# 【距离场】
# 圆形
float sdCircle( vec2 p, float r )
{
return length(p) - r;
}
# 圆角盒子
float sdRoundedBox( in vec2 p, in vec2 b, in vec4 r )
{
r.xy = (p.x>0.0)?r.xy : r.zw;
r.x = (p.y>0.0)?r.x : r.y;
vec2 q = abs(p)-b+r.x;
return min(max(q.x,q.y),0.0) + length(max(q,0.0)) - r.x;
}
TIP
参数r：
在左上角为 0，0 右下角 为1，1的uv 坐标系时。
r.x: 右下圆角 （uv 1,1）
r.y: 右上圆角 （uv 1,0）
r.z: 左下圆角 （uv 0,1）
r.w: 左上圆角 （uv 0,0）
# 盒子
float sdBox( in vec2 p, in vec2 b )
{
vec2 d = abs(p)-b;
return length(max(d,0.0)) + min(max(d.x,d.y),0.0);
}
// 计算点到矩形边界的距离
float distToRectEdge(in vec2 p,in vec2 rectStart,in vec2 rectEnd) {
vec2 d = max(rectStart - p, p - rectEnd);
return length(max(d, 0.0)) + min(max(d.x, d.y), 0.0);
}
// 获取世界坐标系下的实心Box距离场
float solidRectDistanceField(in vec2 worldUV, in vec2 rectWorldStart,in vec2 rectWorldEnd) {
// 计算点到矩形边界的距离
float edgeDist = distToRectEdge(worldUV, rectWorldStart, rectWorldEnd);
// 对于矩形内部的点,距离值设置为一个很小的固定值
vec2 rectSize = rectWorldEnd - rectWorldStart;
vec2 cuv = worldUV - rectWorldStart;
float insideRect = min(min(cuv.x, rectSize.x - cuv.x), min(cuv.y, rectSize.y - cuv.y));
insideRect = insideRect < 0.0 ? edgeDist : 0.0;
insideRect = min(insideRect,1.0);
insideRect = max(insideRect,0.0);
return insideRect;
}
# 旋转的盒子
float sdOrientedBox( in vec2 p, in vec2 a, in vec2 b, float th )
{
float l = length(b-a);
vec2 d = (b-a)/l;
vec2 q = (p-(a+b)*0.5);
q = mat2(d.x,-d.y,d.y,d.x)*q;
q = abs(q)-vec2(l,th)*0.5;
return length(max(q,0.0)) + min(max(q.x,q.y),0.0);
}
# 线段
float sdSegment( in vec2 p, in vec2 a, in vec2 b )
{
vec2 pa = p-a, ba = b-a;
float h = clamp( dot(pa,ba)/dot(ba,ba), 0.0, 1.0 );
return length( pa - ba*h );
}
# 菱形
float ndot(vec2 a, vec2 b ) { return a.x*b.x - a.y*b.y; }
float sdRhombus( in vec2 p, in vec2 b )
{
p = abs(p);
float h = clamp( ndot(b-2.0*p,b)/dot(b,b), -1.0, 1.0 );
float d = length( p-0.5*b*vec2(1.0-h,1.0+h) );
return d * sign( p.x*b.y + p.y*b.x - b.x*b.y );
}
# 梯形
float sdTrapezoid( in vec2 p, in float r1, float r2, float he )
{
vec2 k1 = vec2(r2,he);
vec2 k2 = vec2(r2-r1,2.0*he);
p.x = abs(p.x);
vec2 ca = vec2(p.x-min(p.x,(p.y<0.0)?r1:r2), abs(p.y)-he);
vec2 cb = p - k1 + k2*clamp( dot(k1-p,k2)/dot2(k2), 0.0, 1.0 );
float s = (cb.x<0.0 && ca.y<0.0) ? -1.0 : 1.0;
return s*sqrt( min(dot2(ca),dot2(cb)) );
}
# 平行四边形
float sdParallelogram( in vec2 p, float wi, float he, float sk )
{
vec2 e = vec2(sk,he);
p = (p.y<0.0)?-p:p;
vec2 w = p - e; w.x -= clamp(w.x,-wi,wi);
vec2 d = vec2(dot(w,w), -w.y);
float s = p.x*e.y - p.y*e.x;
p = (s<0.0)?-p:p;
vec2 v = p - vec2(wi,0); v -= e*clamp(dot(v,e)/dot(e,e),-1.0,1.0);
d = min( d, vec2(dot(v,v), wi*he-abs(s)));
return sqrt(d.x)*sign(-d.y);
