varying mat4 v_tex_rot; uniform sampler2D tex; void main() { vec2 l_uv = gl_TexCoord[0].xy; const vec2 l_offset = vec2(0.5, 0.5); l_uv -= l_offset; l_uv = vec2(v_tex_rot * vec4(l_uv, 0.0, 1.0)); l_uv += l_offset; gl_FragColor = vec4(texture2D(tex, l_uv)); gl_FragColor.xyz += gl_Color.xyz - gl_Color.xyz * gl_FragColor.x; }