dc-sdk/libs/s3m/S3MTiles/Shaders/S3MTilesNoLightVS.js

export default `
    attribute vec4 aPosition;
    attribute vec4 aColor;
#ifdef TexCoord
    attribute vec4 aTexCoord0;
    uniform float uTexture0Width;
    varying vec4 vTexCoord;
    varying vec4 vTexMatrix;
    varying vec4 vTexCoordTransform;
#endif
    
#ifdef VertexColor
    varying vec4 vColor;
#endif
    
    const float SHIFT_LEFT8 = 256.0;
    const float SHIFT_RIGHT8 = 1.0 / 256.0;
    const float SHIFT_RIGHT4 = 1.0 / 16.0;
    const float SHIFT_LEFT4 = 16.0;
    void getTextureMatrixFromZValue(in float nZ, inout float XTran, inout float YTran, inout float scale)
    {
        if(nZ <= 0.0)
        {
            return;
        }
        float nDel8 = floor(nZ * SHIFT_RIGHT8);
        float nDel16 = floor(nDel8 * SHIFT_RIGHT8);
        float nDel20 = floor(nDel16 * SHIFT_RIGHT4);
        YTran = nZ - nDel8 * SHIFT_LEFT8;
        XTran = nDel8 - nDel16 * SHIFT_LEFT8;
        float nLevel = nDel16 - nDel20 * SHIFT_LEFT4;
        scale = 1.0 / pow(2.0, nLevel);
    }
    
    void main()
    {
    #ifdef TexCoord
        vTexCoord.xy = aTexCoord0.xy;
        vTexMatrix = vec4(0.0,0.0,1.0,0.0);
        vTexCoordTransform.x = aTexCoord0.z;
        if(vTexCoordTransform.x < -90000.0)
        {
            vTexMatrix.z = -1.0;
        }
        getTextureMatrixFromZValue(floor(vTexCoordTransform.x), vTexMatrix.x, vTexMatrix.y, vTexMatrix.z);
        vTexMatrix.w = log2(uTexture0Width * vTexMatrix.z);
    #endif
    
        vec4 vertexPos = aPosition;

    #ifdef VertexColor
         vColor = aColor;
    #endif
    
        gl_Position = czm_modelViewProjection * vec4(vertexPos.xyz, 1.0);
    }
`;