40 lines
1.2 KiB
GLSL
40 lines
1.2 KiB
GLSL
// based on the following Shader Toy entry
|
|
//
|
|
// [SH17A] Matrix rain. Created by Reinder Nijhoff 2017
|
|
// Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.
|
|
// @reindernijhoff
|
|
//
|
|
// https://www.shadertoy.com/view/ldjBW1
|
|
//
|
|
|
|
#define SPEED_MULTIPLIER 1.
|
|
#define GREEN_ALPHA .33
|
|
|
|
#define BLACK_BLEND_THRESHOLD .4
|
|
|
|
#define R fract(1e2 * sin(p.x * 8. + p.y))
|
|
|
|
void mainImage(out vec4 fragColor, vec2 fragCoord) {
|
|
vec3 v = vec3(fragCoord, 1) / iResolution - .5;
|
|
// vec3 s = .5 / abs(v);
|
|
// scale?
|
|
vec3 s = .9 / abs(v);
|
|
s.z = min(s.y, s.x);
|
|
vec3 i = ceil( 8e2 * s.z * ( s.y < s.x ? v.xzz : v.zyz ) ) * .1;
|
|
vec3 j = fract(i);
|
|
i -= j;
|
|
vec3 p = vec3(9, int(iTime * SPEED_MULTIPLIER * (9. + 8. * sin(i).x)), 0) + i;
|
|
vec3 col = fragColor.rgb;
|
|
col.g = R / s.z;
|
|
p *= j;
|
|
col *= (R >.5 && j.x < .6 && j.y < .8) ? GREEN_ALPHA : 0.;
|
|
|
|
// Sample the terminal screen texture including alpha channel
|
|
vec2 uv = fragCoord.xy / iResolution.xy;
|
|
vec4 terminalColor = texture(iChannel0, uv);
|
|
|
|
float alpha = step(length(terminalColor.rgb), BLACK_BLEND_THRESHOLD);
|
|
vec3 blendedColor = mix(terminalColor.rgb * 1.2, col, alpha);
|
|
|
|
fragColor = vec4(blendedColor, terminalColor.a);
|
|
}
|