runtime selectable depth buffer depth

3 files changed, 169 insertions, 92 deletions

diff --git a/src/mesa/drivers/glide/fxddspan.c b/src/mesa/drivers/glide/fxddspan.c
index ec55134802c..89abdda951e 100644
--- a/src/mesa/drivers/glide/fxddspan.c
+++ b/src/mesa/drivers/glide/fxddspan.c
@@ -396,7 +396,7 @@ static void fxDDReadRGBAPixels(const GLcontext *ctx,
 {
   fxMesaContext fxMesa=(fxMesaContext)ctx->DriverCtx;
   GLuint i;
-  GLint bottom=fxMesa->y_delta-1;
+  GLint bottom=fxMesa->height+fxMesa->y_offset-1;
 
   if (MESA_VERBOSE&VERBOSE_DRIVER) {
      fprintf(stderr,"fxmesa: fxDDReadRGBAPixels(...)\n");
@@ -423,11 +423,11 @@ void fxDDWriteDepthSpan(GLcontext *ctx,
                         GLuint n, GLint x, GLint y, const GLdepth depth[],
                         const GLubyte mask[])
 {
-  fxMesaContext fxMesa=(fxMesaContext)ctx->DriverCtx;
-  GLint bottom=fxMesa->height+fxMesa->y_offset-1;
+  fxMesaContext fxMesa = (fxMesaContext)ctx->DriverCtx;
+  GLint bottom = fxMesa->height + fxMesa->y_offset - 1;
 
-  if (MESA_VERBOSE&VERBOSE_DRIVER) {
-     fprintf(stderr,"fxmesa: fxDDReadDepthSpanInt(...)\n");
+  if (MESA_VERBOSE & VERBOSE_DRIVER) {
+     fprintf(stderr, "fxmesa: fxDDWriteDepthSpan(...)\n");
   }
 
   x += fxMesa->x_offset;
@@ -436,14 +436,20 @@ void fxDDWriteDepthSpan(GLcontext *ctx,
     GLint i;
     for (i = 0; i < n; i++) {
       if (mask[i]) {
-        writeRegionClipped(fxMesa, GR_BUFFER_AUXBUFFER, x + i, bottom-y,
-                           GR_LFB_SRC_FMT_ZA16, 1, 1, 0, (void *) &depth[i]);
+        GLshort d = depth[i];
+        writeRegionClipped(fxMesa, GR_BUFFER_AUXBUFFER, x + i, bottom - y,
+                           GR_LFB_SRC_FMT_ZA16, 1, 1, 0, (void *) &d);
       }
     }
   }
   else {
-    writeRegionClipped(fxMesa, GR_BUFFER_AUXBUFFER, x, bottom-y,
-                       GR_LFB_SRC_FMT_ZA16, n, 1, 0, (void *) depth);
+    GLushort depth16[MAX_WIDTH];
+    GLint i;
+    for (i = 0; i < n; i++) {
+      depth16[i] = depth[i];
+    }
+    writeRegionClipped(fxMesa, GR_BUFFER_AUXBUFFER, x, bottom - y,
+                       GR_LFB_SRC_FMT_ZA16, n, 1, 0, (void *) depth16);
   }
 }
 
@@ -451,15 +457,20 @@ void fxDDWriteDepthSpan(GLcontext *ctx,
 void fxDDReadDepthSpan(GLcontext *ctx,
                        GLuint n, GLint x, GLint y, GLdepth depth[])
 {
-  fxMesaContext fxMesa=(fxMesaContext)ctx->DriverCtx;
-  GLint bottom=fxMesa->height+fxMesa->y_offset-1;
+  fxMesaContext fxMesa = (fxMesaContext)ctx->DriverCtx;
+  GLint bottom = fxMesa->height + fxMesa->y_offset - 1;
+  GLushort depth16[MAX_WIDTH];
+  GLuint i;
 
-  if (MESA_VERBOSE&VERBOSE_DRIVER) {
-     fprintf(stderr,"fxmesa: fxDDReadDepthSpanInt(...)\n");
+  if (MESA_VERBOSE & VERBOSE_DRIVER) {
+     fprintf(stderr, "fxmesa: fxDDReadDepthSpan(...)\n");
   }
 
-  x+=fxMesa->x_offset;
-  FX_grLfbReadRegion(GR_BUFFER_AUXBUFFER,x,bottom-y,n,1,0,depth);
+  x += fxMesa->x_offset;
+  FX_grLfbReadRegion(GR_BUFFER_AUXBUFFER, x, bottom - y, n, 1, 0, depth16);
+  for (i = 0; i < n; i++) {
+    depth[i] = depth16[i];
+  }
 }
 
