easeInOutQuad8()

u8 fl::easeInOutQuad8

(

u8

i

)

8-bit quadratic ease-in/ease-out function Takes an input value 0-255 and returns an eased value 0-255 The curve starts slow, accelerates in the middle, then slows down again

Definition at line 55 of file ease.cpp.

                        {
    constexpr u16 MAX = 0xFF;            // 255
    constexpr u16 HALF = (MAX + 1) >> 1; // 128
    constexpr u16 DENOM = MAX;           // divisor for scaling
    constexpr u16 ROUND = DENOM >> 1;    // for rounding
 
    if (i < HALF) {
        // first half: y = 2·(i/MAX)² → y_i = 2·i² / MAX
        u32 t = i;
        u32 num = 2 * t * t + ROUND; // 2*i², +half for rounding
        return u8(num / DENOM);
    } else {
        // second half: y = 1 − 2·(1−i/MAX)²
        // → y_i = MAX − (2·(MAX−i)² / MAX)
        u32 d = MAX - i;
        u32 num = 2 * d * d + ROUND; // 2*(MAX−i)², +half for rounding
        return u8(MAX - (num / DENOM));
    }
}

References MAX, and t.

Referenced by ease8(), and ease8().

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