runtime selectable depth buffer depth

12 files changed, 743 insertions, 170 deletions

diff --git a/src/mesa/main/config.h b/src/mesa/main/config.h
index 8c4af7615a..af11356f36 100644
--- a/src/mesa/main/config.h
+++ b/src/mesa/main/config.h
@@ -1,4 +1,4 @@
-/* $Id: config.h,v 1.6 2000/02/21 14:46:28 brianp Exp $ */
+/* $Id: config.h,v 1.7 2000/03/03 17:47:39 brianp Exp $ */
 
 /*
  * Mesa 3-D graphics library
@@ -126,26 +126,12 @@
 
 
 /*
- * Bits per depth buffer value:  16 or 32
+ * Bits per depth buffer value:  16 or 32 (GLushort or GLuint)
+ * gl_create_visual() can select any depth in [0, 32].
  */
-#ifdef MESAD3D
-   /* Mesa / Direct3D driver only */
-   extern float g_DepthScale, g_MaxDepth;
-#  define DEPTH_BITS 	32
-#  define DEPTH_SCALE 	g_DepthScale
-#  define MAX_DEPTH 	g_MaxDepth
-#else
-#  define DEPTH_BITS 16
-#  if DEPTH_BITS==16
-#     define MAX_DEPTH 0xffff
-#     define DEPTH_SCALE 65535.0F
-#  elif DEPTH_BITS==32
-#     define MAX_DEPTH 0x3fffffff
-#     define DEPTH_SCALE ((GLfloat) MAX_DEPTH)
-#  else
-#     error "illegal number of depth bits"
-#  endif
-#endif
+#define DEFAULT_SOFTWARE_DEPTH_BITS 16
+#define DEFAULT_SOFTWARE_DEPTH_TYPE GLushort
+
 
 
 /*
diff --git a/src/mesa/main/context.c b/src/mesa/main/context.c
index 2fa8848dcf..eb3b7a8121 100644
--- a/src/mesa/main/context.c
+++ b/src/mesa/main/context.c
@@ -1,4 +1,4 @@
-/* $Id: context.c,v 1.43 2000/02/12 17:26:15 brianp Exp $ */
+/* $Id: context.c,v 1.44 2000/03/03 17:47:39 brianp Exp $ */
 
 /*
  * Mesa 3-D graphics library
@@ -255,12 +255,15 @@ static void print_timings( GLcontext *ctx )
  *         alphaFlag - alloc software alpha buffers?
  *         dbFlag - double buffering?
  *         stereoFlag - stereo buffer?
- *         depthFits - requested minimum bits per depth buffer value
- *         stencilFits - requested minimum bits per stencil buffer value
- *         accumFits - requested minimum bits per accum buffer component
- *         indexFits - number of bits per pixel if rgbFlag==GL_FALSE
- *         red/green/blue/alphaFits - number of bits per color component
- *                                     in frame buffer for RGB(A) mode.
+ *         depthBits - requested bits per depth buffer value
+ *                     Any value in [0, 32] is acceptable but the actual
+ *                     depth type will be GLushort or GLuint as needed.
+ *         stencilBits - requested minimum bits per stencil buffer value
+ *         accumBits - requested minimum bits per accum buffer component
+ *         indexBits - number of bits per pixel if rgbFlag==GL_FALSE
+ *         red/green/blue/alphaBits - number of bits per color component
+ *                                    in frame buffer for RGB(A) mode.
+ *                                    We always use 8 in core Mesa though.
  * Return:  pointer to new GLvisual or NULL if requested parameters can't
  *          be met.
  */
@@ -279,16 +282,19 @@ GLvisual *gl_create_visual( GLboolean rgbFlag,
 {
    GLvisual *vis;
 
-   if (depthBits > (GLint) (8*sizeof(GLdepth))) {
-      /* can't meet depth buffer requirements */
+   /* This is to catch bad values from device drivers not updated for
+    * Mesa 3.3.  Some device drivers just passed 1.  That's a REALLY
+    * bad value now (a 1-bit depth buffer!?!).
+    */
+   assert(depthBits == 0 || depthBits > 1);
+
+   if (depthBits < 0 || depthBits > 32) {
       return NULL;
    }
-   if (stencilBits > (GLint) (8*sizeof(GLstencil))) {
-      /* can't meet stencil buffer requirements */
+   if (stencilBits < 0 || stencilBits > (GLint) (8 * sizeof(GLstencil))) {
       return NULL;
    }
-   if (accumBits > (GLint) (8*sizeof(GLaccum))) {
-      /* can't meet accum buffer requirements */
+   if (accumBits < 0 || accumBits > (GLint) (8 * sizeof(GLaccum))) {
       return NULL;
    }
 
@@ -303,15 +309,27 @@ GLvisual *gl_create_visual( GLboolean rgbFlag,
    vis->RedBits    = redBits;
    vis->GreenBits  = greenBits;
    vis->BlueBits   = blueBits;
-   vis->AlphaBits  = alphaFlag ? 8*sizeof(GLubyte) : alphaBits;
+   vis->AlphaBits  = alphaFlag ? (8 * sizeof(GLubyte)) : alphaBits;
 
    vis->IndexBits   = indexBits;
-   vis->DepthBits   = (depthBits>0) ? 8*sizeof(GLdepth) : 0;
-   vis->AccumBits   = (accumBits>0) ? 8*sizeof(GLaccum) : 0;
-   vis->StencilBits = (stencilBits>0) ? 8*sizeof(GLstencil) : 0;
+   vis->DepthBits   = depthBits;
+   vis->AccumBits   = (accumBits > 0) ? (8 * sizeof(GLaccum)) : 0;
+   vis->StencilBits = (stencilBits > 0) ? (8 * sizeof(GLstencil)) : 0;
 
    vis->SoftwareAlpha = alphaFlag;
 
+   if (depthBits == 0) {
+      /* Special case.  Even if we don't have a depth buffer we need
+       * good values for DepthMax for Z vertex transformation purposes.
+       */
+      vis->DepthMax = 1;
+      vis->DepthMaxF = 1.0F;
+   }
+   else {
+      vis->DepthMax = (1 << depthBits) - 1;
+      vis->DepthMaxF = (GLfloat) vis->DepthMax;
+   }
+
    return vis;
 }
 
@@ -1101,8 +1119,8 @@ static void init_attrib_groups( GLcontext *ctx )
 
 #define Sz 10
 #define Tz 14
-   ctx->Viewport.WindowMap.m[Sz] = 0.5 * DEPTH_SCALE;
-   ctx->Viewport.WindowMap.m[Tz] = 0.5 * DEPTH_SCALE;
+   ctx->Viewport.WindowMap.m[Sz] = 0.5 * ctx->Visual->DepthMaxF;
+   ctx->Viewport.WindowMap.m[Tz] = 0.5 * ctx->Visual->DepthMaxF;
 #undef Sz
 #undef Tz
 
diff --git a/src/mesa/main/dd.h b/src/mesa/main/dd.h
index 9a10fd0d4b..d2b985f384 100644
--- a/src/mesa/main/dd.h
+++ b/src/mesa/main/dd.h
@@ -1,4 +1,4 @@
-/* $Id: dd.h,v 1.13 2000/03/03 15:38:57 brianp Exp $ */
+/* $Id: dd.h,v 1.14 2000/03/03 17:54:56 brianp Exp $ */
 
