glFBDev driver from embedded-2 branch.

Probably won't be actively used/maintained, but bring it to the trunk so
it doesn't get lost.

1 files changed, 828 insertions, 0 deletions

diff --git a/src/mesa/drivers/fbdev/glfbdev.c b/src/mesa/drivers/fbdev/glfbdev.c
new file mode 100644
index 00000000000..6d3ed01d7b4
--- /dev/null
+++ b/src/mesa/drivers/fbdev/glfbdev.c
@@ -0,0 +1,828 @@
+/*
+ * Mesa 3-D graphics library
+ * Version:  5.1
+ *
+ * Copyright (C) 1999-2003  Brian Paul   All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * 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.
+ */
+
+
+/*
+ * OpenGL (Mesa) interface for fbdev.
+ * For info about fbdev:
+ * http://www.tldp.org/HOWTO/Framebuffer-HOWTO.html
+ *
+ * known VGA modes
+ * Colours   640x400 640x480 800x600 1024x768 1152x864 1280x1024 1600x1200
+ * --------+--------------------------------------------------------------
+ *  4 bits |    ?       ?     0x302      ?        ?        ?         ?
+ *  8 bits |  0x300   0x301   0x303    0x305    0x161    0x307     0x31C
+ * 15 bits |    ?     0x310   0x313    0x316    0x162    0x319     0x31D
+ * 16 bits |    ?     0x311   0x314    0x317    0x163    0x31A     0x31E
+ * 24 bits |    ?     0x312   0x315    0x318      ?      0x31B     0x31F
+ * 32 bits |    ?       ?       ?        ?      0x164      ?
+ */
+
+
+#ifdef USE_GLFBDEV_DRIVER
+
+#include "glheader.h"
+#include <linux/fb.h>
+#include "GL/glfbdev.h"
+#include "context.h"
+#include "extensions.h"
+#include "imports.h"
+#include "texformat.h"
+#include "teximage.h"
+#include "texstore.h"
+#include "array_cache/acache.h"
+#include "swrast/swrast.h"
+#include "swrast_setup/swrast_setup.h"
+#include "tnl/tnl.h"
+#include "tnl/t_context.h"
+#include "tnl/t_pipeline.h"
+
+
+#define PF_B8G8R8     1
+#define PF_B8G8R8A8   2
+#define PF_B5G6R5     3
+#define PF_B5G5R5     4
+#define PF_CI8        5
+
+
+/*
+ * Derived from Mesa's GLvisual class.
+ */
+struct GLFBDevVisualRec {
+   GLvisual glvisual;              /* base class */
+   struct fb_fix_screeninfo fix;
+   struct fb_var_screeninfo var;
+   int pixelFormat;
+};
+
+/*
+ * Derived from Mesa's GLframebuffer class.
+ */
+struct GLFBDevBufferRec {
+   GLframebuffer glframebuffer;    /* base class */
+   GLFBDevVisualPtr visual;
+   struct fb_fix_screeninfo fix;
+   struct fb_var_screeninfo var;
+   void *frontStart;
+   void *backStart;
+   size_t size;
+   GLuint bytesPerPixel;
+   GLuint rowStride;               /* in bytes */
+   GLubyte *frontBottom;           /* pointer to last row */
+   GLubyte *backBottom;            /* pointer to last row */
+   GLubyte *curBottom;             /* = frontBottom or backBottom */
+   GLboolean mallocBackBuffer;
+};
+
+/*
+ * Derived from Mesa's GLcontext class.
