Initial import.

1 files changed, 1307 insertions, 0 deletions

diff --git a/src/mesa/drivers/osmesa/osmesa.c b/src/mesa/drivers/osmesa/osmesa.c
new file mode 100644
index 0000000..366bb03
--- /dev/null
+++ b/src/mesa/drivers/osmesa/osmesa.c
@@ -0,0 +1,1307 @@
+/*
+ * Mesa 3-D graphics library
+ * Version:  6.1
+ *
+ * Copyright (C) 1999-2004  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"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+ * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+
+/*
+ * Off-Screen Mesa rendering / Rendering into client memory space
+ *
+ * Note on thread safety:  this driver is thread safe.  All
+ * functions are reentrant.  The notion of current context is
+ * managed by the core _mesa_make_current() and _mesa_get_current_context()
+ * functions.  Those functions are thread-safe.
+ */
+
+
+#include "glheader.h"
+#include "GL/osmesa.h"
+#include "buffers.h"
+#include "bufferobj.h"
+#include "context.h"
+#include "colormac.h"
+#include "depth.h"
+#include "extensions.h"
+#include "imports.h"
+#include "macros.h"
+#include "matrix.h"
+#include "mtypes.h"
+#include "texformat.h"
+#include "texobj.h"
+#include "teximage.h"
+#include "texstore.h"
+#include "array_cache/acache.h"
+#include "swrast/swrast.h"
+#include "swrast_setup/swrast_setup.h"
+#include "swrast/s_context.h"
+#include "swrast/s_depth.h"
+#include "swrast/s_lines.h"
+#include "swrast/s_triangle.h"
+#include "tnl/tnl.h"
+#include "tnl/t_context.h"
+#include "tnl/t_pipeline.h"
+#include "drivers/common/driverfuncs.h"
+
+
+
+/*
+ * This is the OS/Mesa context struct.
+ * Notice how it includes a GLcontext.  By doing this we're mimicking
+ * C++ inheritance/derivation.
+ * Later, we can cast a GLcontext pointer into an OSMesaContext pointer
+ * or vice versa.
+ */
+struct osmesa_context {
+   GLcontext mesa;		/* The core GL/Mesa context */
+   GLvisual *gl_visual;		/* Describes the buffers */
+   GLframebuffer *gl_buffer;	/* Depth, stencil, accum, etc buffers */
+   GLenum format;		/* either GL_RGBA or GL_COLOR_INDEX */
+   void *buffer;		/* the image buffer */
+   GLint width, height;		/* size of image buffer */
+   GLint rowlength;		/* number of pixels per row */
+   GLint userRowLength;		/* user-specified number of pixels per row */
+   GLint rshift, gshift;	/* bit shifts for RGBA formats */
+   GLint bshift, ashift;
+   GLint rInd, gInd, bInd, aInd;/* index offsets for RGBA formats */
+   GLchan *rowaddr[MAX_HEIGHT];	/* address of first pixel in each image row */
+   GLboolean yup;		/* TRUE  -> Y increases upward */
+				/* FALSE -> Y increases downward */
+};
+
+
+/* Just cast, since we're using structure containment */
+#define OSMESA_CONTEXT(ctx)  ((OSMesaContext) (ctx->DriverCtx))
+
+
+
+/**********************************************************************/
+/*** Private Device Driver Functions                                ***/
+/**********************************************************************/
+
+
+static const GLubyte *
+get_string( GLcontext *ctx, GLenum name )
+{
+   (void) ctx;
+   switch (name) {
+      case GL_RENDERER:
+#if CHAN_BITS == 32
+         return (const GLubyte *) "Mesa OffScreen32";
+#elif CHAN_BITS == 16
+         return (const GLubyte *) "Mesa OffScreen16";
+#else
+         return (const GLubyte *) "Mesa OffScreen";
+#endif
+      default:
+         return NULL;
+   }
+}
+
+
+static void
+osmesa_update_state( GLcontext *ctx, GLuint new_state )
+{
+   /* easy - just propogate */
+   _swrast_InvalidateState( ctx, new_state );
+   _swsetup_InvalidateState( ctx, new_state );
+   _ac_InvalidateState( ctx, new_state );
+   _tnl_InvalidateState( ctx, new_state );
+}
+
+
+static void
+set_buffer( GLcontext *ctx, GLframebuffer *buffer, GLuint bufferBit )
+{
+   /* separate read buffer not supported */
+   ASSERT(buffer == ctx->DrawBuffer);
+   ASSERT(bufferBit == DD_FRONT_LEFT_BIT);
+}
+
+
+static void
+get_buffer_size( GLframebuffer *buffer, GLuint *width, GLuint *height )
+{
+   /* don't use GET_CURRENT_CONTEXT(ctx) here - it's a problem on Windows */
+   GLcontext *ctx = (GLcontext *) _glapi_get_context();
+   (void) buffer;
+   if (ctx) {
+      OSMesaContext osmesa = OSMESA_CONTEXT(ctx);
+      *width = osmesa->width;
+      *height = osmesa->height;
+   }
+}
+
+
+static void
+clear( GLcontext *ctx, GLbitfield mask, GLboolean all,
+       GLint x, GLint y, GLint width, GLint height )
+{
+   OSMesaContext osmesa = OSMESA_CONTEXT(ctx);
+   const GLuint *colorMask = (GLuint *) &ctx->Color.ColorMask;
+
+   /* sanity check - we only have a front-left buffer */
+   ASSERT((mask & (DD_FRONT_RIGHT_BIT |
+                   DD_BACK_LEFT_BIT |