}
# 等边三角形
float sdEquilateralTriangle( in vec2 p, in float r )
{
const float k = sqrt(3.0);
p.x = abs(p.x) - r;
p.y = p.y + r/k;
if( p.x+k*p.y>0.0 ) p = vec2(p.x-k*p.y,-k*p.x-p.y)/2.0;
p.x -= clamp( p.x, -2.0*r, 0.0 );
return -length(p)*sign(p.y);
}
# 等腰三角形
float sdTriangleIsosceles( in vec2 p, in vec2 q )
{
p.x = abs(p.x);
vec2 a = p - q*clamp( dot(p,q)/dot(q,q), 0.0, 1.0 );
vec2 b = p - q*vec2( clamp( p.x/q.x, 0.0, 1.0 ), 1.0 );
float s = -sign( q.y );
vec2 d = min( vec2( dot(a,a), s*(p.x*q.y-p.y*q.x) ),
vec2( dot(b,b), s*(p.y-q.y) ));
return -sqrt(d.x)*sign(d.y);
}
# 三角形
float sdTriangle( in vec2 p, in vec2 p0, in vec2 p1, in vec2 p2 )
{
vec2 e0 = p1-p0, e1 = p2-p1, e2 = p0-p2;
vec2 v0 = p -p0, v1 = p -p1, v2 = p -p2;
vec2 pq0 = v0 - e0*clamp( dot(v0,e0)/dot(e0,e0), 0.0, 1.0 );
vec2 pq1 = v1 - e1*clamp( dot(v1,e1)/dot(e1,e1), 0.0, 1.0 );
vec2 pq2 = v2 - e2*clamp( dot(v2,e2)/dot(e2,e2), 0.0, 1.0 );
float s = sign( e0.x*e2.y - e0.y*e2.x );
vec2 d = min(min(vec2(dot(pq0,pq0), s*(v0.x*e0.y-v0.y*e0.x)),
vec2(dot(pq1,pq1), s*(v1.x*e1.y-v1.y*e1.x))),
vec2(dot(pq2,pq2), s*(v2.x*e2.y-v2.y*e2.x)));
return -sqrt(d.x)*sign(d.y);
}
# 非对称胶囊
float sdUnevenCapsule( vec2 p, float r1, float r2, float h )
{
p.x = abs(p.x);
float b = (r1-r2)/h;
float a = sqrt(1.0-b*b);
float k = dot(p,vec2(-b,a));
if( k < 0.0 ) return length(p) - r1;
if( k > a*h ) return length(p-vec2(0.0,h)) - r2;
return dot(p, vec2(a,b) ) - r1;
}
# 五边形
float sdPentagon( in vec2 p, in float r )
{
const vec3 k = vec3(0.809016994,0.587785252,0.726542528);
p.x = abs(p.x);
p -= 2.0*min(dot(vec2(-k.x,k.y),p),0.0)*vec2(-k.x,k.y);
p -= 2.0*min(dot(vec2( k.x,k.y),p),0.0)*vec2( k.x,k.y);
p -= vec2(clamp(p.x,-r*k.z,r*k.z),r);
return length(p)*sign(p.y);
}
# 六边形
float sdHexagon( in vec2 p, in float r )
{
const vec3 k = vec3(-0.866025404,0.5,0.577350269);
p = abs(p);
p -= 2.0*min(dot(k.xy,p),0.0)*k.xy;
p -= vec2(clamp(p.x, -k.z*r, k.z*r), r);
return length(p)*sign(p.y);
}
# 八边形
float sdOctogon( in vec2 p, in float r )
{
const vec3 k = vec3(-0.9238795325, 0.3826834323, 0.4142135623 );
p = abs(p);
p -= 2.0*min(dot(vec2( k.x,k.y),p),0.0)*vec2( k.x,k.y);
p -= 2.0*min(dot(vec2(-k.x,k.y),p),0.0)*vec2(-k.x,k.y);
p -= vec2(clamp(p.x, -k.z*r, k.z*r), r);
return length(p)*sign(p.y);
}
# 六芒星
float sdHexagram( in vec2 p, in float r )
{
const vec4 k = vec4(-0.5,0.8660254038,0.5773502692,1.7320508076);
p = abs(p);
p -= 2.0*min(dot(k.xy,p),0.0)*k.xy;
p -= 2.0*min(dot(k.yx,p),0.0)*k.yx;
p -= vec2(clamp(p.x,r*k.z,r*k.w),r);
return length(p)*sign(p.y);
}
# 五角星
float sdStar5(in vec2 p, in float r, in float rf)
{
const vec2 k1 = vec2(0.809016994375, -0.587785252292);
