /* Do the alpha test */
    if (ctx->Color.AlphaEnabled) {
-      if (!_mesa_alpha_test(ctx, span,
-                            (const GLchan (*)[4]) span->color.rgba)) {
+      if (!_mesa_alpha_test(ctx, span)) {
          span->interpMask = origInterpMask;
          span->arrayMask = origArrayMask;
 	 return;
@@ -799,6 +792,13 @@ _mesa_write_rgba_span( GLcontext *ctx, struct sw_span *span,
       return;
    }
 
+   /* Now we may need to interpolate the colors */
+   if ((span->interpMask & SPAN_RGBA) && (span->arrayMask & SPAN_RGBA) == 0) {
+      interpolate_colors(ctx, span);
+      /* clear the bit - this allows the WriteMonoCISpan optimization below */
+      span->interpMask &= ~SPAN_RGBA;
+   }
+
    /* Fog */
    /* XXX try to simplify the fog code! */
    if (ctx->Fog.Enabled) {
@@ -919,11 +919,12 @@ _mesa_write_texture_span( GLcontext *ctx, struct sw_span *span,
    const GLuint origArrayMask = span->arrayMask;
 
    ASSERT((span->interpMask & span->arrayMask) == 0);
-
-   /*   printf("%s()  interp 0x%x  array 0x%x\n", __FUNCTION__, span->interpMask, span->arrayMask);*/
-
    ASSERT(ctx->Texture._ReallyEnabled);
 
+   /*
+   printf("%s()  interp 0x%x  array 0x%x\n", __FUNCTION__, span->interpMask, span->arrayMask);
+   */
+
    MEMSET(span->mask, 1, span->end);
    span->writeAll = GL_TRUE;
 
@@ -964,11 +965,9 @@ _mesa_write_texture_span( GLcontext *ctx, struct sw_span *span,
       _swrast_multitexture_fragments( ctx, span );
 
       /* Do the alpha test */
-      if (!_old_alpha_test(ctx, span->end,
-                           (CONST GLchan (*)[4]) span->color.rgba,
-                           span->mask)) {
+      if (!_mesa_alpha_test(ctx, span)) {
          span->arrayMask = origArrayMask;
-         return;
+	 return;
       }
    }
 
diff --git a/src/mesa/swrast/s_zoom.c b/src/mesa/swrast/s_zoom.c
index 516a5bb582..7a696256a6 100644
--- a/src/mesa/swrast/s_zoom.c
+++ b/src/mesa/swrast/s_zoom.c
@@ -1,4 +1,4 @@
-/* $Id: s_zoom.c,v 1.11 2002/01/28 03:42:28 brianp Exp $ */
+/* $Id: s_zoom.c,v 1.12 2002/01/31 00:27:43 brianp Exp $ */
 
 /*
  * Mesa 3-D graphics library
@@ -35,402 +35,222 @@
 #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.zArray[i] != (span).zArray[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.
- * This is only used by glDrawPixels and glCopyPixels.
- * Input:  n - number of pixels in input row
- *         x, y - destination of the span
- *         z - depth values for the span
- *         red, green, blue, alpha - array of colors
- *         y0 - location of first row in the image we're drawing.
+ * Helper function called from _mesa_write_zoomed_rgba/rgb/index_span().
  */
-void
-_mesa_write_zoomed_rgba_span( GLcontext *ctx,
-                              GLuint n, GLint x, GLint y, const GLdepth z[],
-                              const GLfloat *fog,
-                              CONST GLchan rgba[][4], GLint y0 )
+static void
+zoom_span( GLcontext *ctx, const struct sw_span *span,
+           const GLvoid *src, GLint y0, GLenum format )
 {
    GLint r0, r1, row;
+   GLint c0, c1, skipCol;
    GLint i, j;
-   const GLint maxwidth = MIN2( ctx->DrawBuffer->Width, MAX_WIDTH );
+   const GLint maxWidth = MIN2( ctx->DrawBuffer->Width, MAX_WIDTH );
+   GLchan rgbaSave[MAX_WIDTH][4];
+   GLuint indexSave[MAX_WIDTH];
    struct sw_span zoomed;
+   const GLchan (*rgba)[4] = (const GLchan (*)[4]) src;
+   const GLchan (*rgb)[3] = (const GLchan (*)[3]) src;
+   const GLuint *indexes = (const GLuint *) src;
 