+                   DD_BACK_RIGHT_BIT)) == 0);
+
+   /* use optimized clear for common cases (clear whole buffer to black) */
+   if (mask & DD_FRONT_LEFT_BIT) {
+      if (osmesa->format == OSMESA_COLOR_INDEX) {
+         if (ctx->Color.ClearIndex == 0 &&
+             ctx->Color.IndexMask == (GLuint) ~0 &&
+             osmesa->rowlength == osmesa->width &&
+             all) {
+            /* clear whole buffer to zeros */
+            _mesa_bzero(osmesa->buffer,
+                        osmesa->width * osmesa->height * sizeof(GLchan));
+            mask &= ~DD_FRONT_LEFT_BIT;
+         }
+      }
+      else {
+         /* RGB[A] format */
+         if (*colorMask == 0xffffffff &&
+             ctx->Color.ClearColor[0] == 0.0F &&
+             ctx->Color.ClearColor[1] == 0.0F &&
+             ctx->Color.ClearColor[2] == 0.0F &&
+             ctx->Color.ClearColor[3] == 0.0F &&
+             osmesa->rowlength == osmesa->width &&
+             all) {
+            GLint bytesPerPixel;
+            /* clear whole buffer to black */
+            if (osmesa->format == OSMESA_RGBA ||
+                osmesa->format == OSMESA_BGRA ||
+                osmesa->format == OSMESA_ARGB)
+               bytesPerPixel = 4 * sizeof(GLchan);
+            else if (osmesa->format == OSMESA_RGB ||
+                     osmesa->format == OSMESA_BGR)
+               bytesPerPixel = 3 * sizeof(GLchan);
+            else if (osmesa->format == OSMESA_RGB_565)
+               bytesPerPixel = sizeof(GLushort);
+            else {
+               _mesa_problem(ctx, "bad pixel format in osmesa_clear()");
+               return;
+            }
+            _mesa_bzero(osmesa->buffer,
+                        bytesPerPixel * osmesa->width * osmesa->height);
+            mask &= ~DD_FRONT_LEFT_BIT;
+         }
+      }
+   }
+
+   if (mask) {
+      /* software fallback (spans) for everything else. */
+      _swrast_Clear(ctx, mask, all, x, y, width, height);
+   }
+}
+
+
+/**********************************************************************/
+/*****        Read/write spans/arrays of pixels                   *****/
+/**********************************************************************/
+
+
+/* RGBA */
+#define NAME(PREFIX) PREFIX##_RGBA
+#define SPAN_VARS \
+   const OSMesaContext osmesa = OSMESA_CONTEXT(ctx);
+#define INIT_PIXEL_PTR(P, X, Y) \
+   GLchan *P = osmesa->rowaddr[Y] + 4 * (X)
+#define INC_PIXEL_PTR(P) P += 4
+#if CHAN_TYPE == GL_FLOAT
+#define STORE_RGB_PIXEL(P, X, Y, R, G, B) \
+   P[0] = MAX2((R), 0.0F); \
+   P[1] = MAX2((G), 0.0F); \
+   P[2] = MAX2((B), 0.0F); \
+   P[3] = CHAN_MAXF
+#define STORE_RGBA_PIXEL(P, X, Y, R, G, B, A) \
+   P[0] = MAX2((R), 0.0F); \
+   P[1] = MAX2((G), 0.0F); \
+   P[2] = MAX2((B), 0.0F); \
+   P[3] = CLAMP((A), 0.0F, CHAN_MAXF)
+#else
+#define STORE_RGB_PIXEL(P, X, Y, R, G, B) \
+   P[0] = R;  P[1] = G;  P[2] = B;  P[3] = CHAN_MAX
+#define STORE_RGBA_PIXEL(P, X, Y, R, G, B, A) \
+   P[0] = R;  P[1] = G;  P[2] = B;  P[3] = A
+#endif
+#define FETCH_RGBA_PIXEL(R, G, B, A, P) \
+   R = P[0];  G = P[1];  B = P[2];  A = P[3]
+#include "swrast/s_spantemp.h"
+
+/* BGRA */
+#define NAME(PREFIX) PREFIX##_BGRA
+#define SPAN_VARS \
+   const OSMesaContext osmesa = OSMESA_CONTEXT(ctx);
+#define INIT_PIXEL_PTR(P, X, Y) \
+   GLchan *P = osmesa->rowaddr[Y] + 4 * (X)
+#define INC_PIXEL_PTR(P) P += 4
+#define STORE_RGB_PIXEL(P, X, Y, R, G, B) \
+   P[2] = R;  P[1] = G;  P[0] = B;  P[3] = CHAN_MAX
+#define STORE_RGBA_PIXEL(P, X, Y, R, G, B, A) \
+   P[2] = R;  P[1] = G;  P[0] = B;  P[3] = A
+#define FETCH_RGBA_PIXEL(R, G, B, A, P) \
+   R = P[2];  G = P[1];  B = P[0];  A = P[3]
+#include "swrast/s_spantemp.h"
+
+/* ARGB */
+#define NAME(PREFIX) PREFIX##_ARGB
+#define SPAN_VARS \
+   const OSMesaContext osmesa = OSMESA_CONTEXT(ctx);
+#define INIT_PIXEL_PTR(P, X, Y) \
+   GLchan *P = osmesa->rowaddr[Y] + 4 * (X)
+#define INC_PIXEL_PTR(P) P += 4
+#define STORE_RGB_PIXEL(P, X, Y, R, G, B) \
+   P[1] = R;  P[2] = G;  P[3] = B;  P[0] = CHAN_MAX
+#define STORE_RGBA_PIXEL(P, X, Y, R, G, B, A) \
+   P[1] = R;  P[2] = G;  P[3] = B;  P[0] = A
+#define FETCH_RGBA_PIXEL(R, G, B, A, P) \
+   R = P[1];  G = P[2];  B = P[3];  A = P[0]
+#include "swrast/s_spantemp.h"
+
+/* RGB */
+#define NAME(PREFIX) PREFIX##_RGB
+#define SPAN_VARS \
+   const OSMesaContext osmesa = OSMESA_CONTEXT(ctx);
+#define INIT_PIXEL_PTR(P, X, Y) \
+   GLchan *P = osmesa->rowaddr[Y] + 3 * (X)
+#define INC_PIXEL_PTR(P) P += 3
+#define STORE_RGB_PIXEL(P, X, Y, R, G, B) \
+   P[0] = R;  P[1] = G;  P[2] = B
+#define STORE_RGBA_PIXEL(P, X, Y, R, G, B, A) \
+   P[0] = R;  P[1] = G;  P[2] = B
