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Forked from gre/TEMPLATE.glsl
Last active January 4, 2016 10:29
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#ifdef GL_ES
precision highp float;
#endif
// General parameters
uniform sampler2D from;
uniform sampler2D to;
uniform float progress;
uniform vec2 resolution;
uniform float reflection;
uniform float perspective;
uniform float depth;
const vec4 black = vec4(0.0, 0.0, 0.0, 1.0);
const vec2 boundMin = vec2(0.0, 0.0);
const vec2 boundMax = vec2(1.0, 1.0);
bool inBounds (vec2 p) {
return all(lessThan(boundMin, p)) && all(lessThan(p, boundMax));
}
vec2 project (vec2 p) {
return p * vec2(1.0, -1.2) + vec2(0.0, -0.02);
}
vec4 bgColor (vec2 p, vec2 pfr, vec2 pto) {
vec4 c = black;
pfr = project(pfr);
if (inBounds(pfr)) {
c += mix(black, texture2D(from, pfr), reflection * mix(1.0, 0.0, pfr.y));
}
pto = project(pto);
if (inBounds(pto)) {
c += mix(black, texture2D(to, pto), reflection * mix(1.0, 0.0, pto.y));
}
return c;
}
void main() {
vec2 p = gl_FragCoord.xy / resolution.xy;
vec2 pfr, pto = vec2(-1.);
float size = mix(1.0, depth, progress);
float persp = perspective * progress;
pfr = (p + vec2(-0.0, -0.5)) * vec2(size/(1.0-perspective*progress), size/(1.0-size*persp*p.x)) + vec2(0.0, 0.5);
size = mix(1.0, depth, 1.-progress);
persp = perspective * (1.-progress);
pto = (p + vec2(-1.0, -0.5)) * vec2(size/(1.0-perspective*(1.0-progress)), size/(1.0-size*persp*(0.5-p.x))) + vec2(1.0, 0.5);
bool fromOver = progress < 0.5;
if (fromOver) {
if (inBounds(pfr)) {
gl_FragColor = texture2D(from, pfr);
}
else if (inBounds(pto)) {
gl_FragColor = texture2D(to, pto);
}
else {
gl_FragColor = bgColor(p, pfr, pto);
}
}
else {
if (inBounds(pto)) {
gl_FragColor = texture2D(to, pto);
}
else if (inBounds(pfr)) {
gl_FragColor = texture2D(from, pfr);
}
else {
gl_FragColor = bgColor(p, pfr, pto);
}
}
}
{ "reflection": 0.4, "perspective": 0.2, "depth": 3.0 }
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