    INIT_SPAN(zoomed);
-   zoomed.arrayMask |= SPAN_RGBA;
-
-   /* compute width of output row */
-   zoomed.end = (GLint) ABSF( n * ctx->Pixel.ZoomX );
-   if (zoomed.end == 0) {
+   if (format == GL_RGBA || format == GL_RGB) {
+      zoomed.z = span->z;
+      zoomed.zStep = span->z;
+      zoomed.fog = span->fog;
+      zoomed.fogStep = span->fogStep;
+      zoomed.interpMask = span->interpMask & ~SPAN_RGBA;
+      zoomed.arrayMask |= SPAN_RGBA;
+   }
+   else if (format == GL_COLOR_INDEX) {
+      zoomed.z = span->z;
+      zoomed.zStep = span->z;
+      zoomed.fog = span->fog;
+      zoomed.fogStep = span->fogStep;
+      zoomed.interpMask = span->interpMask & ~SPAN_INDEX;
+      zoomed.arrayMask |= SPAN_INDEX;
+   }
+
+   /*
+    * Compute which columns to draw: [c0, c1)
+    */
+   c0 = (GLint) span->x;
+   c1 = (GLint) (span->x + span->end * ctx->Pixel.ZoomX);
+   if (c0 == c1) {
       return;
    }
-   /*here ok or better latter? like it was before */
-   else if (zoomed.end > maxwidth) {
-     zoomed.end = maxwidth;
+   else if (c1 < c0) {
+      /* swap */
+      GLint ctmp = c1;
+      c1 = c0;
+      c0 = ctmp;
    }
-
-   if (ctx->Pixel.ZoomX<0.0) {
-      /* adjust x coordinate for left/right mirroring */
-      zoomed.x = x - zoomed.end;
+   if (c0 < 0) {
+      zoomed.x = 0;
+      zoomed.start = 0;
+      zoomed.end = c1;
+      skipCol = -c0;
    }
-   else
-     zoomed.x = x;
-
-
-   /* compute which rows to draw */
-   row = y-y0;
+   else {
+      zoomed.x = c0;
+      zoomed.start = 0;
+      zoomed.end = c1 - c0;
+      skipCol = 0;
+   }
+   if (zoomed.end > maxWidth)
+      zoomed.end = maxWidth;
+
+   /*
+    * Compute which rows to draw: [r0, r1)
+    */
+   row = span->y - y0;
    r0 = y0 + (GLint) (row * ctx->Pixel.ZoomY);
    r1 = y0 + (GLint) ((row+1) * ctx->Pixel.ZoomY);
-   if (r0==r1) {
+   if (r0 == r1) {
       return;
    }
-   else if (r1<r0) {
+   else if (r1 < r0) {
+      /* swap */
       GLint rtmp = r1;
       r1 = r0;
       r0 = rtmp;
    }
 
-   /* return early if r0...r1 is above or below window */
-   if (r0<0 && r1<0) {
-      /* below window */
+   ASSERT(r0 < r1);
+   ASSERT(c0 < c1);
+
+   /*
+    * Trivial clip rejection testing.
+    */
+   if (r1 < 0) /* below window */
       return;
-   }
-   if (r0>=ctx->DrawBuffer->Height && r1>=ctx->DrawBuffer->Height) {
-      /* above window */
+   if (r0 >= ctx->DrawBuffer->Height) /* above window */
       return;
-   }
-
-   /* check if left edge is outside window */
-   if (zoomed.x < 0) {
-      zoomed.start = -x;
-   }
-
-   /* make sure span isn't too long or short */
-   /*   if (m>maxwidth) {
-      m = maxwidth;
-      }*/
-
-   if (zoomed.end <= zoomed.start) {
+   if (c1 < 0) /* left of window */
+      return;
+   if (c0 >= ctx->DrawBuffer->Width) /* right of window */
       return;
-   }
-
-   ASSERT( zoomed.end <= MAX_WIDTH );
 
