interp8()

template<typename T>

T fl::LUT< T >::interp8 ( u8 alpha )

inline

Definition at line 59 of file lut.h.

                        {
        if (length == 0)
            return T();
        if (alpha == 0)
            return data[0];
        if (alpha == 255)
            return data[length - 1];
 
        // treat alpha/255 as fraction, scale to [0..length-1]
        u32 maxIndex = length - 1;
        u32 pos = u32(alpha) * maxIndex; // numerator
        u32 idx0 = pos / 255;                 // floor(position)
        u32 idx1 = idx0 < maxIndex ? idx0 + 1 : maxIndex;
        u8 blend = pos % 255; // fractional part
 
        const T &a = data[idx0];
        const T &b = data[idx1];
        // a + (b-a) * blend/255
        return a + (b - a) * blend / 255;
    }