 /*
  * Mesa 3-D graphics library
@@ -391,6 +391,8 @@ struct dd_function_table {
    /***
     *** For supporting hardware Z buffers:
     *** Either ALL or NONE of these functions must be implemented!
+    *** NOTE that Each depth value is a 32-bit GLuint.  If the depth
+    *** buffer is less than 32 bits deep then the extra upperbits are zero.
     ***/
 
    void (*WriteDepthSpan)( GLcontext *ctx, GLuint n, GLint x, GLint y,
diff --git a/src/mesa/main/depth.c b/src/mesa/main/depth.c
index 3d8b1a190b..ba7f6248ab 100644
--- a/src/mesa/main/depth.c
+++ b/src/mesa/main/depth.c
@@ -1,10 +1,10 @@
-/* $Id: depth.c,v 1.12 2000/02/02 22:16:04 brianp Exp $ */
+/* $Id: depth.c,v 1.13 2000/03/03 17:47:39 brianp Exp $ */
 
 /*
  * Mesa 3-D graphics library
  * Version:  3.3
  * 
- * Copyright (C) 1999  Brian Paul   All Rights Reserved.
+ * Copyright (C) 1999-2000  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"),
@@ -125,6 +125,33 @@ _mesa_DepthMask( GLboolean flag )
 
 
 /**********************************************************************/
+/*****                           Misc                             *****/
+/**********************************************************************/
+
+/*
+ * Return address of depth buffer value for given window coord.
+ */
+GLvoid *
+_mesa_zbuffer_address(GLcontext *ctx, GLint x, GLint y)
+{
+   if (ctx->Visual->DepthBits <= 16)
+      return (GLushort *) ctx->DrawBuffer->DepthBuffer + ctx->DrawBuffer->Width * y + x;
+   else
+      return (GLuint *) ctx->DrawBuffer->DepthBuffer + ctx->DrawBuffer->Width * y + x;
+}
+
+
+#define Z_ADDRESS16( CTX, X, Y )				\
+            ( ((GLushort *) (CTX)->DrawBuffer->DepthBuffer)	\
+              + (CTX)->DrawBuffer->Width * (Y) + (X) )
+
+#define Z_ADDRESS32( CTX, X, Y )				\
+            ( ((GLuint *) (CTX)->DrawBuffer->DepthBuffer)	\
+              + (CTX)->DrawBuffer->Width * (Y) + (X) )
+
+
+
+/**********************************************************************/
 /*****                   Depth Testing Functions                  *****/
 /**********************************************************************/
 
@@ -137,8 +164,8 @@ _mesa_DepthMask( GLboolean flag )
  * Return:  number of fragments which pass the test.
  */
 static GLuint
-depth_test_span( GLcontext *ctx, GLuint n, GLint x, GLint y,
-                 GLdepth zbuffer[], const GLdepth z[], GLubyte mask[] )
+depth_test_span16( GLcontext *ctx, GLuint n, GLint x, GLint y,
+                   GLushort zbuffer[], const GLdepth z[], GLubyte mask[] )
 {
    GLuint passed = 0;
 
@@ -358,7 +385,236 @@ depth_test_span( GLcontext *ctx, GLuint n, GLint x, GLint y,
          MEMSET(mask, 0, n * sizeof(GLubyte));
 	 break;
       default:
-         gl_problem(ctx, "Bad depth func in depth_test_span");
+         gl_problem(ctx, "Bad depth func in depth_test_span16");
+   }
+
+   return passed;
+}
+
+
+static GLuint
+depth_test_span32( GLcontext *ctx, GLuint n, GLint x, GLint y,
+                   GLuint zbuffer[], const GLdepth z[], GLubyte mask[] )
+{
+   GLuint passed = 0;
+
+   /* switch cases ordered from most frequent to less frequent */
+   switch (ctx->Depth.Func) {
+      case GL_LESS:
+         if (ctx->Depth.Mask) {
+	    /* Update Z buffer */
+            GLuint i;
+	    for (i=0; i<n; i++) {
+	       if (mask[i]) {
+		  if (z[i] < zbuffer[i]) {
+		     /* pass */
+		     zbuffer[i] = z[i];
+		     passed++;
+		  }
+		  else {
+		     /* fail */
+		     mask[i] = 0;
+		  }
+	       }
+	    }
+	 }
+	 else {
+	    /* Don't update Z buffer */
+            GLuint i;
+	    for (i=0; i<n; i++) {
+	       if (mask[i]) {
+		  if (z[i] < zbuffer[i]) {
+		     /* pass */
+		     passed++;
+		  }
+		  else {
+		     mask[i] = 0;
+		  }
+	       }
+	    }
+	 }
+	 break;
+      case GL_LEQUAL:
+	 if (ctx->Depth.Mask) {
+	    /* Update Z buffer */
+            GLuint i;
+	    for (i=0;i<n;i++) {
+	       if (mask[i]) {
+		  if (z[i] <= zbuffer[i]) {
+		     zbuffer[i] = z[i];
+		     passed++;
+		  }
+		  else {
+		     mask[i] = 0;
+		  }
+	       }
+	    }
+	 }
+	 else {
+	    /* Don't update Z buffer */
+            GLuint i;
+	    for (i=0;i<n;i++) {
+	       if (mask[i]) {
+		  if (z[i] <= zbuffer[i]) {
+		     /* pass */
+		     passed++;
+		  }
+		  else {
+		     mask[i] = 0;
+		  }
+	       }
+	    }
+	 }
+	 break;
+      case GL_GEQUAL:
+	 if (ctx->Depth.Mask) {
+	    /* Update Z buffer */
+            GLuint i;
+	    for (i=0;i<n;i++) {
+	       if (mask[i]) {
+		  if (z[i] >= zbuffer[i]) {
+		     zbuffer[i] = z[i];
+		     passed++;
+		  }
+		  else {
+		     mask[i] = 0;
+		  }
+	       }
+	    }
+	 }
+	 else {
+	    /* Don't update Z buffer */
+            GLuint i;
+	    for (i=0;i<n;i++) {
+	       if (mask[i]) {
+		  if (z[i] >= zbuffer[i]) {
+		     /* pass */
+		     passed++;
+		  }
+		  else {
+		     mask[i] = 0;
+		  }
+	       }
+	    }
+	 }
+	 break;
+      case GL_GREATER:
+	 if (ctx->Depth.Mask) {
+	    /* Update Z buffer */
+            GLuint i;
+	    for (i=0;i<n;i++) {
+	       if (mask[i]) {
+		  if (z[i] > zbuffer[i]) {
+		     zbuffer[i] = z[i];
+		     passed++;
+		  }
+		  else {
+		     mask[i] = 0;
+		  }
+	       }
+	    }
+	 }
+	 else {
+	    /* Don't update Z buffer */
+            GLuint i;
+	    for (i=0;i<n;i++) {
+	       if (mask[i]) {
+		  if (z[i] > zbuffer[i]) {
+		     /* pass */
+		     passed++;
+		  }
+		  else {
+		     mask[i] = 0;
+		  }
+	       }
+	    }
+	 }
+	 break;
+      case GL_NOTEQUAL:
+	 if (ctx->Depth.Mask) {
+	    /* Update Z buffer */
+            GLuint i;
+	    for (i=0;i<n;i++) {
+	       if (mask[i]) {
+		  if (z[i] != zbuffer[i]) {
+		     zbuffer[i] = z[i];
+		     passed++;
+		  }
+		  else {
+		     mask[i] = 0;
+		  }
+	       }
+	    }
+	 }
+	 else {
+	    /* Don't update Z buffer */
+            GLuint i;
+	    for (i=0;i<n;i++) {
+	       if (mask[i]) {
+		  if (z[i] != zbuffer[i]) {
+		     /* pass */
+		     passed++;
+		  }
+		  else {
+		     mask[i] = 0;
+		  }
+	       }
+	    }
+	 }
+	 break;
+      case GL_EQUAL:
+	 if (ctx->Depth.Mask) {
+	    /* Update Z buffer */
+            GLuint i;
+	    for (i=0;i<n;i++) {
+	       if (mask[i]) {
+		  if (z[i] == zbuffer[i]) {
+		     zbuffer[i] = z[i];
+		     passed++;
+		  }
+		  else {
+		     mask[i] = 0;
+		  }
+	       }
+	    }
+	 }
+	 else {
+	    /* Don't update Z buffer */
+            GLuint i;
+	    for (i=0;i<n;i++) {
+	       if (mask[i]) {
+		  if (z[i] == zbuffer[i]) {
+		     /* pass */
+		     passed++;
+		  }
+		  else {
+		     mask[i] = 0;
+		  }
+	       }
+	    }
+	 }
+	 break;
+      case GL_ALWAYS:
+	 if (ctx->Depth.Mask) {
+	    /* Update Z buffer */
+            GLuint i;
+	    for (i=0;i<n;i++) {
+	       if (mask[i]) {
+		  zbuffer[i] = z[i];
+		  passed++;
+	       }
+	    }
+	 }
+	 else {
+	    /* Don't update Z buffer or mask */
+	    passed = n;
+	 }
+	 break;
+      case GL_NEVER:
+         MEMSET(mask, 0, n * sizeof(GLubyte));
+	 break;
+      default:
+         gl_problem(ctx, "Bad depth func in depth_test_span32");
    }
 
