X-Git-Url: https://git.libre-soc.org/?a=blobdiff_plain;f=src%2Fmesa%2Fswrast%2Fs_zoom.c;h=b67a2970109ea0656ec4ffa9322c5334b936164e;hb=4102a3045cb64a7875c524a58f13766a48bbe164;hp=516a5bb5826f20e7e36e78c743ca2cc5356c8bcc;hpb=7956292a765910077f50352d7cd0174e1e66d26c;p=mesa.git

diff --git a/src/mesa/swrast/s_zoom.c b/src/mesa/swrast/s_zoom.c
index 516a5bb5826..b67a2970109 100644
--- a/src/mesa/swrast/s_zoom.c
+++ b/src/mesa/swrast/s_zoom.c
@@ -1,10 +1,9 @@
-/* $Id: s_zoom.c,v 1.11 2002/01/28 03:42:28 brianp Exp $ */
 
 /*
  * Mesa 3-D graphics library
- * Version:  4.1
+ * Version:  5.1
  *
- * Copyright (C) 1999-2002  Brian Paul   All Rights Reserved.
+ * Copyright (C) 1999-2003  Brian Paul   All Rights Reserved.
  *
  * Permission is hereby granted, free of charge, to any person obtaining a
  * copy of this software and associated documentation files (the "Software"),
@@ -26,7 +25,7 @@
 
 #include "glheader.h"
 #include "macros.h"
-#include "mem.h"
+#include "imports.h"
 #include "colormac.h"
 
