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.
differences and improve maintainability.
* clutter/cogl/gl/cogl-context.h:
Adds a CoglTextureGLVertex typedef + texture_vertices and
texture_vertices_size members to CoglContext for using vertex arrays
like GLES does
* clutter/cogl/gl/cogl-context.c:
Initializes texture_vertices + texture_vertices_size members
* clutter/cogl/gl/cogl-internal.h:
Adds COGL_ENABLE_COLOR_ARRAY
* clutter/cogl/gl/cogl.c:
Add COGL_ENABLE_COLOR_ARRAY support to cogl_enable
* clutter/cogl/gles/cogl-context.h:
Change the CoglTextureGLVertex to use GLfloat for the position
and texture coord attributes and GLubyte for the color.
* clutter/cogl/gles/cogl-texture-private.h:
Adds a wrap_mode member like GL has.
* clutter/cogl/gl/cogl-texture.c
* clutter/cogl/gles/cogl-texture.c:
Improves the comparability of the files, such that the remaining
differences, better reflect the fundamental differences needed
between GL and GLES. Notably GL no longer uses glBegin/glEnd for
submitting vertices, it uses vertex arrays like GLES and this gives
a small but measurable fps improvement for test-text.
Bug 1219 - Clean up cogl.h
* clutter/cogl/cogl.h.in:
* clutter/cogl/cogl-offscreen.h:
* clutter/cogl/cogl-path.h:
* clutter/cogl/cogl-shader.h:
* clutter/cogl/cogl-texture.h:
* clutter/cogl/cogl-types.h: Split up the massive cogl.h file
into sub-header for each section of the API.
* clutter/cogl/gl/*:
* clutter/cogl/gles/*: Update the GL and GLES implementations
of COGL to cope with the new header structure.
* doc/reference/cogl/Makefile.am: Fix symbol retrieval.