    return passed;
@@ -373,31 +629,277 @@ GLuint
 _mesa_depth_test_span( GLcontext *ctx, GLuint n, GLint x, GLint y,
                        const GLdepth z[], GLubyte mask[] )
 {
-   GLdepth zbuffer[MAX_WIDTH];
-   GLdepth *zptr;
-   GLuint passed;
-
    if (ctx->Driver.ReadDepthSpan) {
-      /* read depth values out of hardware Z buffer */
+      /* hardware-based depth buffer */
+      GLdepth zbuffer[MAX_WIDTH];
+      GLuint passed;
       (*ctx->Driver.ReadDepthSpan)(ctx, n, x, y, zbuffer);
-      zptr = zbuffer;
+      passed = depth_test_span32(ctx, n, x, y, zbuffer, z, mask);
+      assert(ctx->Driver.WriteDepthSpan);
+      (*ctx->Driver.WriteDepthSpan)(ctx, n, x, y, zbuffer, mask);
+      return passed;
    }
    else {
-      /* test against software depth buffer values */
-      zptr = Z_ADDRESS( ctx, x, y );
+      /* software depth buffer */
+      if (ctx->Visual->DepthBits <= 16) {
+         GLushort *zptr = (GLushort *) Z_ADDRESS16(ctx, x, y);
+         GLuint passed = depth_test_span16(ctx, n, x, y, zptr, z, mask);
+         return passed;
+      }
+      else {
+         GLuint *zptr = (GLuint *) Z_ADDRESS32(ctx, x, y);
+         GLuint passed = depth_test_span32(ctx, n, x, y, zptr, z, mask);
+         return passed;
+      }
    }
+}
 
-   passed = depth_test_span( ctx, n, x, y, zptr, z, mask );
 
-   if (ctx->Driver.WriteDepthSpan) {
-      /* write updated depth values into hardware Z buffer */
-      assert(zptr == zbuffer);
-      (*ctx->Driver.WriteDepthSpan)(ctx, n, x, y, zbuffer, mask);
-   }
 
-   return passed;
-}
 
+/*
+ * Do depth testing for an array of fragments using software Z buffer.
+ */
+static void
+software_depth_test_pixels16( GLcontext *ctx, GLuint n,
+                              const GLint x[], const GLint y[],
+                              const GLdepth z[], GLubyte mask[] )
+{
+   /* switch cases ordered from most frequent to less frequent */
+   switch (ctx->Depth.Func) {
+      case GL_LESS:
+         if (ctx->Depth.Mask) {
+	    /* Update Z buffer */
+            GLuint i;
+	    for (i=0; i<n; i++) {
+	       if (mask[i]) {
+		  GLushort *zptr = Z_ADDRESS16(ctx,x[i],y[i]);
+		  if (z[i] < *zptr) {
+		     /* pass */
+		     *zptr = z[i];
+		  }
+		  else {
+		     /* fail */
+		     mask[i] = 0;
+		  }
+	       }
+	    }
+	 }
+	 else {
+	    /* Don't update Z buffer */
+            GLuint i;
+	    for (i=0; i<n; i++) {
+	       if (mask[i]) {
+		  GLushort *zptr = Z_ADDRESS16(ctx,x[i],y[i]);
+		  if (z[i] < *zptr) {
+		     /* pass */
+		  }
+		  else {
+		     /* fail */
+		     mask[i] = 0;
+		  }
+	       }
+	    }
+	 }
+	 break;
+      case GL_LEQUAL:
+         if (ctx->Depth.Mask) {
+	    /* Update Z buffer */
+            GLuint i;
+	    for (i=0; i<n; i++) {
+	       if (mask[i]) {
+		  GLushort *zptr = Z_ADDRESS16(ctx,x[i],y[i]);
+		  if (z[i] <= *zptr) {
+		     /* pass */
+		     *zptr = z[i];
+		  }
+		  else {
+		     /* fail */
+		     mask[i] = 0;
+		  }
+	       }
+	    }
+	 }
+	 else {
+	    /* Don't update Z buffer */
+            GLuint i;
+	    for (i=0; i<n; i++) {
+	       if (mask[i]) {
+		  GLushort *zptr = Z_ADDRESS16(ctx,x[i],y[i]);
+		  if (z[i] <= *zptr) {
+		     /* pass */
+		  }
+		  else {
+		     /* fail */
+		     mask[i] = 0;
+		  }
+	       }
+	    }
+	 }
+	 break;
+      case GL_GEQUAL:
+         if (ctx->Depth.Mask) {
+	    /* Update Z buffer */
+            GLuint i;
+	    for (i=0; i<n; i++) {
+	       if (mask[i]) {
+		  GLushort *zptr = Z_ADDRESS16(ctx,x[i],y[i]);
+		  if (z[i] >= *zptr) {
+		     /* pass */
+		     *zptr = z[i];
+		  }
+		  else {
+		     /* fail */
+		     mask[i] = 0;
+		  }
+	       }
+	    }
+	 }
+	 else {
+	    /* Don't update Z buffer */
+            GLuint i;
+	    for (i=0; i<n; i++) {
+	       if (mask[i]) {
+		  GLushort *zptr = Z_ADDRESS16(ctx,x[i],y[i]);
+		  if (z[i] >= *zptr) {
+		     /* pass */
+		  }
+		  else {
+		     /* fail */
+		     mask[i] = 0;
+		  }
+	       }
+	    }
+	 }
+	 break;
+      case GL_GREATER:
+         if (ctx->Depth.Mask) {
+	    /* Update Z buffer */
+            GLuint i;
+	    for (i=0; i<n; i++) {
+	       if (mask[i]) {
+		  GLushort *zptr = Z_ADDRESS16(ctx,x[i],y[i]);
+		  if (z[i] > *zptr) {
+		     /* pass */
+		     *zptr = z[i];
+		  }
+		  else {
+		     /* fail */
+		     mask[i] = 0;
+		  }
+	       }
+	    }
+	 }
+	 else {
+	    /* Don't update Z buffer */
+            GLuint i;
+	    for (i=0; i<n; i++) {
+	       if (mask[i]) {
+		  GLushort *zptr = Z_ADDRESS16(ctx,x[i],y[i]);
+		  if (z[i] > *zptr) {
+		     /* pass */
+		  }
+		  else {
+		     /* fail */
+		     mask[i] = 0;
+		  }
+	       }
+	    }
+	 }
+	 break;
+      case GL_NOTEQUAL:
+         if (ctx->Depth.Mask) {
+	    /* Update Z buffer */
+            GLuint i;
+	    for (i=0; i<n; i++) {
+	       if (mask[i]) {
+		  GLushort *zptr = Z_ADDRESS16(ctx,x[i],y[i]);
+		  if (z[i] != *zptr) {
+		     /* pass */
+		     *zptr = z[i];
+		  }
+		  else {
+		     /* fail */
+		     mask[i] = 0;
+		  }
+	       }
+	    }
+	 }
+	 else {
+	    /* Don't update Z buffer */
+            GLuint i;
+	    for (i=0; i<n; i++) {
+	       if (mask[i]) {
+		  GLushort *zptr = Z_ADDRESS16(ctx,x[i],y[i]);
+		  if (z[i] != *zptr) {
+		     /* pass */
+		  }
+		  else {
+		     /* fail */
+		     mask[i] = 0;
+		  }
+	       }
+	    }
+	 }
+	 break;
+      case GL_EQUAL:
+         if (ctx->Depth.Mask) {
+	    /* Update Z buffer */
+            GLuint i;
+	    for (i=0; i<n; i++) {
+	       if (mask[i]) {
+		  GLushort *zptr = Z_ADDRESS16(ctx,x[i],y[i]);
+		  if (z[i] == *zptr) {
+		     /* pass */
+		     *zptr = z[i];
+		  }
+		  else {
+		     /* fail */
+		     mask[i] = 0;
+		  }
+	       }
+	    }
+	 }
+	 else {
+	    /* Don't update Z buffer */
+            GLuint i;
+	    for (i=0; i<n; i++) {
+	       if (mask[i]) {
+		  GLushort *zptr = Z_ADDRESS16(ctx,x[i],y[i]);
+		  if (z[i] == *zptr) {
+		     /* pass */
+		  }
+		  else {
+		     /* fail */
+		     mask[i] = 0;
+		  }
+	       }
+	    }
+	 }
+	 break;
+      case GL_ALWAYS:
+	 if (ctx->Depth.Mask) {
+	    /* Update Z buffer */
+            GLuint i;
+	    for (i=0; i<n; i++) {
+	       if (mask[i]) {
+		  GLushort *zptr = Z_ADDRESS16(ctx,x[i],y[i]);
+		  *zptr = z[i];
+	       }
+	    }
+	 }
+	 else {
+	    /* Don't update Z buffer or mask */
+	 }
+	 break;
+      case GL_NEVER:
+	 /* depth test never passes */
+         MEMSET(mask, 0, n * sizeof(GLubyte));
+	 break;
+      default:
+         gl_problem(ctx, "Bad depth func in software_depth_test_pixels");
+   }
+}
 
