svn merge ^/branches/released . --username marha

1 files changed, 1672 insertions, 0 deletions

diff --git a/mesalib/src/mesa/main/context.c b/mesalib/src/mesa/main/context.c
new file mode 100644
index 000000000..f6d4ac459
--- /dev/null
+++ b/mesalib/src/mesa/main/context.c
@@ -0,0 +1,1672 @@
+/*
+ * Mesa 3-D graphics library
+ * Version:  7.3
+ *
+ * Copyright (C) 1999-2007  Brian Paul   All Rights Reserved.
+ * Copyright (C) 2008  VMware, Inc.  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.
+ */
+
+/**
+ * \file context.c
+ * Mesa context/visual/framebuffer management functions.
+ * \author Brian Paul
+ */
+
+/**
+ * \mainpage Mesa Main Module
+ *
+ * \section MainIntroduction Introduction
+ *
+ * The Mesa Main module consists of all the files in the main/ directory.
+ * Among the features of this module are:
+ * <UL>
+ * <LI> Structures to represent most GL state </LI>
+ * <LI> State set/get functions </LI>
+ * <LI> Display lists </LI>
+ * <LI> Texture unit, object and image handling </LI>
+ * <LI> Matrix and attribute stacks </LI>
+ * </UL>
+ *
+ * Other modules are responsible for API dispatch, vertex transformation,
+ * point/line/triangle setup, rasterization, vertex array caching,
+ * vertex/fragment programs/shaders, etc.
+ *
+ *
+ * \section AboutDoxygen About Doxygen
+ *
+ * If you're viewing this information as Doxygen-generated HTML you'll
+ * see the documentation index at the top of this page.
+ *
+ * The first line lists the Mesa source code modules.
+ * The second line lists the indexes available for viewing the documentation
+ * for each module.
+ *
+ * Selecting the <b>Main page</b> link will display a summary of the module
+ * (this page).
+ *
+ * Selecting <b>Data Structures</b> will list all C structures.
+ *
+ * Selecting the <b>File List</b> link will list all the source files in
+ * the module.
+ * Selecting a filename will show a list of all functions defined in that file.
+ *
+ * Selecting the <b>Data Fields</b> link will display a list of all
+ * documented structure members.
+ *
+ * Selecting the <b>Globals</b> link will display a list
+ * of all functions, structures, global variables and macros in the module.
+ *
+ */
+
+
+#include "glheader.h"
+#include "mfeatures.h"
+#include "imports.h"
+#if FEATURE_accum
+#include "accum.h"
+#endif
+#include "api_exec.h"
+#include "arrayobj.h"
+#if FEATURE_attrib_stack
+#include "attrib.h"
+#endif
+#include "blend.h"
+#include "buffers.h"
+#include "bufferobj.h"
+#if FEATURE_colortable
+#include "colortab.h"
+#endif
+#include "context.h"
+#include "cpuinfo.h"
+#include "debug.h"
+#include "depth.h"
+#if FEATURE_dlist
+#include "dlist.h"
+#endif
+#if FEATURE_evaluators
+#include "eval.h"
+#endif
+#include "enums.h"
+#include "extensions.h"
+#include "fbobject.h"
+#if FEATURE_feedback
+#include "feedback.h"
+#endif
+#include "fog.h"
+#include "framebuffer.h"
+#include "get.h"
+#if FEATURE_histogram
+#include "histogram.h"
+#endif
+#include "hint.h"
+#include "hash.h"
+#include "light.h"
+#include "lines.h"
+#include "macros.h"
+#include "matrix.h"
+#include "multisample.h"
+#include "pixel.h"
+#include "pixelstore.h"
+#include "points.h"
+#include "polygon.h"
+#if FEATURE_ARB_occlusion_query
+#include "queryobj.h"
+#endif
+#if FEATURE_ARB_sync
+#include "syncobj.h"
+#endif
+#if FEATURE_drawpix
+#include "rastpos.h"
+#endif
+#include "scissor.h"
+#include "shared.h"
+#include "simple_list.h"
+#include "state.h"
+#include "stencil.h"
+#include "texcompress.h"
+#include "teximage.h"
+#include "texobj.h"
+#include "texstate.h"
+#include "mtypes.h"
+#include "varray.h"
+#include "version.h"
+#include "viewport.h"
+#include "vtxfmt.h"
+#include "glapi/glthread.h"
+#include "glapi/glapioffsets.h"
+#include "glapi/glapitable.h"
+#include "shader/program.h"
+#include "shader/prog_print.h"
+#include "shader/shader_api.h"
+#if FEATURE_ATI_fragment_shader
+#include "shader/atifragshader.h"
+#endif
+#if _HAVE_FULL_GL
+#include "math/m_matrix.h"
+#endif
+
+#ifdef USE_SPARC_ASM
+#include "sparc/sparc.h"
+#endif
+
+#ifndef MESA_VERBOSE
+int MESA_VERBOSE = 0;
+#endif
+
+#ifndef MESA_DEBUG_FLAGS
+int MESA_DEBUG_FLAGS = 0;
+#endif
+
+
+/* ubyte -> float conversion */
+GLfloat _mesa_ubyte_to_float_color_tab[256];
+
+
+
+/**
+ * Swap buffers notification callback.
+ * 
+ * \param ctx GL context.
+ *
+ * Called by window system just before swapping buffers.
+ * We have to finish any pending rendering.
+ */
+void
+_mesa_notifySwapBuffers(__GLcontext *ctx)
+{
+   FLUSH_CURRENT( ctx, 0 );
+   if (ctx->Driver.Flush) {
+      ctx->Driver.Flush(ctx);
+   }
+}
+
+
+/**********************************************************************/
+/** \name GL Visual allocation/destruction                            */
+/**********************************************************************/
+/*@{*/
+
+/**
+ * Allocates a GLvisual structure and initializes it via
+ * _mesa_initialize_visual().
+ * 
+ * \param rgbFlag GL_TRUE for RGB(A) mode, GL_FALSE for Color Index mode.
+ * \param dbFlag double buffering
+ * \param stereoFlag stereo buffer
+ * \param 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.
+ * \param stencilBits requested minimum bits per stencil buffer value
+ * \param accumRedBits, accumGreenBits, accumBlueBits, accumAlphaBits number of bits per color component in accum buffer.
+ * \param indexBits number of bits per pixel if \p rgbFlag is GL_FALSE
+ * \param redBits number of bits per color component in frame buffer for RGB(A)
+ * mode.  We always use 8 in core Mesa though.
+ * \param greenBits same as above.
+ * \param blueBits same as above.
+ * \param alphaBits same as above.
+ * \param numSamples not really used.
+ * 
+ * \return pointer to new GLvisual or NULL if requested parameters can't be
+ * met.
+ *
+ * \note Need to add params for level and numAuxBuffers (at least)
+ */
+GLvisual *
+_mesa_create_visual( GLboolean rgbFlag,
+                     GLboolean dbFlag,
+                     GLboolean stereoFlag,
+                     GLint redBits,
+                     GLint greenBits,
+                     GLint blueBits,
+                     GLint alphaBits,
+                     GLint indexBits,
+                     GLint depthBits,
+                     GLint stencilBits,
+                     GLint accumRedBits,
+                     GLint accumGreenBits,
+                     GLint accumBlueBits,
+                     GLint accumAlphaBits,
+                     GLint numSamples )
+{
+   GLvisual *vis = (GLvisual *) _mesa_calloc(sizeof(GLvisual));
+   if (vis) {
+      if (!_mesa_initialize_visual(vis, rgbFlag, dbFlag, stereoFlag,
+                                   redBits, greenBits, blueBits, alphaBits,
+                                   indexBits, depthBits, stencilBits,
+                                   accumRedBits, accumGreenBits,
+                                   accumBlueBits, accumAlphaBits,
+                                   numSamples)) {
+         _mesa_free(vis);
+         return NULL;
+      }
+   }
+   return vis;
+}
+
+/**
+ * Makes some sanity checks and fills in the fields of the
+ * GLvisual object with the given parameters.  If the caller needs
+ * to set additional fields, he should just probably init the whole GLvisual
+ * object himself.