+#define FETCH_RGBA_PIXEL(R, G, B, A, P) \
+   R = P[0];  G = P[1];  B = P[2];  A = CHAN_MAX
+#include "swrast/s_spantemp.h"
+
+/* BGR */
+#define NAME(PREFIX) PREFIX##_BGR
+#define SPAN_VARS \
+   const OSMesaContext osmesa = OSMESA_CONTEXT(ctx);
+#define INIT_PIXEL_PTR(P, X, Y) \
+   GLchan *P = osmesa->rowaddr[Y] + 3 * (X)
+#define INC_PIXEL_PTR(P) P += 3
+#define STORE_RGB_PIXEL(P, X, Y, R, G, B) \
+   P[0] = B;  P[1] = G;  P[2] = R
+#define STORE_RGBA_PIXEL(P, X, Y, R, G, B, A) \
+   P[0] = B;  P[1] = G;  P[2] = R
+#define FETCH_RGBA_PIXEL(R, G, B, A, P) \
+   B = P[0];  G = P[1];  R = P[2];  A = CHAN_MAX
+#include "swrast/s_spantemp.h"
+
+/* 16-bit BGR */
+#if CHAN_TYPE == GL_UNSIGNED_BYTE
+#define NAME(PREFIX) PREFIX##_RGB_565
+#define SPAN_VARS \
+   const OSMesaContext osmesa = OSMESA_CONTEXT(ctx);
+#define INIT_PIXEL_PTR(P, X, Y) \
+   GLushort *P = (GLushort *) osmesa->rowaddr[Y] + (X)
+#define INC_PIXEL_PTR(P) P += 1
+#define STORE_RGB_PIXEL(P, X, Y, R, G, B) \
+   *P = ( (((R) & 0xf8) << 8) | (((G) & 0xfc) << 3) | ((B) >> 3) )
+#define STORE_RGBA_PIXEL(P, X, Y, R, G, B, A) \
+   *P = ( (((R) & 0xf8) << 8) | (((G) & 0xfc) << 3) | ((B) >> 3) )
+#define FETCH_RGBA_PIXEL(R, G, B, A, P) \
+   R = ( (((*P) >> 8) & 0xf8) | (((*P) >> 11) & 0x7) ); \
+   G = ( (((*P) >> 3) & 0xfc) | (((*P) >>  5) & 0x3) ); \
+   B = ( (((*P) << 3) & 0xf8) | (((*P)      ) & 0x7) ); \
+   A = CHAN_MAX
+#include "swrast/s_spantemp.h"
+#endif
+
+/* color index */
+#define NAME(PREFIX) PREFIX##_CI
+#define SPAN_VARS \
+   const OSMesaContext osmesa = OSMESA_CONTEXT(ctx);
+#define INIT_PIXEL_PTR(P, X, Y) \
+   GLchan *P = osmesa->rowaddr[Y] + (X)
+#define INC_PIXEL_PTR(P) P += 1
+#define STORE_CI_PIXEL(P, CI) \
+   P[0] = CI
+#define FETCH_CI_PIXEL(CI, P) \
+   CI = P[0]
+#include "swrast/s_spantemp.h"
+
+
+/**********************************************************************/
+/*****                   Optimized line rendering                 *****/
+/**********************************************************************/
+
+
+#if CHAN_TYPE == GL_FLOAT
+#define PACK_RGBA(DST, R, G, B, A)	\
+do {					\
+   (DST)[0] = MAX2( R, 0.0F );		\
+   (DST)[1] = MAX2( G, 0.0F );		\
+   (DST)[2] = MAX2( B, 0.0F );		\
+   (DST)[3] = CLAMP(A, 0.0F, CHAN_MAXF);\
+} while (0)
+#else
+#define PACK_RGBA(DST, R, G, B, A)	\
+do {					\
+   (DST)[osmesa->rInd] = R;		\
+   (DST)[osmesa->gInd] = G;		\
+   (DST)[osmesa->bInd] = B;		\
+   (DST)[osmesa->aInd] = A;		\
+} while (0)
+#endif
+
+#define PACK_RGB(DST, R, G, B)  \
+do {				\
+   (DST)[0] = R;		\
+   (DST)[1] = G;		\
+   (DST)[2] = B;		\
+} while (0)
+
+#define PACK_BGR(DST, R, G, B)  \
+do {				\
+   (DST)[0] = B;		\
+   (DST)[1] = G;		\
+   (DST)[2] = R;		\
+} while (0)
+
+#define PACK_RGB_565(DST, R, G, B)					\
+do {									\
+   (DST) = (((int) (R) << 8) & 0xf800) | (((int) (G) << 3) & 0x7e0) | ((int) (B) >> 3);\
+} while (0)
+
+#define UNPACK_RED(P)      ( (P)[osmesa->rInd] )
+#define UNPACK_GREEN(P)    ( (P)[osmesa->gInd] )
+#define UNPACK_BLUE(P)     ( (P)[osmesa->bInd] )
+#define UNPACK_ALPHA(P)    ( (P)[osmesa->aInd] )
+
+#define PIXELADDR1(X,Y)  (osmesa->rowaddr[Y] + (X))
+#define PIXELADDR2(X,Y)  (osmesa->rowaddr[Y] + 2 * (X))
+#define PIXELADDR3(X,Y)  (osmesa->rowaddr[Y] + 3 * (X))
+#define PIXELADDR4(X,Y)  (osmesa->rowaddr[Y] + 4 * (X))
+
+
+/*
+ * Draw a flat-shaded, RGB line into an osmesa buffer.
+ */
+#define NAME flat_rgba_line
+#define CLIP_HACK 1
+#define SETUP_CODE						\
+   const OSMesaContext osmesa = OSMESA_CONTEXT(ctx);		\
+   const GLchan *color = vert1->color;
+
+#define PLOT(X, Y)						\
+do {								\
+   GLchan *p = PIXELADDR4(X, Y);				\
+   PACK_RGBA(p, color[0], color[1], color[2], color[3]);	\
+} while (0)
+
+#ifdef WIN32
+#include "..\swrast\s_linetemp.h"
+#else
+#include "swrast/s_linetemp.h"
+#endif
+
+
+
+/*
+ * Draw a flat-shaded, Z-less, RGB line into an osmesa buffer.
+ */
+#define NAME flat_rgba_z_line
+#define CLIP_HACK 1
+#define INTERP_Z 1
+#define DEPTH_TYPE DEFAULT_SOFTWARE_DEPTH_TYPE
+#define SETUP_CODE					\
+   const OSMesaContext osmesa = OSMESA_CONTEXT(ctx);	\
+   const GLchan *color = vert1->color;
+
+#define PLOT(X, Y)					\
+do {							\
+   if (Z < *zPtr) {					\
+      GLchan *p = PIXELADDR4(X, Y);			\
+      PACK_RGBA(p, color[RCOMP], color[GCOMP],		\
+                   color[BCOMP], color[ACOMP]);		\
+      *zPtr = Z;					\
+   }							\
+} while (0)
+
+#ifdef WIN32
+#include "..\swrast\s_linetemp.h"
+#else
+#include "swrast/s_linetemp.h"
+#endif
+
+
+
+/*
+ * Analyze context state to see if we can provide a fast line drawing
+ * function, like those in lines.c.  Otherwise, return NULL.
