Bug #1457 - Creating a new texture messes up the cogl material state
cache; reported by Neil Roberts
We still don't have caching of bound texture state so we always have to
re-bind the texture when flushing the GL state of any material layers.
Bug #1460 - Handling of flags in cogl_material_set_color
Cogl automatically enables/disables blending based on whether the source color
has an alhpa < 1.0, or if any textures with an alpha component are in use, but
it wasn't doing it quite right.
At the same time I removed some of the dirty flags which on second thought
are nothing more than micro-optimsations that only helped clutter the code.
thanks to Owen Taylor for reporting the bug
All GL functions that are defined in a version later than 1.1 need to
be called through cogl_get_proc_address because the Windows GL DLL
does not export them to directly link against.
- In cogl-material.h it directly sets the values of the
CoglMaterialLayerCombineFunc to some GL_* constants. However these
aren't defined in GLES 2 beacuse it has no fixed function texture
combining. Instead the CGL_* versions are now used. cogl-defines.h
now sets these to either the GL_* version if it is available,
otherwise it directly uses the number.
- Under GLES 2 cogl-material.c needs to access the CoglTexture struct
so it needs to include cogl-texture-private.h
- There are now #define's in cogl-gles2-wrapper.h to remap the GL
function names to the wrapper names. These are disabled in
cogl-gles2-wrapper.c by defining COGL_GLES2_WRAPPER_NO_REMAP.
- Added missing wrappers for glLoadMatrixf and glMaterialfv.
- Renamed the TexEnvf wrapper to TexEnvi because the latter is used
instead from the material API.
Cogl previously tried to cache the currently bound texture when
drawing through the material API to avoid excessive GL calls. However,
a few other places in Cogl and Clutter rebind the texture as well so
this can cause problems.
This was causing shaped windows to fail in Mutter because
ClutterGLXTexturePixmap was binding a different texture to update it
while the second texture unit was still active which meant the mask
texture would not be selected when the shaped window was drawn
subsequent times.
Ideally we would fix this by providing a wrapper around glBindTexture
which would affect the cached value. The cache would also have to be
cleared if a selected texture was deleted.
This updates cogl/gles in line with the integration of CoglMaterial throughout
Cogl that has been done for cogl/gl.
Note: This is still buggy, but at least it builds again and test-actors works.
Some GLES2 specific changes were made, but these haven't been tested yet.
The GL blend function and alpha function are now controlled by the material
code, and even internally Cogl should now be using the material API when
it needs control of these.
This glues CoglMaterial in as the fundamental way that Cogl describes how to
fill in geometry.
It adds cogl_set_source (), which is used to set the material which will be
used by all subsequent drawing functions
It adds cogl_set_source_texture as a convenience for setting up a default
material with a single texture layer, and cogl_set_source_color is now also
a convenience for setting up a material with a solid fill.
"drawing functions" include, cogl_rectangle, cogl_texture_rectangle,
cogl_texture_multiple_rectangles, cogl_texture_polygon (though the
cogl_texture_* funcs have been renamed; see below for details),
cogl_path_fill/stroke and cogl_vertex_buffer_draw*.
cogl_texture_rectangle, cogl_texture_multiple_rectangles and
cogl_texture_polygon no longer take a texture handle; instead the current
source material is referenced. The functions have also been renamed to:
cogl_rectangle_with_texture_coords, cogl_rectangles_with_texture_coords
and cogl_polygon respectivly.
Most code that previously did:
cogl_texture_rectangle (tex_handle, x, y,...);
needs to be changed to now do:
cogl_set_source_texture (tex_handle);
cogl_rectangle_with_texture_coords (x, y,....);
In the less likely case where you were blending your source texture with a color
like:
cogl_set_source_color4ub (r,g,b,a); /* where r,g,b,a isn't just white */
cogl_texture_rectangle (tex_handle, x, y,...);
you will need your own material to do that:
mat = cogl_material_new ();
cogl_material_set_color4ub (r,g,b,a);
cogl_material_set_layer (mat, 0, tex_handle));
cogl_set_source_material (mat);
Code that uses the texture coordinates, 0, 0, 1, 1 don't need to use
cog_rectangle_with_texure_coords since these are the coordinates that
cogl_rectangle will use.
For cogl_texture_polygon; as well as dropping the texture handle, the
n_vertices and vertices arguments were transposed for consistency. So
code previously written as:
cogl_texture_polygon (tex_handle, 3, verts, TRUE);
need to be written as:
cogl_set_source_texture (tex_handle);
cogl_polygon (verts, 3, TRUE);
All of the unit tests have been updated to now use the material API and
test-cogl-material has been renamed to test-cogl-multitexture since any
textured quad is now technically a test of CoglMaterial but this test
specifically creates a material with multiple texture layers.
Note: The GLES backend has not been updated yet; that will be done in a
following commit.
The other colors of a material; such as the ambient and diffuse color are
only relevent when we can enable lighting. This adds a basic unlit
color property.
Later cogl_set_source_color can be integrated to either modify the color
of the current source material, or maintain a special singlton CoglMaterial
that is modified by calls to cogl_set_source_color and implicitly made
current.
This flattens the three functions: cogl_material_flush_gl_material_state,
.._flush_gl_alpha_func and .._flush_gl_blend_func into one:
cogl_flush_material_gl_state which doesn't takes a material handle. (the handle
is instead taken from the context.)
This has allows us to avoid re-submitting some state to OpenGL when the
material has not been replaced.
Note: Avoiding redundant state changes for material layers isn't dealt with
in this patch.
My previous work to provide muti-texturing support has been extended into
a CoglMaterial abstraction that adds control over the texture combine
functions (controlling how multiple texture layers are blended together),
the gl blend function (used for blending the final primitive with the
framebuffer), the alpha function (used to discard fragments based on
their alpha channel), describing attributes such as a diffuse, ambient and
specular color (for use with the standard OpenGL lighting model), and
per layer rotations. (utilizing the new CoglMatrix utility API)
For now the only way this abstraction is exposed is via a new
cogl_material_rectangle function, that is similar to cogl_texture_rectangle
but doesn't take a texture handle (the source material is pulled from
the context), and the array of texture coordinates is extended to be able
to supply coordinates for each layer.
Note: this function doesn't support sliced textures; supporting sliced
textures is a non trivial problem, considering the ability to rotate layers.
Note: cogl_material_rectangle, has quite a few workarounds, for a number of
other limitations within Cogl a.t.m.
Note: The GLES1/2 multi-texturing support has yet to be updated to use
the material abstraction.