+ */
+struct GLFBDevContextRec {
+   GLcontext glcontext;            /* base class */
+   GLFBDevVisualPtr visual;
+   GLFBDevBufferPtr drawBuffer;
+   GLFBDevBufferPtr readBuffer;
+   GLFBDevBufferPtr curBuffer;
+};
+
+
+
+#define GLFBDEV_CONTEXT(CTX)  ((GLFBDevContextPtr) (CTX))
+#define GLFBDEV_BUFFER(BUF)  ((GLFBDevBufferPtr) (BUF))
+
+
+/**********************************************************************/
+/* Internal device driver functions                                   */
+/**********************************************************************/
+
+
+static const GLubyte *
+get_string(GLcontext *ctx, GLenum pname)
+{
+   (void) ctx;
+   switch (pname) {
+      case GL_RENDERER:
+         return (const GLubyte *) "Mesa glfbdev";
+      default:
+         return NULL;
+   }
+}
+
+
+static void
+update_state( GLcontext *ctx, GLuint new_state )
+{
+   /* not much to do here - pass it on */
+   _swrast_InvalidateState( ctx, new_state );
+   _swsetup_InvalidateState( ctx, new_state );
+   _ac_InvalidateState( ctx, new_state );
+   _tnl_InvalidateState( ctx, new_state );
+}
+
+
+static void
+get_buffer_size( GLframebuffer *buffer, GLuint *width, GLuint *height )
+{
+   const GLFBDevBufferPtr fbdevbuffer = (GLFBDevBufferPtr) buffer;
+   *width = fbdevbuffer->var.xres_virtual;
+   *height = fbdevbuffer->var.yres_virtual;
+}
+
+
+/* specifies the buffer for swrast span rendering/reading */
+static void
+set_buffer( GLcontext *ctx, GLframebuffer *buffer, GLuint bufferBit )
+{
+   GLFBDevContextPtr fbdevctx = GLFBDEV_CONTEXT(ctx);
+   GLFBDevBufferPtr fbdevbuf = GLFBDEV_BUFFER(buffer);
+   fbdevctx->curBuffer = fbdevbuf;
+   switch (bufferBit) {
+   case FRONT_LEFT_BIT:
+      fbdevbuf->curBottom = fbdevbuf->frontBottom;
+      break;
+   case BACK_LEFT_BIT:
+      fbdevbuf->curBottom = fbdevbuf->backBottom;
+      break;
+   default:
+      _mesa_problem(ctx, "bad bufferBit in set_buffer()");
+   }
+}
+
+
+static void
+init_core_functions( GLcontext *ctx )
+{
+   ctx->Driver.GetString = get_string;
+   ctx->Driver.UpdateState = update_state;
+   ctx->Driver.ResizeBuffers = _swrast_alloc_buffers;
+   ctx->Driver.GetBufferSize = get_buffer_size;
+
+   ctx->Driver.Accum = _swrast_Accum;
+   ctx->Driver.Bitmap = _swrast_Bitmap;
+   ctx->Driver.Clear = _swrast_Clear;  /* would be good to optimize */
+   ctx->Driver.CopyPixels = _swrast_CopyPixels;
+   ctx->Driver.DrawPixels = _swrast_DrawPixels;
+   ctx->Driver.ReadPixels = _swrast_ReadPixels;
+   ctx->Driver.DrawBuffer = _swrast_DrawBuffer;
+
+   ctx->Driver.ChooseTextureFormat = _mesa_choose_tex_format;
+   ctx->Driver.TexImage1D = _mesa_store_teximage1d;
+   ctx->Driver.TexImage2D = _mesa_store_teximage2d;
+   ctx->Driver.TexImage3D = _mesa_store_teximage3d;
+   ctx->Driver.TexSubImage1D = _mesa_store_texsubimage1d;
+   ctx->Driver.TexSubImage2D = _mesa_store_texsubimage2d;
+   ctx->Driver.TexSubImage3D = _mesa_store_texsubimage3d;
+   ctx->Driver.TestProxyTexImage = _mesa_test_proxy_teximage;
+
+   ctx->Driver.CompressedTexImage1D = _mesa_store_compressed_teximage1d;
+   ctx->Driver.CompressedTexImage2D = _mesa_store_compressed_teximage2d;
+   ctx->Driver.CompressedTexImage3D = _mesa_store_compressed_teximage3d;
+   ctx->Driver.CompressedTexSubImage1D = _mesa_store_compressed_texsubimage1d;
+   ctx->Driver.CompressedTexSubImage2D = _mesa_store_compressed_texsubimage2d;
+   ctx->Driver.CompressedTexSubImage3D = _mesa_store_compressed_texsubimage3d;
+
+   ctx->Driver.CopyTexImage1D = _swrast_copy_teximage1d;
+   ctx->Driver.CopyTexImage2D = _swrast_copy_teximage2d;
+   ctx->Driver.CopyTexSubImage1D = _swrast_copy_texsubimage1d;
+   ctx->Driver.CopyTexSubImage2D = _swrast_copy_texsubimage2d;
+   ctx->Driver.CopyTexSubImage3D = _swrast_copy_texsubimage3d;
+   ctx->Driver.CopyColorTable = _swrast_CopyColorTable;
+   ctx->Driver.CopyColorSubTable = _swrast_CopyColorSubTable;
+   ctx->Driver.CopyConvolutionFilter1D = _swrast_CopyConvolutionFilter1D;
+   ctx->Driver.CopyConvolutionFilter2D = _swrast_CopyConvolutionFilter2D;
+}
+
+
+/*
+ * Generate code for span functions.