 
 
@@ -405,9 +907,9 @@ _mesa_depth_test_span( GLcontext *ctx, GLuint n, GLint x, GLint y,
  * Do depth testing for an array of fragments using software Z buffer.
  */
 static void
-software_depth_test_pixels( GLcontext *ctx, GLuint n,
-                            const GLint x[], const GLint y[],
-                            const GLdepth z[], GLubyte mask[] )
+software_depth_test_pixels32( GLcontext *ctx, GLuint n,
+                              const GLint x[], const GLint y[],
+                              const GLdepth z[], GLubyte mask[] )
 {
    /* switch cases ordered from most frequent to less frequent */
    switch (ctx->Depth.Func) {
@@ -417,7 +919,7 @@ software_depth_test_pixels( GLcontext *ctx, GLuint n,
             GLuint i;
 	    for (i=0; i<n; i++) {
 	       if (mask[i]) {
-		  GLdepth *zptr = Z_ADDRESS(ctx,x[i],y[i]);
+		  GLuint *zptr = Z_ADDRESS32(ctx,x[i],y[i]);
 		  if (z[i] < *zptr) {
 		     /* pass */
 		     *zptr = z[i];
@@ -434,7 +936,7 @@ software_depth_test_pixels( GLcontext *ctx, GLuint n,
             GLuint i;
 	    for (i=0; i<n; i++) {
 	       if (mask[i]) {
-		  GLdepth *zptr = Z_ADDRESS(ctx,x[i],y[i]);
+		  GLuint *zptr = Z_ADDRESS32(ctx,x[i],y[i]);
 		  if (z[i] < *zptr) {
 		     /* pass */
 		  }
@@ -452,7 +954,7 @@ software_depth_test_pixels( GLcontext *ctx, GLuint n,
             GLuint i;
 	    for (i=0; i<n; i++) {
 	       if (mask[i]) {
-		  GLdepth *zptr = Z_ADDRESS(ctx,x[i],y[i]);
+		  GLuint *zptr = Z_ADDRESS32(ctx,x[i],y[i]);
 		  if (z[i] <= *zptr) {
 		     /* pass */
 		     *zptr = z[i];
@@ -469,7 +971,7 @@ software_depth_test_pixels( GLcontext *ctx, GLuint n,
             GLuint i;
 	    for (i=0; i<n; i++) {
 	       if (mask[i]) {
-		  GLdepth *zptr = Z_ADDRESS(ctx,x[i],y[i]);
+		  GLuint *zptr = Z_ADDRESS32(ctx,x[i],y[i]);
 		  if (z[i] <= *zptr) {
 		     /* pass */
 		  }
@@ -487,7 +989,7 @@ software_depth_test_pixels( GLcontext *ctx, GLuint n,
             GLuint i;
 	    for (i=0; i<n; i++) {
 	       if (mask[i]) {
-		  GLdepth *zptr = Z_ADDRESS(ctx,x[i],y[i]);
+		  GLuint *zptr = Z_ADDRESS32(ctx,x[i],y[i]);
 		  if (z[i] >= *zptr) {
 		     /* pass */
 		     *zptr = z[i];
@@ -504,7 +1006,7 @@ software_depth_test_pixels( GLcontext *ctx, GLuint n,
             GLuint i;
 	    for (i=0; i<n; i++) {
 	       if (mask[i]) {
-		  GLdepth *zptr = Z_ADDRESS(ctx,x[i],y[i]);
+		  GLuint *zptr = Z_ADDRESS32(ctx,x[i],y[i]);
 		  if (z[i] >= *zptr) {
 		     /* pass */
 		  }
@@ -522,7 +1024,7 @@ software_depth_test_pixels( GLcontext *ctx, GLuint n,
             GLuint i;
 	    for (i=0; i<n; i++) {
 	       if (mask[i]) {
-		  GLdepth *zptr = Z_ADDRESS(ctx,x[i],y[i]);
+		  GLuint *zptr = Z_ADDRESS32(ctx,x[i],y[i]);
 		  if (z[i] > *zptr) {
 		     /* pass */
 		     *zptr = z[i];
@@ -539,7 +1041,7 @@ software_depth_test_pixels( GLcontext *ctx, GLuint n,
             GLuint i;
 	    for (i=0; i<n; i++) {
 	       if (mask[i]) {
-		  GLdepth *zptr = Z_ADDRESS(ctx,x[i],y[i]);
+		  GLuint *zptr = Z_ADDRESS32(ctx,x[i],y[i]);
 		  if (z[i] > *zptr) {
 		     /* pass */
 		  }
@@ -557,7 +1059,7 @@ software_depth_test_pixels( GLcontext *ctx, GLuint n,
             GLuint i;
 	    for (i=0; i<n; i++) {
 	       if (mask[i]) {
-		  GLdepth *zptr = Z_ADDRESS(ctx,x[i],y[i]);
+		  GLuint *zptr = Z_ADDRESS32(ctx,x[i],y[i]);
 		  if (z[i] != *zptr) {
 		     /* pass */
 		     *zptr = z[i];
@@ -574,7 +1076,7 @@ software_depth_test_pixels( GLcontext *ctx, GLuint n,
             GLuint i;
 	    for (i=0; i<n; i++) {
 	       if (mask[i]) {
-		  GLdepth *zptr = Z_ADDRESS(ctx,x[i],y[i]);
+		  GLuint *zptr = Z_ADDRESS32(ctx,x[i],y[i]);
 		  if (z[i] != *zptr) {
 		     /* pass */
 		  }
@@ -592,7 +1094,7 @@ software_depth_test_pixels( GLcontext *ctx, GLuint n,
             GLuint i;
 	    for (i=0; i<n; i++) {
 	       if (mask[i]) {
-		  GLdepth *zptr = Z_ADDRESS(ctx,x[i],y[i]);
+		  GLuint *zptr = Z_ADDRESS32(ctx,x[i],y[i]);
 		  if (z[i] == *zptr) {
 		     /* pass */
 		     *zptr = z[i];
@@ -609,7 +1111,7 @@ software_depth_test_pixels( GLcontext *ctx, GLuint n,
             GLuint i;
 	    for (i=0; i<n; i++) {
 	       if (mask[i]) {
-		  GLdepth *zptr = Z_ADDRESS(ctx,x[i],y[i]);
+		  GLuint *zptr = Z_ADDRESS32(ctx,x[i],y[i]);
 		  if (z[i] == *zptr) {
 		     /* pass */
 		  }
@@ -627,7 +1129,7 @@ software_depth_test_pixels( GLcontext *ctx, GLuint n,
             GLuint i;
 	    for (i=0; i<n; i++) {
 	       if (mask[i]) {
-		  GLdepth *zptr = Z_ADDRESS(ctx,x[i],y[i]);
+		  GLuint *zptr = Z_ADDRESS32(ctx,x[i],y[i]);
 		  *zptr = z[i];
 	       }
 	    }
@@ -895,11 +1397,14 @@ _mesa_depth_test_pixels( GLcontext *ctx,
 
