mutter/clutter/cogl/gl/cogl-context.c
Robert Bragg 33400c0aae [cogl] Improve ability to break out into raw OpenGL via begin/end mechanism
Although we wouldn't recommend developers try and interleve OpenGL drawing
with Cogl drawing - we would prefer patches that improve Cogl to avoid this
if possible - we are providing a simple mechanism that will at least give
developers a fighting chance if they find it necissary.

Note: we aren't helping developers change OpenGL state to modify the
behaviour of Cogl drawing functions - it's unlikley that can ever be
reliably supported - but if they are trying to do something like:

   - setup some OpenGL state.
   - draw using OpenGL (e.g. glDrawArrays() )
   - reset modified OpenGL state.
   - continue using Cogl to draw

They should surround their blocks of raw OpenGL with cogl_begin_gl() and
cogl_end_gl():

   cogl_begin_gl ();
   - setup some OpenGL state.
   - draw using OpenGL (e.g. glDrawArrays() )
   - reset modified OpenGL state.
   cogl_end_gl ();
   - continue using Cogl to draw

Again; we aren't supporting code like this:
   - setup some OpenGL state.
   - use Cogl to draw
   - reset modified OpenGL state.
When the internals of Cogl evolves, this is very liable to break.

cogl_begin_gl() will flush all internally batched Cogl primitives, and emit
all internal Cogl state to OpenGL as if it were going to draw something
itself.

The result is that the OpenGL modelview matrix will be setup; the state
corresponding to the current source material will be setup and other world
state such as backface culling, depth and fogging enabledness will be also
be sent to OpenGL.

Note: no special material state is flushed, so if developers want Cogl to setup
a simplified material state it is the their responsibility to set a simple
source material before calling cogl_begin_gl. E.g. by calling
cogl_set_source_color4ub().

Note: It is the developers responsibility to restore any OpenGL state that they
modify to how it was after calling cogl_begin_gl() if they don't do this then
the result of further Cogl calls is undefined.
2009-06-30 17:13:38 +01:00

259 lines
8.2 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;
static 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->journal_vbo = 0;
_context->journal_vbo_len = 0;
_context->current_material = NULL;
_context->current_material_flags = 0;
memset (&_context->current_material_flush_options,
0, sizeof (CoglMaterialFlushOptions));
_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->in_begin_gl_block = FALSE;
_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_PRE, /* data format */
/* internal format */
COGL_PIXEL_FORMAT_RGBA_8888_PRE,
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_PRE, /* data format */
/* internal format */
COGL_PIXEL_FORMAT_RGBA_8888_PRE,
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);
_context->quad_indices_byte = COGL_INVALID_HANDLE;
_context->quad_indices_short = COGL_INVALID_HANDLE;
_context->quad_indices_short_len = 0;
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->current_layers)
g_array_free (_context->current_layers, TRUE);
if (_context->quad_indices_byte)
cogl_handle_unref (_context->quad_indices_byte);
if (_context->quad_indices_short)
cogl_handle_unref (_context->quad_indices_short);
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;
}