+ */
+static swrast_line_func
+osmesa_choose_line_function( GLcontext *ctx )
+{
+   const OSMesaContext osmesa = OSMESA_CONTEXT(ctx);
+   const SWcontext *swrast = SWRAST_CONTEXT(ctx);
+
+   if (CHAN_BITS != 8)                    return NULL;
+   if (ctx->RenderMode != GL_RENDER)      return NULL;
+   if (ctx->Line.SmoothFlag)              return NULL;
+   if (ctx->Texture._EnabledUnits)        return NULL;
+   if (ctx->Light.ShadeModel != GL_FLAT)  return NULL;
+   if (ctx->Line.Width != 1.0F)           return NULL;
+   if (ctx->Line.StippleFlag)             return NULL;
+   if (ctx->Line.SmoothFlag)              return NULL;
+   if (osmesa->format != OSMESA_RGBA &&
+       osmesa->format != OSMESA_BGRA &&
+       osmesa->format != OSMESA_ARGB)     return NULL;
+
+   if (swrast->_RasterMask==DEPTH_BIT
+       && ctx->Depth.Func==GL_LESS
+       && ctx->Depth.Mask==GL_TRUE
+       && ctx->Visual.depthBits == DEFAULT_SOFTWARE_DEPTH_BITS) {
+      return (swrast_line_func) flat_rgba_z_line;
+   }
+
+   if (swrast->_RasterMask == 0) {
+      return (swrast_line_func) flat_rgba_line;
+   }
+
+   return (swrast_line_func) NULL;
+}
+
+
+/**********************************************************************/
+/*****                 Optimized triangle rendering               *****/
+/**********************************************************************/
+
+
+/*
+ * Smooth-shaded, z-less triangle, RGBA color.
+ */
+#define NAME smooth_rgba_z_triangle
+#define INTERP_Z 1
+#define DEPTH_TYPE DEFAULT_SOFTWARE_DEPTH_TYPE
+#define INTERP_RGB 1
+#define INTERP_ALPHA 1
+#define SETUP_CODE \
+   const OSMesaContext osmesa = OSMESA_CONTEXT(ctx);
+#define RENDER_SPAN( span )					\
+   GLuint i;							\
+   GLchan *img = PIXELADDR4(span.x, span.y); 			\
+   for (i = 0; i < span.end; i++, img += 4) {			\
+      const GLdepth z = FixedToDepth(span.z);			\
+      if (z < zRow[i]) {					\
+         PACK_RGBA(img, FixedToChan(span.red),			\
+            FixedToChan(span.green), FixedToChan(span.blue),	\
+            FixedToChan(span.alpha));				\
+         zRow[i] = z;						\
+      }								\
+      span.red += span.redStep;					\
+      span.green += span.greenStep;				\
+      span.blue += span.blueStep;				\
+      span.alpha += span.alphaStep;				\
+      span.z += span.zStep;					\
+   }
+#ifdef WIN32
+#include "..\swrast\s_tritemp.h"
+#else
+#include "swrast/s_tritemp.h"
+#endif
+
+
+
+/*
+ * Flat-shaded, z-less triangle, RGBA color.
+ */
+#define NAME flat_rgba_z_triangle
+#define INTERP_Z 1
+#define DEPTH_TYPE DEFAULT_SOFTWARE_DEPTH_TYPE
+#define SETUP_CODE						\
+   const OSMesaContext osmesa = OSMESA_CONTEXT(ctx);		\
+   GLuint pixel;						\
+   PACK_RGBA((GLchan *) &pixel, v2->color[0], v2->color[1],	\
+                                v2->color[2], v2->color[3]);
+
+#define RENDER_SPAN( span )				\
+   GLuint i;						\
+   GLuint *img = (GLuint *) PIXELADDR4(span.x, span.y);	\
+   for (i = 0; i < span.end; i++) {			\
+      const GLdepth z = FixedToDepth(span.z);		\
+      if (z < zRow[i]) {				\
+         img[i] = pixel;				\
+         zRow[i] = z;					\
+      }							\
+      span.z += span.zStep;				\
+   }
+#ifdef WIN32
+#include "..\swrast\s_tritemp.h"
+#else
+#include "swrast/s_tritemp.h"
+#endif
+
+
+
+/*
+ * Return pointer to an accelerated triangle function if possible.
+ */
+static swrast_tri_func
+osmesa_choose_triangle_function( GLcontext *ctx )
+{
+   const OSMesaContext osmesa = OSMESA_CONTEXT(ctx);
+   const SWcontext *swrast = SWRAST_CONTEXT(ctx);
+
+   if (CHAN_BITS != 8)                  return (swrast_tri_func) NULL;
+   if (ctx->RenderMode != GL_RENDER)    return (swrast_tri_func) NULL;
+   if (ctx->Polygon.SmoothFlag)         return (swrast_tri_func) NULL;
+   if (ctx->Polygon.StippleFlag)        return (swrast_tri_func) NULL;
+   if (ctx->Texture._EnabledUnits)      return (swrast_tri_func) NULL;
+   if (osmesa->format != OSMESA_RGBA &&
+       osmesa->format != OSMESA_BGRA &&
+       osmesa->format != OSMESA_ARGB)   return (swrast_tri_func) NULL;
+   if (ctx->Polygon.CullFlag && 
+       ctx->Polygon.CullFaceMode == GL_FRONT_AND_BACK)
+                                        return (swrast_tri_func) NULL;
+
+   if (swrast->_RasterMask == DEPTH_BIT &&
+       ctx->Depth.Func == GL_LESS &&
+       ctx->Depth.Mask == GL_TRUE &&
+       ctx->Visual.depthBits == DEFAULT_SOFTWARE_DEPTH_BITS) {
+      if (ctx->Light.ShadeModel == GL_SMOOTH) {
+         return (swrast_tri_func) smooth_rgba_z_triangle;
+      }
+      else {
+         return (swrast_tri_func) flat_rgba_z_triangle;
+      }
+   }
+   return (swrast_tri_func) NULL;
+}
+
+
+
+/* Override for the swrast triangle-selection function.  Try to use one
+ * of our internal triangle functions, otherwise fall back to the
+ * standard swrast functions.
