mutter/cogl/cogl-context.c
Robert Bragg acc44161c1 material: Adds backend abstraction for fragment processing
As part of an effort to improve the architecture of CoglMaterial
internally this overhauls how we flush layer state to OpenGL by adding a
formal backend abstraction for fragment processing and further
formalizing the CoglTextureUnit abstraction.

There are three backends: "glsl", "arbfp" and "fixed". The fixed backend
uses the OpenGL fixed function APIs to setup the fragment processing,
the arbfp backend uses code generation to handle fragment processing
using an ARBfp program, and the GLSL backend is currently only there as
a formality to handle user programs associated with a material. (i.e.
the glsl backend doesn't yet support code generation)

The GLSL backend has highest precedence, then arbfp and finally the
fixed. If a backend can't support some particular CoglMaterial feature
then it will fallback to the next backend.

This adds three new COGL_DEBUG options:
* "disable-texturing" as expected should disable all texturing
* "disable-arbfp" always make the arbfp backend fallback
* "disable-glsl" always make the glsl backend fallback
* "show-source" show code generated by the arbfp/glsl backends
2010-06-09 17:15:59 +01:00

274 lines
8.5 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, see <http://www.gnu.org/licenses/>.
*
*
*/
#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-journal-private.h"
#include "cogl-texture-private.h"
#include "cogl-material-private.h"
#include "cogl-framebuffer-private.h"
#include "cogl-path-private.h"
#include <string.h>
extern void
_cogl_create_context_driver (CoglContext *context);
static CoglContext *_context = NULL;
static gboolean gl_is_indirect = FALSE;
static gboolean
cogl_create_context (void)
{
GLubyte default_texture_data[] = { 0xff, 0xff, 0xff, 0x0 };
unsigned long enable_flags = 0;
CoglHandle window_buffer;
if (_context != NULL)
return FALSE;
/* Allocate context memory */
_context = (CoglContext*) g_malloc (sizeof (CoglContext));
/* Init default values */
_context->feature_flags = 0;
_context->feature_flags_private = 0;
_context->features_cached = FALSE;
/* Initialise the driver specific state */
/* TODO: combine these two into one function */
_cogl_create_context_driver (_context);
_cogl_features_init ();
_cogl_material_init_default_material ();
_context->enable_flags = 0;
_context->color_alpha = 0;
_context->fog_enabled = FALSE;
_context->enable_backface_culling = FALSE;
_context->flushed_front_winding = COGL_FRONT_WINDING_COUNTER_CLOCKWISE;
_context->indirect = gl_is_indirect;
cogl_matrix_init_identity (&_context->identity_matrix);
cogl_matrix_init_identity (&_context->y_flip_matrix);
cogl_matrix_scale (&_context->y_flip_matrix, 1, -1, 1);
_context->flushed_matrix_mode = COGL_MATRIX_MODELVIEW;
_context->texture_units =
g_array_new (FALSE, FALSE, sizeof (CoglTextureUnit));
/* See cogl-material.c for more details about why we leave texture unit 1
* active by default... */
_context->active_texture_unit = 1;
GE (glActiveTexture (GL_TEXTURE1));
_context->simple_material = cogl_material_new ();
_context->source_material = NULL;
_context->arbfp_source_buffer = g_string_new ("");
_context->legacy_state_set = 0;
_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->current_material = NULL;
_context->current_material_flags = COGL_MATERIAL_FLAGS_INIT;
_context->current_material_fallback_layers = 0;
_context->current_material_disable_layers = 0;
_context->current_material_layer0_override = 0;
_context->current_material_skip_gl_color = FALSE;
_cogl_bitmask_init (&_context->texcoord_arrays_enabled);
_cogl_bitmask_init (&_context->temp_bitmask);
_cogl_bitmask_init (&_context->texcoord_arrays_to_disable);
_context->max_texture_units = -1;
_context->max_texture_image_units = -1;
_context->max_activateable_texture_units = -1;
_context->current_program = COGL_INVALID_HANDLE;
_context->current_use_program_type = COGL_MATERIAL_PROGRAM_TYPE_FIXED;
_context->current_gl_program = 0;
_context->framebuffer_stack = _cogl_create_framebuffer_stack ();
window_buffer = _cogl_onscreen_new ();
cogl_set_framebuffer (window_buffer);
/* XXX: the deprecated _cogl_set_draw_buffer API expects to
* find the window buffer here... */
_context->window_buffer = window_buffer;
_context->dirty_bound_framebuffer = TRUE;
_context->dirty_gl_viewport = TRUE;
_context->current_path = _cogl_path_new ();
_context->stencil_material = cogl_material_new ();
_context->in_begin_gl_block = FALSE;
_context->quad_indices_byte = COGL_INVALID_HANDLE;
_context->quad_indices_short = COGL_INVALID_HANDLE;
_context->quad_indices_short_len = 0;
_context->texture_download_material = COGL_INVALID_HANDLE;
/* The default for GL_ALPHA_TEST is to always pass which is equivalent to
* the test being disabled therefore we assume that for all drivers there
* will be no performance impact if we always leave the test enabled which
* makes things a bit simpler for us. */
GE (glEnable (GL_ALPHA_TEST));
/* 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->simple_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);
_cogl_flush_face_winding ();
_context->atlas = NULL;
_context->atlas_texture = COGL_INVALID_HANDLE;
_context->current_pbo = NULL;
return TRUE;
}
void
_cogl_destroy_context (void)
{
if (_context == NULL)
return;
_cogl_destroy_texture_units ();
_cogl_free_framebuffer_stack (_context->framebuffer_stack);
if (_context->current_path)
cogl_handle_unref (_context->current_path);
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->simple_material)
cogl_handle_unref (_context->simple_material);
if (_context->journal)
g_array_free (_context->journal, TRUE);
if (_context->logged_vertices)
g_array_free (_context->logged_vertices, 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);
if (_context->default_material)
cogl_handle_unref (_context->default_material);
if (_context->atlas)
_cogl_atlas_free (_context->atlas);
if (_context->atlas_texture)
cogl_handle_unref (_context->atlas_texture);
_cogl_bitmask_destroy (&_context->texcoord_arrays_enabled);
_cogl_bitmask_destroy (&_context->temp_bitmask);
_cogl_bitmask_destroy (&_context->texcoord_arrays_to_disable);
g_free (_context);
}
CoglContext *
_cogl_context_get_default (void)
{
/* 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;
}