context.c

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/**
 * \file context.c
 * Mesa context/visual/framebuffer management functions.
 * \author Brian Paul
 */

/*
 * Mesa 3-D graphics library
 * Version:  7.1
 *
 * Copyright (C) 1999-2007  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.
 */


/**
 * \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 "imports.h"
#include "accum.h"
#include "arrayobj.h"
#include "attrib.h"
#include "blend.h"
#include "buffers.h"
#include "bufferobj.h"
#include "colortab.h"
#include "context.h"
#include "debug.h"
#include "depth.h"
#include "dlist.h"
#include "eval.h"
#include "enums.h"
#include "extensions.h"
#include "fbobject.h"
#include "feedback.h"
#include "fog.h"
#include "framebuffer.h"
#include "get.h"
#include "histogram.h"
#include "hint.h"
#include "hash.h"
#include "light.h"
#include "lines.h"
#include "macros.h"
#include "matrix.h"
#include "pixel.h"
#include "points.h"
#include "polygon.h"
#include "queryobj.h"
#include "rastpos.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 "vtxfmt.h"
#include "glapi/glthread.h"
#if FEATURE_NV_vertex_program || FEATURE_NV_fragment_program
#include "shader/program.h"
#endif
#include "shader/shader_api.h"
#include "shader/atifragshader.h"
#if _HAVE_FULL_GL
#include "math/m_translate.h"
#include "math/m_matrix.h"
#include "math/m_xform.h"
#include "math/mathmod.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 gc GL context.
 *
 * Called by window system just before swapping buffers.
 * We have to finish any pending rendering.
 */
void
_mesa_notifySwapBuffers(__GLcontext *gc)
{
   FLUSH_VERTICES( gc, 0 );
}


/**********************************************************************/
/** \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.
 */
/**********************************************************************/
/*@{*/

/**
 * 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_init_sqrt_table();

#if _HAVE_FULL_GL
      _math_init();

      for (i = 0; i < 256; i++) {
         _mesa_ubyte_to_float_color_tab[i] = (float) i / 255.0F;
      }
#endif

#ifdef USE_SPARC_ASM
      _mesa_init_sparc_glapi_relocs();
#endif
      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);
}


/**
 * Allocate and initialize a shared context state structure.
 * Initializes the display list, texture objects and vertex programs hash
 * tables, allocates the texture objects. If it runs out of memory, frees
 * everything already allocated before returning NULL.
 *
 * \return pointer to a gl_shared_state structure on success, or NULL on
 * failure.
 */
static GLboolean
alloc_shared_state( GLcontext *ctx )
{
   struct gl_shared_state *ss = CALLOC_STRUCT(gl_shared_state);
   if (!ss)
      return GL_FALSE;

   ctx->Shared = ss;

   _glthread_INIT_MUTEX(ss->Mutex);

   ss->DisplayList = _mesa_NewHashTable();
   ss->TexObjects = _mesa_NewHashTable();
#if FEATURE_NV_vertex_program || FEATURE_NV_fragment_program
   ss->Programs = _mesa_NewHashTable();
#endif

#if FEATURE_ARB_vertex_program
   ss->DefaultVertexProgram = (struct gl_vertex_program *)
      ctx->Driver.NewProgram(ctx, GL_VERTEX_PROGRAM_ARB, 0);
   if (!ss->DefaultVertexProgram)
      goto cleanup;
#endif
#if FEATURE_ARB_fragment_program
   ss->DefaultFragmentProgram = (struct gl_fragment_program *)
      ctx->Driver.NewProgram(ctx, GL_FRAGMENT_PROGRAM_ARB, 0);
   if (!ss->DefaultFragmentProgram)
      goto cleanup;
#endif
#if FEATURE_ATI_fragment_shader
   ss->ATIShaders = _mesa_NewHashTable();
   ss->DefaultFragmentShader = _mesa_new_ati_fragment_shader(ctx, 0);
   if (!ss->DefaultFragmentShader)
      goto cleanup;
#endif

#if FEATURE_ARB_vertex_buffer_object || FEATURE_ARB_pixel_buffer_object
   ss->BufferObjects = _mesa_NewHashTable();
#endif

   ss->ArrayObjects = _mesa_NewHashTable();