+ * \return GL_TRUE on success, or GL_FALSE on failure.
+ *
+ * \sa _mesa_create_visual() above for the parameter description.
+ */
+GLboolean
+_mesa_initialize_visual( GLvisual *vis,
+                         GLboolean rgbFlag,
+                         GLboolean dbFlag,
+                         GLboolean stereoFlag,
+                         GLint redBits,
+                         GLint greenBits,
+                         GLint blueBits,
+                         GLint alphaBits,
+                         GLint indexBits,
+                         GLint depthBits,
+                         GLint stencilBits,
+                         GLint accumRedBits,
+                         GLint accumGreenBits,
+                         GLint accumBlueBits,
+                         GLint accumAlphaBits,
+                         GLint numSamples )
+{
+   assert(vis);
+
+   if (depthBits < 0 || depthBits > 32) {
+      return GL_FALSE;
+   }
+   if (stencilBits < 0 || stencilBits > STENCIL_BITS) {
+      return GL_FALSE;
+   }
+   assert(accumRedBits >= 0);
+   assert(accumGreenBits >= 0);
+   assert(accumBlueBits >= 0);
+   assert(accumAlphaBits >= 0);
+
+   vis->rgbMode          = rgbFlag;
+   vis->doubleBufferMode = dbFlag;
+   vis->stereoMode       = stereoFlag;
+
+   vis->redBits          = redBits;
+   vis->greenBits        = greenBits;
+   vis->blueBits         = blueBits;
+   vis->alphaBits        = alphaBits;
+   vis->rgbBits          = redBits + greenBits + blueBits;
+
+   vis->indexBits      = indexBits;
+   vis->depthBits      = depthBits;
+   vis->stencilBits    = stencilBits;
+
+   vis->accumRedBits   = accumRedBits;
+   vis->accumGreenBits = accumGreenBits;
+   vis->accumBlueBits  = accumBlueBits;
+   vis->accumAlphaBits = accumAlphaBits;
+
+   vis->haveAccumBuffer   = accumRedBits > 0;
+   vis->haveDepthBuffer   = depthBits > 0;
+   vis->haveStencilBuffer = stencilBits > 0;
+
+   vis->numAuxBuffers = 0;
+   vis->level = 0;
+   vis->pixmapMode = 0;
+   vis->sampleBuffers = numSamples > 0 ? 1 : 0;
+   vis->samples = numSamples;
+
+   return GL_TRUE;
+}
+
+
+/**
+ * Destroy a visual and free its memory.
+ *
+ * \param vis visual.
+ * 
+ * Frees the visual structure.
+ */
+void
+_mesa_destroy_visual( GLvisual *vis )
+{
+   _mesa_free(vis);
+}
+
+/*@}*/
+
+
+/**********************************************************************/
+/** \name Context allocation, initialization, destroying
+ *
+ * The purpose of the most initialization functions here is to provide the
+ * default state values according to the OpenGL specification.
+ */
+/**********************************************************************/
+/*@{*/
+
+
+/**
+ * This is lame.  gdb only seems to recognize enum types that are
+ * actually used somewhere.  We want to be able to print/use enum
+ * values such as TEXTURE_2D_INDEX in gdb.  But we don't actually use
+ * the gl_texture_index type anywhere.  Thus, this lame function.
+ */
+static void
+dummy_enum_func(void)
+{
+   gl_buffer_index bi;
+   gl_colortable_index ci;
+   gl_face_index fi;
+   gl_frag_attrib fa;
+   gl_frag_result fr;
+   gl_texture_index ti;
+   gl_vert_attrib va;
+   gl_vert_result vr;
+
+   (void) bi;
+   (void) ci;
+   (void) fi;
+   (void) fa;
+   (void) fr;
+   (void) ti;
+   (void) va;
+   (void) vr;
+}
+
+
+/**
+ * One-time initialization mutex lock.
+ *
+ * \sa Used by one_time_init().
+ */
+_glthread_DECLARE_STATIC_MUTEX(OneTimeLock);
+
+/**
+ * Calls all the various one-time-init functions in Mesa.
+ *
+ * While holding a global mutex lock, calls several initialization functions,
+ * and sets the glapi callbacks if the \c MESA_DEBUG environment variable is
+ * defined.
+ *
+ * \sa _math_init().
+ */
+static void
+one_time_init( GLcontext *ctx )
+{
+   static GLboolean alreadyCalled = GL_FALSE;
+   (void) ctx;
+   _glthread_LOCK_MUTEX(OneTimeLock);
+   if (!alreadyCalled) {
+      GLuint i;
+
+      /* do some implementation tests */
+      assert( sizeof(GLbyte) == 1 );
+      assert( sizeof(GLubyte) == 1 );
+      assert( sizeof(GLshort) == 2 );
+      assert( sizeof(GLushort) == 2 );
+      assert( sizeof(GLint) == 4 );
+      assert( sizeof(GLuint) == 4 );
+
+      _mesa_get_cpu_features();
+
+      _mesa_init_sqrt_table();
+
+      for (i = 0; i < 256; i++) {
+         _mesa_ubyte_to_float_color_tab[i] = (float) i / 255.0F;
+      }
+
+      if (_mesa_getenv("MESA_DEBUG")) {
+         _glapi_noop_enable_warnings(GL_TRUE);
+         _glapi_set_warning_func( (_glapi_warning_func) _mesa_warning );
+      }
+      else {
+         _glapi_noop_enable_warnings(GL_FALSE);
+      }
+
+#if defined(DEBUG) && defined(__DATE__) && defined(__TIME__)
+      _mesa_debug(ctx, "Mesa %s DEBUG build %s %s\n",
+                  MESA_VERSION_STRING, __DATE__, __TIME__);
+#endif
+
+      alreadyCalled = GL_TRUE;
+   }
+   _glthread_UNLOCK_MUTEX(OneTimeLock);
+
+   dummy_enum_func();
+}
+
+
+/**
+ * Initialize fields of gl_current_attrib (aka ctx->Current.*)
+ */
+static void
+_mesa_init_current(GLcontext *ctx)
+{
+   GLuint i;
+
+   /* Init all to (0,0,0,1) */
+   for (i = 0; i < Elements(ctx->Current.Attrib); i++) {
+      ASSIGN_4V( ctx->Current.Attrib[i], 0.0, 0.0, 0.0, 1.0 );
+   }
+
+   /* redo special cases: */
+   ASSIGN_4V( ctx->Current.Attrib[VERT_ATTRIB_WEIGHT], 1.0, 0.0, 0.0, 0.0 );
+   ASSIGN_4V( ctx->Current.Attrib[VERT_ATTRIB_NORMAL], 0.0, 0.0, 1.0, 1.0 );
+   ASSIGN_4V( ctx->Current.Attrib[VERT_ATTRIB_COLOR0], 1.0, 1.0, 1.0, 1.0 );
+   ASSIGN_4V( ctx->Current.Attrib[VERT_ATTRIB_COLOR1], 0.0, 0.0, 0.0, 1.0 );
+   ASSIGN_4V( ctx->Current.Attrib[VERT_ATTRIB_COLOR_INDEX], 1.0, 0.0, 0.0, 1.0 );
+   ASSIGN_4V( ctx->Current.Attrib[VERT_ATTRIB_EDGEFLAG], 1.0, 0.0, 0.0, 1.0 );
+}
+
+
+/**
+ * Init vertex/fragment program limits.
+ * Important: drivers should override these with actual limits.
