glsl comment // from OGRE3D's skinningTwoWeightsShadowCasterVp.glsl
glsl comment // Example GLSL program for skinning with two bone weights per vertex
glsl blank
glsl code attribute vec4 vertex;
glsl code attribute vec4 uv0;
glsl code attribute vec4 blendIndices;
glsl code attribute vec4 blendWeights;
glsl blank
glsl comment // 3x4 matrix, passed as vec4's for compatibility with GL 2.0
glsl comment // GL 2.0 supports 3x4 matrices
glsl comment // Support 24 bones ie 24*3, but use 72 since our parser can pick that out for sizing
glsl code uniform vec4 worldMatrix3x4Array[72];
glsl code uniform mat4 viewProjectionMatrix;
glsl code uniform vec4 ambient;
glsl blank
glsl code void main()
glsl code {
glsl code vec3 blendPos = vec3(0,0,0);
glsl blank
glsl code for (int bone = 0; bone < 2; ++bone)
glsl code {
glsl comment // perform matrix multiplication manually since no 3x4 matrices
glsl comment // ATI GLSL compiler can't handle indexing an array within an array so calculate the inner index first
glsl code int idx = int(blendIndices[bone]) * 3;
glsl comment // ATI GLSL compiler can't handle unrolling the loop so do it manually
glsl comment // ATI GLSL has better performance when mat4 is used rather than using individual dot product
glsl comment // There is a bug in ATI mat4 constructor (Cat 7.2) when indexed uniform array elements are used as vec4 parameter so manually assign
glsl code mat4 worldMatrix;
glsl code worldMatrix[0] = worldMatrix3x4Array[idx];
glsl code worldMatrix[1] = worldMatrix3x4Array[idx + 1];
glsl code worldMatrix[2] = worldMatrix3x4Array[idx + 2];
glsl code worldMatrix[3] = vec4(0);
glsl comment // now weight this into final
glsl code blendPos += (vertex * worldMatrix).xyz * blendWeights[bone];
glsl code }
glsl blank
glsl comment // apply view / projection to position
glsl code gl_Position = viewProjectionMatrix * vec4(blendPos, 1);
glsl blank
glsl code gl_FrontSecondaryColor = vec4(0,0,0,0);
glsl code gl_FrontColor = ambient;
glsl code gl_TexCoord[0] = uv0;
glsl code }