    /* zoom the span horizontally */
-   if (ctx->Pixel.ZoomX==-1.0F) {
-      /* n==m */
-      for (j=zoomed.start; j<zoomed.end; j++) {
-         i = n - j - 1;
-	 COPY_CHAN4(zoomed.color.rgba[j], rgba[i]);
-         zoomed.zArray[j] = z[i];
+   if (format == GL_RGBA) {
+      if (ctx->Pixel.ZoomX == -1.0F) {
+         /* common case */
+         for (j = zoomed.start; j < zoomed.end; j++) {
+            i = span->end - (j + skipCol) - 1;
+            COPY_CHAN4(zoomed.color.rgba[j], rgba[i]);
+         }
       }
-      if (fog && ctx->Fog.Enabled) {
-	 for (j=zoomed.start; j<zoomed.end; j++) {
-	    i = n - j - 1;
-	    zoomed.fogArray[j] = fog[i];
-	 }
+      else {
+         /* general solution */
+         const GLfloat xscale = 1.0F / ctx->Pixel.ZoomX;
+         for (j = zoomed.start; j < zoomed.end; j++) {
+            i = (GLint) ((j + skipCol) * xscale);
+            if (i < 0)
+               i = span->end + i - 1;
+            COPY_CHAN4(zoomed.color.rgba[j], rgba[i]);
+         }
       }
    }
-   else {
-      const GLfloat xscale = 1.0F / ctx->Pixel.ZoomX;
-      for (j=zoomed.start; j<zoomed.end; j++) {
-         i = (GLint) (j * xscale);
-         if (i<0)  i = n + i - 1;
-	 COPY_CHAN4(zoomed.color.rgba[j], rgba[i]);
-         zoomed.zArray[j] = z[i];
+   else if (format == GL_RGB) {
+      if (ctx->Pixel.ZoomX == -1.0F) {
+         /* common case */
+         for (j = zoomed.start; j < zoomed.end; j++) {
+            i = span->end - (j + skipCol) - 1;
+            zoomed.color.rgba[j][0] = rgb[i][0];
+            zoomed.color.rgba[j][1] = rgb[i][1];
+            zoomed.color.rgba[j][2] = rgb[i][2];
+            zoomed.color.rgba[j][3] = CHAN_MAX;
+         }
       }
-      if (fog && ctx->Fog.Enabled) {
-	 for (j=zoomed.start; j<zoomed.end; j++) {
-	    i = (GLint) (j * xscale);
-	    if (i<0)  i = n + i - 1;
-	    zoomed.fogArray[j] = fog[i];
-	 }
+      else {
+         /* general solution */
+         const GLfloat xscale = 1.0F / ctx->Pixel.ZoomX;
+         for (j = zoomed.start; j < zoomed.end; j++) {
+            i = (GLint) ((j + skipCol) * xscale);
+            if (i < 0)
+               i = span->end + i - 1;
+            zoomed.color.rgba[j][0] = rgb[i][0];
+            zoomed.color.rgba[j][1] = rgb[i][1];
+            zoomed.color.rgba[j][2] = rgb[i][2];
+            zoomed.color.rgba[j][3] = CHAN_MAX;
+         }
       }
    }
-
-   zoomed.arrayMask |= SPAN_Z;
-   if (fog)
-      zoomed.arrayMask |= SPAN_FOG;
-
-   /* write the span */
-   for (zoomed.y = r0; zoomed.y < r1; zoomed.y++) {
-      SAVE_SPAN(zoomed);
-      ASSERT((zoomed.interpMask & SPAN_RGBA) == 0);
-      _mesa_write_rgba_span(ctx, &zoomed, GL_BITMAP);
-      RESTORE_SPAN(zoomed);
-      /* problem here: "zoomed" can change inside
-	 "_mesa_write_rgba_span". Best solution: make copy "tmpspan"
-	 and give to function, but too slow */
-   }
-}
-
-
-
-void
-_mesa_write_zoomed_rgb_span( GLcontext *ctx,
-                             GLuint n, GLint x, GLint y, const GLdepth z[],
-                             const GLfloat *fog,
-                             CONST GLchan rgb[][3], GLint y0 )
-{
-   GLint m;
-   GLint r0, r1, row, r;
-   GLint i, j, skipcol;
-   GLint maxwidth = MIN2( ctx->DrawBuffer->Width, MAX_WIDTH );
-   struct sw_span zoomed;
-
-   INIT_SPAN(zoomed);
-   zoomed.arrayMask |= SPAN_RGBA;
-
-   if (fog && ctx->Fog.Enabled)
-      zoomed.arrayMask |= SPAN_FOG;
-
-
-   /* compute width of output row */
-   m = (GLint) ABSF( n * ctx->Pixel.ZoomX );
-   if (m==0) {
-      return;
-   }
-   if (ctx->Pixel.ZoomX<0.0) {
-      /* adjust x coordinate for left/right mirroring */
-      x = x - m;
-   }
-
-   /* compute which rows to draw */
-   row = y-y0;
-   r0 = y0 + (GLint) (row * ctx->Pixel.ZoomY);
-   r1 = y0 + (GLint) ((row+1) * ctx->Pixel.ZoomY);
-   if (r0==r1) {
-      return;
-   }
-   else if (r1<r0) {
-      GLint rtmp = r1;
-      r1 = r0;
-      r0 = rtmp;
-   }
-
-   /* return early if r0...r1 is above or below window */
-   if (r0<0 && r1<0) {
-      /* below window */
-      return;
-   }
-   if (r0>=ctx->DrawBuffer->Height && r1>=ctx->DrawBuffer->Height) {
-      /* above window */
-      return;
-   }
-
-   /* check if left edge is outside window */
-   skipcol = 0;
-   if (x<0) {
-      skipcol = -x;
-      m += x;
-   }
-   /* make sure span isn't too long or short */
-   if (m>maxwidth) {
-      m = maxwidth;
-   }
-   else if (m<=0) {
-      return;
+   else if (format == GL_COLOR_INDEX) {
+      if (ctx->Pixel.ZoomX == -1.0F) {
+         /* common case */
+         for (j = zoomed.start; j < zoomed.end; j++) {
+            i = span->end - (j + skipCol) - 1;
+            zoomed.color.index[j] = indexes[i];
+         }
+      }
+      else {
+         /* general solution */
+         const GLfloat xscale = 1.0F / ctx->Pixel.ZoomX;
+         for (j = zoomed.start; j < zoomed.end; j++) {
+            i = (GLint) ((j + skipCol) * xscale);
+            if (i < 0)
+               i = span->end + i - 1;
+            zoomed.color.index[j] = indexes[i];
+         }
+      }
    }
 
