mutter/clutter/cogl/gl/cogl-context.c
Robert Bragg ea643ca0f8 [multi-texturing] This adds a new cogl_multi_texture API for GL,GLES1 + GLES2
Multitexturing allows blending multiple layers of texture data when texturing
some geometry. A common use is for pre-baked light maps which can give nice
lighting effects relativly cheaply. Another is for dot-3 bump mapping, and
another is applying alpha channel masks.

The dot-3 bump mapping would be really nice one day, but currently cogl doesn't
support lighting so that's not dealt with in this patch.

notable limitations:
- It can only texture rectangles a.t.m - and like cogl_texture_rectangle there
is no support for rotated texturing.
- Sliced textures are not supported. I think I've figured out how to handle
layers with different slice sizes at least for rectangular geometry, but I'm
not sure how complex it becomes once rotations are possible and texturing
arbitrary cogl_polygons.
- Except for this new API, cogl still doesn't know about more than one texture
unit, and so has no way of caching any enables related to other units. So that
things don't break it's currently necessary to disable anything to do with
additional units as soon as we are done with them which isn't ideal.
- No clutter API yet.
2008-12-22 16:35:51 +00:00

166 lines
4.8 KiB
C

/*
* Clutter COGL
*
* A basic GL/GLES Abstraction/Utility Layer
*
* Authored By Matthew Allum <mallum@openedhand.com>
*
* Copyright (C) 2007 OpenedHand
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "cogl.h"
#include "cogl-internal.h"
#include "cogl-util.h"
#include "cogl-context.h"
#include <string.h>
static CoglContext *_context = NULL;
gboolean
cogl_create_context ()
{
if (_context != NULL)
return FALSE;
/* Allocate context memory */
_context = (CoglContext*) g_malloc (sizeof (CoglContext));
/* Init default values */
_context->feature_flags = 0;
_context->features_cached = FALSE;
_context->enable_flags = 0;
_context->color_alpha = 255;
_context->path_nodes = g_array_new (FALSE, FALSE, sizeof (CoglPathNode));
_context->last_path = 0;
_context->texture_handles = NULL;
_context->texture_vertices_size = 0;
_context->texture_vertices = NULL;
_context->multi_texture_handles = NULL;
_context->multi_texture_layer_handles = NULL;
_context->fbo_handles = NULL;
_context->draw_buffer = COGL_WINDOW_BUFFER;
_context->blend_src_factor = CGL_SRC_ALPHA;
_context->blend_dst_factor = CGL_ONE_MINUS_SRC_ALPHA;
_context->shader_handles = NULL;
_context->program_handles = NULL;
_context->mesh_handles = NULL;
_context->pf_glGenRenderbuffersEXT = NULL;
_context->pf_glBindRenderbufferEXT = NULL;
_context->pf_glRenderbufferStorageEXT = NULL;
_context->pf_glGenFramebuffersEXT = NULL;
_context->pf_glBindFramebufferEXT = NULL;
_context->pf_glFramebufferTexture2DEXT = NULL;
_context->pf_glFramebufferRenderbufferEXT = NULL;
_context->pf_glCheckFramebufferStatusEXT = NULL;
_context->pf_glDeleteFramebuffersEXT = NULL;
_context->pf_glBlitFramebufferEXT = NULL;
_context->pf_glRenderbufferStorageMultisampleEXT = NULL;
_context->pf_glCreateProgramObjectARB = NULL;
_context->pf_glCreateShaderObjectARB = NULL;
_context->pf_glShaderSourceARB = NULL;
_context->pf_glCompileShaderARB = NULL;
_context->pf_glAttachObjectARB = NULL;
_context->pf_glLinkProgramARB = NULL;
_context->pf_glUseProgramObjectARB = NULL;
_context->pf_glGetUniformLocationARB = NULL;
_context->pf_glDeleteObjectARB = NULL;
_context->pf_glGetInfoLogARB = NULL;
_context->pf_glGetObjectParameterivARB = NULL;
_context->pf_glUniform1fARB = NULL;
_context->pf_glUniform2fARB = NULL;
_context->pf_glUniform3fARB = NULL;
_context->pf_glUniform4fARB = NULL;
_context->pf_glUniform1fvARB = NULL;
_context->pf_glUniform2fvARB = NULL;
_context->pf_glUniform3fvARB = NULL;
_context->pf_glUniform4fvARB = NULL;
_context->pf_glUniform1iARB = NULL;
_context->pf_glUniform2iARB = NULL;
_context->pf_glUniform3iARB = NULL;
_context->pf_glUniform4iARB = NULL;
_context->pf_glUniform1ivARB = NULL;
_context->pf_glUniform2ivARB = NULL;
_context->pf_glUniform3ivARB = NULL;
_context->pf_glUniform4ivARB = NULL;
_context->pf_glUniformMatrix2fvARB = NULL;
_context->pf_glUniformMatrix3fvARB = NULL;
_context->pf_glUniformMatrix4fvARB = NULL;
_context->pf_glDrawRangeElements = NULL;
/* Init OpenGL state */
GE( glTexEnvi (GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE) );
GE( glColorMask (TRUE, TRUE, TRUE, FALSE) );
GE( glBlendFunc (GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA) );
cogl_enable (0);
/* Initialise the clip stack */
_cogl_clip_stack_state_init ();
return TRUE;
}
void
cogl_destroy_context ()
{
if (_context == NULL)
return;
_cogl_clip_stack_state_destroy ();
if (_context->path_nodes)
g_array_free (_context->path_nodes, TRUE);
if (_context->texture_handles)
g_array_free (_context->texture_handles, TRUE);
if (_context->fbo_handles)
g_array_free (_context->fbo_handles, TRUE);
if (_context->shader_handles)
g_array_free (_context->shader_handles, TRUE);
if (_context->program_handles)
g_array_free (_context->program_handles, TRUE);
g_free (_context);
}
CoglContext *
_cogl_context_get_default ()
{
/* Create if doesn't exist yet */
if (_context == NULL)
cogl_create_context ();
return _context;
}