Blending
OpenGL Programmable Blending – APPLE_shader_framebuffer_fetch
Large parts of the rendering pipeline are user programmable through shaders nowadays. One of the remaining fixed-functions is fragment blending: The new fragments (shaded by the fragment shader) don’t neccessarily have to overwrite the corresponding framebuffer entry, we can set different blending operations. The set of possible operations however is fixed. There have been requests […]
Photoshop Blendmodi in GLSL
I once wrote a texturing tool in which you could paint on a 3D model on multiple layers. These layers were composing the final texture just as you know it from photoshop, complete with alpha, opacity slider and: blend modes. these blend modes are quite simple to implement and it can be useful to use […]