source: data/data_extern/programs/GLSL120/OffsetMappingShadowsVp.glsl @ 12232

#version 120

uniform vec4 lightPosition; // object space 
uniform vec4 lightPosition1; // object space 
uniform vec4 eyePosition;   // object space 
uniform vec4 spotDirection; // object space
uniform vec4 spotDirection1; // object space
uniform mat4 worldViewProj; // not actually used but here for compat with HLSL
uniform mat4 worldMatrix;
uniform mat4 texViewProj1;
uniform mat4 texViewProj2;

varying vec3 tangentEyeDir;
varying vec3 tangentLightDir[2];
varying vec3 tangentSpotDir[2];
varying vec4 shadowUV[2];
varying vec4 oUv0;

attribute vec3 tangent;
attribute vec4 position;
attribute vec3 normal;
attribute vec4 uv0;

void main()
{
        gl_Position = worldViewProj * position;

        vec4 worldPos = worldMatrix * position;

    oUv0 = uv0;

        shadowUV[0] = texViewProj1 * worldPos;
        shadowUV[1] = texViewProj2 * worldPos;

        // calculate tangent space light vector 
        // Get object space light direction 
    vec3 lightDir = normalize(lightPosition.xyz -  (position.xyz * lightPosition.w));
        vec3 lightDir1 = normalize(lightPosition1.xyz -  (position.xyz * lightPosition1.w));
        
        vec3 eyeDir = (eyePosition - position).xyz; 

        // Calculate the binormal (NB we assume both normal and tangent are 
        // already normalised) 
        vec3 binormal = cross(normal, tangent); 

        // Form a rotation matrix out of the vectors, column major for glsl es 
        mat3 rotation = mat3(vec3(tangent[0], binormal[0], normal[0]),
                                                vec3(tangent[1], binormal[1], normal[1]),
                                                vec3(tangent[2], binormal[2], normal[2]));
    
        // Transform the light vector according to this matrix 
        tangentLightDir[0] = normalize(rotation * lightDir); 
        tangentLightDir[1] = normalize(rotation * lightDir1); 
        // Invert the Y on the eye dir since we'll be using this to alter UVs and
        // GL has Y inverted
        tangentEyeDir = normalize(rotation * eyeDir) * vec3(1.0, -1.0, 1.0); 

        tangentSpotDir[0] = normalize(rotation * -spotDirection.xyz);
        tangentSpotDir[1] = normalize(rotation * -spotDirection1.xyz);  
}