+ */
+static void
+osmesa_choose_triangle( GLcontext *ctx )
+{
+   SWcontext *swrast = SWRAST_CONTEXT(ctx);
+
+   swrast->Triangle = osmesa_choose_triangle_function( ctx );
+   if (!swrast->Triangle)
+      _swrast_choose_triangle( ctx );
+}
+
+static void
+osmesa_choose_line( GLcontext *ctx )
+{
+   SWcontext *swrast = SWRAST_CONTEXT(ctx);
+
+   swrast->Line = osmesa_choose_line_function( ctx );
+   if (!swrast->Line)
+      _swrast_choose_line( ctx );
+}
+
+
+#define OSMESA_NEW_LINE   (_NEW_LINE | \
+                           _NEW_TEXTURE | \
+                           _NEW_LIGHT | \
+                           _NEW_DEPTH | \
+                           _NEW_RENDERMODE | \
+                           _SWRAST_NEW_RASTERMASK)
+
+#define OSMESA_NEW_TRIANGLE (_NEW_POLYGON | \
+                             _NEW_TEXTURE | \
+                             _NEW_LIGHT | \
+                             _NEW_DEPTH | \
+                             _NEW_RENDERMODE | \
+                             _SWRAST_NEW_RASTERMASK)
+
+
+/* one-time, per-context initialization */
+static void
+hook_in_driver_functions( GLcontext *ctx )
+{
+   OSMesaContext osmesa = OSMESA_CONTEXT(ctx);
+   SWcontext *swrast = SWRAST_CONTEXT( ctx );
+   struct swrast_device_driver *swdd = _swrast_GetDeviceDriverReference( ctx );
+   TNLcontext *tnl = TNL_CONTEXT(ctx);
+
+   ASSERT((void *) osmesa == (void *) ctx->DriverCtx);
+
+   /* use default TCL pipeline */
+   tnl->Driver.RunPipeline = _tnl_run_pipeline;
+
+   swdd->SetBuffer = set_buffer;
+
+   /* RGB(A) span/pixel functions */
+   if (osmesa->format == OSMESA_RGB) {
+      swdd->WriteRGBASpan = write_rgba_span_RGB;
+      swdd->WriteRGBSpan = write_rgb_span_RGB;
+      swdd->WriteMonoRGBASpan = write_monorgba_span_RGB;
+      swdd->WriteRGBAPixels = write_rgba_pixels_RGB;
+      swdd->WriteMonoRGBAPixels = write_monorgba_pixels_RGB;
+      swdd->ReadRGBASpan = read_rgba_span_RGB;
+      swdd->ReadRGBAPixels = read_rgba_pixels_RGB;
+   }
+   else if (osmesa->format == OSMESA_BGR) {
+      swdd->WriteRGBASpan = write_rgba_span_BGR;
+      swdd->WriteRGBSpan = write_rgb_span_BGR;
+      swdd->WriteMonoRGBASpan = write_monorgba_span_BGR;
+      swdd->WriteRGBAPixels = write_rgba_pixels_BGR;
+      swdd->WriteMonoRGBAPixels = write_monorgba_pixels_BGR;
+      swdd->ReadRGBASpan = read_rgba_span_BGR;
+      swdd->ReadRGBAPixels = read_rgba_pixels_BGR;
+   }
+#if CHAN_TYPE == GL_UNSIGNED_BYTE
+   else if (osmesa->format == OSMESA_RGB_565) {
+      swdd->WriteRGBASpan = write_rgba_span_RGB_565;
+      swdd->WriteRGBSpan = write_rgb_span_RGB_565;
+      swdd->WriteMonoRGBASpan = write_monorgba_span_RGB_565;
+      swdd->WriteRGBAPixels = write_rgba_pixels_RGB_565;
+      swdd->WriteMonoRGBAPixels = write_monorgba_pixels_RGB_565;
+      swdd->ReadRGBASpan = read_rgba_span_RGB_565;
+      swdd->ReadRGBAPixels = read_rgba_pixels_RGB_565;
+   }
+#endif
+   else if (osmesa->format == OSMESA_RGBA) {
+      swdd->WriteRGBASpan = write_rgba_span_RGBA;
+      swdd->WriteRGBSpan = write_rgb_span_RGBA;
+      swdd->WriteMonoRGBASpan = write_monorgba_span_RGBA;
+      swdd->WriteRGBAPixels = write_rgba_pixels_RGBA;
+      swdd->WriteMonoRGBAPixels = write_monorgba_pixels_RGBA;
+      swdd->ReadRGBASpan = read_rgba_span_RGBA;
+      swdd->ReadRGBAPixels = read_rgba_pixels_RGBA;
+   }
+   else if (osmesa->format == OSMESA_BGRA) {
+      swdd->WriteRGBASpan = write_rgba_span_BGRA;
+      swdd->WriteRGBSpan = write_rgb_span_BGRA;
+      swdd->WriteMonoRGBASpan = write_monorgba_span_BGRA;
+      swdd->WriteRGBAPixels = write_rgba_pixels_BGRA;
+      swdd->WriteMonoRGBAPixels = write_monorgba_pixels_BGRA;
+      swdd->ReadRGBASpan = read_rgba_span_BGRA;
+      swdd->ReadRGBAPixels = read_rgba_pixels_BGRA;
+   }
+   else if (osmesa->format == OSMESA_ARGB) {
+      swdd->WriteRGBASpan = write_rgba_span_ARGB;
+      swdd->WriteRGBSpan = write_rgb_span_ARGB;
+      swdd->WriteMonoRGBASpan = write_monorgba_span_ARGB;
+      swdd->WriteRGBAPixels = write_rgba_pixels_ARGB;
+      swdd->WriteMonoRGBAPixels = write_monorgba_pixels_ARGB;
+      swdd->ReadRGBASpan = read_rgba_span_ARGB;
+      swdd->ReadRGBAPixels = read_rgba_pixels_ARGB;
+   }
+   else if (osmesa->format == OSMESA_COLOR_INDEX) {
+      swdd->WriteCI32Span = write_index32_span_CI;
+      swdd->WriteCI8Span = write_index8_span_CI;
+      swdd->WriteMonoCISpan = write_monoindex_span_CI;
+      swdd->WriteCI32Pixels = write_index_pixels_CI;
+      swdd->WriteMonoCIPixels = write_monoindex_pixels_CI;
+      swdd->ReadCI32Span = read_index_span_CI;
+      swdd->ReadCI32Pixels = read_index_pixels_CI;
+   }
+   else {
+      _mesa_problem(ctx, "bad pixel format in osmesa_update_state!\n");
+   }
+
+   /* Extend the software rasterizer with our optimized line and triangle
+    * drawin functions.
+    */
+   swrast->choose_line = osmesa_choose_line;
+   swrast->choose_triangle = osmesa_choose_triangle;
+   swrast->invalidate_line |= OSMESA_NEW_LINE;
+   swrast->invalidate_triangle |= OSMESA_NEW_TRIANGLE;
+}
+
+
+
+
+/**********************************************************************/
+/*****                    Public Functions                        *****/
+/**********************************************************************/
+
+
+/*
+ * Create an Off-Screen Mesa rendering context.  The only attribute needed is
+ * an RGBA vs Color-Index mode flag.
+ *
+ * Input:  format - either GL_RGBA or GL_COLOR_INDEX
+ *         sharelist - specifies another OSMesaContext with which to share
+ *                     display lists.  NULL indicates no sharing.