+ */
+static void
+init_program_limits(GLenum type, struct gl_program_constants *prog)
+{
+   prog->MaxInstructions = MAX_PROGRAM_INSTRUCTIONS;
+   prog->MaxAluInstructions = MAX_PROGRAM_INSTRUCTIONS;
+   prog->MaxTexInstructions = MAX_PROGRAM_INSTRUCTIONS;
+   prog->MaxTexIndirections = MAX_PROGRAM_INSTRUCTIONS;
+   prog->MaxTemps = MAX_PROGRAM_TEMPS;
+   prog->MaxEnvParams = MAX_PROGRAM_ENV_PARAMS;
+   prog->MaxLocalParams = MAX_PROGRAM_LOCAL_PARAMS;
+   prog->MaxUniformComponents = 4 * MAX_UNIFORMS;
+
+   if (type == GL_VERTEX_PROGRAM_ARB) {
+      prog->MaxParameters = MAX_VERTEX_PROGRAM_PARAMS;
+      prog->MaxAttribs = MAX_NV_VERTEX_PROGRAM_INPUTS;
+      prog->MaxAddressRegs = MAX_VERTEX_PROGRAM_ADDRESS_REGS;
+   }
+   else {
+      prog->MaxParameters = MAX_NV_FRAGMENT_PROGRAM_PARAMS;
+      prog->MaxAttribs = MAX_NV_FRAGMENT_PROGRAM_INPUTS;
+      prog->MaxAddressRegs = MAX_FRAGMENT_PROGRAM_ADDRESS_REGS;
+   }
+
+   /* Set the native limits to zero.  This implies that there is no native
+    * support for shaders.  Let the drivers fill in the actual values.
+    */
+   prog->MaxNativeInstructions = 0;
+   prog->MaxNativeAluInstructions = 0;
+   prog->MaxNativeTexInstructions = 0;
+   prog->MaxNativeTexIndirections = 0;
+   prog->MaxNativeAttribs = 0;
+   prog->MaxNativeTemps = 0;
+   prog->MaxNativeAddressRegs = 0;
+   prog->MaxNativeParameters = 0;
+}
+
+
+/**
+ * Initialize fields of gl_constants (aka ctx->Const.*).
+ * Use defaults from config.h.  The device drivers will often override
+ * some of these values (such as number of texture units).
+ */
+static void 
+_mesa_init_constants(GLcontext *ctx)
+{
+   assert(ctx);
+
+   assert(MAX_TEXTURE_LEVELS >= MAX_3D_TEXTURE_LEVELS);
+   assert(MAX_TEXTURE_LEVELS >= MAX_CUBE_TEXTURE_LEVELS);
+
+   /* Max texture size should be <= max viewport size (render to texture) */
+   assert((1 << (MAX_TEXTURE_LEVELS - 1)) <= MAX_WIDTH);
+
+   /* Constants, may be overriden (usually only reduced) by device drivers */
+   ctx->Const.MaxTextureLevels = MAX_TEXTURE_LEVELS;
+   ctx->Const.Max3DTextureLevels = MAX_3D_TEXTURE_LEVELS;
+   ctx->Const.MaxCubeTextureLevels = MAX_CUBE_TEXTURE_LEVELS;
+   ctx->Const.MaxTextureRectSize = MAX_TEXTURE_RECT_SIZE;
+   ctx->Const.MaxArrayTextureLayers = MAX_ARRAY_TEXTURE_LAYERS;
+   ctx->Const.MaxTextureCoordUnits = MAX_TEXTURE_COORD_UNITS;
+   ctx->Const.MaxTextureImageUnits = MAX_TEXTURE_IMAGE_UNITS;
+   ctx->Const.MaxTextureUnits = MIN2(ctx->Const.MaxTextureCoordUnits,
+                                     ctx->Const.MaxTextureImageUnits);
+   ctx->Const.MaxTextureMaxAnisotropy = MAX_TEXTURE_MAX_ANISOTROPY;
+   ctx->Const.MaxTextureLodBias = MAX_TEXTURE_LOD_BIAS;
+   ctx->Const.MaxArrayLockSize = MAX_ARRAY_LOCK_SIZE;
+   ctx->Const.SubPixelBits = SUB_PIXEL_BITS;
+   ctx->Const.MinPointSize = MIN_POINT_SIZE;
+   ctx->Const.MaxPointSize = MAX_POINT_SIZE;
+   ctx->Const.MinPointSizeAA = MIN_POINT_SIZE;
+   ctx->Const.MaxPointSizeAA = MAX_POINT_SIZE;
+   ctx->Const.PointSizeGranularity = (GLfloat) POINT_SIZE_GRANULARITY;
+   ctx->Const.MinLineWidth = MIN_LINE_WIDTH;
+   ctx->Const.MaxLineWidth = MAX_LINE_WIDTH;
+   ctx->Const.MinLineWidthAA = MIN_LINE_WIDTH;
+   ctx->Const.MaxLineWidthAA = MAX_LINE_WIDTH;
+   ctx->Const.LineWidthGranularity = (GLfloat) LINE_WIDTH_GRANULARITY;
+   ctx->Const.MaxColorTableSize = MAX_COLOR_TABLE_SIZE;
+   ctx->Const.MaxConvolutionWidth = MAX_CONVOLUTION_WIDTH;
+   ctx->Const.MaxConvolutionHeight = MAX_CONVOLUTION_HEIGHT;
+   ctx->Const.MaxClipPlanes = MAX_CLIP_PLANES;
+   ctx->Const.MaxLights = MAX_LIGHTS;
+   ctx->Const.MaxShininess = 128.0;
+   ctx->Const.MaxSpotExponent = 128.0;
+   ctx->Const.MaxViewportWidth = MAX_WIDTH;
+   ctx->Const.MaxViewportHeight = MAX_HEIGHT;
+#if FEATURE_ARB_vertex_program
+   init_program_limits(GL_VERTEX_PROGRAM_ARB, &ctx->Const.VertexProgram);
+#endif
+#if FEATURE_ARB_fragment_program
+   init_program_limits(GL_FRAGMENT_PROGRAM_ARB, &ctx->Const.FragmentProgram);
+#endif
+   ctx->Const.MaxProgramMatrices = MAX_PROGRAM_MATRICES;
+   ctx->Const.MaxProgramMatrixStackDepth = MAX_PROGRAM_MATRIX_STACK_DEPTH;
+
+   /* CheckArrayBounds is overriden by drivers/x11 for X server */
+   ctx->Const.CheckArrayBounds = GL_FALSE;
+
+   /* GL_ARB_draw_buffers */
+   ctx->Const.MaxDrawBuffers = MAX_DRAW_BUFFERS;
+
+   /* GL_OES_read_format */
+   ctx->Const.ColorReadFormat = GL_RGBA;
+   ctx->Const.ColorReadType = GL_UNSIGNED_BYTE;
+
+#if FEATURE_EXT_framebuffer_object
+   ctx->Const.MaxColorAttachments = MAX_COLOR_ATTACHMENTS;
+   ctx->Const.MaxRenderbufferSize = MAX_WIDTH;
+#endif
+
+#if FEATURE_ARB_vertex_shader
+   ctx->Const.MaxVertexTextureImageUnits = MAX_VERTEX_TEXTURE_IMAGE_UNITS;
+   ctx->Const.MaxVarying = MAX_VARYING;
+#endif
+
+   /* GL_ARB_framebuffer_object */
+   ctx->Const.MaxSamples = 0;
+
+   /* GL_ARB_sync */
+   ctx->Const.MaxServerWaitTimeout = (GLuint64) ~0;
+
+   /* GL_ATI_envmap_bumpmap */
+   ctx->Const.SupportedBumpUnits = SUPPORTED_ATI_BUMP_UNITS;
+
+   /* GL_EXT_provoking_vertex */
+   ctx->Const.QuadsFollowProvokingVertexConvention = GL_TRUE;
+
+   /* sanity checks */
+   ASSERT(ctx->Const.MaxTextureUnits == MIN2(ctx->Const.MaxTextureImageUnits,
+                                             ctx->Const.MaxTextureCoordUnits));
+   ASSERT(ctx->Const.FragmentProgram.MaxLocalParams <= MAX_PROGRAM_LOCAL_PARAMS);
+   ASSERT(ctx->Const.VertexProgram.MaxLocalParams <= MAX_PROGRAM_LOCAL_PARAMS);
+
+   ASSERT(MAX_NV_FRAGMENT_PROGRAM_TEMPS <= MAX_PROGRAM_TEMPS);
+   ASSERT(MAX_NV_VERTEX_PROGRAM_TEMPS <= MAX_PROGRAM_TEMPS);
+   ASSERT(MAX_NV_VERTEX_PROGRAM_INPUTS <= VERT_ATTRIB_MAX);
+   ASSERT(MAX_NV_VERTEX_PROGRAM_OUTPUTS <= VERT_RESULT_MAX);
+
+   /* check that we don't exceed various 32-bit bitfields */
+   ASSERT(VERT_RESULT_MAX <= 32);
+   ASSERT(FRAG_ATTRIB_MAX <= 32);
+}
+
+
+/**
+ * Do some sanity checks on the limits/constants for the given context.