-   ASSERT( m <= MAX_WIDTH );
-
-   /* zoom the span horizontally */
-   if (ctx->Pixel.ZoomX==-1.0F) {
-      /* n==m */
-      for (j=0;j<m;j++) {
-         i = n - (j+skipcol) - 1;
-         zoomed.color.rgba[j][0] = rgb[i][0];
-         zoomed.color.rgba[j][1] = rgb[i][1];
-         zoomed.color.rgba[j][2] = rgb[i][2];
-         zoomed.color.rgba[j][3] = CHAN_MAX;
-         zoomed.zArray[j] = z[i];
+   /* write the span in rows [r0, r1) */
+   if (format == GL_RGBA || format == GL_RGB) {
+      /* Writing the span may modify the colors, so make a backup now if we're
+       * going to call _mesa_write_zoomed_span() more than once.
+       */
+      if (r1 - r0 > 1) {
+         MEMCPY(rgbaSave, zoomed.color.rgba, zoomed.end * 4 * sizeof(GLchan));
       }
-      if (zoomed.arrayMask & SPAN_FOG) {
-	 for (j=0;j<m;j++) {
-	    i = n - (j+skipcol) - 1;
-	    zoomed.fogArray[j] = fog[i];
-	 }
+      for (zoomed.y = r0; zoomed.y < r1; zoomed.y++) {
+         _mesa_write_rgba_span(ctx, &zoomed, GL_BITMAP);
+         if (r1 - r0 > 1) {
+            /* restore the colors */
+            MEMCPY(zoomed.color.rgba, rgbaSave, zoomed.end*4 * sizeof(GLchan));
+         }
       }
    }
-   else {
-      GLfloat xscale = 1.0F / ctx->Pixel.ZoomX;
-      for (j=0;j<m;j++) {
-         i = (GLint) ((j+skipcol) * xscale);
-         if (i<0)  i = n + i - 1;
-         zoomed.color.rgba[j][0] = rgb[i][0];
-         zoomed.color.rgba[j][1] = rgb[i][1];
-         zoomed.color.rgba[j][2] = rgb[i][2];
-         zoomed.color.rgba[j][3] = CHAN_MAX;
-         zoomed.zArray[j] = z[i];
+   else if (format == GL_COLOR_INDEX) {
+      if (r1 - r0 > 1) {
+         MEMCPY(indexSave, zoomed.color.index, zoomed.end * sizeof(GLuint));
       }
-      if (zoomed.arrayMask & SPAN_FOG) {
-	 for (j=0;j<m;j++) {
-	    i = (GLint) ((j+skipcol) * xscale);
-	    if (i<0)  i = n + i - 1;
-	    zoomed.fogArray[j] = fog[i];
-	 }
+      for (zoomed.y = r0; zoomed.y < r1; zoomed.y++) {
+         _mesa_write_index_span(ctx, &zoomed, GL_BITMAP);
+         if (r1 - r0 > 1) {
+            /* restore the colors */
+            MEMCPY(zoomed.color.index, indexSave, zoomed.end * sizeof(GLuint));
+         }
       }
    }
-
-   /* write the span */
-   for (r=r0; r<r1; r++) {
-      zoomed.x = x + skipcol;
-      zoomed.y = r;
-      zoomed.end = m;
-      ASSERT((zoomed.interpMask & SPAN_RGBA) == 0);
-      _mesa_write_rgba_span( ctx, &zoomed, GL_BITMAP );
-   }
 }
 
