Every block in Minecraft is rendered by a shader program, but the shader has no idea which block it is currently rendering. It just receives the geometry and textures and happily renders the block.

Luckily, Minecraft uses a texture atlas. At startup, it generates a huge texture by combining all block textures from resourcepacks. Instead of a texture, the shader is given the coordinates of the texture on the atlas. Using these coordinates, we can find out which texture is used and thus which block is beeing rendered.

However, the generated atlas changes with every new Minecraft version and so do the coordinates of each block texture. Thats why I have to make a new patch every release.

The normal shader does not work with Optifine. Instead download the patched version "WindShader-<shader-version>_optifine" from GitHub .