+ * Only called the first time a context is bound.
+ */
+static void
+check_context_limits(GLcontext *ctx)
+{
+   /* Many context limits/constants are limited by the size of
+    * internal arrays.
+    */
+   assert(ctx->Const.MaxTextureImageUnits <= MAX_TEXTURE_IMAGE_UNITS);
+   assert(ctx->Const.MaxTextureCoordUnits <= MAX_TEXTURE_COORD_UNITS);
+   assert(ctx->Const.MaxTextureUnits <= MAX_TEXTURE_IMAGE_UNITS);
+   assert(ctx->Const.MaxTextureUnits <= MAX_TEXTURE_COORD_UNITS);
+
+   /* number of coord units cannot be greater than number of image units */
+   assert(ctx->Const.MaxTextureCoordUnits <= ctx->Const.MaxTextureImageUnits);
+
+   assert(ctx->Const.MaxTextureLevels <= MAX_TEXTURE_LEVELS);
+   assert(ctx->Const.Max3DTextureLevels <= MAX_3D_TEXTURE_LEVELS);
+   assert(ctx->Const.MaxCubeTextureLevels <= MAX_CUBE_TEXTURE_LEVELS);
+   assert(ctx->Const.MaxTextureRectSize <= MAX_TEXTURE_RECT_SIZE);
+
+   /* make sure largest texture image is <= MAX_WIDTH in size */
+   assert((1 << (ctx->Const.MaxTextureLevels - 1)) <= MAX_WIDTH);
+   assert((1 << (ctx->Const.MaxCubeTextureLevels - 1)) <= MAX_WIDTH);
+   assert((1 << (ctx->Const.Max3DTextureLevels - 1)) <= MAX_WIDTH);
+
+   assert(ctx->Const.MaxViewportWidth <= MAX_WIDTH);
+   assert(ctx->Const.MaxViewportHeight <= MAX_WIDTH);
+
+   assert(ctx->Const.MaxDrawBuffers <= MAX_DRAW_BUFFERS);
+
+   /* XXX probably add more tests */
+}
+
+
+/**
+ * Initialize the attribute groups in a GL context.
+ *
+ * \param ctx GL context.
+ *
+ * Initializes all the attributes, calling the respective <tt>init*</tt>
+ * functions for the more complex data structures.
+ */
+static GLboolean
+init_attrib_groups(GLcontext *ctx)
+{
+   assert(ctx);
+
+   /* Constants */
+   _mesa_init_constants( ctx );
+
+   /* Extensions */
+   _mesa_init_extensions( ctx );
+
+   /* Attribute Groups */
+#if FEATURE_accum
+   _mesa_init_accum( ctx );
+#endif
+#if FEATURE_attrib_stack
+   _mesa_init_attrib( ctx );
+#endif
+   _mesa_init_buffer_objects( ctx );
+   _mesa_init_color( ctx );
+#if FEATURE_colortable
+   _mesa_init_colortables( ctx );
+#endif
+   _mesa_init_current( ctx );
+   _mesa_init_depth( ctx );
+   _mesa_init_debug( ctx );
+#if FEATURE_dlist
+   _mesa_init_display_list( ctx );
+#endif
+#if FEATURE_evaluators
+   _mesa_init_eval( ctx );
+#endif
+   _mesa_init_fbobjects( ctx );
+#if FEATURE_feedback
+   _mesa_init_feedback( ctx );
+#else
+   ctx->RenderMode = GL_RENDER;
+#endif
+   _mesa_init_fog( ctx );
+#if FEATURE_histogram
+   _mesa_init_histogram( ctx );
+#endif
+   _mesa_init_hint( ctx );
+   _mesa_init_line( ctx );
+   _mesa_init_lighting( ctx );
+   _mesa_init_matrix( ctx );
+   _mesa_init_multisample( ctx );
+   _mesa_init_pixel( ctx );
+   _mesa_init_pixelstore( ctx );
+   _mesa_init_point( ctx );
+   _mesa_init_polygon( ctx );
+   _mesa_init_program( ctx );
+#if FEATURE_ARB_occlusion_query
+   _mesa_init_query( ctx );
+#endif
+#if FEATURE_ARB_sync
+   _mesa_init_sync( ctx );
+#endif
+#if FEATURE_drawpix
+   _mesa_init_rastpos( ctx );
+#endif
+   _mesa_init_scissor( ctx );
+   _mesa_init_shader_state( ctx );
+   _mesa_init_stencil( ctx );
+   _mesa_init_transform( ctx );
+   _mesa_init_varray( ctx );
+   _mesa_init_viewport( ctx );
+
+   if (!_mesa_init_texture( ctx ))
+      return GL_FALSE;
+
+#if FEATURE_texture_s3tc
+   _mesa_init_texture_s3tc( ctx );
+#endif
+#if FEATURE_texture_fxt1
+   _mesa_init_texture_fxt1( ctx );
+#endif
+
+   /* Miscellaneous */
+   ctx->NewState = _NEW_ALL;
+   ctx->ErrorValue = (GLenum) GL_NO_ERROR;
+   ctx->varying_vp_inputs = ~0;
+
+   return GL_TRUE;
+}
+
+
+/**
+ * Update default objects in a GL context with respect to shared state.
+ *
+ * \param ctx GL context.
+ *
+ * Removes references to old default objects, (texture objects, program
+ * objects, etc.) and changes to reference those from the current shared
+ * state.
+ */
+static GLboolean
+update_default_objects(GLcontext *ctx)
+{
+   assert(ctx);
+
+   _mesa_update_default_objects_program(ctx);
+   _mesa_update_default_objects_texture(ctx);
+   _mesa_update_default_objects_buffer_objects(ctx);
+
+   return GL_TRUE;
+}
+
+
+/**
+ * This is the default function we plug into all dispatch table slots
+ * This helps prevents a segfault when someone calls a GL function without
+ * first checking if the extension's supported.
+ */
+static int
+generic_nop(void)
+{
+   _mesa_warning(NULL, "User called no-op dispatch function (an unsupported extension function?)");
+   return 0;
+}
+
+
+/**
+ * Allocate and initialize a new dispatch table.
+ */
+static struct _glapi_table *
+alloc_dispatch_table(void)
+{
+   /* Find the larger of Mesa's dispatch table and libGL's dispatch table.
+    * In practice, this'll be the same for stand-alone Mesa.  But for DRI
+    * Mesa we do this to accomodate different versions of libGL and various
+    * DRI drivers.