 
@@ -468,20 +479,21 @@ void fxDDWriteDepthPixels(GLcontext *ctx,
                           GLuint n, const GLint x[], const GLint y[],
                           const GLdepth depth[], const GLubyte mask[])
 {
-  fxMesaContext fxMesa=(fxMesaContext)ctx->DriverCtx;
-  GLint bottom=fxMesa->height+fxMesa->y_offset-1;
+  fxMesaContext fxMesa = (fxMesaContext)ctx->DriverCtx;
+  GLint bottom = fxMesa->height + fxMesa->y_offset - 1;
   GLuint i;
 
-  if (MESA_VERBOSE&VERBOSE_DRIVER) {
-     fprintf(stderr,"fxmesa: fxDDReadDepthSpanInt(...)\n");
+  if (MESA_VERBOSE & VERBOSE_DRIVER) {
+    fprintf(stderr, "fxmesa: fxDDWriteDepthPixels(...)\n");
   }
 
   for (i = 0; i < n; i++) {
     if (mask[i]) {
       int xpos = x[i] + fxMesa->x_offset;
       int ypos = bottom - y[i];
+      GLushort d = depth[i];
       writeRegionClipped(fxMesa, GR_BUFFER_AUXBUFFER, xpos, ypos,
-                         GR_LFB_SRC_FMT_ZA16, 1, 1, 0, (void *) &depth[i]);
+                         GR_LFB_SRC_FMT_ZA16, 1, 1, 0, (void *) &d);
     }
   }
 }
@@ -490,19 +502,20 @@ void fxDDWriteDepthPixels(GLcontext *ctx,
 void fxDDReadDepthPixels(GLcontext *ctx, GLuint n,
                          const GLint x[], const GLint y[], GLdepth depth[])
 {
-  fxMesaContext fxMesa=(fxMesaContext)ctx->DriverCtx;
-  GLint bottom=fxMesa->height+fxMesa->y_offset-1;
+  fxMesaContext fxMesa = (fxMesaContext)ctx->DriverCtx;
+  GLint bottom = fxMesa->height + fxMesa->y_offset - 1;
   GLuint i;
 
-  if (MESA_VERBOSE&VERBOSE_DRIVER) {
-     fprintf(stderr,"fxmesa: fxDDReadDepthSpanInt(...)\n");
+  if (MESA_VERBOSE & VERBOSE_DRIVER) {
+    fprintf(stderr, "fxmesa: fxDDReadDepthPixels(...)\n");
   }
 
-
   for (i = 0; i < n; i++) {
     int xpos = x[i] + fxMesa->x_offset;
     int ypos = bottom - y[i];
-    FX_grLfbReadRegion(GR_BUFFER_AUXBUFFER,xpos,ypos,1,1,0,&depth[i]);
+    GLushort d;
+    FX_grLfbReadRegion(GR_BUFFER_AUXBUFFER, xpos, ypos, 1, 1, 0, &d);
+    depth[i] = d;
   }
 }
 
diff --git a/src/mesa/drivers/osmesa/osmesa.c b/src/mesa/drivers/osmesa/osmesa.c
index a5a71bfc2dc..ea015236f00 100644
--- a/src/mesa/drivers/osmesa/osmesa.c
+++ b/src/mesa/drivers/osmesa/osmesa.c
@@ -1,4 +1,4 @@
-/* $Id: osmesa.c,v 1.9 2000/01/15 06:13:26 rjfrank Exp $ */
+/* $Id: osmesa.c,v 1.10 2000/03/03 17:50:09 brianp Exp $ */
 
 /*
  * Mesa 3-D graphics library
@@ -206,7 +206,7 @@ OSMesaCreateContext( GLenum format, OSMesaContext sharelist )
                                             swalpha,    /* software alpha */
                                             GL_FALSE,	/* double buffer */
                                             GL_FALSE,	/* stereo */
-                                            DEPTH_BITS,
+                                            DEFAULT_SOFTWARE_DEPTH_BITS,
                                             STENCIL_BITS,
                                             rgbmode ? ACCUM_BITS : 0,
                                             indexBits,
@@ -400,7 +400,6 @@ OSMesaMakeCurrent( OSMesaContext ctx, void *buffer, GLenum type,
 
 
 