const vec2 k2 = vec2(-k1.x,k1.y);
p.x = abs(p.x);
p -= 2.0*max(dot(k1,p),0.0)*k1;
p -= 2.0*max(dot(k2,p),0.0)*k2;
p.x = abs(p.x);
p.y -= r;
vec2 ba = rf*vec2(-k1.y,k1.x) - vec2(0,1);
float h = clamp( dot(p,ba)/dot(ba,ba), 0.0, r );
return length(p-ba*h) * sign(p.y*ba.x-p.x*ba.y);
}
# 多角星
float sdStar( in vec2 p, in float r, in int n, in float m)
{
// next 4 lines can be precomputed for a given shape
float an = 3.141593/float(n);
float en = 3.141593/m; // m is between 2 and n
vec2 acs = vec2(cos(an),sin(an));
vec2 ecs = vec2(cos(en),sin(en)); // ecs=vec2(0,1) for regular polygon
float bn = mod(atan(p.x,p.y),2.0*an) - an;
p = length(p)*vec2(cos(bn),abs(sin(bn)));
p -= r*acs;
p += ecs*clamp( -dot(p,ecs), 0.0, r*acs.y/ecs.y);
return length(p)*sign(p.x);
}
# 伞形
float sdPie( in vec2 p, in vec2 c, in float r )
{
p.x = abs(p.x);
float l = length(p) - r;
float m = length(p-c*clamp(dot(p,c),0.0,r)); // c=sin/cos of aperture
return max(l,m*sign(c.y*p.x-c.x*p.y));
}
# 裁剪碟片
float sdCutDisk( in vec2 p, in float r, in float h )
{
float w = sqrt(r*r-h*h); // constant for any given shape
p.x = abs(p.x);
float s = max( (h-r)*p.x*p.x+w*w*(h+r-2.0*p.y), h*p.x-w*p.y );
return (s<0.0) ? length(p)-r :
(p.x<w) ? h - p.y :
length(p-vec2(w,h));
}
# 弧形
float sdArc( in vec2 p, in vec2 sc, in float ra, float rb )
{
// sc is the sin/cos of the arc's aperture
p.x = abs(p.x);
return ((sc.y*p.x>sc.x*p.y) ? length(p-sc*ra) :
abs(length(p)-ra)) - rb;
}
# 马蹄
float sdHorseshoe( in vec2 p, in vec2 c, in float r, in vec2 w )
{
p.x = abs(p.x);
float l = length(p);
p = mat2(-c.x, c.y, c.y, c.x)*p;
p = vec2((p.y>0.0 || p.x>0.0)?p.x:l*sign(-c.x),
(p.x>0.0)?p.y:l );
p = vec2(p.x,abs(p.y-r))-w;
return length(max(p,0.0)) + min(0.0,max(p.x,p.y));
}
# 凸透镜
float sdVesica(vec2 p, float r, float d)
{
p = abs(p);
float b = sqrt(r*r-d*d);
return ((p.y-b)*d>p.x*b) ? length(p-vec2(0.0,b))
: length(p-vec2(-d,0.0))-r;
}
# 旋转凸透镜
float sdOrientedVesica( vec2 p, vec2 a, vec2 b, float w )
{
float r = 0.5*length(b-a);
float d = 0.5*(r*r-w*w)/w;
vec2 v = (b-a)/r;
vec2 c = (b+a)*0.5;
vec2 q = 0.5*abs(mat2(v.y,v.x,-v.x,v.y)*(p-c));
vec3 h = (r*q.x<d*(q.y-r)) ? vec3(0.0,r,0.0) : vec3(-d,0.0,d+w);
return length( q-h.xy) - h.z;
}
# 月亮
float sdMoon(vec2 p, float d, float ra, float rb )
{
p.y = abs(p.y);
float a = (ra*ra - rb*rb + d*d)/(2.0*d);
float b = sqrt(max(ra*ra-a*a,0.0));
if( d*(p.x*b-p.y*a) > d*d*max(b-p.y,0.0) )
return length(p-vec2(a,b));
return max( (length(p )-ra),
-(length(p-vec2(d,0))-rb));
}
# 圆形十字
float sdRoundedCross( in vec2 p, in float h )
{
float k = 0.5*(h+1.0/h);
p = abs(p);
return ( p.x<1.0 && p.y<p.x*(k-h)+h ) ?
