thebookofshaders/15/texture-kaleidoscope.frag
Patricio Gonzalez Vivo 67cdcf2af6 fixing licenses
2021-10-22 08:30:14 -04:00

57 lines
1.6 KiB
GLSL

// Author @patriciogv - 2015
// http://patriciogonzalezvivo.com
#ifdef GL_ES
precision mediump float;
#endif
// Copyright (c) Patricio Gonzalez Vivo, 2015 - http://patriciogonzalezvivo.com/
// I am the sole copyright owner of this Work.
//
// You cannot host, display, distribute or share this Work in any form,
// including physical and digital. You cannot use this Work in any
// commercial or non-commercial product, website or project. You cannot
// sell this Work and you cannot mint an NFTs of it.
// I share this Work for educational purposes, and you can link to it,
// through an URL, proper attribution and unmodified screenshot, as part
// of your educational material. If these conditions are too restrictive
// please contact me and we'll definitely work it out.
#define PI 3.14159265359
#define TWO_PI 6.28318530718
uniform sampler2D u_tex0;
uniform vec2 u_tex0Resolution;
uniform vec2 u_resolution;
uniform vec2 u_mouse;
uniform float u_time;
// Based on Asalga shader
// https://www.shadertoy.com/view/4ss3WX
void main () {
vec2 st = gl_FragCoord.xy/u_resolution.xy;
float time = u_time*0.1;
// move to the center
st = st - 0.5;
// cartesian to polar coordinates
float r = length(st);
float a = atan(st.y, st.x);
// Repeat side according to angle
float sides = 10.;
float ma = mod(a, TWO_PI/sides);
ma = abs(ma - PI/sides);
// polar to cartesian coordinates
st = r * vec2(cos(ma), sin(ma));
st = fract(st+time);
vec4 color = vec4(st.x,st.y,0.0,1.0);
color = texture2D(u_tex0,st);
gl_FragColor = color;
}