mutter/clutter/cogl/gl/cogl-context.c
Robert Bragg 33994caa71 [cogl-material] Support string based blending and layer combine descriptions
Setting up layer combine functions and blend modes is very awkward to do
programatically.  This adds a parser for string based descriptions which are
more consise and readable.

E.g. a material layer combine function could now be given as:
  "RGBA = ADD (TEXTURE[A], PREVIOUS[RGB])"
or
  "RGB = REPLACE (PREVIOUS)"
  "A = MODULATE (PREVIOUS, TEXTURE)"

The simple syntax and grammar are only designed to expose standard fixed
function hardware, more advanced combining must be done with shaders.

This includes standalone documentation of blend strings covering the aspects
that are common to blending and texture combining, and adds documentation
with examples specific to the new cogl_material_set_blend() and
cogl_material_layer_set_combine() functions.

Note: The hope is to remove the now redundant bits of the material API
before 1.0
2009-05-28 02:43:28 +01:00

251 lines
8.1 KiB
C

/*
* Cogl
*
* An object oriented GL/GLES Abstraction/Utility Layer
*
* Copyright (C) 2007,2008,2009 Intel Corporation.
*
* 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 "cogl-texture-private.h"
#include "cogl-material-private.h"
#include <string.h>
static CoglContext *_context = NULL;
static gboolean gl_is_indirect = FALSE;
gboolean
cogl_create_context ()
{
GLubyte default_texture_data[] = { 0xff, 0xff, 0xff, 0x0 };
gulong enable_flags = 0;
CoglDrawBufferState *draw_buffer;
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 = 0;
_context->enable_backface_culling = FALSE;
_context->indirect = gl_is_indirect;
_context->default_material = cogl_material_new ();
_context->source_material = NULL;
_context->default_gl_texture_2d_tex = COGL_INVALID_HANDLE;
_context->default_gl_texture_rect_tex = COGL_INVALID_HANDLE;
_context->journal = g_array_new (FALSE, FALSE, sizeof (CoglJournalEntry));
_context->logged_vertices = g_array_new (FALSE, FALSE, sizeof (GLfloat));
_context->static_indices = g_array_new (FALSE, FALSE, sizeof (GLushort));
_context->polygon_vertices = g_array_new (FALSE, FALSE,
sizeof (CoglTextureGLVertex));
_context->current_material = NULL;
_context->current_material_flags = 0;
_context->current_layers = g_array_new (FALSE, FALSE,
sizeof (CoglLayerInfo));
_context->n_texcoord_arrays_enabled = 0;
draw_buffer = g_slice_new0 (CoglDrawBufferState);
draw_buffer->target = COGL_WINDOW_BUFFER;
draw_buffer->offscreen = COGL_INVALID_HANDLE;
_context->draw_buffer_stack =
g_slist_prepend (NULL, draw_buffer);
_context->path_nodes = g_array_new (FALSE, FALSE, sizeof (CoglPathNode));
_context->last_path = 0;
_context->stencil_material = cogl_material_new ();
_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;
_context->pf_glActiveTexture = NULL;
_context->pf_glClientActiveTexture = NULL;
_context->pf_glBlendFuncSeparate = NULL;
_context->pf_glBlendEquationSeparate = NULL;
/* Initialise the clip stack */
_cogl_clip_stack_state_init ();
/* Initialise matrix stack */
_cogl_current_matrix_state_init ();
/* Create default textures used for fall backs */
_context->default_gl_texture_2d_tex =
cogl_texture_new_from_data (1, /* width */
1, /* height */
COGL_TEXTURE_NO_SLICING,
COGL_PIXEL_FORMAT_RGBA_8888, /* data format */
/* internal format */
COGL_PIXEL_FORMAT_RGBA_8888,
0, /* auto calc row stride */
default_texture_data);
_context->default_gl_texture_rect_tex =
cogl_texture_new_from_data (1, /* width */
1, /* height */
COGL_TEXTURE_NO_SLICING,
COGL_PIXEL_FORMAT_RGBA_8888, /* data format */
/* internal format */
COGL_PIXEL_FORMAT_RGBA_8888,
0, /* auto calc row stride */
default_texture_data);
cogl_set_source (_context->default_material);
cogl_material_flush_gl_state (_context->source_material, NULL);
enable_flags =
cogl_material_get_cogl_enable_flags (_context->source_material);
cogl_enable (enable_flags);
return TRUE;
}
void
cogl_destroy_context ()
{
if (_context == NULL)
return;
_cogl_clip_stack_state_destroy ();
_cogl_current_matrix_state_destroy ();
if (_context->path_nodes)
g_array_free (_context->path_nodes, TRUE);
if (_context->default_gl_texture_2d_tex)
cogl_handle_unref (_context->default_gl_texture_2d_tex);
if (_context->default_gl_texture_rect_tex)
cogl_handle_unref (_context->default_gl_texture_rect_tex);
if (_context->default_material)
cogl_handle_unref (_context->default_material);
if (_context->journal)
g_array_free (_context->journal, TRUE);
if (_context->logged_vertices)
g_array_free (_context->logged_vertices, TRUE);
if (_context->static_indices)
g_array_free (_context->static_indices, TRUE);
if (_context->polygon_vertices)
g_array_free (_context->polygon_vertices, TRUE);
if (_context->current_layers)
g_array_free (_context->current_layers, TRUE);
g_free (_context);
}
CoglContext *
_cogl_context_get_default ()
{
/* Create if doesn't exist yet */
if (_context == NULL)
cogl_create_context ();
return _context;
}
/**
* _cogl_set_indirect_context:
* @indirect: TRUE if GL context is indirect
*
* Advises COGL that the GL context is indirect (commands are sent
* over a socket). COGL uses this information to try to avoid
* round-trips in its use of GL, for example.
*
* This function cannot be called "on the fly," only before COGL
* initializes.
*/
void
_cogl_set_indirect_context (gboolean indirect)
{
/* we get called multiple times if someone creates
* more than the default stage
*/
if (_context != NULL)
{
if (indirect != _context->indirect)
g_warning ("Right now all stages will be treated as "
"either direct or indirect, ignoring attempt "
"to change to indirect=%d", indirect);
return;
}
gl_is_indirect = indirect;
}