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https://github.com/bvanroll/shaders.git
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35 lines
1.0 KiB
GLSL
35 lines
1.0 KiB
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 squigly_line(in float midpoint, in float deviation, in vec2 st) {
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return step(midpoint+(cos(st.y*PI)*deviation),st.x)-step(midpoint+deviation+(cos(st.y*PI)*deviation),st.x);
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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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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 dev = .1;
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// stagger for .3 .5 and .7, since we don't want any chance of deviation overlap
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//color += squigly_line(.3, dev, st) + squigly_line(.5,dev,st)+squigly_line(.7,dev,st);
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// after finishing the high priestess decided to come back to this one and try using the stroke function again.
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float c = cos(st.y*PI)*dev;
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color += stroke(st.x,.35+c,.1)+stroke(st.x,.5+c,.1)+stroke(st.x,.65+c,.1);;
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gl_FragColor = vec4(color, alpha);
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}
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