+    */
+   GLint numEntries = MAX2(_glapi_get_dispatch_table_size(),
+                           sizeof(struct _glapi_table) / sizeof(_glapi_proc));
+   struct _glapi_table *table =
+      (struct _glapi_table *) _mesa_malloc(numEntries * sizeof(_glapi_proc));
+   if (table) {
+      _glapi_proc *entry = (_glapi_proc *) table;
+      GLint i;
+      for (i = 0; i < numEntries; i++) {
+         entry[i] = (_glapi_proc) generic_nop;
+      }
+   }
+   return table;
+}
+
+
+/**
+ * Initialize a GLcontext struct (rendering context).
+ *
+ * This includes allocating all the other structs and arrays which hang off of
+ * the context by pointers.
+ * Note that the driver needs to pass in its dd_function_table here since
+ * we need to at least call driverFunctions->NewTextureObject to create the
+ * default texture objects.
+ * 
+ * Called by _mesa_create_context().
+ *
+ * Performs the imports and exports callback tables initialization, and
+ * miscellaneous one-time initializations. If no shared context is supplied one
+ * is allocated, and increase its reference count.  Setups the GL API dispatch
+ * tables.  Initialize the TNL module. Sets the maximum Z buffer depth.
+ * Finally queries the \c MESA_DEBUG and \c MESA_VERBOSE environment variables
+ * for debug flags.
+ *
+ * \param ctx the context to initialize
+ * \param visual describes the visual attributes for this context
+ * \param share_list points to context to share textures, display lists,
+ *        etc with, or NULL
+ * \param driverFunctions table of device driver functions for this context
+ *        to use
+ * \param driverContext pointer to driver-specific context data
+ */
+GLboolean
+_mesa_initialize_context(GLcontext *ctx,
+                         const GLvisual *visual,
+                         GLcontext *share_list,
+                         const struct dd_function_table *driverFunctions,
+                         void *driverContext)
+{
+   struct gl_shared_state *shared;
+
+   /*ASSERT(driverContext);*/
+   assert(driverFunctions->NewTextureObject);
+   assert(driverFunctions->FreeTexImageData);
+
+   /* misc one-time initializations */
+   one_time_init(ctx);
+
+   ctx->Visual = *visual;
+   ctx->DrawBuffer = NULL;
+   ctx->ReadBuffer = NULL;
+   ctx->WinSysDrawBuffer = NULL;
+   ctx->WinSysReadBuffer = NULL;
+
+   /* Plug in driver functions and context pointer here.
+    * This is important because when we call alloc_shared_state() below
+    * we'll call ctx->Driver.NewTextureObject() to create the default
+    * textures.
+    */
+   ctx->Driver = *driverFunctions;
+   ctx->DriverCtx = driverContext;
+
+   if (share_list) {
+      /* share state with another context */
+      shared = share_list->Shared;
+   }
+   else {
+      /* allocate new, unshared state */
+      shared = _mesa_alloc_shared_state(ctx);
+      if (!shared)
+         return GL_FALSE;
+   }
+
+   _glthread_LOCK_MUTEX(shared->Mutex);
+   ctx->Shared = shared;
+   shared->RefCount++;
+   _glthread_UNLOCK_MUTEX(shared->Mutex);
+
+   if (!init_attrib_groups( ctx )) {
+      _mesa_free_shared_state(ctx, ctx->Shared);
+      return GL_FALSE;
+   }
+
+   /* setup the API dispatch tables */
+   ctx->Exec = alloc_dispatch_table();
+   ctx->Save = alloc_dispatch_table();
+   if (!ctx->Exec || !ctx->Save) {
+      _mesa_free_shared_state(ctx, ctx->Shared);
+      if (ctx->Exec)
+         _mesa_free(ctx->Exec);
+   }
+#if FEATURE_dispatch
+   _mesa_init_exec_table(ctx->Exec);
+#endif
+   ctx->CurrentDispatch = ctx->Exec;
+#if FEATURE_dlist
+   _mesa_init_dlist_table(ctx->Save);
+   _mesa_install_save_vtxfmt( ctx, &ctx->ListState.ListVtxfmt );
+#endif
+   /* Neutral tnl module stuff */
+   _mesa_init_exec_vtxfmt( ctx ); 
+   ctx->TnlModule.Current = NULL;
+   ctx->TnlModule.SwapCount = 0;
+
+   ctx->FragmentProgram._MaintainTexEnvProgram
+      = (_mesa_getenv("MESA_TEX_PROG") != NULL);
+
+   ctx->VertexProgram._MaintainTnlProgram
+      = (_mesa_getenv("MESA_TNL_PROG") != NULL);
+   if (ctx->VertexProgram._MaintainTnlProgram) {
+      /* this is required... */
+      ctx->FragmentProgram._MaintainTexEnvProgram = GL_TRUE;
+   }
+
+#ifdef FEATURE_extra_context_init
+   _mesa_initialize_context_extra(ctx);
+#endif
+
+   ctx->FirstTimeCurrent = GL_TRUE;
+
+   return GL_TRUE;
+}
+
+
+/**
+ * Allocate and initialize a GLcontext structure.
+ * Note that the driver needs to pass in its dd_function_table here since
+ * we need to at least call driverFunctions->NewTextureObject to initialize
+ * the rendering context.
+ *
+ * \param visual a GLvisual pointer (we copy the struct contents)
+ * \param share_list another context to share display lists with or NULL
+ * \param driverFunctions points to the dd_function_table into which the
+ *        driver has plugged in all its special functions.
+ * \param driverContext points to the device driver's private context state
+ * 
+ * \return pointer to a new __GLcontextRec or NULL if error.
+ */
+GLcontext *
+_mesa_create_context(const GLvisual *visual,
+                     GLcontext *share_list,
+                     const struct dd_function_table *driverFunctions,
+                     void *driverContext)
+{
+   GLcontext *ctx;
+
+   ASSERT(visual);
+   /*ASSERT(driverContext);*/
+
+   ctx = (GLcontext *) _mesa_calloc(sizeof(GLcontext));
+   if (!ctx)
+      return NULL;
+
+   if (_mesa_initialize_context(ctx, visual, share_list,
+                                driverFunctions, driverContext)) {
+      return ctx;
+   }
+   else {
+      _mesa_free(ctx);
+      return NULL;
+   }
+}
+
+
+/**
+ * Free the data associated with the given context.
+ * 
+ * But doesn't free the GLcontext struct itself.
+ *
+ * \sa _mesa_initialize_context() and init_attrib_groups().
+ */
+void
+_mesa_free_context_data( GLcontext *ctx )
+{
+   GLint RefCount;
+
+   if (!_mesa_get_current_context()){
+      /* No current context, but we may need one in order to delete
+       * texture objs, etc.  So temporarily bind the context now.