 #include "s_context.h"
@@ -35,409 +34,317 @@
 #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 _swrast_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 skipPixels )
 {
    GLint r0, r1, row;
+   GLint c0, c1, skipCol;
    GLint i, j;
-   const GLint maxwidth = MIN2( ctx->DrawBuffer->Width, MAX_WIDTH );
+   const GLuint maxWidth = MIN2( ctx->DrawBuffer->Width, MAX_WIDTH );
    struct sw_span zoomed;
-
-   INIT_SPAN(zoomed);
-   zoomed.arrayMask |= SPAN_RGBA;
-
-   /* compute width of output row */
-   zoomed.end = (GLint) ABSF( n * ctx->Pixel.ZoomX );
-   if (zoomed.end == 0) {
+   struct span_arrays zoomed_arrays;  /* this is big! */
+
+   /* no pixel arrays! must be horizontal spans. */
+   ASSERT((span->arrayMask & SPAN_XY) == 0);
+   ASSERT(span->primitive == GL_BITMAP);
+
+   INIT_SPAN(zoomed, GL_BITMAP, 0, 0, 0);
+   zoomed.array = &zoomed_arrays;
+
+   /* copy fog interp info */
+   zoomed.fog = span->fog;
+   zoomed.fogStep = span->fogStep;
+   /* XXX copy texcoord info? */
+
+   if (format == GL_RGBA || format == GL_RGB) {
+      /* copy Z info */
+      zoomed.z = span->z;
+      zoomed.zStep = span->zStep;
+      /* we'll generate an array of colorss */
+      zoomed.interpMask = span->interpMask & ~SPAN_RGBA;
+      zoomed.arrayMask |= SPAN_RGBA;
+   }
+   else if (format == GL_COLOR_INDEX) {
+      /* copy Z info */
+      zoomed.z = span->z;
+      zoomed.zStep = span->zStep;
+      /* we'll generate an array of color indexes */
+      zoomed.interpMask = span->interpMask & ~SPAN_INDEX;
+      zoomed.arrayMask |= SPAN_INDEX;
+   }
+   else {
+      assert(format == GL_DEPTH_COMPONENT);
+      /* Copy color info */
+      zoomed.red = span->red;
+      zoomed.green = span->green;
+      zoomed.blue = span->blue;
+      zoomed.alpha = span->alpha;
+      zoomed.redStep = span->redStep;
+      zoomed.greenStep = span->greenStep;
+      zoomed.blueStep = span->blueStep;
+      zoomed.alphaStep = span->alphaStep;
+      /* we'll generate an array of depth values */
+      zoomed.interpMask = span->interpMask & ~SPAN_Z;
+      zoomed.arrayMask |= SPAN_Z;
+   }
+
+   /*
+    * Compute which columns to draw: [c0, c1)
+    */
+   c0 = (GLint) (span->x + skipPixels * ctx->Pixel.ZoomX);
+   c1 = (GLint) (span->x + (skipPixels + 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 >= (GLint) 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 >= (GLint) 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) {
+      const GLchan (*rgba)[4] = (const GLchan (*)[4]) src;
+      if (ctx->Pixel.ZoomX == -1.0F) {
+         /* common case */
+         for (j = (GLint) zoomed.start; j < (GLint) zoomed.end; j++) {
+            i = span->end - (j + skipCol) - 1;
+            COPY_CHAN4(zoomed.array->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 = (GLint) zoomed.start; j < (GLint) zoomed.end; j++) {
+            i = (GLint) ((j + skipCol) * xscale);
+            if (ctx->Pixel.ZoomX < 0.0) {
+               ASSERT(i <= 0);
+               i = span->end + i - 1;
+            }
+            ASSERT(i >= 0);
+            ASSERT(i < (GLint)  span->end);
+            COPY_CHAN4(zoomed.array->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) {
+      const GLchan (*rgb)[3] = (const GLchan (*)[3]) src;
+      if (ctx->Pixel.ZoomX == -1.0F) {
+         /* common case */
+         for (j = (GLint) zoomed.start; j < (GLint) zoomed.end; j++) {
+            i = span->end - (j + skipCol) - 1;
+            zoomed.array->rgba[j][0] = rgb[i][0];
+            zoomed.array->rgba[j][1] = rgb[i][1];
+            zoomed.array->rgba[j][2] = rgb[i][2];
+            zoomed.array->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 = (GLint) zoomed.start; j < (GLint) zoomed.end; j++) {
+            i = (GLint) ((j + skipCol) * xscale);
+            if (ctx->Pixel.ZoomX < 0.0) {
+               ASSERT(i <= 0);
+               i = span->end + i - 1;
+            }
+            ASSERT(i >= 0);
+            ASSERT(i < (GLint) span->end);
+            zoomed.array->rgba[j][0] = rgb[i][0];
+            zoomed.array->rgba[j][1] = rgb[i][1];
+            zoomed.array->rgba[j][2] = rgb[i][2];
+            zoomed.array->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;
-   }
-
-   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];
+   else if (format == GL_COLOR_INDEX) {
+      const GLuint *indexes = (const GLuint *) src;
+      if (ctx->Pixel.ZoomX == -1.0F) {
+         /* common case */
+         for (j = (GLint) zoomed.start; j < (GLint) zoomed.end; j++) {
+            i = span->end - (j + skipCol) - 1;
+            zoomed.array->index[j] = indexes[i];
+         }
       }
-      if (zoomed.arrayMask & SPAN_FOG) {
-	 for (j=0;j<m;j++) {
-	    i = n - (j+skipcol) - 1;
-	    zoomed.fogArray[j] = fog[i];
-	 }
+      else {
+         /* general solution */
+         const GLfloat xscale = 1.0F / ctx->Pixel.ZoomX;
+         for (j = (GLint) zoomed.start; j < (GLint) zoomed.end; j++) {
+            i = (GLint) ((j + skipCol) * xscale);
+            if (ctx->Pixel.ZoomX < 0.0) {
+               ASSERT(i <= 0);
+               i = span->end + i - 1;
+            }
+            ASSERT(i >= 0);
+            ASSERT(i < (GLint) span->end);
+            zoomed.array->index[j] = indexes[i];
+         }
       }
    }
    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];
+      const GLdepth *zValues = (const GLuint *) src;
+      assert(format == GL_DEPTH_COMPONENT);
+      if (ctx->Pixel.ZoomX == -1.0F) {
+         /* common case */
+         for (j = (GLint) zoomed.start; j < (GLint) zoomed.end; j++) {
+            i = span->end - (j + skipCol) - 1;
+            zoomed.array->z[j] = zValues[i];
+         }
       }
-      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];
-	 }
+      else {
+         /* general solution */
+         const GLfloat xscale = 1.0F / ctx->Pixel.ZoomX;
+         for (j = (GLint) zoomed.start; j < (GLint) zoomed.end; j++) {
+            i = (GLint) ((j + skipCol) * xscale);
+            if (ctx->Pixel.ZoomX < 0.0) {
+               ASSERT(i <= 0);
+               i = span->end + i - 1;
+            }
+            ASSERT(i >= 0);
+            ASSERT(i < (GLint) span->end);
+            zoomed.array->z[j] = zValues[i];
+         }
+      }
+      /* Now, fall into either the RGB or COLOR_INDEX path below */
+      if (ctx->Visual.rgbMode)
+         format = GL_RGBA;
+      else
+         format = GL_COLOR_INDEX;
+   }
+
+
+   /* 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 _swrast_write_zoomed_span() more than once.
+       * Also, clipping may change the span end value, so store it as well.
+       */
+      GLchan rgbaSave[MAX_WIDTH][4];
+      const GLint end = zoomed.end; /* save */
+      if (r1 - r0 > 1) {
+         MEMCPY(rgbaSave, zoomed.array->rgba, zoomed.end * 4 * sizeof(GLchan));
+      }
+      for (zoomed.y = r0; zoomed.y < r1; zoomed.y++) {
+         _swrast_write_rgba_span(ctx, &zoomed);
+         zoomed.end = end;  /* restore */
+         if (r1 - r0 > 1) {
+            /* restore the colors */
+            MEMCPY(zoomed.array->rgba, rgbaSave, zoomed.end*4 * sizeof(GLchan));
+         }
       }
    }
-
-   /* 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 );
+   else if (format == GL_COLOR_INDEX) {
+      GLuint indexSave[MAX_WIDTH];
+      const GLint end = zoomed.end; /* save */
+      if (r1 - r0 > 1) {
+         MEMCPY(indexSave, zoomed.array->index, zoomed.end * sizeof(GLuint));
+      }
+      for (zoomed.y = r0; zoomed.y < r1; zoomed.y++) {
+         _swrast_write_index_span(ctx, &zoomed);
+         zoomed.end = end;  /* restore */
+         if (r1 - r0 > 1) {
+            /* restore the colors */
+            MEMCPY(zoomed.array->index, indexSave, zoomed.end * sizeof(GLuint));
+         }
+      }
    }
 }
 
