tdsw_hou04

generate_circumcircle

vector2 calc_angle_range(vector c; vector p0; vector p1) {
    vector2 p = set(p0.x, p0.y) - set(c.x, c.y);
    vector2 q = set(p1.x, p1.y) - set(c.x, c.y);
    
    float start = atan(p.y, p.x);vector2 calc_angle_range(vector c; vector p0; vector p1) {
    vector2 p = set(p0.x, p0.y) - set(c.x, c.y);
    vector2 q = set(p1.x, p1.y) - set(c.x, c.y);
    
    float start = atan(p.y, p.x);
    
    matrix2 rot = ident();
    rotate(rot, -start);
    vector q_ = q * rot;
    
    float end = start + atan(q_.y, q_.x);
    
    return set(degrees(start), degrees(end));
}


vector A = point(1, "P", 0);
vector B = point(1, "P", 1);
vector C = point(1, "P", 2);

float a = distance(B, C);
float b = distance(C, A);
float c = distance(A, B);

float a2 = a * a;
float b2 = b * b;
float c2 = c * c;

float aw = a2 * (b2 + c2 - a2);
float bw = b2 * (c2 + a2 - b2);
float cw = c2 * (a2 + b2 - c2);

vector center = (A * aw + B * bw + C * cw) / (aw + bw + cw);
float radius = distance(center, A);

int pt = addpoint(0, center);

setpointattrib(0, "pscale", pt, radius);

vector pts[];

if (a < c && b < c) {
    push(pts, B);
    push(pts, C);
    push(pts, A);
} else if (a < b && c < b) {
    push(pts, A);
    push(pts, B);
    push(pts, C);
} else {
    push(pts, C);
    push(pts, A);
    push(pts, B);
}

v@center = center;

u@arc0 = calc_angle_range(center, pts[0], pts[1]);
u@arc1 = calc_angle_range(center, pts[1], pts[2]);

@radius = radius;




    
    matrix2 rot = ident();
    rotate(rot, -start);
    vector q_ = q * rot;
    
    float end = start + atan(q_.y, q_.x);
    
    return set(degrees(start), degrees(end));
}


vector A = point(1, "P", 0);
vector B = point(1, "P", 1);
vector C = point(1, "P", 2);

float a = distance(B, C);
float b = distance(C, A);
float c = distance(A, B);

float a2 = a * a;
float b2 = b * b;
float c2 = c * c;

float aw = a2 * (b2 + c2 - a2);
float bw = b2 * (c2 + a2 - b2);
float cw = c2 * (a2 + b2 - c2);

vector center = (A * aw + B * bw + C * cw) / (aw + bw + cw);
float radius = distance(center, A);

int pt = addpoint(0, center);

setpointattrib(0, "pscale", pt, radius);

vector pts[];

if (a < c && b < c) {
    push(pts, B);
    push(pts, C);
    push(pts, A);
} else if (a < b && c < b) {
    push(pts, A);
    push(pts, B);
    push(pts, C);
} else {
    push(pts, C);
    push(pts, A);
    push(pts, B);
}

v@center = center;

u@arc0 = calc_angle_range(center, pts[0], pts[1]);
u@arc1 = calc_angle_range(center, pts[1], pts[2]);

@radius = radius;