k-sqrt(dot2(p-vec2(1,k))) :
sqrt(min(dot2(p-vec2(0,h)),
dot2(p-vec2(1,0))));
}
# 鸡蛋
float sdEgg( in vec2 p, in float ra, in float rb )
{
const float k = sqrt(3.0);
p.x = abs(p.x);
float r = ra - rb;
return ((p.y<0.0) ? length(vec2(p.x, p.y )) - r :
(k*(p.x+r)<p.y) ? length(vec2(p.x, p.y-k*r)) :
length(vec2(p.x+r,p.y )) - 2.0*r) - rb;
}
# 心形
float sdHeart( in vec2 p )
{
p.x = abs(p.x);
if( p.y+p.x>1.0 )
return sqrt(dot2(p-vec2(0.25,0.75))) - sqrt(2.0)/4.0;
return sqrt(min(dot2(p-vec2(0.00,1.00)),
dot2(p-0.5*max(p.x+p.y,0.0)))) * sign(p.x-p.y);
}
# 十字
float sdCross( in vec2 p, in vec2 b, float r )
{
p = abs(p); p = (p.y>p.x) ? p.yx : p.xy;
vec2 q = p - b;
float k = max(q.y,q.x);
vec2 w = (k>0.0) ? q : vec2(b.y-p.x,-k);
return sign(k)*length(max(w,0.0)) + r;
}
# 交叉X
float sdRoundedX( in vec2 p, in float w, in float r )
{
p = abs(p);
return length(p-min(p.x+p.y,w)*0.5) - r;
}
# 多边形
float sdPolygon( in vec2[N] v, in vec2 p )
{
float d = dot(p-v[0],p-v[0]);
float s = 1.0;
for( int i=0, j=N-1; i<N; j=i, i++ )
{
vec2 e = v[j] - v[i];
vec2 w = p - v[i];
vec2 b = w - e*clamp( dot(w,e)/dot(e,e), 0.0, 1.0 );
d = min( d, dot(b,b) );
bvec3 c = bvec3(p.y>=v[i].y,p.y<v[j].y,e.x*w.y>e.y*w.x);
if( all(c) || all(not(c)) ) s*=-1.0;
}
return s*sqrt(d);
}
# 椭圆形
float sdEllipse( in vec2 p, in vec2 ab )
{
p = abs(p); if( p.x > p.y ) {p=p.yx;ab=ab.yx;}
float l = ab.y*ab.y - ab.x*ab.x;
float m = ab.x*p.x/l; float m2 = m*m;
float n = ab.y*p.y/l; float n2 = n*n;
float c = (m2+n2-1.0)/3.0; float c3 = c*c*c;
float q = c3 + m2*n2*2.0;
float d = c3 + m2*n2;
float g = m + m*n2;
float co;
if d<0.0 )
{
float h = acos(q/c3)/3.0;
float s = cos(h);
float t = sin(h)*sqrt(3.0);
float rx = sqrt( -c*(s + t + 2.0) + m2 );
float ry = sqrt( -c*(s - t + 2.0) + m2 );
co = (ry+sign(l)*rx+abs(g)/(rx*ry)- m)/2.0;
}
else
{
float h = 2.0*m*n*sqrt( d );
float s = sign(q+h)*pow(abs(q+h), 1.0/3.0);
float u = sign(q-h)*pow(abs(q-h), 1.0/3.0);
float rx = -s - u - c*4.0 + 2.0*m2;
float ry = (s - u)*sqrt(3.0);
float rm = sqrt( rx*rx + ry*ry );
co = (ry/sqrt(rm-rx)+2.0*g/rm-m)/2.0;
}
vec2 r = ab * vec2(co, sqrt(1.0-co*co));
return length(r-p) * sign(p.y-r.y);
}
# 抛物线
float sdParabola( in vec2 pos, in float k )
{
pos.x = abs(pos.x);
float ik = 1.0/k;
float p = ik*(pos.y - 0.5*ik)/3.0;
float q = 0.25*ik*ik*pos.x;
float h = q*q - p*p*p;
float r = sqrt(abs(h));
float x = (h>0.0) ?