+ * Return:  an OSMesaContext or 0 if error
+ */
+GLAPI OSMesaContext GLAPIENTRY
+OSMesaCreateContext( GLenum format, OSMesaContext sharelist )
+{
+   const GLint accumBits = (format == OSMESA_COLOR_INDEX) ? 0 : 16;
+   return OSMesaCreateContextExt(format, DEFAULT_SOFTWARE_DEPTH_BITS,
+                                 8, accumBits, sharelist);
+}
+
+
+
+/*
+ * New in Mesa 3.5
+ *
+ * Create context and specify size of ancillary buffers.
+ */
+GLAPI OSMesaContext GLAPIENTRY
+OSMesaCreateContextExt( GLenum format, GLint depthBits, GLint stencilBits,
+                        GLint accumBits, OSMesaContext sharelist )
+{
+   OSMesaContext osmesa;
+   struct dd_function_table functions;
+   GLint rshift, gshift, bshift, ashift;
+   GLint rind, gind, bind, aind;
+   GLint indexBits = 0, redBits = 0, greenBits = 0, blueBits = 0, alphaBits =0;
+   GLboolean rgbmode;
+   const GLuint i4 = 1;
+   const GLubyte *i1 = (GLubyte *) &i4;
+   const GLint little_endian = *i1;
+
+   rind = gind = bind = aind = 0;
+   if (format==OSMESA_COLOR_INDEX) {
+      indexBits = 8;
+      rshift = gshift = bshift = ashift = 0;
+      rgbmode = GL_FALSE;
+   }
+   else if (format==OSMESA_RGBA) {
+      indexBits = 0;
+      redBits = CHAN_BITS;
+      greenBits = CHAN_BITS;
+      blueBits = CHAN_BITS;
+      alphaBits = CHAN_BITS;
+      rind = 0;
+      gind = 1;
+      bind = 2;
+      aind = 3;
+      if (little_endian) {
+         rshift = 0;
+         gshift = 8;
+         bshift = 16;
+         ashift = 24;
+      }
+      else {
+         rshift = 24;
+         gshift = 16;
+         bshift = 8;
+         ashift = 0;
+      }
+      rgbmode = GL_TRUE;
+   }
+   else if (format==OSMESA_BGRA) {
+      indexBits = 0;
+      redBits = CHAN_BITS;
+      greenBits = CHAN_BITS;
+      blueBits = CHAN_BITS;
+      alphaBits = CHAN_BITS;
+      bind = 0;
+      gind = 1;
+      rind = 2;
+      aind = 3;
+      if (little_endian) {
+         bshift = 0;
+         gshift = 8;
+         rshift = 16;
+         ashift = 24;
+      }
+      else {
+         bshift = 24;
+         gshift = 16;
+         rshift = 8;
+         ashift = 0;
+      }
+      rgbmode = GL_TRUE;
+   }
+   else if (format==OSMESA_ARGB) {
+      indexBits = 0;
+      redBits = CHAN_BITS;
+      greenBits = CHAN_BITS;
+      blueBits = CHAN_BITS;
+      alphaBits = CHAN_BITS;
+      aind = 0;
+      rind = 1;
+      gind = 2;
+      bind = 3;
+      if (little_endian) {
+         ashift = 0;
+         rshift = 8;
+         gshift = 16;
+         bshift = 24;
+      }
+      else {
+         ashift = 24;
+         rshift = 16;
+         gshift = 8;
+         bshift = 0;
+      }
+      rgbmode = GL_TRUE;
+   }
+   else if (format==OSMESA_RGB) {
+      indexBits = 0;
+      redBits = CHAN_BITS;
+      greenBits = CHAN_BITS;
+      blueBits = CHAN_BITS;
+      alphaBits = 0;
+      bshift = 0;
+      gshift = 8;
+      rshift = 16;
+      ashift = 24;
+      rind = 0;
+      gind = 1;
+      bind = 2;
+      rgbmode = GL_TRUE;
+   }
+   else if (format==OSMESA_BGR) {
+      indexBits = 0;
+      redBits = CHAN_BITS;
+      greenBits = CHAN_BITS;
+      blueBits = CHAN_BITS;
+      alphaBits = 0;
+      bshift = 0;
+      gshift = 8;
+      rshift = 16;
+      ashift = 24;
+      rind = 2;
+      gind = 1;
+      bind = 0;
+      rgbmode = GL_TRUE;
+   }
+#if CHAN_TYPE == GL_UNSIGNED_BYTE
+   else if (format==OSMESA_RGB_565) {
+      indexBits = 0;
+      redBits = 5;
+      greenBits = 6;
+      blueBits = 5;
+      alphaBits = 0;
+      rshift = 11;
+      gshift = 5;
+      bshift = 0;
+      ashift = 0;
+      rind = 0; /* not used */
+      gind = 0;
+      bind = 0;
+      rgbmode = GL_TRUE;
+   }
+#endif
+   else {
+      return NULL;
+   }
+
+
+   osmesa = (OSMesaContext) CALLOC_STRUCT(osmesa_context);
+   if (osmesa) {
+      osmesa->gl_visual = _mesa_create_visual( rgbmode,
+                                               GL_FALSE,    /* double buffer */
+                                               GL_FALSE,    /* stereo */
+                                               redBits,
+                                               greenBits,
+                                               blueBits,
+                                               alphaBits,
+                                               indexBits,
+                                               depthBits,
+                                               stencilBits,
+                                               accumBits,
+                                               accumBits,
+                                               accumBits,
+                                               alphaBits ? accumBits : 0,
+                                               1            /* num samples */
+                                               );
+      if (!osmesa->gl_visual) {
+         FREE(osmesa);
+         return NULL;
+      }
+
+      /* Initialize device driver function table */
+      _mesa_init_driver_functions(&functions);
+      /* override with our functions */
+      functions.GetString = get_string;
+      functions.UpdateState = osmesa_update_state;
+      functions.GetBufferSize = get_buffer_size;
+      functions.Clear = clear;
+
+      if (!_mesa_initialize_context(&osmesa->mesa,
+                                    osmesa->gl_visual,
+                                    sharelist ? &sharelist->mesa
+                                              : (GLcontext *) NULL,
+                                    &functions, (void *) osmesa)) {
+         _mesa_destroy_visual( osmesa->gl_visual );
+         FREE(osmesa);
+         return NULL;
+      }
+
+      _mesa_enable_sw_extensions(&(osmesa->mesa));
+      _mesa_enable_1_3_extensions(&(osmesa->mesa));
+      _mesa_enable_1_4_extensions(&(osmesa->mesa));
+      _mesa_enable_1_5_extensions(&(osmesa->mesa));
+
+      osmesa->gl_buffer = _mesa_create_framebuffer( osmesa->gl_visual,
+                           (GLboolean) ( osmesa->gl_visual->depthBits > 0 ),
+                           (GLboolean) ( osmesa->gl_visual->stencilBits > 0 ),
+                           (GLboolean) ( osmesa->gl_visual->accumRedBits > 0 ),
+                           GL_FALSE /* s/w alpha */ );
+
+      if (!osmesa->gl_buffer) {
+         _mesa_destroy_visual( osmesa->gl_visual );
+         _mesa_free_context_data( &osmesa->mesa );
+         FREE(osmesa);
+         return NULL;
+      }
+      osmesa->format = format;
+      osmesa->buffer = NULL;
+      osmesa->width = 0;
+      osmesa->height = 0;
+      osmesa->userRowLength = 0;
+      osmesa->rowlength = 0;
+      osmesa->yup = GL_TRUE;
+      osmesa->rshift = rshift;
+      osmesa->gshift = gshift;
+      osmesa->bshift = bshift;
+      osmesa->ashift = ashift;
+      osmesa->rInd = rind;
+      osmesa->gInd = gind;
+      osmesa->bInd = bind;
+      osmesa->aInd = aind;
+
+      /* Initialize the software rasterizer and helper modules. */
+      {
+	 GLcontext *ctx = &osmesa->mesa;
+
+	 if (!_swrast_CreateContext( ctx ) ||
+             !_ac_CreateContext( ctx ) ||
+             !_tnl_CreateContext( ctx ) ||
+             !_swsetup_CreateContext( ctx )) {
+            _mesa_destroy_visual(osmesa->gl_visual);
+            _mesa_free_context_data(ctx);
+            _mesa_free(osmesa);
+            return NULL;
+         }
+	
+	 _swsetup_Wakeup( ctx );
+         hook_in_driver_functions( ctx );
+      }
+   }
+   return osmesa;
+}
+
+
+/*
+ * Destroy an Off-Screen Mesa rendering context.
