CalculateArcsinDeg.inc.c File Reference

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Functions
u32 N	ArcsinDeg (f32 x, f32 y)

Function Documentation

ArcsinDeg()

u32 N ArcsinDeg	(	f32	x,
		f32	y )

Definition at line 18 of file CalculateArcsinDeg.inc.c.

                               {
    f32 sinAngle = abs(y) / length2D(x, y);
    u16 minAngle = 0;
    u16 maxAngle = 90;
    u16 ret;
    u16 i;
 
    for (i = 0; i < 7; i++) {
        u16 midAngle = minAngle + ((maxAngle - minAngle) / 2);
 
        if (N(sinTable)[midAngle] < sinAngle) {
            minAngle = midAngle;
        } else {
            maxAngle = midAngle;
        }
    }
 
    if (fabsf(N(sinTable)[minAngle] - sinAngle) < fabsf(N(sinTable)[maxAngle] - sinAngle)) {
        ret = minAngle;
    } else {
        ret = maxAngle;
    }
 
    if (x < 0.0f && y >= 0.0f) {
        ret = 180 - ret;
    }
 
    if (x < 0.0f && y < 0.0f) {
        ret += 180;
    }
 
    if (x >= 0.0f && y < 0.0f) {
        ret = 360 - ret;
    }
 
    return ret;
}