+       */
+      _mesa_make_current(ctx, NULL, NULL);
+   }
+
+   /* unreference WinSysDraw/Read buffers */
+   _mesa_reference_framebuffer(&ctx->WinSysDrawBuffer, NULL);
+   _mesa_reference_framebuffer(&ctx->WinSysReadBuffer, NULL);
+   _mesa_reference_framebuffer(&ctx->DrawBuffer, NULL);
+   _mesa_reference_framebuffer(&ctx->ReadBuffer, NULL);
+
+   _mesa_reference_vertprog(ctx, &ctx->VertexProgram.Current, NULL);
+   _mesa_reference_vertprog(ctx, &ctx->VertexProgram._Current, NULL);
+   _mesa_reference_vertprog(ctx, &ctx->VertexProgram._TnlProgram, NULL);
+
+   _mesa_reference_fragprog(ctx, &ctx->FragmentProgram.Current, NULL);
+   _mesa_reference_fragprog(ctx, &ctx->FragmentProgram._Current, NULL);
+   _mesa_reference_fragprog(ctx, &ctx->FragmentProgram._TexEnvProgram, NULL);
+
+#if FEATURE_attrib_stack
+   _mesa_free_attrib_data(ctx);
+#endif
+   _mesa_free_lighting_data( ctx );
+#if FEATURE_evaluators
+   _mesa_free_eval_data( ctx );
+#endif
+   _mesa_free_texture_data( ctx );
+   _mesa_free_matrix_data( ctx );
+   _mesa_free_viewport_data( ctx );
+#if FEATURE_colortable
+   _mesa_free_colortables_data( ctx );
+#endif
+   _mesa_free_program_data(ctx);
+   _mesa_free_shader_state(ctx);
+#if FEATURE_ARB_occlusion_query
+   _mesa_free_query_data(ctx);
+#endif
+#if FEATURE_ARB_sync
+   _mesa_free_sync_data(ctx);
+#endif
+   _mesa_free_varray_data(ctx);
+
+   _mesa_delete_array_object(ctx, ctx->Array.DefaultArrayObj);
+
+#if FEATURE_ARB_pixel_buffer_object
+   _mesa_reference_buffer_object(ctx, &ctx->Pack.BufferObj, NULL);
+   _mesa_reference_buffer_object(ctx, &ctx->Unpack.BufferObj, NULL);
+#endif
+
+#if FEATURE_ARB_vertex_buffer_object
+   _mesa_reference_buffer_object(ctx, &ctx->Array.ArrayBufferObj, NULL);
+   _mesa_reference_buffer_object(ctx, &ctx->Array.ElementArrayBufferObj, NULL);
+#endif
+
+   /* free dispatch tables */
+   _mesa_free(ctx->Exec);
+   _mesa_free(ctx->Save);
+
+   /* Shared context state (display lists, textures, etc) */
+   _glthread_LOCK_MUTEX(ctx->Shared->Mutex);
+   RefCount = --ctx->Shared->RefCount;
+   _glthread_UNLOCK_MUTEX(ctx->Shared->Mutex);
+   assert(RefCount >= 0);
+   if (RefCount == 0) {
+      /* free shared state */
+      _mesa_free_shared_state( ctx, ctx->Shared );
+   }
+
+   if (ctx->Extensions.String)
+      _mesa_free((void *) ctx->Extensions.String);
+
+   /* unbind the context if it's currently bound */
+   if (ctx == _mesa_get_current_context()) {
+      _mesa_make_current(NULL, NULL, NULL);
+   }
+}
+
+
+/**
+ * Destroy a GLcontext structure.
+ *
+ * \param ctx GL context.
+ * 
+ * Calls _mesa_free_context_data() and frees the GLcontext structure itself.
+ */
+void
+_mesa_destroy_context( GLcontext *ctx )
+{
+   if (ctx) {
+      _mesa_free_context_data(ctx);
+      _mesa_free( (void *) ctx );
+   }
+}
+
+
+#if _HAVE_FULL_GL
+/**
+ * Copy attribute groups from one context to another.
+ * 
+ * \param src source context
+ * \param dst destination context
+ * \param mask bitwise OR of GL_*_BIT flags
+ *
+ * According to the bits specified in \p mask, copies the corresponding
+ * attributes from \p src into \p dst.  For many of the attributes a simple \c
+ * memcpy is not enough due to the existence of internal pointers in their data
+ * structures.
+ */
+void
+_mesa_copy_context( const GLcontext *src, GLcontext *dst, GLuint mask )
+{
+   if (mask & GL_ACCUM_BUFFER_BIT) {
+      /* OK to memcpy */
+      dst->Accum = src->Accum;
+   }
+   if (mask & GL_COLOR_BUFFER_BIT) {
+      /* OK to memcpy */
+      dst->Color = src->Color;
+   }
+   if (mask & GL_CURRENT_BIT) {
+      /* OK to memcpy */
+      dst->Current = src->Current;
+   }
+   if (mask & GL_DEPTH_BUFFER_BIT) {
+      /* OK to memcpy */
+      dst->Depth = src->Depth;
+   }
+   if (mask & GL_ENABLE_BIT) {
+      /* no op */
+   }
+   if (mask & GL_EVAL_BIT) {
+      /* OK to memcpy */
+      dst->Eval = src->Eval;
+   }
+   if (mask & GL_FOG_BIT) {
+      /* OK to memcpy */
+      dst->Fog = src->Fog;
+   }
+   if (mask & GL_HINT_BIT) {
+      /* OK to memcpy */
+      dst->Hint = src->Hint;
+   }
+   if (mask & GL_LIGHTING_BIT) {
+      GLuint i;
+      /* begin with memcpy */
+      dst->Light = src->Light;
+      /* fixup linked lists to prevent pointer insanity */
+      make_empty_list( &(dst->Light.EnabledList) );
+      for (i = 0; i < MAX_LIGHTS; i++) {
+         if (dst->Light.Light[i].Enabled) {
+            insert_at_tail(&(dst->Light.EnabledList), &(dst->Light.Light[i]));
+         }
+      }
+   }
+   if (mask & GL_LINE_BIT) {
+      /* OK to memcpy */
+      dst->Line = src->Line;
+   }
+   if (mask & GL_LIST_BIT) {
+      /* OK to memcpy */
+      dst->List = src->List;
+   }
+   if (mask & GL_PIXEL_MODE_BIT) {
+      /* OK to memcpy */
+      dst->Pixel = src->Pixel;
+   }
+   if (mask & GL_POINT_BIT) {
+      /* OK to memcpy */
+      dst->Point = src->Point;
+   }
+   if (mask & GL_POLYGON_BIT) {
+      /* OK to memcpy */
+      dst->Polygon = src->Polygon;
+   }
+   if (mask & GL_POLYGON_STIPPLE_BIT) {
+      /* Use loop instead of MEMCPY due to problem with Portland Group's
+       * C compiler.  Reported by John Stone.
+       */
+      GLuint i;
+      for (i = 0; i < 32; i++) {
+         dst->PolygonStipple[i] = src->PolygonStipple[i];
+      }
+   }
+   if (mask & GL_SCISSOR_BIT) {
+      /* OK to memcpy */
+      dst->Scissor = src->Scissor;
+   }
+   if (mask & GL_STENCIL_BUFFER_BIT) {
+      /* OK to memcpy */
+      dst->Stencil = src->Stencil;
+   }
+   if (mask & GL_TEXTURE_BIT) {
+      /* Cannot memcpy because of pointers */
+      _mesa_copy_texture_state(src, dst);
+   }
+   if (mask & GL_TRANSFORM_BIT) {
+      /* OK to memcpy */
+      dst->Transform = src->Transform;
+   }
+   if (mask & GL_VIEWPORT_BIT) {
+      /* Cannot use memcpy, because of pointers in GLmatrix _WindowMap */
+      dst->Viewport.X = src->Viewport.X;
+      dst->Viewport.Y = src->Viewport.Y;
+      dst->Viewport.Width = src->Viewport.Width;
+      dst->Viewport.Height = src->Viewport.Height;
+      dst->Viewport.Near = src->Viewport.Near;
+      dst->Viewport.Far = src->Viewport.Far;
+      _math_matrix_copy(&dst->Viewport._WindowMap, &src->Viewport._WindowMap);
+   }
+
+   /* XXX FIXME:  Call callbacks?
+    */
+   dst->NewState = _NEW_ALL;
+}
+#endif
+
+
+/**
+ * Check if the given context can render into the given framebuffer
+ * by checking visual attributes.
+ *
+ * Most of these tests could go away because Mesa is now pretty flexible
+ * in terms of mixing rendering contexts with framebuffers.  As long
+ * as RGB vs. CI mode agree, we're probably good.
+ *
+ * \return GL_TRUE if compatible, GL_FALSE otherwise.