+ */
+
+/* 24-bit BGR */
+#define NAME(PREFIX) PREFIX##_B8G8R8
+#define SPAN_VARS \
+   const GLFBDevContextPtr fbdevctx = GLFBDEV_CONTEXT(ctx); \
+   const GLFBDevBufferPtr fbdevbuf = fbdevctx->curBuffer;
+#define INIT_PIXEL_PTR(P, X, Y) \
+   GLubyte *P = fbdevbuf->curBottom - (Y) * fbdevbuf->rowStride + (X) * 3
+#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) \
+   R = P[2];  G = P[1];  B = P[0];  A = CHAN_MAX
+
+#include "swrast/s_spantemp.h"
+
+
+/* 32-bit BGRA */
+#define NAME(PREFIX) PREFIX##_B8G8R8A8
+#define SPAN_VARS \
+   const GLFBDevContextPtr fbdevctx = GLFBDEV_CONTEXT(ctx); \
+   const GLFBDevBufferPtr fbdevbuf = fbdevctx->curBuffer;
+#define INIT_PIXEL_PTR(P, X, Y) \
+   GLubyte *P = fbdevbuf->curBottom - (Y) * fbdevbuf->rowStride + (X) * 4
+#define INC_PIXEL_PTR(P) P += 4
+#define STORE_RGB_PIXEL(P, X, Y, R, G, B) \
+   P[0] = B;  P[1] = G;  P[2] = R;  P[3] = 255
+#define STORE_RGBA_PIXEL(P, X, Y, R, G, B, A) \
+   P[0] = B;  P[1] = G;  P[2] = R;  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"
+
+
+/* 16-bit BGR (XXX implement dithering someday) */
+#define NAME(PREFIX) PREFIX##_B5G6R5
+#define SPAN_VARS \
+   const GLFBDevContextPtr fbdevctx = GLFBDEV_CONTEXT(ctx); \
+   const GLFBDevBufferPtr fbdevbuf = fbdevctx->curBuffer;
+#define INIT_PIXEL_PTR(P, X, Y) \
+   GLushort *P = (GLushort *) (fbdevbuf->curBottom - (Y) * fbdevbuf->rowStride + (X) * 2)
+#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"
+
+
+/* 15-bit BGR (XXX implement dithering someday) */
+#define NAME(PREFIX) PREFIX##_B5G5R5
+#define SPAN_VARS \
+   const GLFBDevContextPtr fbdevctx = GLFBDEV_CONTEXT(ctx); \
+   const GLFBDevBufferPtr fbdevbuf = fbdevctx->curBuffer;
+#define INIT_PIXEL_PTR(P, X, Y) \
+   GLushort *P = (GLushort *) (fbdevbuf->curBottom - (Y) * fbdevbuf->rowStride + (X) * 2)
+#define INC_PIXEL_PTR(P) P += 1
+#define STORE_RGB_PIXEL(P, X, Y, R, G, B) \
+   *P = ( (((R) & 0xf8) << 7) | (((G) & 0xf8) << 2) | ((B) >> 3) )
+#define STORE_RGBA_PIXEL(P, X, Y, R, G, B, A) \
+   *P = ( (((R) & 0xf8) << 7) | (((G) & 0xf8) << 2) | ((B) >> 3) )
+#define FETCH_RGBA_PIXEL(R, G, B, A, P) \
+   R = ( (((*P) >> 7) & 0xf8) | (((*P) >> 10) & 0x7) ); \
+   G = ( (((*P) >> 2) & 0xf8) | (((*P) >>  5) & 0x7) ); \
+   B = ( (((*P) << 3) & 0xf8) | (((*P)      ) & 0x7) ); \
+   A = CHAN_MAX
+
+#include "swrast/s_spantemp.h"
+
+
+/* 8-bit color index */
+#define NAME(PREFIX) PREFIX##_CI8
+#define SPAN_VARS \
+   const GLFBDevContextPtr fbdevctx = GLFBDEV_CONTEXT(ctx); \
+   const GLFBDevBufferPtr fbdevbuf = fbdevctx->curBuffer;
+#define INIT_PIXEL_PTR(P, X, Y) \
+   GLubyte *P = fbdevbuf->curBottom - (Y) * fbdevbuf->rowStride + (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"
+
+/**********************************************************************/
+/* Public API functions                                               */
+/**********************************************************************/
+
+
+const char *
+glFBDevGetString( int str )
+{
+   switch (str) {
+   case GLFBDEV_VENDOR:
+      return "Mesa Project";
+   case GLFBDEV_VERSION:
+      return "1.0.0";
+   default:
+      return NULL;
+   }
+}
+
+
+const void *
+glFBDevGetProcAddress( const char *procName )
