Pixel-Composer/shaders/sh_shape/sh_shape.fsh
2023-03-13 16:45:56 +07:00

147 lines
4.1 KiB
GLSL

#extension GL_OES_standard_derivatives : require
varying vec2 v_vTexcoord;
varying vec4 v_vColour;
uniform int shape;
uniform int bg;
uniform int aa;
uniform int sides;
uniform int drawDF;
uniform float angle;
uniform float inner;
uniform float outer;
uniform float corner;
uniform float stRad;
uniform float edRad;
uniform vec2 angle_range;
uniform vec2 dimension;
uniform vec2 center;
uniform vec2 scale;
uniform vec4 bgColor;
#define PI 3.14159265359
#define TAU 6.283185307179586
float sdRegularPolygon(in vec2 p, in float r, in int n, in float ang ) {
// these 4 lines can be precomputed for a given shape
float an = PI / float(n);
vec2 acs = vec2(cos(an), sin(an));
// reduce to first sector
float bn = mod(atan(p.x, p.y) + PI - ang, 2.0 * an) - an;
p = length(p) * vec2(cos(bn), abs(sin(bn)));
// line sdf
p -= r * acs;
p.y += clamp( -p.y, 0.0, r * acs.y);
return length(p) * sign(p.x);
}
// signed distance to a n-star polygon with external angle en
float sdStar(in vec2 p, in float r, in int n, in float m, in float ang) { // m=[2,n]
// these 4 lines can be precomputed for a given shape
float an = PI / float(n);
float en = PI / m;
vec2 acs = vec2(cos(an), sin(an));
vec2 ecs = vec2(cos(en), sin(en)); // ecs=vec2(0,1) and simplify, for regular polygon,
// reduce to first sector
float bn = mod( atan(p.x, p.y) + PI - ang, 2.0 * an) - an;
p = length(p) * vec2(cos(bn), abs(sin(bn)));
// line sdf
p -= r * acs;
p += ecs * clamp( -dot(p, ecs), 0.0, r * acs.y / ecs.y);
return length(p)*sign(p.x);
}
// sca is the sin/cos of the orientation
// scb is the sin/cos of the aperture
float sdArc( in vec2 p, in vec2 sca, in vec2 scb, in float ra, in float rb ) {
p *= mat2(sca.x, sca.y, -sca.y, sca.x);
p.x = abs(p.x);
float k = (scb.y * p.x > scb.x * p.y) ? dot(p.xy,scb) : length(p);
return sqrt( dot(p, p) + ra * ra - 2.0 * ra * k ) - rb;
}
float sdRoundBox( 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;
}
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);
}
float sdTearDrop( 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;
}
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;
}
float sdVesica(vec2 p, float r, float d) {
p = abs(p);
float b = sqrt(r*r-d*d); // can delay this sqrt by rewriting the comparison
return ((p.y-b)*d > p.x*b) ? length(p-vec2(0.0,b))*sign(d)
: length(p-vec2(-d,0.0))-r;
}
void main() {
float color = 0.;
vec2 cen = (v_vTexcoord - center) / scale;
vec2 ratio = dimension / dimension.y;
float d;
if(shape == 0) {
d = sdBox( (v_vTexcoord - center) * ratio, (scale * ratio - corner));
d -= corner;
} else if(shape == 1) {
d = length(cen) - 1.;
} else if(shape == 2) {
d = sdRegularPolygon( cen, 0.9 - corner, sides, angle );
d -= corner;
} else if(shape == 3) {
d = sdStar( cen, 0.9 - corner, sides, 2. + inner * (float(sides) - 2.), angle );
d -= corner;
} else if(shape == 4) {
d = sdArc( cen, vec2(sin(angle), cos(angle)), angle_range, 0.9 - inner, inner );
} else if(shape == 5) {
d = sdTearDrop( cen + vec2(0., 0.5), stRad, edRad, 1. );
} else if(shape == 6) {
d = sdCross( cen, vec2(1. + corner, outer), corner );
} else if(shape == 7) {
d = sdVesica( cen, inner, outer );
}
//d = d;
if(drawDF == 1)
color = -d;
else if(aa == 0)
color = step(d, 0.0);
else
color = smoothstep(0.02, -0.02, d);
gl_FragColor = mix(bgColor, v_vColour, color);
}