diff options
Diffstat (limited to 'src/math.c')
| -rw-r--r-- | src/math.c | 12 |
1 files changed, 6 insertions, 6 deletions
@@ -35,15 +35,14 @@ c3_t rotate_c3_zr(c3_t p1,c3_t p2,radians zr) {//rotate x and y around camera ba //sin(90deg) = 1 //cos(0) = 1 //cos(90deg) = 0 -c2_t rotate_c2(c2_t p1,c2_t p2,radians dr) {//dr is in radians +//// rotate first point about second point +c2_t rotate_c2(c2_t p1,c2_t p2,radians dr) { c2_t p3; real d=distance2(p1,p2); - radians r=points_to_angle(p1,p2); + radians r=points_to_angle(p2,p1); r.r=r.r+dr.r; - p3.x=(sinl(r.r) * d) + p2.x;//switchiing this to cos and the next line to sin seems - p3.y=(cosl(r.r) * d) + p2.y;//to make some bug less weird. -// p3.x=(cosl(r.r) * d) + p2.x;//switchiing this to cos and the next line to sin seems -// p3.y=(sinl(r.r) * d) + p2.y;//to make some bug less weird. + p3.x=(cosl(r.r) * d) + p2.x; + p3.y=(sinl(r.r) * d) + p2.y; return p3; } real distance2(c2_t p1,c2_t p2) { @@ -54,6 +53,7 @@ radians d2r(degrees d) { while(d.d<0) d.d+=360; return (radians){(real)(d.d%360) / (real)180 * M_PIl}; } +//the angle from the first point to the second point. not the other way around. radians points_to_angle(c2_t p1,c2_t p2) { real a=atan2l(p2.y-p1.y,p2.x-p1.x); return (radians){a>=0?a:M_PIl+M_PIl+a}; |