mutter/gles/cogl-context.h
Robert Bragg 509928cc76 [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

112 lines
2.8 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.
*/
#ifndef __COGL_CONTEXT_H
#define __COGL_CONTEXT_H
#include "cogl-primitives.h"
#include "cogl-clip-stack.h"
#include "cogl-gles2-wrapper.h"
typedef struct
{
GLfloat v[3];
GLfloat t[2];
GLubyte c[4];
} CoglTextureGLVertex;
typedef struct
{
/* Features cache */
CoglFeatureFlags feature_flags;
gboolean features_cached;
/* Enable cache */
gulong enable_flags;
guint8 color_alpha;
COGLenum blend_src_factor;
COGLenum blend_dst_factor;
gboolean enable_backface_culling;
/* Primitives */
CoglFixedVec2 path_start;
CoglFixedVec2 path_pen;
GArray *path_nodes;
guint last_path;
CoglFixedVec2 path_nodes_min;
CoglFixedVec2 path_nodes_max;
/* Cache of inverse projection matrix */
CoglFixed inverse_projection[16];
/* Textures */
GArray *texture_handles;
CoglTextureGLVertex *texture_vertices;
gulong texture_vertices_size;
/* Multi Textures */
GArray *multi_texture_handles;
/* Multi Texture Layers */
GArray *multi_texture_layer_handles;
/* Framebuffer objects */
GArray *fbo_handles;
CoglBufferTarget draw_buffer;
/* Shaders */
GArray *program_handles;
GArray *shader_handles;
/* Mesh */
GArray *mesh_handles;
/* Clip stack */
CoglClipStackState clip;
#ifdef HAVE_COGL_GLES2
CoglGles2Wrapper gles2;
/* Viewport store for FBOs. Needed because glPushAttrib() isn't
supported */
GLint viewport_store[4];
#endif
} CoglContext;
CoglContext *
_cogl_context_get_default ();
/* Obtains the context and returns retval if NULL */
#define _COGL_GET_CONTEXT(ctxvar, retval) \
CoglContext *ctxvar = _cogl_context_get_default (); \
if (ctxvar == NULL) return retval;
#define NO_RETVAL
#endif /* __COGL_CONTEXT_H */