       /* update hardware Z buffer with new values */
       assert(ctx->Driver.WriteDepthPixels);
-      (*ctx->Driver.WriteDepthPixels)(ctx, n, x, y, z, mask );
+      (*ctx->Driver.WriteDepthPixels)(ctx, n, x, y, zbuffer, mask );
    }
    else {
       /* software depth testing */
-      software_depth_test_pixels(ctx, n, x, y, z, mask);
+      if (ctx->Visual->DepthBits <= 16)
+         software_depth_test_pixels16(ctx, n, x, y, z, mask);
+      else
+         software_depth_test_pixels32(ctx, n, x, y, z, mask);
    }
 }
 
@@ -923,14 +1428,23 @@ void
 _mesa_read_depth_span_float( GLcontext* ctx,
                              GLuint n, GLint x, GLint y, GLfloat depth[] )
 {
-   const GLfloat scale = 1.0F / DEPTH_SCALE;
+   const GLfloat scale = 1.0F / ctx->Visual->DepthMaxF;
 
-   if (ctx->DrawBuffer->Depth) {
+   if (ctx->DrawBuffer->DepthBuffer) {
       /* read from software depth buffer */
-      const GLdepth *zptr = Z_ADDRESS( ctx, x, y );
-      GLuint i;
-      for (i = 0; i < n; i++) {
-	 depth[i] = (GLfloat) zptr[i] * scale;
+      if (ctx->Visual->DepthBits <= 16) {
+         const GLushort *zptr = Z_ADDRESS16( ctx, x, y );
+         GLuint i;
+         for (i = 0; i < n; i++) {
+            depth[i] = (GLfloat) zptr[i] * scale;
+         }
+      }
+      else {
+         const GLuint *zptr = Z_ADDRESS32( ctx, x, y );
+         GLuint i;
+         for (i = 0; i < n; i++) {
+            depth[i] = (GLfloat) zptr[i] * scale;
+         }
       }
    }
    else if (ctx->Driver.ReadDepthSpan) {
@@ -963,19 +1477,29 @@ _mesa_read_depth_span_float( GLcontext* ctx,
  * This function is only called through Driver.alloc_depth_buffer.
  */
 void
-_mesa_alloc_depth_buffer( GLcontext* ctx )
+_mesa_alloc_depth_buffer( GLcontext *ctx )
 {
    /* deallocate current depth buffer if present */
    if (ctx->DrawBuffer->UseSoftwareDepthBuffer) {
+      GLint bytesPerValue;
+
       if (ctx->DrawBuffer->Depth) {
          FREE(ctx->DrawBuffer->Depth);
+         ctx->DrawBuffer->DepthBuffer = NULL;
          ctx->DrawBuffer->Depth = NULL;
       }
 
       /* allocate new depth buffer, but don't initialize it */
-      ctx->DrawBuffer->Depth = (GLdepth *) MALLOC( ctx->DrawBuffer->Width
-                                                   * ctx->DrawBuffer->Height
-                                                   * sizeof(GLdepth) );
+      if (ctx->Visual->DepthBits <= 16)
+         bytesPerValue = sizeof(GLushort);
+      else
+         bytesPerValue = sizeof(GLuint);
+
+      ctx->DrawBuffer->DepthBuffer = MALLOC( ctx->DrawBuffer->Width
+                                             * ctx->DrawBuffer->Height
+                                             * bytesPerValue );
+      ctx->DrawBuffer->Depth = (GLdepth *) ctx->DrawBuffer->DepthBuffer;
+
       if (!ctx->DrawBuffer->Depth) {
          /* out of memory */
          ctx->Depth.Test = GL_FALSE;
@@ -994,11 +1518,11 @@ _mesa_alloc_depth_buffer( GLcontext* ctx )
  * This function is only called through Driver.clear_depth_buffer.
  */
 void
-_mesa_clear_depth_buffer( GLcontext* ctx )
+_mesa_clear_depth_buffer( GLcontext *ctx )
 {
-   GLdepth clear_value = (GLdepth) (ctx->Depth.Clear * DEPTH_SCALE);
-   
-   if (ctx->Visual->DepthBits==0 || !ctx->DrawBuffer->Depth || !ctx->Depth.Mask) {
+   if (ctx->Visual->DepthBits == 0
+       || !ctx->DrawBuffer->DepthBuffer
+       || !ctx->Depth.Mask) {
       /* no depth buffer, or writing to it is disabled */
       return;
    }
@@ -1009,40 +1533,84 @@ _mesa_clear_depth_buffer( GLcontext* ctx )
 
