1 // from OGRE3D's skinningTwoWeightsShadowCasterVp.glsl
2 // Example GLSL program for skinning with two bone weights per vertex
6 attribute vec4 blendIndices;
7 attribute vec4 blendWeights;
9 // 3x4 matrix, passed as vec4's for compatibility with GL 2.0
10 // GL 2.0 supports 3x4 matrices
11 // Support 24 bones ie 24*3, but use 72 since our parser can pick that out for sizing
12 uniform vec4 worldMatrix3x4Array[72];
13 uniform mat4 viewProjectionMatrix;
18 vec3 blendPos = vec3(0,0,0);
20 for (int bone = 0; bone < 2; ++bone)
22 // perform matrix multiplication manually since no 3x4 matrices
23 // ATI GLSL compiler can't handle indexing an array within an array so calculate the inner index first
24 int idx = int(blendIndices[bone]) * 3;
25 // ATI GLSL compiler can't handle unrolling the loop so do it manually
26 // ATI GLSL has better performance when mat4 is used rather than using individual dot product
27 // There is a bug in ATI mat4 constructor (Cat 7.2) when indexed uniform array elements are used as vec4 parameter so manually assign
29 worldMatrix[0] = worldMatrix3x4Array[idx];
30 worldMatrix[1] = worldMatrix3x4Array[idx + 1];
31 worldMatrix[2] = worldMatrix3x4Array[idx + 2];
32 worldMatrix[3] = vec4(0);
33 // now weight this into final
34 blendPos += (vertex * worldMatrix).xyz * blendWeights[bone];
37 // apply view / projection to position
38 gl_Position = viewProjectionMatrix * vec4(blendPos, 1);
40 gl_FrontSecondaryColor = vec4(0,0,0,0);
41 gl_FrontColor = ambient;