+ *
+ * Input:  ctx - the context to destroy
+ */
+GLAPI void GLAPIENTRY
+OSMesaDestroyContext( OSMesaContext ctx )
+{
+   if (ctx) {
+      _swsetup_DestroyContext( &ctx->mesa );
+      _tnl_DestroyContext( &ctx->mesa );
+      _ac_DestroyContext( &ctx->mesa );
+      _swrast_DestroyContext( &ctx->mesa );
+
+      _mesa_destroy_visual( ctx->gl_visual );
+      _mesa_destroy_framebuffer( ctx->gl_buffer );
+      _mesa_free_context_data( &ctx->mesa );
+      FREE( ctx );
+   }
+}
+
+
+/*
+ * Recompute the values of the context's rowaddr array.
+ */
+static void
+compute_row_addresses( OSMesaContext ctx )
+{
+   GLint bytesPerPixel, bytesPerRow, i;
+   GLubyte *origin = (GLubyte *) ctx->buffer;
+
+   if (ctx->format == OSMESA_COLOR_INDEX) {
+      /* CI mode */
+      bytesPerPixel = 1 * sizeof(GLchan);
+   }
+   else if ((ctx->format == OSMESA_RGB) || (ctx->format == OSMESA_BGR)) {
+      /* RGB mode */
+      bytesPerPixel = 3 * sizeof(GLchan);
+   }
+   else if (ctx->format == OSMESA_RGB_565) {
+      /* 5/6/5 RGB pixel in 16 bits */
+      bytesPerPixel = 2;
+   }
+   else {
+      /* RGBA mode */
+      bytesPerPixel = 4 * sizeof(GLchan);
+   }
+
+   bytesPerRow = ctx->rowlength * bytesPerPixel;
+
+   if (ctx->yup) {
+      /* Y=0 is bottom line of window */
+      for (i = 0; i < MAX_HEIGHT; i++) {
+         ctx->rowaddr[i] = (GLchan *) ((GLubyte *) origin + i * bytesPerRow);
+      }
+   }
+   else {
+      /* Y=0 is top line of window */
+      for (i = 0; i < MAX_HEIGHT; i++) {
+         GLint j = ctx->height - i - 1;
+         ctx->rowaddr[i] = (GLchan *) ((GLubyte *) origin + j * bytesPerRow);
+      }
+   }
+}
+
+
+/*
+ * Bind an OSMesaContext to an image buffer.  The image buffer is just a
+ * block of memory which the client provides.  Its size must be at least
+ * as large as width*height*sizeof(type).  Its address should be a multiple
+ * of 4 if using RGBA mode.
+ *
+ * Image data is stored in the order of glDrawPixels:  row-major order
+ * with the lower-left image pixel stored in the first array position
+ * (ie. bottom-to-top).
+ *
+ * If the context's viewport hasn't been initialized yet, it will now be
+ * initialized to (0,0,width,height).
+ *
+ * Input:  ctx - the rendering context
+ *         buffer - the image buffer memory
+ *         type - data type for pixel components
+ *            Normally, only GL_UNSIGNED_BYTE and GL_UNSIGNED_SHORT_5_6_5
+ *            are supported.  But if Mesa's been compiled with CHAN_BITS==16
+ *            then type must be GL_UNSIGNED_SHORT.  And if Mesa's been build
+ *            with CHAN_BITS==32 then type must be GL_FLOAT.
+ *         width, height - size of image buffer in pixels, at least 1
+ * Return:  GL_TRUE if success, GL_FALSE if error because of invalid ctx,
+ *          invalid buffer address, invalid type, width<1, height<1,
+ *          width>internal limit or height>internal limit.