    if (ctx->Scissor.Enabled) {
       /* only clear scissor region */
-      GLint y;
-      for (y=ctx->DrawBuffer->Ymin; y<=ctx->DrawBuffer->Ymax; y++) {
-         GLdepth *d = Z_ADDRESS( ctx, ctx->DrawBuffer->Xmin, y );
-         GLint n = ctx->DrawBuffer->Xmax - ctx->DrawBuffer->Xmin + 1;
-         do {
-            *d++ = clear_value;
-            n--;
-         } while (n);
+      if (ctx->Visual->DepthBits <= 16) {
+         const GLushort clearValue = (GLushort) (ctx->Depth.Clear * ctx->Visual->DepthMax);
+         const GLint rows = ctx->DrawBuffer->Ymax - ctx->DrawBuffer->Ymin + 1;
+         const GLint width = ctx->DrawBuffer->Width;
+         GLushort *dRow = (GLushort *) ctx->DrawBuffer->DepthBuffer
+            + ctx->DrawBuffer->Ymin * width + ctx->DrawBuffer->Xmin;
+         GLint i, j;
+         for (i = 0; i < rows; i++) {
+            for (j = 0; j < width; j++) {
+               dRow[j] = clearValue;
+            }
+            dRow += width;
+         }
+      }
+      else {
+         const GLuint clearValue = (GLuint) (ctx->Depth.Clear * ctx->Visual->DepthMax);
+         const GLint rows = ctx->DrawBuffer->Ymax - ctx->DrawBuffer->Ymin + 1;
+         const GLint width = ctx->DrawBuffer->Width;
+         GLuint *dRow = (GLuint *) ctx->DrawBuffer->DepthBuffer
+            + ctx->DrawBuffer->Ymin * width + ctx->DrawBuffer->Xmin;
+         GLint i, j;
+         for (i = 0; i < rows; i++) {
+            for (j = 0; j < width; j++) {
+               dRow[j] = clearValue;
+            }
+            dRow += width;
+         }
       }
    }
    else {
       /* clear whole buffer */
-      if (sizeof(GLdepth)==2 && (clear_value&0xff)==(clear_value>>8)) {
-         /* lower and upper bytes of clear_value are same, use MEMSET */
-         MEMSET( ctx->DrawBuffer->Depth, clear_value & 0xff,
-                 2*ctx->DrawBuffer->Width * ctx->DrawBuffer->Height);
+      if (ctx->Visual->DepthBits <= 16) {
+         const GLushort clearValue = (GLushort) (ctx->Depth.Clear * ctx->Visual->DepthMax);
+         if ((clearValue & 0xff) == (clearValue >> 8)) {
+            /* lower and upper bytes of clear_value are same, use MEMSET */
+            MEMSET( ctx->DrawBuffer->DepthBuffer, clearValue & 0xff,
+                    2 * ctx->DrawBuffer->Width * ctx->DrawBuffer->Height);
+         }
+         else {
+            GLushort *d = ctx->DrawBuffer->DepthBuffer;
+            GLint n = ctx->DrawBuffer->Width * ctx->DrawBuffer->Height;
+            while (n >= 16) {
+               d[0] = clearValue;    d[1] = clearValue;
+               d[2] = clearValue;    d[3] = clearValue;
+               d[4] = clearValue;    d[5] = clearValue;
+               d[6] = clearValue;    d[7] = clearValue;
+               d[8] = clearValue;    d[9] = clearValue;
+               d[10] = clearValue;   d[11] = clearValue;
+               d[12] = clearValue;   d[13] = clearValue;
+               d[14] = clearValue;   d[15] = clearValue;
+               d += 16;
+               n -= 16;
+            }
+            while (n > 0) {
+               *d++ = clearValue;
+               n--;
+            }
+         }
       }
       else {
-         GLdepth *d = ctx->DrawBuffer->Depth;
+         /* >16 bit depth buffer */
+         GLuint *d = (GLuint *) ctx->DrawBuffer->DepthBuffer;
+         const GLuint clearValue = (GLuint) (ctx->Depth.Clear * ctx->Visual->DepthMax);
          GLint n = ctx->DrawBuffer->Width * ctx->DrawBuffer->Height;
-         while (n>=16) {
-            d[0] = clear_value;    d[1] = clear_value;
-            d[2] = clear_value;    d[3] = clear_value;
-            d[4] = clear_value;    d[5] = clear_value;
-            d[6] = clear_value;    d[7] = clear_value;
-            d[8] = clear_value;    d[9] = clear_value;
-            d[10] = clear_value;   d[11] = clear_value;
-            d[12] = clear_value;   d[13] = clear_value;
-            d[14] = clear_value;   d[15] = clear_value;
+         while (n >= 16) {
+            d[0] = clearValue;    d[1] = clearValue;
+            d[2] = clearValue;    d[3] = clearValue;
+            d[4] = clearValue;    d[5] = clearValue;
+            d[6] = clearValue;    d[7] = clearValue;
+            d[8] = clearValue;    d[9] = clearValue;
+            d[10] = clearValue;   d[11] = clearValue;
+            d[12] = clearValue;   d[13] = clearValue;
+            d[14] = clearValue;   d[15] = clearValue;
             d += 16;
             n -= 16;
          }
-         while (n>0) {
-            *d++ = clear_value;
+         while (n > 0) {
+            *d++ = clearValue;
             n--;
          }
       }
diff --git a/src/mesa/main/depth.h b/src/mesa/main/depth.h
index 39064a653b..ec16ecf37d 100644
--- a/src/mesa/main/depth.h
+++ b/src/mesa/main/depth.h
@@ -1,10 +1,10 @@
-/* $Id: depth.h,v 1.6 2000/02/02 22:16:04 brianp Exp $ */
+/* $Id: depth.h,v 1.7 2000/03/03 17:47:39 brianp Exp $ */
 
 /*
  * Mesa 3-D graphics library
  * Version:  3.3
  * 
- * Copyright (C) 1999  Brian Paul   All Rights Reserved.
+ * Copyright (C) 1999-2000  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"),
@@ -49,14 +49,12 @@ _mesa_DepthMask( GLboolean flag );
 
 
 
-
 /*
- * Return the address of the Z-buffer value for window coordinate (x,y):
+ * Internal functions
  */
-#define Z_ADDRESS( CTX, X, Y )  \
-            ((CTX)->DrawBuffer->Depth + (CTX)->DrawBuffer->Width * (Y) + (X))
-
 
+extern GLvoid *
+_mesa_zbuffer_address(GLcontext *ctx, GLint x, GLint y);
 
 
 extern GLuint
diff --git a/src/mesa/main/dlist.c b/src/mesa/main/dlist.c
index fc4fbbd48b..2a317c7ba7 100644
--- a/src/mesa/main/dlist.c
+++ b/src/mesa/main/dlist.c
@@ -1,4 +1,4 @@
-/* $Id: dlist.c,v 1.33 2000/03/03 17:45:21 brianp Exp $ */
+/* $Id: dlist.c,v 1.34 2000/03/03 17:47:39 brianp Exp $ */
 