+{
+   struct name_address {
+      const char *name;
+      const void *func;
+   };
+   static const struct name_address functions[] = {
+      { "glFBDevGetString", (void *) glFBDevGetString },
+      { "glFBDevGetProcAddress", (void *) glFBDevGetProcAddress },
+      { "glFBDevCreateVisual", (void *) glFBDevCreateVisual },
+      { "glFBDevDestroyVisual", (void *) glFBDevDestroyVisual },
+      { "glFBDevGetVisualAttrib", (void *) glFBDevGetVisualAttrib },
+      { "glFBDevCreateBuffer", (void *) glFBDevCreateBuffer },
+      { "glFBDevDestroyBuffer", (void *) glFBDevDestroyBuffer },
+      { "glFBDevGetBufferAttrib", (void *) glFBDevGetBufferAttrib },
+      { "glFBDevGetCurrentDrawBuffer", (void *) glFBDevGetCurrentDrawBuffer },
+      { "glFBDevGetCurrentReadBuffer", (void *) glFBDevGetCurrentReadBuffer },
+      { "glFBDevSwapBuffers", (void *) glFBDevSwapBuffers },
+      { "glFBDevCreateContext", (void *) glFBDevCreateContext },
+      { "glFBDevDestroyContext", (void *) glFBDevDestroyContext },
+      { "glFBDevGetContextAttrib", (void *) glFBDevGetContextAttrib },
+      { "glFBDevGetCurrentContext", (void *) glFBDevGetCurrentContext },
+      { "glFBDevMakeCurrent", (void *) glFBDevMakeCurrent },
+      { NULL, NULL }
+   };
+   const struct name_address *entry;
+   for (entry = functions; entry->name; entry++) {
+      if (_mesa_strcmp(entry->name, procName) == 0) {
+         return entry->func;
+      }
+   }
+   return _glapi_get_proc_address(procName);
+}
+
+
+GLFBDevVisualPtr
+glFBDevCreateVisual( const struct fb_fix_screeninfo *fixInfo,
+                     const struct fb_var_screeninfo *varInfo,
+                     const int *attribs )
+{
+   GLFBDevVisualPtr vis;
+   const int *attrib;
+   GLboolean rgbFlag = GL_TRUE, dbFlag = GL_FALSE, stereoFlag = GL_FALSE;
+   GLint redBits = 0, greenBits = 0, blueBits = 0, alphaBits = 0;
+   GLint indexBits = 0, depthBits = 0, stencilBits = 0;
+   GLint accumRedBits = 0, accumGreenBits = 0;
+   GLint accumBlueBits = 0, accumAlphaBits = 0;
+   GLint numSamples = 0;
+
+   ASSERT(fixInfo);
+   ASSERT(varInfo);
+
+   vis = CALLOC_STRUCT(GLFBDevVisualRec);
+   if (!vis)
+      return NULL;
+
+   vis->fix = *fixInfo;  /* struct assignment */
+   vis->var = *varInfo;  /* struct assignment */
+
+   for (attrib = attribs; attrib && *attrib != GLFBDEV_NONE; attrib++) {
+      switch (*attrib) {
+      case GLFBDEV_DOUBLE_BUFFER:
+         dbFlag = GL_TRUE;
+         break;
+      case GLFBDEV_COLOR_INDEX:
+         rgbFlag = GL_FALSE;
+         break;
+      case GLFBDEV_DEPTH_SIZE:
+         depthBits = attrib[1];
+         attrib++;
+         break;
+      case GLFBDEV_STENCIL_SIZE:
+         stencilBits = attrib[1];
+         attrib++;
+         break;
+      case GLFBDEV_ACCUM_SIZE:
+         accumRedBits = accumGreenBits = accumBlueBits = accumAlphaBits
+            = attrib[1];
+         attrib++;
+         break;
+      case GLFBDEV_LEVEL:
+         /* ignored for now */
+         break;
+      default:
+         /* unexpected token */
+         _mesa_free(vis);
+         return NULL;
+      }
+   }
+
+   if (rgbFlag) {
+      redBits   = varInfo->red.length;
