source: data/data_extern/programs/Cg/DualQuaternion.cg

#include "DualQuaternionSkinning_Shadow.cg"

//Dual quaternion skinning with per-vertex antipodality handling (this is the most robust, but not the most efficient way):
void dualQuaternionHardwareSkinningTwoWeights_vp(       
        float4 position : POSITION,
        float3 normal   : NORMAL,
        float2 uv       : TEXCOORD0,
        float4 blendIdx : BLENDINDICES,
        float4 blendWgt : BLENDWEIGHT,
        
        out float4 oPosition : POSITION,
        out float2 oUv       : TEXCOORD0,
        out float4 colour    : COLOR,
        // Support up to 24 bones of float3x4
        // vs_1_1 only supports 96 params so more than this is not feasible
        uniform float2x4 worldDualQuaternion2x4Array[24],
        uniform float4x4 viewProjectionMatrix,
        uniform float4   lightPos[2],
        uniform float4   lightDiffuseColour[2],
        uniform float4   ambient,
        uniform float4   diffuse)
{               
        float2x4 blendDQ = blendTwoWeightsAntipod(blendWgt, blendIdx, worldDualQuaternion2x4Array);

        float len = length(blendDQ[0]);
        blendDQ /= len;

        float3 blendPosition = calculateBlendPosition(position, blendDQ);

        //No need to normalize, the magnitude of the normal is preserved because only rotation is performed
        float3 blendNormal = calculateBlendNormal(normal, blendDQ);
        
        oPosition = mul(viewProjectionMatrix, float4(blendPosition, 1.0));
        
        // Lighting - support point and directional
        float3 lightDir0 = normalize(lightPos[0].xyz - (blendPosition.xyz * lightPos[0].w));
        float3 lightDir1 = normalize(lightPos[1].xyz - (blendPosition.xyz * lightPos[1].w));

        oUv = uv;

        colour = diffuse * (ambient + (saturate(dot(lightDir0, blendNormal)) * lightDiffuseColour[0]) + 
                (saturate(dot(lightDir1, blendNormal)) * lightDiffuseColour[1]));               
}

//Two-phase skinning: dual quaternion skinning with scale and shear transformations
void dualQuaternionHardwareSkinningTwoWeightsTwoPhase_vp(
        float4 position : POSITION,
        float3 normal   : NORMAL,
        float2 uv       : TEXCOORD0,
        float4 blendIdx : BLENDINDICES,
        float4 blendWgt : BLENDWEIGHT,
        

        out float4 oPosition : POSITION,
        out float2 oUv       : TEXCOORD0,
        out float4 colour    : COLOR,
        // Support up to 24 bones of float3x4
        // vs_1_1 only supports 96 params so more than this is not feasible
        uniform float2x4 worldDualQuaternion2x4Array[24],
        uniform float3x4 scaleM[24],
        uniform float4x4 viewProjectionMatrix,
        uniform float4   lightPos[2],
        uniform float4   lightDiffuseColour[2],
        uniform float4   ambient,
        uniform float4   diffuse)
{
        //First phase - applies scaling and shearing:
        float3x4 blendS = blendWgt.x*scaleM[blendIdx.x];
        blendS += blendWgt.y*scaleM[blendIdx.y];        
                
        float3 pass1_position = mul(blendS, position);
        float3x3 blendSrotAT = adjointTransposeMatrix(float3x3(blendS));
        float3 pass1_normal = normalize(mul(blendSrotAT, normal.xyz));

        //Second phase
        float2x4 blendDQ = blendTwoWeightsAntipod(blendWgt, blendIdx, worldDualQuaternion2x4Array);
        
        float len = length(blendDQ[0]);
        blendDQ /= len;

        float3 blendPosition = calculateBlendPosition(float4(pass1_position, 1.0), blendDQ);

        //No need to normalize, the magnitude of the normal is preserved because only rotation is performed
        float3 blendNormal = calculateBlendNormal(pass1_normal, blendDQ);

        oPosition = mul(viewProjectionMatrix, float4(blendPosition, 1.0));

        // Lighting - support point and directional
        float3 lightDir0 = normalize(lightPos[0].xyz - (blendPosition.xyz * lightPos[0].w));
        float3 lightDir1 = normalize(lightPos[1].xyz - (blendPosition.xyz * lightPos[1].w));

        oUv = uv;
        colour = diffuse * (ambient + (saturate(dot(lightDir0, blendNormal)) * lightDiffuseColour[0]) + 
                (saturate(dot(lightDir1, blendNormal)) * lightDiffuseColour[1]));
}