+ */
+GLAPI GLboolean GLAPIENTRY
+OSMesaMakeCurrent( OSMesaContext ctx, void *buffer, GLenum type,
+                   GLsizei width, GLsizei height )
+{
+   if (!ctx || !buffer ||
+       width < 1 || height < 1 ||
+       width > MAX_WIDTH || height > MAX_HEIGHT) {
+      return GL_FALSE;
+   }
+
+   if (ctx->format == OSMESA_RGB_565) {
+      if (type != GL_UNSIGNED_SHORT_5_6_5)
+         return GL_FALSE;
+   }
+   else if (type != CHAN_TYPE) {
+      return GL_FALSE;
+   }
+
+   osmesa_update_state( &ctx->mesa, 0 );
+   _mesa_make_current( &ctx->mesa, ctx->gl_buffer );
+
+   ctx->buffer = buffer;
+   ctx->width = width;
+   ctx->height = height;
+   if (ctx->userRowLength)
+      ctx->rowlength = ctx->userRowLength;
+   else
+      ctx->rowlength = width;
+
+   compute_row_addresses( ctx );
+
+   /* init viewport */
+   if (ctx->mesa.Viewport.Width == 0) {
+      /* initialize viewport and scissor box to buffer size */
+      _mesa_Viewport( 0, 0, width, height );
+      ctx->mesa.Scissor.Width = width;
+      ctx->mesa.Scissor.Height = height;
+   }
+   else {
+      /* this will make ensure we recognize the new buffer size */
+      _mesa_ResizeBuffersMESA();
+   }
+
+   /* Added by Gerk Huisma: */
+   _tnl_MakeCurrent( &ctx->mesa, ctx->mesa.DrawBuffer,
+                     ctx->mesa.ReadBuffer );
+
+   return GL_TRUE;
+}
+
+
+
+GLAPI OSMesaContext GLAPIENTRY OSMesaGetCurrentContext( void )
+{
+   GLcontext *ctx = _mesa_get_current_context();
+   if (ctx)
+      return (OSMesaContext) ctx;
+   else
+      return NULL;
+}
+
+
+
+GLAPI void GLAPIENTRY OSMesaPixelStore( GLint pname, GLint value )
+{
+   OSMesaContext osmesa = OSMesaGetCurrentContext();
+
+   switch (pname) {
+      case OSMESA_ROW_LENGTH:
+         if (value<0) {
+            _mesa_error( &osmesa->mesa, GL_INVALID_VALUE,
+                      "OSMesaPixelStore(value)" );
+            return;
+         }
+         osmesa->userRowLength = value;
+         osmesa->rowlength = value ? value : osmesa->width;
+         break;
+      case OSMESA_Y_UP:
+         osmesa->yup = value ? GL_TRUE : GL_FALSE;
+         break;
+      default:
+         _mesa_error( &osmesa->mesa, GL_INVALID_ENUM, "OSMesaPixelStore(pname)" );
+         return;
+   }
+
+   compute_row_addresses( osmesa );
+}
+
+
+GLAPI void GLAPIENTRY OSMesaGetIntegerv( GLint pname, GLint *value )
+{
+   OSMesaContext osmesa = OSMesaGetCurrentContext();
+
+   switch (pname) {
+      case OSMESA_WIDTH:
+         *value = osmesa->width;
+         return;
+      case OSMESA_HEIGHT:
+         *value = osmesa->height;
+         return;
+      case OSMESA_FORMAT:
+         *value = osmesa->format;
+         return;
+      case OSMESA_TYPE:
+         *value = CHAN_TYPE;
+         return;
+      case OSMESA_ROW_LENGTH:
+         *value = osmesa->userRowLength;
+         return;
+      case OSMESA_Y_UP:
+         *value = osmesa->yup;
+         return;
+      case OSMESA_MAX_WIDTH:
+         *value = MAX_WIDTH;
+         return;
+      case OSMESA_MAX_HEIGHT:
+         *value = MAX_HEIGHT;
+         return;
+      default:
+         _mesa_error(&osmesa->mesa, GL_INVALID_ENUM, "OSMesaGetIntergerv(pname)");
+         return;
+   }
+}
+
+/*
+ * Return the depth buffer associated with an OSMesa context.
+ * Input:  c - the OSMesa context
+ * Output:  width, height - size of buffer in pixels
+ *          bytesPerValue - bytes per depth value (2 or 4)
+ *          buffer - pointer to depth buffer values
+ * Return:  GL_TRUE or GL_FALSE to indicate success or failure.
+ */
+GLAPI GLboolean GLAPIENTRY
+OSMesaGetDepthBuffer( OSMesaContext c, GLint *width, GLint *height,
+                      GLint *bytesPerValue, void **buffer )
+{
+   if ((!c->gl_buffer) || (!c->gl_buffer->DepthBuffer)) {
+      *width = 0;
+      *height = 0;
+      *bytesPerValue = 0;
+      *buffer = 0;
+      return GL_FALSE;
+   }
+   else {
+      *width = c->gl_buffer->Width;
+      *height = c->gl_buffer->Height;
+      if (c->gl_visual->depthBits <= 16)
+         *bytesPerValue = sizeof(GLushort);
+      else
+         *bytesPerValue = sizeof(GLuint);
+      *buffer = c->gl_buffer->DepthBuffer;
+      return GL_TRUE;
+   }
+}
+
+/*
+ * Return the color buffer associated with an OSMesa context.
+ * Input:  c - the OSMesa context
+ * Output:  width, height - size of buffer in pixels
+ *          format - the pixel format (OSMESA_FORMAT)
+ *          buffer - pointer to color buffer values
+ * Return:  GL_TRUE or GL_FALSE to indicate success or failure.
+ */
+GLAPI GLboolean GLAPIENTRY
+OSMesaGetColorBuffer( OSMesaContext c, GLint *width,
+                      GLint *height, GLint *format, void **buffer )
+{
+   if (!c->buffer) {
+      *width = 0;
+      *height = 0;
+      *format = 0;
+      *buffer = 0;
+      return GL_FALSE;
+   }
+   else {
+      *width = c->width;
+      *height = c->height;
+      *format = c->format;
+      *buffer = c->buffer;
+      return GL_TRUE;
+   }
+}
+
+
+typedef void (*OSMESAproc)(void);
+
+struct name_function
+{
+   const char *Name;
+   OSMESAproc Function;
+};
+
+static struct name_function functions[] = {
+   { "OSMesaCreateContext", (OSMESAproc) OSMesaCreateContext },
+   { "OSMesaCreateContextExt", (OSMESAproc) OSMesaCreateContextExt },
+   { "OSMesaDestroyContext", (OSMESAproc) OSMesaDestroyContext },
+   { "OSMesaMakeCurrent", (OSMESAproc) OSMesaMakeCurrent },
+   { "OSMesaGetCurrentContext", (OSMESAproc) OSMesaGetCurrentContext },
+   { "OSMesaPixelsStore", (OSMESAproc) OSMesaPixelStore },
+   { "OSMesaGetIntegerv", (OSMESAproc) OSMesaGetIntegerv },
+   { "OSMesaGetDepthBuffer", (OSMESAproc) OSMesaGetDepthBuffer },
+   { "OSMesaGetColorBuffer", (OSMESAproc) OSMesaGetColorBuffer },
+   { "OSMesaGetProcAddress", (OSMESAproc) OSMesaGetProcAddress },
+   { NULL, NULL }
+};
+
+GLAPI void * GLAPIENTRY
+OSMesaGetProcAddress( const char *funcName )
+{
+   int i;
+   for (i = 0; functions[i].Name; i++) {
+      if (_mesa_strcmp(functions[i].Name, funcName) == 0)
+         return (void *) functions[i].Function;
+   }
+   return (void *) _glapi_get_proc_address(funcName);
+}