pow(q+r,1.0/3.0) - pow(abs(q-r),1.0/3.0)*sign(r-q) :
2.0*cos(atan(r,q)/3.0)*sqrt(p);
return length(pos-vec2(x,k*x*x)) * sign(pos.x-x);
}
# 抛物线2
float sdParabola( in vec2 pos, in float wi, in float he )
{
pos.x = abs(pos.x);
float ik = wi*wi/he;
float p = ik*(he-pos.y-0.5*ik)/3.0;
float q = pos.x*ik*ik*0.25;
float h = q*q - p*p*p;
float r = sqrt(abs(h));
float x = (h>0.0) ?
pow(q+r,1.0/3.0) - pow(abs(q-r),1.0/3.0)*sign(r-q) :
2.0*cos(atan(r/q)/3.0)*sqrt(p);
x = min(x,wi);
return length(pos-vec2(x,he-x*x/ik)) *
sign(ik*(pos.y-he)+pos.x*pos.x);
}
# 贝塞尔曲线
float sdBezier( in vec2 pos, in vec2 A, in vec2 B, in vec2 C )
{
vec2 a = B - A;
vec2 b = A - 2.0*B + C;
vec2 c = a * 2.0;
vec2 d = A - pos;
float kk = 1.0/dot(b,b);
float kx = kk * dot(a,b);
float ky = kk * (2.0*dot(a,a)+dot(d,b)) / 3.0;
float kz = kk * dot(d,a);
float res = 0.0;
float p = ky - kx*kx;
float p3 = p*p*p;
float q = kx*(2.0*kx*kx-3.0*ky) + kz;
float h = q*q + 4.0*p3;
if( h >= 0.0)
{
h = sqrt(h);
vec2 x = (vec2(h,-h)-q)/2.0;
vec2 uv = sign(x)*pow(abs(x), vec2(1.0/3.0));
float t = clamp( uv.x+uv.y-kx, 0.0, 1.0 );
res = dot2(d + (c + b*t)*t);
}
else
{
float z = sqrt(-p);
float v = acos( q/(p*z*2.0) ) / 3.0;
float m = cos(v);
float n = sin(v)*1.732050808;
vec3 t = clamp(vec3(m+m,-n-m,n-m)*z-kx,0.0,1.0);
res = min( dot2(d+(c+b*t.x)*t.x),
dot2(d+(c+b*t.y)*t.y) );
// the third root cannot be the closest
// res = min(res,dot2(d+(c+b*t.z)*t.z));
}
return sqrt( res );
}
# 水滴形十字
float sdBlobbyCross( in vec2 pos, float he )
{
pos = abs(pos);
pos = vec2(abs(pos.x-pos.y),1.0-pos.x-pos.y)/sqrt(2.0);
float p = (he-pos.y-0.25/he)/(6.0*he);
float q = pos.x/(he*he*16.0);
float h = q*q - p*p*p;
float x;
if( h>0.0 ) { float r = sqrt(h); x = pow(q+r,1.0/3.0)-pow(abs(q-r),1.0/3.0)*sign(r-q); }
else { float r = sqrt(p); x = 2.0*r*cos(acos(q/(p*r))/3.0); }
x = min(x,sqrt(2.0)/2.0);
vec2 z = vec2(x,he*(1.0-2.0*x*x)) - pos;
return length(z) * sign(z.y);
}
# 隧道
float sdTunnel( in vec2 p, in vec2 wh )
{
p.x = abs(p.x); p.y = -p.y;
vec2 q = p - wh;
float d1 = dot2(vec2(max(q.x,0.0),q.y));
q.x = (p.y>0.0) ? q.x : length(p)-wh.x;
float d2 = dot2(vec2(q.x,max(q.y,0.0)));
float d = sqrt( min(d1,d2) );
return (max(q.x,q.y)<0.0) ? -d : d;
}
# 楼梯
float sdStairs( in vec2 p, in vec2 wh, in float n )
{
vec2 ba = wh*n;
float d = min(dot2(p-vec2(clamp(p.x,0.0,ba.x),0.0)),
dot2(p-vec2(ba.x,clamp(p.y,0.0,ba.y))) );