-
 OSMesaContext GLAPIENTRY OSMesaGetCurrentContext( void )
 {
    GLcontext *ctx = gl_get_current_context();
@@ -1220,6 +1219,7 @@ static void flat_rgba_z_line( GLcontext *ctx,
 
 #define INTERP_XY 1
 #define INTERP_Z 1
+#define DEPTH_TYPE DEFAULT_SOFTWARE_DEPTH_TYPE
 #define CLIP_HACK 1
 #define PLOT(X,Y)				\
 	if (Z < *zPtr) {			\
@@ -1272,6 +1272,7 @@ static void flat_blend_rgba_line( GLcontext *ctx,
 #endif
 }
 
+
 /*
  * Draw a flat-shaded, Z-less, alpha-blended, RGB line into an osmesa buffer.
  */
@@ -1292,16 +1293,16 @@ static void flat_blend_rgba_z_line( GLcontext *ctx,
 
 #define INTERP_XY 1
 #define INTERP_Z 1
+#define DEPTH_TYPE DEFAULT_SOFTWARE_DEPTH_TYPE
 #define CLIP_HACK 1
-#define PLOT(X,Y)				\
-	if (Z < *zPtr) {			\
-   { GLuint *ptr4 = PIXELADDR4(X,Y); \
-     GLuint  pixel = 0; \
-     pixel |=((((((*ptr4) >> rshift) & 0xff)*msavalue+rvalue)>>8) << rshift);\
-     pixel |=((((((*ptr4) >> gshift) & 0xff)*msavalue+gvalue)>>8) << gshift);\
-     pixel |=((((((*ptr4) >> bshift) & 0xff)*msavalue+bvalue)>>8) << bshift);\
-     *ptr4 = pixel; \
-   } \
+#define PLOT(X,Y)									\
+	if (Z < *zPtr) {								\
+	   GLuint *ptr4 = PIXELADDR4(X,Y);						\
+	   GLuint  pixel = 0;								\
+	   pixel |=((((((*ptr4) >> rshift) & 0xff)*msavalue+rvalue)>>8) << rshift);	\
+	   pixel |=((((((*ptr4) >> gshift) & 0xff)*msavalue+gvalue)>>8) << gshift);	\
+	   pixel |=((((((*ptr4) >> bshift) & 0xff)*msavalue+bvalue)>>8) << bshift);	\
+	   *ptr4 = pixel; 								\
 	}
 
 #ifdef WIN32
@@ -1311,6 +1312,7 @@ static void flat_blend_rgba_z_line( GLcontext *ctx,
 #endif
 }
 
+
 /*
  * Draw a flat-shaded, Z-less, alpha-blended, RGB line into an osmesa buffer.
  */
@@ -1331,17 +1333,17 @@ static void flat_blend_rgba_z_line_write( GLcontext *ctx,
 
 #define INTERP_XY 1
 #define INTERP_Z 1
+#define DEPTH_TYPE DEFAULT_SOFTWARE_DEPTH_TYPE
 #define CLIP_HACK 1
-#define PLOT(X,Y)				\
-	if (Z < *zPtr) {			\
-   { GLuint *ptr4 = PIXELADDR4(X,Y); \
-     GLuint  pixel = 0; \
-     pixel |=((((((*ptr4) >> rshift) & 0xff)*msavalue+rvalue)>>8) << rshift);\
-     pixel |=((((((*ptr4) >> gshift) & 0xff)*msavalue+gvalue)>>8) << gshift);\
-     pixel |=((((((*ptr4) >> bshift) & 0xff)*msavalue+bvalue)>>8) << bshift);\
-     *ptr4 = pixel; \
-   } \
-	   *zPtr = Z;				\
+#define PLOT(X,Y)									\
+	if (Z < *zPtr) {								\
+	   GLuint *ptr4 = PIXELADDR4(X,Y);						\
+	   GLuint  pixel = 0;								\
+	   pixel |=((((((*ptr4) >> rshift) & 0xff)*msavalue+rvalue)>>8) << rshift);	\
+	   pixel |=((((((*ptr4) >> gshift) & 0xff)*msavalue+gvalue)>>8) << gshift);	\
+	   pixel |=((((((*ptr4) >> bshift) & 0xff)*msavalue+bvalue)>>8) << bshift);	\
+	   *ptr4 = pixel;								\
+	   *zPtr = Z;									\
 	}
 
