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.
wrapped in reference-counted CoglHandles instead.
* clutter/cogl/gl/cogl-shader.c:
* clutter/cogl/gl/cogl-shader.h:
* clutter/cogl/gl/cogl-program.c:
* clutter/cogl/gl/cogl-program.h:
New files to hold the shader and program functions.
* clutter/cogl/gl/cogl.c: Removed shader and program functions.
* clutter/cogl/common/cogl-handle.h: New header to define
COGL_HANDLE_DEFINE which helps build functions to create
reference-counted handles. This reduces the amount of duplicated
code.
* clutter/cogl/gl/cogl-texture.c:
* clutter/cogl/gles/cogl-texture.c:
* clutter/cogl/gl/cogl-fbo.c: Converted to use COGL_HANDLE_DEFINE
from cogl-handle.h to avoid duplicating some of the common code.
* clutter/cogl/gles/cogl-defines.h.in:
* clutter/cogl/gl/cogl-defines.h.in: Removed COGLhandle
* clutter/cogl/gl/cogl-context.h: Added handle arrays for programs
and shaders.
* clutter/cogl/gl/cogl-context.c (cogl_create_context): Added
initialisers for shader_handles and program_handles.
(cogl_destroy_context): Added calls to g_array_free for all handle
arrays.
* clutter/cogl/gl/Makefile.am (libclutter_cogl_la_SOURCES): Added
cogl-{program,shader}.{c,h}
* clutter/cogl/common/Makefile.am
(libclutter_cogl_common_la_SOURCES): Added cogl-handle.h
* clutter/cogl/gles/cogl.c:
* clutter/cogl/cogl.h.in: Programs and shaders are now wrapped in
CoglHandles instead of COGLhandles. cogl_program_destroy and
cogl_shader_destroy is now replaced with cogl_program_unref and
cogl_shader_unref. cogl_program_ref and cogl_shader_ref are also
added.
* clutter/clutter-shader.c: Converted to use CoglHandles for the
programs and shaders instead of COGLhandles.
* cogl/cogl-sections.txt: Added cogl_shader_ref,
cogl_shader_unref, cogl_is_shader, cogl_program_ref,
cogl_program_unref, cogl_is_program and cogl_is_offscreen.