 
-
-/*
- * As above, but write CI pixels.
- */
 void
-_mesa_write_zoomed_index_span( GLcontext *ctx,
-                               GLuint n, GLint x, GLint y, const GLdepth z[],
-                               const GLfloat *fog,
-                               const GLuint indexes[], GLint y0 )
+_mesa_write_zoomed_rgba_span( GLcontext *ctx, const struct sw_span *span,
+                              CONST GLchan rgba[][4], GLint y0 )
 {
-   GLint m;
-   GLint r0, r1, row, r;
-   GLint i, j, skipcol;
-   GLint maxwidth = MIN2( ctx->DrawBuffer->Width, MAX_WIDTH );
-   struct sw_span zoomed;
-
-   INIT_SPAN(zoomed);
-   zoomed.arrayMask |= SPAN_INDEX;
-
-   /* compute width of output row */
-   m = (GLint) ABSF( n * ctx->Pixel.ZoomX );
-   if (m==0) {
-      return;
-   }
-   if (ctx->Pixel.ZoomX<0.0) {
-      /* adjust x coordinate for left/right mirroring */
-      x = x - m;
-   }
-
-   /* compute which rows to draw */
-   row = y-y0;
-   r0 = y0 + (GLint) (row * ctx->Pixel.ZoomY);
-   r1 = y0 + (GLint) ((row+1) * ctx->Pixel.ZoomY);
-   if (r0==r1) {
-      return;
-   }
-   else if (r1<r0) {
-      GLint rtmp = r1;
-      r1 = r0;
-      r0 = rtmp;
-   }
-
-   /* return early if r0...r1 is above or below window */
-   if (r0<0 && r1<0) {
-      /* below window */
-      return;
-   }
-   if (r0>=ctx->DrawBuffer->Height && r1>=ctx->DrawBuffer->Height) {
-      /* above window */
-      return;
-   }
-
-   /* check if left edge is outside window */
-   skipcol = 0;
-   if (x<0) {
-      skipcol = -x;
-      m += x;
-   }
-   /* make sure span isn't too long or short */
-   if (m>maxwidth) {
-      m = maxwidth;
-   }
-   else if (m<=0) {
-      return;
-   }
+   zoom_span(ctx, span, (const GLvoid *) rgba, y0, GL_RGBA);
+}
 
-   ASSERT( m <= MAX_WIDTH );
 