+      greenBits = varInfo->green.length;
+      blueBits  = varInfo->blue.length;
+      alphaBits = varInfo->transp.length;
+
+      if ((fixInfo->visual == FB_VISUAL_TRUECOLOR ||
+           fixInfo->visual == FB_VISUAL_DIRECTCOLOR)
+          && varInfo->bits_per_pixel == 24
+          && varInfo->red.offset == 16
+          && varInfo->green.offset == 8
+          && varInfo->blue.offset == 0) {
+         vis->pixelFormat = PF_B8G8R8;
+      }
+      else if ((fixInfo->visual == FB_VISUAL_TRUECOLOR ||
+                fixInfo->visual == FB_VISUAL_DIRECTCOLOR)
+               && varInfo->bits_per_pixel == 32
+               && varInfo->red.offset == 16
+               && varInfo->green.offset == 8
+               && varInfo->blue.offset == 0
+               && varInfo->transp.offset == 24) {
+         vis->pixelFormat = PF_B8G8R8A8;
+      }
+      else if ((fixInfo->visual == FB_VISUAL_TRUECOLOR ||
+                fixInfo->visual == FB_VISUAL_DIRECTCOLOR)
+               && varInfo->bits_per_pixel == 16
+               && varInfo->red.offset == 11
+               && varInfo->green.offset == 5
+               && varInfo->blue.offset == 0) {
+         vis->pixelFormat = PF_B5G6R5;
+      }
+      else if ((fixInfo->visual == FB_VISUAL_TRUECOLOR ||
+                fixInfo->visual == FB_VISUAL_DIRECTCOLOR)
+               && varInfo->bits_per_pixel == 16
+               && varInfo->red.offset == 10
+               && varInfo->green.offset == 5
+               && varInfo->blue.offset == 0) {
+         vis->pixelFormat = PF_B5G5R5;
+      }
+      else {
+         _mesa_problem(NULL, "Unsupported fbdev RGB visual/bitdepth!\n");
+         /*
+         printf("fixInfo->visual = 0x%x\n", fixInfo->visual);
+         printf("varInfo->bits_per_pixel = %d\n", varInfo->bits_per_pixel);
+         printf("varInfo->red.offset = %d\n", varInfo->red.offset);
+         printf("varInfo->green.offset = %d\n", varInfo->green.offset);
+         printf("varInfo->blue.offset = %d\n", varInfo->blue.offset);
+         */
+         _mesa_free(vis);
+         return NULL;
+      }
+   }
+   else {
+      indexBits = varInfo->bits_per_pixel;
+      if ((fixInfo->visual == FB_VISUAL_PSEUDOCOLOR ||
+           fixInfo->visual == FB_VISUAL_STATIC_PSEUDOCOLOR)
+          && varInfo->bits_per_pixel == 8) {
+         vis->pixelFormat = PF_CI8;
+      }
+      else {
+         _mesa_problem(NULL, "Unsupported fbdev CI visual/bitdepth!\n");
+         _mesa_free(vis);
+         return NULL;
+      }
+   }
+
+   if (!_mesa_initialize_visual(&vis->glvisual, rgbFlag, dbFlag, stereoFlag,
+                                redBits, greenBits, blueBits, alphaBits,
+                                indexBits, depthBits, stencilBits,
+                                accumRedBits, accumGreenBits,
+                                accumBlueBits, accumAlphaBits,
+                                numSamples)) {
+      /* something was invalid */
+      _mesa_free(vis);
+      return NULL;
+   }
+
+   return vis;
+}
+
+
+void
+glFBDevDestroyVisual( GLFBDevVisualPtr visual )
+{
+   if (visual)
+      _mesa_free(visual);
+}
+
+
+int
+glFBDevGetVisualAttrib( const GLFBDevVisualPtr visual, int attrib)
+{