 #ifdef WIN32
@@ -1369,7 +1371,8 @@ static line_func choose_line_function( GLcontext *ctx )
 
        if (ctx->RasterMask==DEPTH_BIT
            && ctx->Depth.Func==GL_LESS
-           && ctx->Depth.Mask==GL_TRUE) {
+           && ctx->Depth.Mask==GL_TRUE
+           && ctx->Visual->DepthBits == DEFAULT_SOFTWARE_DEPTH_BITS) {
            switch(osmesa->format) {
        		case OSMESA_RGBA:
        		case OSMESA_BGRA:
@@ -1394,6 +1397,7 @@ static line_func choose_line_function( GLcontext *ctx )
        if (ctx->RasterMask==(DEPTH_BIT|BLEND_BIT)
            && ctx->Depth.Func==GL_LESS
            && ctx->Depth.Mask==GL_TRUE
+           && ctx->Visual->DepthBits == DEFAULT_SOFTWARE_DEPTH_BITS
            && ctx->Color.BlendSrcRGB==GL_SRC_ALPHA
            && ctx->Color.BlendDstRGB==GL_ONE_MINUS_SRC_ALPHA
            && ctx->Color.BlendSrcA==GL_SRC_ALPHA
@@ -1412,6 +1416,7 @@ static line_func choose_line_function( GLcontext *ctx )
        if (ctx->RasterMask==(DEPTH_BIT|BLEND_BIT)
            && ctx->Depth.Func==GL_LESS
            && ctx->Depth.Mask==GL_FALSE
+           && ctx->Visual->DepthBits == DEFAULT_SOFTWARE_DEPTH_BITS
            && ctx->Color.BlendSrcRGB==GL_SRC_ALPHA
            && ctx->Color.BlendDstRGB==GL_ONE_MINUS_SRC_ALPHA
            && ctx->Color.BlendSrcA==GL_SRC_ALPHA
@@ -1467,6 +1472,7 @@ static void smooth_rgba_z_triangle( GLcontext *ctx, GLuint v0, GLuint v1,
    (void) pv;
    osmesa->bVisible = GL_TRUE; /* if here, the occlusion test is misused  */
 #define INTERP_Z 1
+#define DEPTH_TYPE DEFAULT_SOFTWARE_DEPTH_TYPE
 #define INTERP_RGB 1
 #define INTERP_ALPHA 1
 #define INNER_LOOP( LEFT, RIGHT, Y )				\
@@ -1502,6 +1508,7 @@ static void flat_rgba_z_triangle( GLcontext *ctx, GLuint v0, GLuint v1,
 {
    OSMesaContext osmesa = (OSMesaContext) ctx;
 #define INTERP_Z 1
+#define DEPTH_TYPE DEFAULT_SOFTWARE_DEPTH_TYPE
 #define SETUP_CODE			\
    GLubyte r = VB->ColorPtr->data[pv][0];	\
    GLubyte g = VB->ColorPtr->data[pv][1];	\
@@ -1547,6 +1554,7 @@ static triangle_func choose_triangle_function( GLcontext *ctx )
    if (ctx->RasterMask==DEPTH_BIT
        && ctx->Depth.Func==GL_LESS
        && ctx->Depth.Mask==GL_TRUE
+       && ctx->Visual->DepthBits == DEFAULT_SOFTWARE_DEPTH_BITS
        && osmesa->format!=OSMESA_COLOR_INDEX) {
       if (ctx->Light.ShadeModel==GL_SMOOTH) {
          return smooth_rgba_z_triangle;
@@ -1558,6 +1566,8 @@ static triangle_func choose_triangle_function( GLcontext *ctx )
    return NULL;
 }
 
+
+
 /**********************************************************************/
 /*****                 Occlusion rendering routines               *****/
 /**********************************************************************/
@@ -1576,87 +1586,113 @@ static triangle_func choose_triangle_function( GLcontext *ctx )
    } \
    return;
 