-   /* zoom the span horizontally */
-   if (ctx->Pixel.ZoomX==-1.0F) {
-      /* n==m */
-      for (j=0;j<m;j++) {
-         i = n - (j+skipcol) - 1;
-         zoomed.color.index[j] = indexes[i];
-         zoomed.zArray[j]   = z[i];
-      }
-      if (fog && ctx->Fog.Enabled) {
-	 for (j=0;j<m;j++) {
-	    i = n - (j+skipcol) - 1;
-	    zoomed.fogArray[j] = fog[i];
-	 }
-         zoomed.arrayMask |= SPAN_FOG;
-      }
-   }
-   else {
-      GLfloat xscale = 1.0F / ctx->Pixel.ZoomX;
-      for (j=0;j<m;j++) {
-         i = (GLint) ((j+skipcol) * xscale);
-         if (i<0)  i = n + i - 1;
-         zoomed.color.index[j] = indexes[i];
-         zoomed.zArray[j] = z[i];
-      }
-      if (fog && ctx->Fog.Enabled) {
-	 for (j=0;j<m;j++) {
-	    i = (GLint) ((j+skipcol) * xscale);
-	    if (i<0)  i = n + i - 1;
-	    zoomed.fogArray[j] = fog[i];
-	 }
-         zoomed.arrayMask |= SPAN_FOG;
-      }
-   }
+void
+_mesa_write_zoomed_rgb_span( GLcontext *ctx, const struct sw_span *span,
+                             CONST GLchan rgb[][3], GLint y0 )
+{
+   zoom_span(ctx, span, (const GLvoid *) rgb, y0, GL_RGB);
+}
 
-   zoomed.arrayMask |= SPAN_Z;
 
-   /* write the span */
-   for (r=r0; r<r1; r++) {
-      SAVE_SPAN(zoomed);
-      ASSERT((zoomed.interpMask & SPAN_INDEX) == 0);
-      zoomed.x = x + skipcol;
-      zoomed.y = r;
-      zoomed.end = m;
-      _mesa_write_index_span(ctx, &zoomed, GL_BITMAP);
-      RESTORE_SPAN(zoomed);
-   }
+void
+_mesa_write_zoomed_index_span( GLcontext *ctx, const struct sw_span *span,
+                               GLint y0 )
+{
+  zoom_span(ctx, span, (const GLvoid *) span->color.index, y0, GL_COLOR_INDEX);
 }
 
 
-
 /*
  * As above, but write stencil values.
  */
diff --git a/src/mesa/swrast/s_zoom.h b/src/mesa/swrast/s_zoom.h
index 2891d305e7..77ddb47823 100644
--- a/src/mesa/swrast/s_zoom.h
+++ b/src/mesa/swrast/s_zoom.h
@@ -1,4 +1,4 @@
-/* $Id: s_zoom.h,v 1.6 2002/01/21 18:12:34 brianp Exp $ */
+/* $Id: s_zoom.h,v 1.7 2002/01/31 00:27:43 brianp Exp $ */
 
 /*
  * Mesa 3-D graphics library
@@ -24,39 +24,26 @@
  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  */
 
-
 #ifndef S_ZOOM_H
 #define S_ZOOM_H
 
-
 #include "mtypes.h"
 #include "swrast.h"
 
 extern void
-_mesa_write_zoomed_rgba_span( GLcontext *ctx,
-                              GLuint n, GLint x, GLint y, const GLdepth z[],
-                              const GLfloat *fog,
-                              CONST GLchan rgba[][4], GLint y0 );
-
+_mesa_write_zoomed_rgba_span( GLcontext *ctx, const struct sw_span *span,
+                              CONST GLchan rgb[][4], GLint y0 );
 
 extern void
-_mesa_write_zoomed_rgb_span( GLcontext *ctx,
-                             GLuint n, GLint x, GLint y, const GLdepth z[],
-                             const GLfloat *fog,
+_mesa_write_zoomed_rgb_span( GLcontext *ctx, const struct sw_span *span,
                              CONST GLchan rgb[][3], GLint y0 );
 
-
 extern void
-_mesa_write_zoomed_index_span( GLcontext *ctx,
-                               GLuint n, GLint x, GLint y, const GLdepth z[],
-                               const GLfloat *fog,
-                               const GLuint indexes[], GLint y0 );
-
+_mesa_write_zoomed_index_span( GLcontext *ctx, const struct sw_span *span,
+                               GLint y0 );
 
 extern void
-_mesa_write_zoomed_stencil_span( GLcontext *ctx,
-                                 GLuint n, GLint x, GLint y,
+_mesa_write_zoomed_stencil_span( GLcontext *ctx, GLuint n, GLint x, GLint y,
                                  const GLstencil stencil[], GLint y0 );
 
-
 #endif