+   (void) visual;
+   (void) attrib;
+   return -1;
+}
+
+
+
+GLFBDevBufferPtr
+glFBDevCreateBuffer( const struct fb_fix_screeninfo *fixInfo,
+                     const struct fb_var_screeninfo *varInfo,
+                     const GLFBDevVisualPtr visual,
+                     void *frontBuffer, void *backBuffer, size_t size )
+{
+   GLFBDevBufferPtr buf;
+
+   ASSERT(visual);
+   ASSERT(frontBuffer);
+   ASSERT(size > 0);
+
+   if (visual->fix.visual != fixInfo->visual ||
+       visual->fix.type != fixInfo->type ||
+       visual->var.bits_per_pixel != varInfo->bits_per_pixel ||
+       visual->var.grayscale != varInfo->grayscale ||
+       visual->var.red.offset != varInfo->red.offset ||
+       visual->var.green.offset != varInfo->green.offset ||
+       visual->var.blue.offset != varInfo->blue.offset ||
+       visual->var.transp.offset != varInfo->transp.offset) {
+      /* visual mismatch! */
+      return NULL;
+   }
+
+   buf = CALLOC_STRUCT(GLFBDevBufferRec);
+   if (!buf)
+      return NULL;
+
+   _mesa_initialize_framebuffer(&buf->glframebuffer, &visual->glvisual,
+                                visual->glvisual.haveDepthBuffer,
+                                visual->glvisual.haveStencilBuffer,
+                                visual->glvisual.haveAccumBuffer,
+                                GL_FALSE);
+
+   buf->fix = *fixInfo;   /* struct assignment */
+   buf->var = *varInfo;   /* struct assignment */
+   buf->visual = visual;  /* ptr assignment */
+   buf->frontStart = frontBuffer;
+   buf->size = size;
+   buf->bytesPerPixel = visual->var.bits_per_pixel / 8;
+   buf->rowStride = visual->var.xres_virtual * buf->bytesPerPixel;
+   buf->frontBottom = (GLubyte *) buf->frontStart
+                    + (visual->var.yres_virtual - 1) * buf->rowStride;
+
+   if (visual->glvisual.doubleBufferMode) {
+      if (backBuffer) {
+         buf->backStart = backBuffer;
+         buf->mallocBackBuffer = GL_FALSE;
+      }
+      else {
+         buf->backStart = _mesa_malloc(size);
+         if (!buf->backStart) {
+            _mesa_free_framebuffer_data(&buf->glframebuffer);
+            _mesa_free(buf);
+            return NULL;
+         }
+         buf->mallocBackBuffer = GL_TRUE;
+      }
+      buf->backBottom = (GLubyte *) buf->backStart
+                      + (visual->var.yres_virtual - 1) * buf->rowStride;
+      buf->curBottom = buf->backBottom;
+   }
+   else {
+      buf->backStart = NULL;
+      buf->mallocBackBuffer = GL_FALSE;
+      buf->backBottom = NULL;
+      buf->curBottom = buf->frontBottom;
+   }
+
+   return buf;
+}
+
+
+void
+glFBDevDestroyBuffer( GLFBDevBufferPtr buffer )
+{
+   if (buffer) {
+      /* check if destroying the current buffer */
+      GLFBDevBufferPtr curDraw = glFBDevGetCurrentDrawBuffer();
+      GLFBDevBufferPtr curRead = glFBDevGetCurrentReadBuffer();
+      if (buffer == curDraw || buffer == curRead) {
+         glFBDevMakeCurrent( NULL, NULL, NULL);
+      }
+      if (buffer->mallocBackBuffer) {
+         _mesa_free(buffer->backStart);
+      }
+      /* free the software depth, stencil, accum buffers */
+      _mesa_free_framebuffer_data(&buffer->glframebuffer);
+      _mesa_free(buffer);
+   }
+}
