ledbanner-shaders/game-of-life.glsl
2018-05-19 17:23:49 +02:00

55 lines
1.5 KiB
GLSL

// Conway's game of life
#ifdef GL_ES
precision highp float;
#endif
uniform float time;
uniform vec2 mouse;
uniform vec2 resolution;
uniform sampler2D backbuffer;
vec4 live = vec4(0.5,1.0,0.7,1.);
vec4 dead = vec4(0.,0.,0.,1.);
vec4 blue = vec4(0.,0.,1.,1.);
void main( void ) {
vec2 position = ( gl_FragCoord.xy / resolution.xy );
vec2 pixel = 1./resolution;
if (length(position-mouse) < 0.01) {
float rnd1 = mod(fract(sin(dot(position + time * 0.001, vec2(14.9898,78.233))) * 43758.5453), 1.0);
if (rnd1 > 0.5) {
gl_FragColor = live;
} else {
gl_FragColor = blue;
}
} else {
float sum = 0.;
sum += texture2D(backbuffer, position + pixel * vec2(-1., -1.)).g;
sum += texture2D(backbuffer, position + pixel * vec2(-1., 0.)).g;
sum += texture2D(backbuffer, position + pixel * vec2(-1., 1.)).g;
sum += texture2D(backbuffer, position + pixel * vec2(1., -1.)).g;
sum += texture2D(backbuffer, position + pixel * vec2(1., 0.)).g;
sum += texture2D(backbuffer, position + pixel * vec2(1., 1.)).g;
sum += texture2D(backbuffer, position + pixel * vec2(0., -1.)).g;
sum += texture2D(backbuffer, position + pixel * vec2(0., 1.)).g;
vec4 me = texture2D(backbuffer, position);
if (me.g <= 0.1) {
if ((sum >= 2.9) && (sum <= 3.1)) {
gl_FragColor = live;
} else if (me.b > 0.004) {
gl_FragColor = vec4(0., 0., max(me.b - 0.004, 0.25), 0.);
} else {
gl_FragColor = dead;
}
} else {
if ((sum >= 1.9) && (sum <= 3.1)) {
gl_FragColor = live;
} else {
gl_FragColor = blue;
}
}
}
}