source: data/data_extern/programs/GLSL120/ShaderInstancing.vert @ 12397

//---------------------------------------------------------------------------
//These materials/shaders are part of the NEW InstanceManager implementation
//Written by Matias N. Goldberg ("dark_sylinc")
//---------------------------------------------------------------------------
#version 120

//Vertex input
attribute vec4 vertex;
attribute vec3 normal;
attribute vec3 tangent;
attribute vec4 uv0;
attribute vec4 blendIndices;
attribute vec4 blendWeights;

//Parameters
uniform mat4 viewProjMatrix;
//uniform mat4x3 worldMatrix3x4Array[80];
#ifdef ST_DUAL_QUATERNION
uniform vec4 worldDualQuaternion2x4Array[240];
#else
uniform vec4 worldMatrix3x4Array[240]; //240 = 80*3
#endif


#if (DEPTH_SHADOWCASTER || DEPTH_SHADOWRECEIVER)
uniform vec4 depthRange;
#endif

#if DEPTH_SHADOWRECEIVER
uniform mat4 texViewProjMatrix;
#endif

//Output
#if DEPTH_SHADOWCASTER
        varying vec2 depth;
#else
        varying vec2 _uv0;
        varying vec3 oNormal;
        varying vec3 oVPos;
        #if DEPTH_SHADOWRECEIVER
                varying vec4 oLightSpacePos;
        #endif
#endif

vec3 calculateBlendPosition(vec3 position, mat2x4 blendDQ)
{
        vec3 blendPosition = position + 2.0*cross(blendDQ[0].yzw, cross(blendDQ[0].yzw, position) + blendDQ[0].x*position);
        vec3 trans = 2.0*(blendDQ[0].x*blendDQ[1].yzw - blendDQ[1].x*blendDQ[0].yzw + cross(blendDQ[0].yzw, blendDQ[1].yzw));
        blendPosition += trans;

        return blendPosition;
}

vec3 calculateBlendNormal(vec3 normal, mat2x4 blendDQ)
{
        return normal + 2.0*cross(blendDQ[0].yzw, cross(blendDQ[0].yzw, normal) + blendDQ[0].x*normal);
}

//---------------------------------------------
//Main Vertex Shader
//---------------------------------------------
void main(void)
{
vec4 worldPos;
vec3 worldNorm;

#ifdef ST_DUAL_QUATERNION
        int idx = int(blendIndices[0]) * 2;
        mat2x4 blendDQ;
        blendDQ[0] = worldDualQuaternion2x4Array[idx];
        blendDQ[1] = worldDualQuaternion2x4Array[idx + 1];
#ifdef BONE_TWO_WEIGHTS
        int idx2 = int(blendIndices[1]) * 2;
        mat2x4 blendDQ2;
        blendDQ2[0] = worldDualQuaternion2x4Array[idx2];
        blendDQ2[1] = worldDualQuaternion2x4Array[idx2 + 1];

        //Accurate antipodality handling. For speed increase, remove the following line
        if (dot(blendDQ[0], blendDQ2[0]) < 0.0) blendDQ2 *= -1.0;
        
        //Blend the dual quaternions based on the weights
        blendDQ *= blendWeights.x;
        blendDQ += blendWeights.y*blendDQ2;
        //Normalize the resultant dual quaternion
        blendDQ /= length(blendDQ[0]);
#endif
        worldPos = vec4(calculateBlendPosition(vertex.xyz, blendDQ), 1.0);
        worldNorm = calculateBlendNormal(normal, blendDQ);
#else
        mat4 worldMatrix;
        int idx = int(blendIndices[0]) * 3;
        worldMatrix[0] = worldMatrix3x4Array[idx];
        worldMatrix[1] = worldMatrix3x4Array[idx + 1];
        worldMatrix[2] = worldMatrix3x4Array[idx + 2];
        worldMatrix[3] = vec4( 0, 0, 0, 1 );

        worldPos                = vertex * worldMatrix;
        worldNorm               = normal * mat3(worldMatrix);
#endif

        //Transform the position
        gl_Position                     = viewProjMatrix * worldPos;

#if DEPTH_SHADOWCASTER
        depth.x                         = (gl_Position.z - depthRange.x) * depthRange.w;
        depth.y                         = depthRange.w;
#else
        _uv0            = uv0.xy;
        oNormal         = worldNorm;
        oVPos           = worldPos.xyz;

        #if DEPTH_SHADOWRECEIVER
                oLightSpacePos          = texViewProjMatrix * worldPos;
                oLightSpacePos.z        = (oLightSpacePos.z - depthRange.x) * depthRange.w;
        #endif
#endif
}