+
+
+int
+glFBDevGetBufferAttrib( const GLFBDevBufferPtr buffer, int attrib)
+{
+   (void) buffer;
+   (void) attrib;
+   return -1;
+}
+
+
+GLFBDevBufferPtr
+glFBDevGetCurrentDrawBuffer( void )
+{
+   GLFBDevContextPtr fbdevctx = glFBDevGetCurrentContext();
+   if (fbdevctx)
+      return fbdevctx->drawBuffer;
+   else
+      return NULL;
+}
+
+
+GLFBDevBufferPtr
+glFBDevGetCurrentReadBuffer( void )
+{
+   GLFBDevContextPtr fbdevctx = glFBDevGetCurrentContext();
+   if (fbdevctx)
+      return fbdevctx->readBuffer;
+   else
+      return NULL;
+}
+
+
+void
+glFBDevSwapBuffers( GLFBDevBufferPtr buffer )
+{
+   GLFBDevContextPtr fbdevctx = glFBDevGetCurrentContext();
+
+   if (!buffer || !buffer->visual->glvisual.doubleBufferMode)
+      return;
+
+   /* check if swapping currently bound buffer */
+   if (fbdevctx->drawBuffer == buffer) {
+      /* flush pending rendering */
+      _mesa_notifySwapBuffers(&fbdevctx->glcontext);
+   }
+
+   ASSERT(buffer->frontStart);
+   ASSERT(buffer->backStart);
+   _mesa_memcpy(buffer->frontStart, buffer->backStart, buffer->size);
+}
+
+
+GLFBDevContextPtr
+glFBDevCreateContext( const GLFBDevVisualPtr visual, GLFBDevContextPtr share )
+{
+   GLFBDevContextPtr ctx;
+   GLcontext *glctx;
+
+   ASSERT(visual);
+
+   ctx = CALLOC_STRUCT(GLFBDevContextRec);
+   if (!ctx)
+      return NULL;
+
+   if (!_mesa_initialize_context(&ctx->glcontext, &visual->glvisual,
+                                 share ? &share->glcontext : NULL,
+                                 (void *) ctx, GL_FALSE)) {
+      _mesa_free(ctx);
+      return NULL;
+   }
+
+   ctx->visual = visual;
+
+   /* Create module contexts */
+   glctx = (GLcontext *) &ctx->glcontext;
+   init_core_functions( glctx );
+   _swrast_CreateContext( glctx );
+   _ac_CreateContext( glctx );
+   _tnl_CreateContext( glctx );
+   _swsetup_CreateContext( glctx );
+   _swsetup_Wakeup( glctx );
+
+   /* swrast init */
+   {
+      struct swrast_device_driver *swdd;
+      swdd = _swrast_GetDeviceDriverReference( glctx );
+      swdd->SetBuffer = set_buffer;
+      if (visual->pixelFormat == PF_B8G8R8) {
+         swdd->WriteRGBASpan = write_rgba_span_B8G8R8;
+         swdd->WriteRGBSpan = write_rgb_span_B8G8R8;
+         swdd->WriteMonoRGBASpan = write_monorgba_span_B8G8R8;
+         swdd->WriteRGBAPixels = write_rgba_pixels_B8G8R8;
+         swdd->WriteMonoRGBAPixels = write_monorgba_pixels_B8G8R8;
+         swdd->ReadRGBASpan = read_rgba_span_B8G8R8;
+         swdd->ReadRGBAPixels = read_rgba_pixels_B8G8R8;
+      }
+      else if (visual->pixelFormat == PF_B8G8R8A8) {
+         swdd->WriteRGBASpan = write_rgba_span_B8G8R8A8;
+         swdd->WriteRGBSpan = write_rgb_span_B8G8R8A8;
+         swdd->WriteMonoRGBASpan = write_monorgba_span_B8G8R8A8;
+         swdd->WriteRGBAPixels = write_rgba_pixels_B8G8R8A8;
+         swdd->WriteMonoRGBAPixels = write_monorgba_pixels_B8G8R8A8;
+         swdd->ReadRGBASpan = read_rgba_span_B8G8R8A8;
+         swdd->ReadRGBAPixels = read_rgba_pixels_B8G8R8A8;
+      }
+      else if (visual->pixelFormat == PF_B5G6R5) {
+         swdd->WriteRGBASpan = write_rgba_span_B5G6R5;
+         swdd->WriteRGBSpan = write_rgb_span_B5G6R5;
