mutter/cogl/cogl-context.c
Neil Roberts 992d5f7fb6 cogl-vertex-buffer: Don't disable layers with no texture coords
It should be quite acceptable to use a texture without defining any
texture coords. For example a shader may be in use that is doing
texture lookups without referencing the texture coordinates. Also it
should be possible to replace the vertex colors using a texture layer
without a texture but with a constant layer color.

enable_state_for_drawing_buffer no longer sets any disabled layers in
the overrides. Instead of counting the number of units with texture
coordinates it now keeps them in a mask. This means there can now be
gaps in the list of enabled texture coordinate arrays. To cope with
this, the Cogl context now also stores a mask to track the enabled
arrays. Instead of code manually iterating each enabled array to
disable them, there is now an internal function called
_cogl_disable_texcoord_arrays which disables a given mask.

I think this could also fix potential bugs when a vertex buffer has
gaps in the texture coordinate attributes that it provides. For
example if the vertex buffer only had texture coordinates for layer 2
then the disabling code would not disable the coordinates for layers 0
and 1 even though they are not used. This could cause a crash if the
previous data for those arrays is no longer valid.

http://bugzilla.openedhand.com/show_bug.cgi?id=2132
2010-05-24 16:10:56 +01:00

245 lines
7.3 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->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->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 = NULL;
_context->simple_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->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->texcoord_arrays_enabled = 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;
/* 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;
_context->max_texture_units = -1;
return TRUE;
}
void
_cogl_destroy_context ()
{
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->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);
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);
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;
}