-/*****                 Color Index                                *****/
+/**
+*** Color Index
+**/
+
 static void write_index32_span_occ( const GLcontext *ctx,
-                                GLuint n, GLint x, GLint y,
-                                const GLuint index[], const GLubyte mask[] )
+                                    GLuint n, GLint x, GLint y,
+                                    const GLuint index[], const GLubyte mask[] )
 {
-	OCC_STD_MASK_TEST
+   OCC_STD_MASK_TEST
 }
+
+
 static void write_index8_span_occ( const GLcontext *ctx,
-                               GLuint n, GLint x, GLint y,
-                               const GLubyte index[], const GLubyte mask[] )
+                                   GLuint n, GLint x, GLint y,
+                                   const GLubyte index[], const GLubyte mask[] )
 {
-	OCC_STD_MASK_TEST
+   OCC_STD_MASK_TEST
 }
+
+
 static void write_monoindex_span_occ( const GLcontext *ctx,
-                                  GLuint n, GLint x, GLint y,
-                                  const GLubyte mask[] )
+                                      GLuint n, GLint x, GLint y,
+                                      const GLubyte mask[] )
 {
-	OCC_STD_MASK_TEST
+   OCC_STD_MASK_TEST
 }
+
+
 static void write_index_pixels_occ( const GLcontext *ctx,
-                                GLuint n, const GLint x[], const GLint y[],
-                                const GLuint index[], const GLubyte mask[] )
+                                    GLuint n, const GLint x[], const GLint y[],
+                                    const GLuint index[], const GLubyte mask[] )
 {
-	OCC_STD_MASK_TEST
+   OCC_STD_MASK_TEST
 }
+
+
 static void write_monoindex_pixels_occ( const GLcontext *ctx,
-                                    GLuint n, const GLint x[], const GLint y[],
-                                    const GLubyte mask[] )
+                                        GLuint n, const GLint x[], const GLint y[],
+                                        const GLubyte mask[] )
 {
-	OCC_STD_MASK_TEST
+   OCC_STD_MASK_TEST
 }
 
-/*****                 RGB/RGBA                                   *****/
+/**
+*** RGB/RGBA
+**/
 static void write_rgba_span_occ( const GLcontext *ctx,
-                             GLuint n, GLint x, GLint y,
-                             CONST GLubyte rgba[][4], const GLubyte mask[] )
+                                 GLuint n, GLint x, GLint y,
+                                 CONST GLubyte rgba[][4], const GLubyte mask[] )
 {
-	OCC_STD_MASK_TEST
+   OCC_STD_MASK_TEST
 }
+
+
 static void write_rgb_span_occ( const GLcontext *ctx,
-                                  GLuint n, GLint x, GLint y,
-                                  CONST GLubyte rgb[][3],
-                                  const GLubyte mask[] )
+                                GLuint n, GLint x, GLint y,
+                                CONST GLubyte rgb[][3],
+                                const GLubyte mask[] )
 {
-	OCC_STD_MASK_TEST
+   OCC_STD_MASK_TEST
 }
+
+
 static void write_rgba_pixels_occ( const GLcontext *ctx,
-                               GLuint n, const GLint x[], const GLint y[],
-                               CONST GLubyte rgba[][4], const GLubyte mask[] )
+                                   GLuint n, const GLint x[], const GLint y[],
+                                   CONST GLubyte rgba[][4], const GLubyte mask[] )
 {
-	OCC_STD_MASK_TEST
+   OCC_STD_MASK_TEST
 }
+
+
 static void write_monocolor_span_occ( const GLcontext *ctx,
-                                  GLuint n, GLint x, GLint y,
-                                  const GLubyte mask[] )
+                                      GLuint n, GLint x, GLint y,
+                                      const GLubyte mask[] )
 {
-	OCC_STD_MASK_TEST
+   OCC_STD_MASK_TEST
 }
+
+
 static void write_monocolor_pixels_occ( const GLcontext *ctx,
-                                    GLuint n, const GLint x[], const GLint y[],
-                                    const GLubyte mask[] )
+                                        GLuint n, const GLint x[], const GLint y[],
+                                        const GLubyte mask[] )
 {
-	OCC_STD_MASK_TEST
+   OCC_STD_MASK_TEST
 }
 
-/*****                 Line Drawing                               *****/
+
+/**
+*** Line Drawing
+**/
 static void line_occ( GLcontext *ctx,
-                            GLuint vert0, GLuint vert1, GLuint pvert )
+                      GLuint vert0, GLuint vert1, GLuint pvert )
 {
    OSMesaContext osmesa = (OSMesaContext) ctx->DriverCtx; 
    osmesa->bVisible = GL_TRUE; 
 }
 
+
 static void line_z_occ( GLcontext *ctx,
-                            GLuint vert0, GLuint vert1, GLuint pvert )
+                        GLuint vert0, GLuint vert1, GLuint pvert )
 {
    OSMesaContext osmesa = (OSMesaContext) ctx->DriverCtx; 
    if (osmesa->bVisible) return; 
 