+         swdd->WriteMonoRGBASpan = write_monorgba_span_B5G6R5;
+         swdd->WriteRGBAPixels = write_rgba_pixels_B5G6R5;
+         swdd->WriteMonoRGBAPixels = write_monorgba_pixels_B5G6R5;
+         swdd->ReadRGBASpan = read_rgba_span_B5G6R5;
+         swdd->ReadRGBAPixels = read_rgba_pixels_B5G6R5;
+      }
+      else if (visual->pixelFormat == PF_B5G5R5) {
+         swdd->WriteRGBASpan = write_rgba_span_B5G5R5;
+         swdd->WriteRGBSpan = write_rgb_span_B5G5R5;
+         swdd->WriteMonoRGBASpan = write_monorgba_span_B5G5R5;
+         swdd->WriteRGBAPixels = write_rgba_pixels_B5G5R5;
+         swdd->WriteMonoRGBAPixels = write_monorgba_pixels_B5G5R5;
+         swdd->ReadRGBASpan = read_rgba_span_B5G5R5;
+         swdd->ReadRGBAPixels = read_rgba_pixels_B5G5R5;
+      }
+      else if (visual->pixelFormat == PF_CI8) {
+         swdd->WriteCI32Span = write_index32_span_CI8;
+         swdd->WriteCI8Span = write_index8_span_CI8;
+         swdd->WriteMonoCISpan = write_monoindex_span_CI8;
+         swdd->WriteCI32Pixels = write_index_pixels_CI8;
+         swdd->WriteMonoCIPixels = write_monoindex_pixels_CI8;
+         swdd->ReadCI32Span = read_index_span_CI8;
+         swdd->ReadCI32Pixels = read_index_pixels_CI8;
+      }
+      else {
+         _mesa_printf("bad pixelformat: %d\n", visual->pixelFormat);
+      }
+   }
+
+   /* use default TCL pipeline */
+   {
+      TNLcontext *tnl = TNL_CONTEXT(glctx);
+      tnl->Driver.RunPipeline = _tnl_run_pipeline;
+   }
+
+   _mesa_enable_sw_extensions(glctx);
+
+   return ctx;
+}
+
+
+void
+glFBDevDestroyContext( GLFBDevContextPtr context )
+{
+   GLFBDevContextPtr fbdevctx = glFBDevGetCurrentContext();
+
+   if (context) {
+      if (fbdevctx == context) {
+         /* destroying current context */
+         _mesa_make_current2(NULL, NULL, NULL);
+         _mesa_notifyDestroy(&context->glcontext);
+      }
+      _mesa_free_context_data(&context->glcontext);
+      _mesa_free(context);
+   }
+}
+
+
+int
+glFBDevGetContextAttrib( const GLFBDevContextPtr context, int attrib)
+{
+   (void) context;
+   (void) attrib;
+   return -1;
+}
+
+
+GLFBDevContextPtr
+glFBDevGetCurrentContext( void )
+{
+   GET_CURRENT_CONTEXT(ctx);
+   return (GLFBDevContextPtr) ctx;
+}
+
+
+int
+glFBDevMakeCurrent( GLFBDevContextPtr context,
+                    GLFBDevBufferPtr drawBuffer,
+                    GLFBDevBufferPtr readBuffer )
+{
+   if (context && drawBuffer && readBuffer) {
+      /* Make sure the context's visual and the buffers' visuals match.
+       * XXX we might do this by comparing specific fields like bits_per_pixel,
+       * visual, etc. in the future.
+       */
+      if (context->visual != drawBuffer->visual ||
+          context->visual != readBuffer->visual) {
+         return 0;
+      }
+      _mesa_make_current2( &context->glcontext,
+                           &drawBuffer->glframebuffer,
+                           &readBuffer->glframebuffer );
+      context->drawBuffer = drawBuffer;
+      context->readBuffer = readBuffer;
+      context->curBuffer = drawBuffer;
+   }
+   else {
+      /* unbind */
+      _mesa_make_current2( NULL, NULL, NULL );
+   }
+
+   return 1;
+}
+
+#endif /* USE_GLFBDEV_DRIVER */
+