Function MapXYSToDirection

SampleFramework11/v1.01/Graphics/Textures.cpp:307–338

Utility function to map a XY + Side coordinate to a direction vector

// Utility function to map a XY + Side coordinate to a direction vector
Float3 MapXYSToDirection(uint64 x, uint64 y, uint64 s, uint64 width, uint64 height)
{
    float u = ((x + 0.5f) / float(width)) * 2.0f - 1.0f;
    float v = ((y + 0.5f) / float(height)) * 2.0f - 1.0f;
    v *= -1.0f;

    Float3 dir = 0.0f;

    // +x, -x, +y, -y, +z, -z
    switch(s) {
    case 0:
        dir = Float3::Normalize(Float3(1.0f, v, -u));
        break;
    case 1:
        dir = Float3::Normalize(Float3(-1.0f, v, u));
        break;
    case 2:
        dir = Float3::Normalize(Float3(u, 1.0f, -v));
        break;
    case 3:
        dir = Float3::Normalize(Float3(u, -1.0f, v));
        break;
    case 4:
        dir = Float3::Normalize(Float3(u, v, 1.0f));
        break;
    case 5:
        dir = Float3::Normalize(Float3(-u, v, -1.0f));
        break;
    }

    return dir;
}

}