 /*
  * Mesa 3-D graphics library
@@ -2177,7 +2177,8 @@ static void save_PolygonOffset( GLfloat factor, GLfloat units )
 
 static void save_PolygonOffsetEXT( GLfloat factor, GLfloat bias )
 {
-   save_PolygonOffset(factor, DEPTH_SCALE * bias);
+   GET_CURRENT_CONTEXT(ctx);
+   save_PolygonOffset(factor, ctx->Visual->DepthMaxF * bias);
 }
 
 
diff --git a/src/mesa/main/drawpix.c b/src/mesa/main/drawpix.c
index 56ee2d76e3..49321a9459 100644
--- a/src/mesa/main/drawpix.c
+++ b/src/mesa/main/drawpix.c
@@ -1,4 +1,4 @@
-/* $Id: drawpix.c,v 1.13 2000/03/03 15:39:13 brianp Exp $ */
+/* $Id: drawpix.c,v 1.14 2000/03/03 17:54:56 brianp Exp $ */
 
 /*
  * Mesa 3-D graphics library
@@ -34,6 +34,7 @@
 #include "feedback.h"
 #include "image.h"
 #include "macros.h"
+#include "mem.h"
 #include "mmath.h"
 #include "pixel.h"
 #include "span.h"
@@ -174,7 +175,7 @@ simple_DrawPixels( GLcontext *ctx, GLint x, GLint y,
       }
       else {
          /* setup array of fragment Z value to pass to zoom function */
-         GLdepth z = (GLdepth) (ctx->Current.RasterPos[2] * DEPTH_SCALE);
+         GLdepth z = (GLdepth) (ctx->Current.RasterPos[2] * ctx->Visual->DepthMaxF);
          GLint i;
          assert(drawWidth < MAX_WIDTH);
          for (i=0; i<drawWidth; i++)
@@ -412,7 +413,7 @@ draw_index_pixels( GLcontext *ctx, GLint x, GLint y,
 
    /* Fragment depth values */
    if (ctx->Depth.Test || ctx->Fog.Enabled) {
-      GLdepth zval = (GLdepth) (ctx->Current.RasterPos[2] * DEPTH_SCALE);
+      GLdepth zval = (GLdepth) (ctx->Current.RasterPos[2] * ctx->Visual->DepthMaxF);
       GLint i;
       for (i = 0; i < drawWidth; i++) {
 	 zspan[i] = zval;
@@ -539,30 +540,23 @@ draw_depth_pixels( GLcontext *ctx, GLint x, GLint y,
       /* Special case: directly write 16-bit depth values */
       GLint row;
       for (row = 0; row < height; row++, y++) {
-         const GLdepth *zptr = gl_pixel_addr_in_image(&ctx->Unpack,
+         GLdepth zspan[MAX_WIDTH];
+         const GLushort *zptr = gl_pixel_addr_in_image(&ctx->Unpack,
                 pixels, width, height, GL_DEPTH_COMPONENT, type, 0, row, 0);
-         gl_write_rgba_span( ctx, width, x, y, zptr, rgba, GL_BITMAP );
+         GLint i;
+         for (i = 0; i < width; i++)
+            zspan[i] = zptr[i];
+         gl_write_rgba_span( ctx, width, x, y, zspan, rgba, GL_BITMAP );
       }
    }
-   else if (type==GL_UNSIGNED_INT && sizeof(GLdepth)==sizeof(GLuint)
+   else if (type==GL_UNSIGNED_INT && ctx->Visual->DepthBits == 32
        && !bias_or_scale && !zoom && ctx->Visual->RGBAflag) {
       /* Special case: directly write 32-bit depth values */
-      GLint i, row;
-      /* Compute shift value to scale 32-bit uints down to depth values. */
-      GLuint shift = 0;
-      GLuint max = MAX_DEPTH;
-      while ((max & 0x80000000) == 0) {
-         max = max << 1;
-         shift++;
-      }
+      GLint row;
       for (row = 0; row < height; row++, y++) {
-         GLdepth zspan[MAX_WIDTH];
-         const GLdepth *zptr = gl_pixel_addr_in_image(&ctx->Unpack,
+         const GLuint *zptr = gl_pixel_addr_in_image(&ctx->Unpack,
                 pixels, width, height, GL_DEPTH_COMPONENT, type, 0, row, 0);
-         for (i=0;i<width;i++) {
-            zspan[i] = zptr[i] >> shift;
-         }
-         gl_write_rgba_span( ctx, width, x, y, zspan, rgba, GL_BITMAP );
+         gl_write_rgba_span( ctx, width, x, y, zptr, rgba, GL_BITMAP );
       }
    }
    else {
@@ -619,7 +613,7 @@ draw_rgba_pixels( GLcontext *ctx, GLint x, GLint y,
    /* Fragment depth values */
    if (ctx->Depth.Test || ctx->Fog.Enabled) {
       /* fill in array of z values */
-      GLdepth z = (GLdepth) (ctx->Current.RasterPos[2] * DEPTH_SCALE);
+      GLdepth z = (GLdepth) (ctx->Current.RasterPos[2] * ctx->Visual->DepthMaxF);
       GLint i;
       for (i=0;i<width;i++) {
 	 zspan[i] = z;
diff --git a/src/mesa/main/feedback.c b/src/mesa/main/feedback.c
index 71c1025d90..3a38db1d62 100644
--- a/src/mesa/main/feedback.c
+++ b/src/mesa/main/feedback.c
@@ -1,4 +1,4 @@
-/* $Id: feedback.c,v 1.8 2000/01/25 16:49:20 brianp Exp $ */
+/* $Id: feedback.c,v 1.9 2000/03/03 17:47:39 brianp Exp $ */
 
 /*
  * Mesa 3-D graphics library
@@ -133,6 +133,7 @@ void gl_feedback_vertex( GLcontext *ctx,
    FEEDBACK_TOKEN( ctx, win[0] );
    FEEDBACK_TOKEN( ctx, win[1] );
    if (ctx->Feedback.Mask & FB_3D) {
+      printf("FB %g\n", win[2]);
       FEEDBACK_TOKEN( ctx, win[2] );
    }
    if (ctx->Feedback.Mask & FB_4D) {
@@ -168,7 +169,7 @@ static void feedback_vertex( GLcontext *ctx, GLuint v, GLuint pv )
 
    win[0] = VB->Win.data[v][0];
    win[1] = VB->Win.data[v][1];
-   win[2] = VB->Win.data[v][2] / DEPTH_SCALE;
+   win[2] = VB->Win.data[v][2] / ctx->Visual->DepthMaxF;
    win[3] = 1.0 / VB->Win.data[v][3];
 
    if (ctx->Light.ShadeModel == GL_SMOOTH)
@@ -299,12 +300,13 @@ void gl_update_hitflag( GLcontext *ctx, GLfloat z )
 void gl_select_triangle( GLcontext *ctx,
 			 GLuint v0, GLuint v1, GLuint v2, GLuint pv )
 {
-   struct vertex_buffer *VB = ctx->VB;
+   const struct vertex_buffer *VB = ctx->VB;
 
    if (gl_cull_triangle( ctx, v0, v1, v2, 0 )) {
-      gl_update_hitflag( ctx, VB->Win.data[v0][2] / DEPTH_SCALE );
-      gl_update_hitflag( ctx, VB->Win.data[v1][2] / DEPTH_SCALE );
-      gl_update_hitflag( ctx, VB->Win.data[v2][2] / DEPTH_SCALE );
+      const GLfloat zs = 1.0F / ctx->Visual->DepthMaxF;
+      gl_update_hitflag( ctx, VB->Win.data[v0][2] * zs );
+      gl_update_hitflag( ctx, VB->Win.data[v1][2] * zs );
+      gl_update_hitflag( ctx, VB->Win.data[v2][2] * zs );
    }
 }
 