+ */
+static GLboolean 
+check_compatible(const GLcontext *ctx, const GLframebuffer *buffer)
+{
+   const GLvisual *ctxvis = &ctx->Visual;
+   const GLvisual *bufvis = &buffer->Visual;
+
+   if (ctxvis == bufvis)
+      return GL_TRUE;
+
+   if (ctxvis->rgbMode != bufvis->rgbMode)
+      return GL_FALSE;
+#if 0
+   /* disabling this fixes the fgl_glxgears pbuffer demo */
+   if (ctxvis->doubleBufferMode && !bufvis->doubleBufferMode)
+      return GL_FALSE;
+#endif
+   if (ctxvis->stereoMode && !bufvis->stereoMode)
+      return GL_FALSE;
+   if (ctxvis->haveAccumBuffer && !bufvis->haveAccumBuffer)
+      return GL_FALSE;
+   if (ctxvis->haveDepthBuffer && !bufvis->haveDepthBuffer)
+      return GL_FALSE;
+   if (ctxvis->haveStencilBuffer && !bufvis->haveStencilBuffer)
+      return GL_FALSE;
+   if (ctxvis->redMask && ctxvis->redMask != bufvis->redMask)
+      return GL_FALSE;
+   if (ctxvis->greenMask && ctxvis->greenMask != bufvis->greenMask)
+      return GL_FALSE;
+   if (ctxvis->blueMask && ctxvis->blueMask != bufvis->blueMask)
+      return GL_FALSE;
+#if 0
+   /* disabled (see bug 11161) */
+   if (ctxvis->depthBits && ctxvis->depthBits != bufvis->depthBits)
+      return GL_FALSE;
+#endif
+   if (ctxvis->stencilBits && ctxvis->stencilBits != bufvis->stencilBits)
+      return GL_FALSE;
+
+   return GL_TRUE;
+}
+
+
+/**
+ * Do one-time initialization for the given framebuffer.  Specifically,
+ * ask the driver for the window's current size and update the framebuffer
+ * object to match.
+ * Really, the device driver should totally take care of this.
+ */
+static void
+initialize_framebuffer_size(GLcontext *ctx, GLframebuffer *fb)
+{
+   GLuint width, height;
+   if (ctx->Driver.GetBufferSize) {
+      ctx->Driver.GetBufferSize(fb, &width, &height);
+      if (ctx->Driver.ResizeBuffers)
+         ctx->Driver.ResizeBuffers(ctx, fb, width, height);
+      fb->Initialized = GL_TRUE;
+   }
+}
+
+
+/**
+ * Check if the viewport/scissor size has not yet been initialized.
+ * Initialize the size if the given width and height are non-zero.
+ */
+void
+_mesa_check_init_viewport(GLcontext *ctx, GLuint width, GLuint height)
+{
+   if (!ctx->ViewportInitialized && width > 0 && height > 0) {
+      /* Note: set flag here, before calling _mesa_set_viewport(), to prevent
+       * potential infinite recursion.
+       */
+      ctx->ViewportInitialized = GL_TRUE;
+      _mesa_set_viewport(ctx, 0, 0, width, height);
+      _mesa_set_scissor(ctx, 0, 0, width, height);
+   }
+}
+
+
+/**
+ * Bind the given context to the given drawBuffer and readBuffer and
+ * make it the current context for the calling thread.
+ * We'll render into the drawBuffer and read pixels from the
+ * readBuffer (i.e. glRead/CopyPixels, glCopyTexImage, etc).
+ *
+ * We check that the context's and framebuffer's visuals are compatible
+ * and return immediately if they're not.
+ *
+ * \param newCtx  the new GL context. If NULL then there will be no current GL
+ *                context.
+ * \param drawBuffer  the drawing framebuffer
+ * \param readBuffer  the reading framebuffer
+ */
+GLboolean
+_mesa_make_current( GLcontext *newCtx, GLframebuffer *drawBuffer,
+                    GLframebuffer *readBuffer )
+{
+   if (MESA_VERBOSE & VERBOSE_API)
+      _mesa_debug(newCtx, "_mesa_make_current()\n");
+
+   /* Check that the context's and framebuffer's visuals are compatible.
+    */
+   if (newCtx && drawBuffer && newCtx->WinSysDrawBuffer != drawBuffer) {
+      if (!check_compatible(newCtx, drawBuffer)) {
+         _mesa_warning(newCtx,
+              "MakeCurrent: incompatible visuals for context and drawbuffer");
+         return GL_FALSE;
+      }
+   }
+   if (newCtx && readBuffer && newCtx->WinSysReadBuffer != readBuffer) {
+      if (!check_compatible(newCtx, readBuffer)) {
+         _mesa_warning(newCtx,
+              "MakeCurrent: incompatible visuals for context and readbuffer");
+         return GL_FALSE;
+      }
+   }
+
+   /* We used to call _glapi_check_multithread() here.  Now do it in drivers */
+   _glapi_set_context((void *) newCtx);
+   ASSERT(_mesa_get_current_context() == newCtx);
+
+   if (!newCtx) {
+      _glapi_set_dispatch(NULL);  /* none current */
+   }
+   else {
+      _glapi_set_dispatch(newCtx->CurrentDispatch);
+
+      if (drawBuffer && readBuffer) {
+	 /* TODO: check if newCtx and buffer's visual match??? */
+
+         ASSERT(drawBuffer->Name == 0);
+         ASSERT(readBuffer->Name == 0);
+         _mesa_reference_framebuffer(&newCtx->WinSysDrawBuffer, drawBuffer);
+         _mesa_reference_framebuffer(&newCtx->WinSysReadBuffer, readBuffer);
+
+         /*
+          * Only set the context's Draw/ReadBuffer fields if they're NULL
+          * or not bound to a user-created FBO.
+          */
+         if (!newCtx->DrawBuffer || newCtx->DrawBuffer->Name == 0) {
+            /* KW: merge conflict here, revisit. 
+             */
+            /* fix up the fb fields - these will end up wrong otherwise
+             * if the DRIdrawable changes, and everything relies on them.
+             * This is a bit messy (same as needed in _mesa_BindFramebufferEXT)
+             */
+            unsigned int i;
+            GLenum buffers[MAX_DRAW_BUFFERS];
+
+            _mesa_reference_framebuffer(&newCtx->DrawBuffer, drawBuffer);
+
+            for(i = 0; i < newCtx->Const.MaxDrawBuffers; i++) {
+               buffers[i] = newCtx->Color.DrawBuffer[i];
+            }
+
+            _mesa_drawbuffers(newCtx, newCtx->Const.MaxDrawBuffers, buffers, NULL);
+         }
+         if (!newCtx->ReadBuffer || newCtx->ReadBuffer->Name == 0) {
+            _mesa_reference_framebuffer(&newCtx->ReadBuffer, readBuffer);
+         }
+
+         /* XXX only set this flag if we're really changing the draw/read
+          * framebuffer bindings.
+          */
+	 newCtx->NewState |= _NEW_BUFFERS;
+
+#if 1
+         /* We want to get rid of these lines: */
+
+#if _HAVE_FULL_GL
+         if (!drawBuffer->Initialized) {
+            initialize_framebuffer_size(newCtx, drawBuffer);
+         }
+         if (readBuffer != drawBuffer && !readBuffer->Initialized) {
+            initialize_framebuffer_size(newCtx, readBuffer);
+         }
+
+	 _mesa_resizebuffers(newCtx);
+#endif
+
+#else
+         /* We want the drawBuffer and readBuffer to be initialized by
+          * the driver.
+          * This generally means the Width and Height match the actual
+          * window size and the renderbuffers (both hardware and software
+          * based) are allocated to match.  The later can generally be
+          * done with a call to _mesa_resize_framebuffer().
+          *
+          * It's theoretically possible for a buffer to have zero width
+          * or height, but for now, assert check that the driver did what's
+          * expected of it.
+          */
+         ASSERT(drawBuffer->Width > 0);
+         ASSERT(drawBuffer->Height > 0);
+#endif
+
+         if (drawBuffer) {
+            _mesa_check_init_viewport(newCtx,
+                                      drawBuffer->Width, drawBuffer->Height);
+         }
+      }
+
+      if (newCtx->FirstTimeCurrent) {
+         check_context_limits(newCtx);
+
+         /* We can use this to help debug user's problems.  Tell them to set
+          * the MESA_INFO env variable before running their app.  Then the
+          * first time each context is made current we'll print some useful
+          * information.