 #define INTERP_XY 1
 #define INTERP_Z 1
+#define DEPTH_TYPE DEFAULT_SOFTWARE_DEPTH_TYPE
 #define CLIP_HACK 1
 #define PLOT(X,Y)                               \
         if (Z < *zPtr) {                        \
@@ -1671,19 +1707,25 @@ static void line_z_occ( GLcontext *ctx,
 #endif
 }
 
-/*****                 Triangle Drawing                           *****/
+
+/**
+*** Triangle Drawing
+**/
 static void triangle_occ( GLcontext *ctx, GLuint v0, GLuint v1,
-                                    GLuint v2, GLuint pv )
+                          GLuint v2, GLuint pv )
 {
    OSMesaContext osmesa = (OSMesaContext) ctx->DriverCtx; 
    osmesa->bVisible = GL_TRUE; 
 }
+
+
 static void triangle_z_occ( GLcontext *ctx, GLuint v0, GLuint v1,
-                                    GLuint v2, GLuint pv )
+                            GLuint v2, GLuint pv )
 {
    OSMesaContext osmesa = (OSMesaContext) ctx->DriverCtx; 
    if (osmesa->bVisible) return; 
 #define INTERP_Z 1
+#define DEPTH_TYPE DEFAULT_SOFTWARE_DEPTH_TYPE
 #define INNER_LOOP( LEFT, RIGHT, Y )    \
 {                                       \
    GLint i, len = RIGHT-LEFT;           \
@@ -1703,6 +1745,7 @@ static void triangle_z_occ( GLcontext *ctx, GLuint v0, GLuint v1,
 #endif
 }
 
+
 static const GLubyte *get_string( GLcontext *ctx, GLenum name )
 {
    (void) ctx;
diff --git a/src/mesa/drivers/x11/fakeglx.c b/src/mesa/drivers/x11/fakeglx.c
index 152e661e983..af8254fed9f 100644
--- a/src/mesa/drivers/x11/fakeglx.c
+++ b/src/mesa/drivers/x11/fakeglx.c
@@ -1,4 +1,4 @@
-/* $Id: fakeglx.c,v 1.24 2000/02/27 18:26:54 brianp Exp $ */
+/* $Id: fakeglx.c,v 1.25 2000/03/03 17:50:09 brianp Exp $ */
 
 /*
  * Mesa 3-D graphics library
@@ -300,6 +300,11 @@ save_glx_visual( Display *dpy, XVisualInfo *vinfo,
 
 /*
  * Create a GLX visual from a regular XVisualInfo.
+ * This is called when Fake GLX is given an XVisualInfo which wasn't
+ * returned by glXChooseVisual.  Since this is the first time we're
+ * considering this visual we'll take a guess at reasonable values
+ * for depth buffer size, stencil size, accum size, etc.
+ * This is the best we can do with a client-side emulation of GLX.
  */
 static XMesaVisual
 create_glx_visual( Display *dpy, XVisualInfo *visinfo )
@@ -329,9 +334,9 @@ create_glx_visual( Display *dpy, XVisualInfo *visinfo )
                               GL_FALSE,  /* alpha */
                               GL_TRUE,   /* double */
                               GL_FALSE,  /* stereo */
-                              8*sizeof(GLdepth),
-                              8*sizeof(GLstencil),
-                              8*sizeof(GLaccum),
+                              DEFAULT_SOFTWARE_DEPTH_BITS,
+                              8 * sizeof(GLstencil),
+                              8 * sizeof(GLaccum),
                               0          /* level */
                             );
    }
@@ -1014,6 +1019,22 @@ Fake_glXChooseVisual( Display *dpy, int screen, int *list )
    }
 
    if (vis) {
+      /* Note: we're not exactly obeying the glXChooseVisual rules here.
+       * When GLX_DEPTH_SIZE = 1 is specified we're supposed to choose the
+       * largest depth buffer size, which is 32bits/value.  However, we
+       * return 16 to maintain performance with earlier versions of Mesa.
+       */
+      if (depth_size == 1)
+         depth_size = DEFAULT_SOFTWARE_DEPTH_BITS;
+      else if (depth_size > 24)
+         depth_size = 31;
+      else if (depth_size > 16)
+         depth_size = 24;
+      /* we only support one size of stencil and accum buffers. */
+      if (stencil_size > 0)
+         stencil_size = STENCIL_BITS;
+      if (accum_size > 0)
+         accum_size = ACCUM_BITS;
       if (!save_glx_visual( dpy, vis, rgb_flag, alpha_flag, double_flag,
                             stereo_flag,
                             depth_size, stencil_size, accum_size, level ))