 
-
-/*
- * 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 )
+_swrast_write_zoomed_rgba_span( GLcontext *ctx, const struct sw_span *span,
+                              CONST GLchan rgba[][4], GLint y0,
+                              GLint skipPixels )
 {
-   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;
-   }
+   zoom_span(ctx, span, (const GLvoid *) rgba, y0, GL_RGBA, skipPixels);
+}
 
-   /* 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;
-   }
+void
+_swrast_write_zoomed_rgb_span( GLcontext *ctx, const struct sw_span *span,
+                             CONST GLchan rgb[][3], GLint y0,
+                             GLint skipPixels )
+{
+   zoom_span(ctx, span, (const GLvoid *) rgb, y0, GL_RGB, skipPixels);
+}
 
-   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
+_swrast_write_zoomed_index_span( GLcontext *ctx, const struct sw_span *span,
+                               GLint y0, GLint skipPixels )
+{
+   zoom_span(ctx, span, (const GLvoid *) span->array->index, y0,
+             GL_COLOR_INDEX, skipPixels);
+}
 
-   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
+_swrast_write_zoomed_depth_span( GLcontext *ctx, const struct sw_span *span,
+                                 GLint y0, GLint skipPixels )
+{
+   zoom_span(ctx, span, (const GLvoid *) span->array->z, y0,
+             GL_DEPTH_COMPONENT, skipPixels);
 }
 
 
-
 /*
  * As above, but write stencil values.
  */
 void
-_mesa_write_zoomed_stencil_span( GLcontext *ctx,
+_swrast_write_zoomed_stencil_span( GLcontext *ctx,
                                  GLuint n, GLint x, GLint y,
-                                 const GLstencil stencil[], GLint y0 )
+                                 const GLstencil stencil[], GLint y0,
+                                 GLint skipPixels )
 {
    GLint m;
    GLint r0, r1, row, r;
@@ -445,8 +352,10 @@ _mesa_write_zoomed_stencil_span( GLcontext *ctx,
    GLstencil zstencil[MAX_WIDTH];  /* zoomed stencil values */
    GLint maxwidth = MIN2( ctx->DrawBuffer->Width, MAX_WIDTH );
 
+   (void) skipPixels;  /* XXX this shouldn't be ignored */
+
    /* compute width of output row */
-   m = (GLint) ABSF( n * ctx->Pixel.ZoomX );
+   m = (GLint) FABSF( n * ctx->Pixel.ZoomX );
    if (m==0) {
       return;
    }
@@ -456,7 +365,7 @@ _mesa_write_zoomed_stencil_span( GLcontext *ctx,
    }
 
    /* compute which rows to draw */
-   row = y-y0;
+   row = y - y0;
    r0 = y0 + (GLint) (row * ctx->Pixel.ZoomY);
    r1 = y0 + (GLint) ((row+1) * ctx->Pixel.ZoomY);
    if (r0==r1) {
@@ -473,7 +382,8 @@ _mesa_write_zoomed_stencil_span( GLcontext *ctx,
       /* below window */
       return;
    }
-   if (r0>=ctx->DrawBuffer->Height && r1>=ctx->DrawBuffer->Height) {
+   if (r0 >= (GLint) ctx->DrawBuffer->Height &&
+       r1 >= (GLint) ctx->DrawBuffer->Height) {
       /* above window */
       return;
    }
@@ -513,6 +423,6 @@ _mesa_write_zoomed_stencil_span( GLcontext *ctx,
 
    /* write the span */
    for (r=r0; r<r1; r++) {
-      _mesa_write_stencil_span( ctx, m, x+skipcol, r, zstencil );
+      _swrast_write_stencil_span( ctx, m, x+skipcol, r, zstencil );
    }
 }