float s = sign(max(-p.y,p.x-ba.x) );
float dia = length(wh);
p = mat2(wh.x,-wh.y, wh.y,wh.x)*p/dia;
float id = clamp(round(p.x/dia),0.0,n-1.0);
p.x = p.x - id*dia;
p = mat2(wh.x, wh.y,-wh.y,wh.x)*p/dia;
float hh = wh.y/2.0;
p.y -= hh;
if( p.y>hh*sign(p.x) ) s=1.0;
p = (id<0.5 || p.x>0.0) ? p : -p;
d = min( d, dot2(p-vec2(0.0,clamp(p.y,-hh,hh))) );
d = min( d, dot2(p-vec2(clamp(p.x,0.0,wh.x),hh)) );
return sqrt(d)*s;
}
# 二次圆
float sdQuadraticCircle( in vec2 p )
{
p = abs(p); if( p.y>p.x ) p=p.yx;
float a = p.x-p.y;
float b = p.x+p.y;
float c = (2.0*b-1.0)/3.0;
float h = a*a + c*c*c;
float t;
if( h>=0.0 )
{
h = sqrt(h);
t = sign(h-a)*pow(abs(h-a),1.0/3.0) - pow(h+a,1.0/3.0);
}
else
{
float z = sqrt(-c);
float v = acos(a/(c*z))/3.0;
t = -z*(cos(v)+sin(v)*1.732050808);
}
t *= 0.5;
vec2 w = vec2(-t,t) + 0.75 - t*t - p;
return length(w) * sign( a*a*0.5+b-1.5 );
}
# Hyberbola
float sdHyberbola( in vec2 p, in float k, in float he ) // k in (0,inf)
{
p = abs(p);
p = vec2(p.x-p.y,p.x+p.y)/sqrt(2.0);
float x2 = p.x*p.x/16.0;
float y2 = p.y*p.y/16.0;
float r = k*(4.0*k - p.x*p.y)/12.0;
float q = (x2 - y2)*k*k;
float h = q*q + r*r*r;
float u;
if( h<0.0 )
{
float m = sqrt(-r);
u = m*cos( acos(q/(r*m))/3.0 );
}
else
{
float m = pow(sqrt(h)-q,1.0/3.0);
u = (m - r/m)/2.0;
}
float w = sqrt( u + x2 );
float b = k*p.y - x2*p.x*2.0;
float t = p.x/4.0 - w + sqrt( 2.0*x2 - u + b/w/4.0 );
t = max(t,sqrt(he*he*0.5+k)-he/sqrt(2.0));
float d = length( p-vec2(t,k/t) );
return p.x*p.y < k ? d : -d;
}
# CoolS
float sdfCoolS( in vec2 p )
{
float six = (p.y<0.0) ? -p.x : p.x;
p.x = abs(p.x);
p.y = abs(p.y) - 0.2;
float rex = p.x - min(round(p.x/0.4),0.4);
float aby = abs(p.y-0.2)-0.6;
float d = dot2(vec2(six,-p.y)-clamp(0.5*(six-p.y),0.0,0.2));
d = min(d,dot2(vec2(p.x,-aby)-clamp(0.5*(p.x-aby),0.0,0.4)));
d = min(d,dot2(vec2(rex,p.y -clamp(p.y ,0.0,0.4))));
float s = 2.0*p.x + aby + abs(aby+0.4) - 0.4;
return sqrt(d) * sign(s);
}
# 圆形波浪
float sdCircleWave( in vec2 p, in float ta, in float tb )
{
tb = 3.1415927*5.0/6.0*max(tb,0.0001);
vec2 co = ra*vec2(sin(tb),cos(tb));
p.x = abs(mod(p.x,co.x*4.0)-co.x*2.0);
vec2 p1 = p;
vec2 p2 = vec2(abs(p.x-2.0*co.x),-p.y+2.0*co.y);
float d1 = ((co.y*p1.x>co.x*p1.y) ? length(p1-co) : abs(length(p1)-ra));
float d2 = ((co.y*p2.x>co.x*p2.y) ? length(p2-co) : abs(length(p2)-ra));
return min( d1, d2);
}
← 【线性和伽马颜色空间】 【均值模糊】 →