+          */
+	 if (_mesa_getenv("MESA_INFO")) {
+	    _mesa_print_info();
+	 }
+
+	 newCtx->FirstTimeCurrent = GL_FALSE;
+      }
+   }
+   
+   return GL_TRUE;
+}
+
+
+/**
+ * Make context 'ctx' share the display lists, textures and programs
+ * that are associated with 'ctxToShare'.
+ * Any display lists, textures or programs associated with 'ctx' will
+ * be deleted if nobody else is sharing them.
+ */
+GLboolean
+_mesa_share_state(GLcontext *ctx, GLcontext *ctxToShare)
+{
+   if (ctx && ctxToShare && ctx->Shared && ctxToShare->Shared) {
+      struct gl_shared_state *oldSharedState = ctx->Shared;
+      GLint RefCount;
+
+      ctx->Shared = ctxToShare->Shared;
+      
+      _glthread_LOCK_MUTEX(ctx->Shared->Mutex);
+      ctx->Shared->RefCount++;
+      _glthread_UNLOCK_MUTEX(ctx->Shared->Mutex);
+
+      update_default_objects(ctx);
+
+      _glthread_LOCK_MUTEX(oldSharedState->Mutex);
+      RefCount = --oldSharedState->RefCount;
+      _glthread_UNLOCK_MUTEX(oldSharedState->Mutex);
+
+      if (RefCount == 0) {
+         _mesa_free_shared_state(ctx, oldSharedState);
+      }
+
+      return GL_TRUE;
+   }
+   else {
+      return GL_FALSE;
+   }
+}
+
+
+
+/**
+ * \return pointer to the current GL context for this thread.
+ * 
+ * Calls _glapi_get_context(). This isn't the fastest way to get the current
+ * context.  If you need speed, see the #GET_CURRENT_CONTEXT macro in
+ * context.h.
+ */
+GLcontext *
+_mesa_get_current_context( void )
+{
+   return (GLcontext *) _glapi_get_context();
+}
+
+
+/**
+ * Get context's current API dispatch table.
+ *
+ * It'll either be the immediate-mode execute dispatcher or the display list
+ * compile dispatcher.
+ * 
+ * \param ctx GL context.
+ *
+ * \return pointer to dispatch_table.
+ *
+ * Simply returns __GLcontextRec::CurrentDispatch.
+ */
+struct _glapi_table *
+_mesa_get_dispatch(GLcontext *ctx)
+{
+   return ctx->CurrentDispatch;
+}
+
+/*@}*/
+
+
+/**********************************************************************/
+/** \name Miscellaneous functions                                     */
+/**********************************************************************/
+/*@{*/
+
+/**
+ * Record an error.
+ *
+ * \param ctx GL context.
+ * \param error error code.
+ * 
+ * Records the given error code and call the driver's dd_function_table::Error
+ * function if defined.
+ *
+ * \sa
+ * This is called via _mesa_error().
+ */
+void
+_mesa_record_error(GLcontext *ctx, GLenum error)
+{
+   if (!ctx)
+      return;
+
+   if (ctx->ErrorValue == GL_NO_ERROR) {
+      ctx->ErrorValue = error;
+   }
+
+   /* Call device driver's error handler, if any.  This is used on the Mac. */
+   if (ctx->Driver.Error) {
+      ctx->Driver.Error(ctx);
+   }
+}
+
+
+/**
+ * Execute glFinish().
+ *
+ * Calls the #ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH macro and the
+ * dd_function_table::Finish driver callback, if not NULL.
+ */
+void GLAPIENTRY
+_mesa_Finish(void)
+{
+   GET_CURRENT_CONTEXT(ctx);
+   ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx);
+   FLUSH_CURRENT( ctx, 0 );
+   if (ctx->Driver.Finish) {
+      ctx->Driver.Finish(ctx);
+   }
+}
+
+
+/**
+ * Execute glFlush().
+ *
+ * Calls the #ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH macro and the
+ * dd_function_table::Flush driver callback, if not NULL.
+ */
+void GLAPIENTRY
+_mesa_Flush(void)
+{
+   GET_CURRENT_CONTEXT(ctx);
+   ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx);
+   FLUSH_CURRENT( ctx, 0 );
+   if (ctx->Driver.Flush) {
+      ctx->Driver.Flush(ctx);
+   }
+}
+
+
+/**
+ * Set mvp_with_dp4 flag.  If a driver has a preference for DP4 over
+ * MUL/MAD, or vice versa, call this function to register that.
+ * Otherwise we default to MUL/MAD.
+ */
+void
+_mesa_set_mvp_with_dp4( GLcontext *ctx,
+                        GLboolean flag )
+{
+   ctx->mvp_with_dp4 = flag;
+}
+
+
+
+/**
+ * Prior to drawing anything with glBegin, glDrawArrays, etc. this function
+ * is called to see if it's valid to render.  This involves checking that
+ * the current shader is valid and the framebuffer is complete.
+ * If an error is detected it'll be recorded here.
+ * \return GL_TRUE if OK to render, GL_FALSE if not
+ */
+GLboolean
+_mesa_valid_to_render(GLcontext *ctx, const char *where)
+{
+   if (ctx->Shader.CurrentProgram) {
+      /* using shaders */
+      if (!ctx->Shader.CurrentProgram->LinkStatus) {
+         _mesa_error(ctx, GL_INVALID_OPERATION,
+                     "%s(shader not linked), where");
+         return GL_FALSE;
+      }
+#if 0 /* not normally enabled */
+      {
+         char errMsg[100];
+         if (!_mesa_validate_shader_program(ctx, ctx->Shader.CurrentProgram,
+                                            errMsg)) {
+            _mesa_warning(ctx, "Shader program %u is invalid: %s",
+                          ctx->Shader.CurrentProgram->Name, errMsg);
+         }
+      }
+#endif
+   }
+   else {
+      if (ctx->VertexProgram.Enabled && !ctx->VertexProgram._Enabled) {
+         _mesa_error(ctx, GL_INVALID_OPERATION,
+                     "%s(vertex program not valid)", where);
+         return GL_FALSE;
+      }
+      if (ctx->FragmentProgram.Enabled && !ctx->FragmentProgram._Enabled) {
+         _mesa_error(ctx, GL_INVALID_OPERATION,
+                     "%s(fragment program not valid)", where);
+         return GL_FALSE;
+      }
+   }
+
+   if (ctx->DrawBuffer->_Status != GL_FRAMEBUFFER_COMPLETE_EXT) {
+      _mesa_error(ctx, GL_INVALID_FRAMEBUFFER_OPERATION_EXT,
+                  "%s(incomplete framebuffer)", where);
+      return GL_FALSE;
+   }
+
+#ifdef DEBUG
+   if (ctx->Shader.Flags & GLSL_LOG) {
+      struct gl_shader_program *shProg = ctx->Shader.CurrentProgram;
+      if (shProg) {
+         if (!shProg->_Used) {
+            /* This is the first time this shader is being used.
+             * Append shader's constants/uniforms to log file.
+             */
+            GLuint i;
+            for (i = 0; i < shProg->NumShaders; i++) {
+               struct gl_shader *sh = shProg->Shaders[i];
+               if (sh->Type == GL_VERTEX_SHADER) {
+                  _mesa_append_uniforms_to_file(sh,
+                                                &shProg->VertexProgram->Base);
+               }
+               else if (sh->Type == GL_FRAGMENT_SHADER) {
+                  _mesa_append_uniforms_to_file(sh,
+                                                &shProg->FragmentProgram->Base);
+               }
+            }
+            shProg->_Used = GL_TRUE;
+         }
+      }
+   }
+#endif
+
+   return GL_TRUE;
+}
+
+
+/*@}*/