@@ -312,21 +314,22 @@ void gl_select_triangle( GLcontext *ctx,
 void gl_select_line( GLcontext *ctx,
 		     GLuint v0, GLuint v1, GLuint pv )
 {
-   struct vertex_buffer *VB = ctx->VB;
-
-   gl_update_hitflag( ctx, VB->Win.data[v0][2] / DEPTH_SCALE );
-   gl_update_hitflag( ctx, VB->Win.data[v1][2] / DEPTH_SCALE );
+   const struct vertex_buffer *VB = ctx->VB;
+   const GLfloat zs = 1.0F / ctx->Visual->DepthMaxF;
+   gl_update_hitflag( ctx, VB->Win.data[v0][2] * zs );
+   gl_update_hitflag( ctx, VB->Win.data[v1][2] * zs );
 }
 
 
 void gl_select_points( GLcontext *ctx, GLuint first, GLuint last )
 {
    struct vertex_buffer *VB = ctx->VB;
+   const GLfloat zs = 1.0F / ctx->Visual->DepthMaxF;
    GLuint i;
 
    for (i=first;i<=last;i++) {
       if (VB->ClipMask[i]==0) {
-         gl_update_hitflag( ctx, VB->Win.data[i][2] / DEPTH_SCALE);
+         gl_update_hitflag( ctx, VB->Win.data[i][2] * zs );
       }
    }
 }
diff --git a/src/mesa/main/image.c b/src/mesa/main/image.c
index e37711e499..a1a0fe20ee 100644
--- a/src/mesa/main/image.c
+++ b/src/mesa/main/image.c
@@ -1,4 +1,4 @@
-/* $Id: image.c,v 1.17 2000/02/21 16:33:20 brianp Exp $ */
+/* $Id: image.c,v 1.18 2000/03/03 17:47:39 brianp Exp $ */
 
 /*
  * Mesa 3-D graphics library
@@ -2644,9 +2644,10 @@ _mesa_unpack_depth_span( const GLcontext *ctx, GLuint n, GLdepth *dest,
 
    /* clamp depth values to [0,1] and convert from floats to integers */
    {
+      const GLfloat zs = ctx->Visual->DepthMaxF;
       GLuint i;
       for (i = 0; i < n; i++) {
-         dest[i] = (GLdepth) (CLAMP(depth[i], 0.0F, 1.0F) * DEPTH_SCALE);
+         dest[i] = (GLdepth) (CLAMP(depth[i], 0.0F, 1.0F) * zs);
       }
    }
 
diff --git a/src/mesa/main/matrix.c b/src/mesa/main/matrix.c
index f340b1ecd1..c8f25c0cd5 100644
--- a/src/mesa/main/matrix.c
+++ b/src/mesa/main/matrix.c
@@ -1,4 +1,4 @@
-/* $Id: matrix.c,v 1.15 2000/02/21 23:00:51 brianp Exp $ */
+/* $Id: matrix.c,v 1.16 2000/03/03 17:47:39 brianp Exp $ */
 
 /*
  * Mesa 3-D graphics library
@@ -1460,8 +1460,8 @@ gl_Viewport( GLcontext *ctx, GLint x, GLint y, GLsizei width, GLsizei height )
    ctx->Viewport.WindowMap.m[MAT_TX] = ctx->Viewport.WindowMap.m[MAT_SX] + x;
    ctx->Viewport.WindowMap.m[MAT_SY] = (GLfloat) height / 2.0F;
    ctx->Viewport.WindowMap.m[MAT_TY] = ctx->Viewport.WindowMap.m[MAT_SY] + y;
-   ctx->Viewport.WindowMap.m[MAT_SZ] = 0.5 * DEPTH_SCALE;
-   ctx->Viewport.WindowMap.m[MAT_TZ] = 0.5 * DEPTH_SCALE;
+   ctx->Viewport.WindowMap.m[MAT_SZ] = 0.5 * ctx->Visual->DepthMaxF;
+   ctx->Viewport.WindowMap.m[MAT_TZ] = 0.5 * ctx->Visual->DepthMaxF;
 
    ctx->Viewport.WindowMap.flags = MAT_FLAG_GENERAL_SCALE|MAT_FLAG_TRANSLATION;
    ctx->Viewport.WindowMap.type = MATRIX_3D_NO_ROT;
@@ -1518,8 +1518,8 @@ _mesa_DepthRange( GLclampd nearval, GLclampd farval )
 
    ctx->Viewport.Near = n;
    ctx->Viewport.Far = f;
-   ctx->Viewport.WindowMap.m[MAT_SZ] = DEPTH_SCALE * ((f - n) / 2.0);
-   ctx->Viewport.WindowMap.m[MAT_TZ] = DEPTH_SCALE * ((f - n) / 2.0 + n);
+   ctx->Viewport.WindowMap.m[MAT_SZ] = ctx->Visual->DepthMaxF * ((f - n) / 2.0);
+   ctx->Viewport.WindowMap.m[MAT_TZ] = ctx->Visual->DepthMaxF * ((f - n) / 2.0 + n);
 
    ctx->ModelProjectWinMatrixUptodate = GL_FALSE;
 
diff --git a/src/mesa/main/polygon.c b/src/mesa/main/polygon.c
index 94a747c402..b461ac2998 100644
--- a/src/mesa/main/polygon.c
+++ b/src/mesa/main/polygon.c
@@ -1,4 +1,4 @@
-/* $Id: polygon.c,v 1.8 2000/02/27 20:38:15 keithw Exp $ */
+/* $Id: polygon.c,v 1.9 2000/03/03 17:47:39 brianp Exp $ */
 
 /*
  * Mesa 3-D graphics library
@@ -188,6 +188,8 @@ _mesa_PolygonOffset( GLfloat factor, GLfloat units )
 void
 _mesa_PolygonOffsetEXT( GLfloat factor, GLfloat bias )
 {
-   _mesa_PolygonOffset(factor, bias * DEPTH_SCALE );
+   GET_CURRENT_CONTEXT(ctx);
+   ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx, "glPolygonOffsetEXT");
+   _mesa_PolygonOffset(factor, bias * ctx->Visual->DepthMaxF );
 }
 
diff --git a/src/mesa/main/rastpos.c b/src/mesa/main/rastpos.c
index 9d852bd59d..722431a948 100644
--- a/src/mesa/main/rastpos.c
+++ b/src/mesa/main/rastpos.c
@@ -1,10 +1,10 @@
-/* $Id: rastpos.c,v 1.5 2000/02/02 19:17:57 brianp Exp $ */
+/* $Id: rastpos.c,v 1.6 2000/03/03 17:47:39 brianp Exp $ */
 
 /*
  * Mesa 3-D graphics library
  * Version:  3.3
  * 
- * Copyright (C) 1999  Brian Paul   All Rights Reserved.
+ * Copyright (C) 1999-2000  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"),
@@ -132,7 +132,7 @@ static void raster_pos4f( GLcontext *ctx,
    ctx->Current.RasterPos[1] = (ndc[1] * ctx->Viewport.WindowMap.m[MAT_SY] + 
 				ctx->Viewport.WindowMap.m[MAT_TY]);
    ctx->Current.RasterPos[2] = (ndc[2] * ctx->Viewport.WindowMap.m[MAT_SZ] + 
-				ctx->Viewport.WindowMap.m[MAT_TZ]) / DEPTH_SCALE;
+				ctx->Viewport.WindowMap.m[MAT_TZ]) / ctx->Visual->DepthMaxF;
    ctx->Current.RasterPos[3] = clip[3];
    ctx->Current.RasterPosValid = GL_TRUE;