diff -r 000000000000 -r 1918ee327afb src/opengl/util/linear_brush.glsl --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/opengl/util/linear_brush.glsl Mon Jan 11 14:00:40 2010 +0000 @@ -0,0 +1,22 @@ +uniform sampler1D palette; +uniform vec3 linear; +uniform vec3 inv_matrix_m0; +uniform vec3 inv_matrix_m1; +uniform vec3 inv_matrix_m2; + +vec4 brush() +{ + mat3 mat; + + mat[0] = inv_matrix_m0; + mat[1] = inv_matrix_m1; + mat[2] = inv_matrix_m2; + + vec3 hcoords = mat * vec3(gl_FragCoord.xy, 1); + vec2 A = hcoords.xy / hcoords.z; + + float val = dot(linear.xy, A) * linear.z; + + return texture1D(palette, val); +} +