509928cc76
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.
62 lines
1.6 KiB
GLSL
62 lines
1.6 KiB
GLSL
/*** cogl_fixed_fragment_shader_variables_start ***/
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/* There is no default precision for floats in fragment shaders in
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GLES 2 so we need to define one */
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precision highp float;
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/*** cogl_fixed_fragment_shader_inputs ***/
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/* Inputs from the vertex shader */
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varying vec4 frag_color;
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varying float fog_amount;
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/*** cogl_fixed_fragment_shader_texturing_options ***/
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/* Texturing options */
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/*** cogl_fixed_fragment_shader_fogging_options ***/
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/* Fogging options */
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uniform vec4 fog_color;
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/* Alpha test options */
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uniform float alpha_test_ref;
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/*** cogl_fixed_fragment_shader_main_declare ***/
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void
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main (void)
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{
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/*** cogl_fixed_fragment_shader_main_start ***/
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/*** cogl_fixed_fragment_shader_fog ***/
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/* Mix the calculated color with the fog color */
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gl_FragColor.rgb = mix (fog_color.rgb, gl_FragColor.rgb, fog_amount);
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/* Alpha testing */
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/*** cogl_fixed_fragment_shader_alpha_never ***/
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discard;
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/*** cogl_fixed_fragment_shader_alpha_less ***/
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if (gl_FragColor.a >= alpha_test_ref)
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discard;
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/*** cogl_fixed_fragment_shader_alpha_equal ***/
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if (gl_FragColor.a != alpha_test_ref)
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discard;
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/*** cogl_fixed_fragment_shader_alpha_lequal ***/
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if (gl_FragColor.a > alpha_test_ref)
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discard;
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/*** cogl_fixed_fragment_shader_alpha_greater ***/
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if (gl_FragColor.a <= alpha_test_ref)
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discard;
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/*** cogl_fixed_fragment_shader_alpha_notequal ***/
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if (gl_FragColor.a == alpha_test_ref)
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discard;
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/*** cogl_fixed_fragment_shader_alpha_gequal ***/
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if (gl_FragColor.a < alpha_test_ref)
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discard;
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/*** cogl_fixed_fragment_shader_end ***/
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}
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