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https://github.com/bvanroll/shaders.git
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36 lines
695 B
GLSL
36 lines
695 B
GLSL
#ifdef GL_ES
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precision mediump float;
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#endif
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uniform vec2 u_resolution;
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uniform vec2 u_mouse;
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uniform float u_time;
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#define PI 3.14159265359
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float rectSDF(vec2 st, vec2 s) {
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st = st*2.-1.;
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return max(abs(st.x/s.x),abs(st.y/s.y));
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}
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float stroke(in float x_coor, float s, float width){
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float d = step(s,x_coor+width*.5)-step(s,x_coor-width*.5);
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return clamp(d, 0.,1.);
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}
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float fill(float x, float size) {
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return 1.-step(size, x);
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}
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void main() {
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vec2 st = gl_FragCoord.xy/u_resolution;
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vec3 color = vec3(0.0,0.0,0.0);
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float alpha = 1.0;
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float sdf = rectSDF(st, vec2(1.));
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color += stroke(sdf,.5,.125);
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color += fill(sdf,.1);
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gl_FragColor = vec4(color, alpha);
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}
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