This is an example MLT transition implemented in HTML. It uses the WebVfx WebGL shader support framework to implement a 2D page curl transition using GLSL. The rendered video can be viewed here demo/mlt/mlt_transition_shader_pagecurl_html
<html>
<head>
<style type="text/css">
body, html {
margin: 0;
width: 100%;
height: 100%;
}
#canvas {
width: 100%;
height: 100%;
}
</style>
<script type="text/javascript" src="qrc:/webvfx/scripts/shaderkit.js"></script>
<script type="text/javascript" src="qrc:/webvfx/scripts/easing.js"></script>
<script type="text/javascript">
function PageCurl() {
var renderer = new ShaderKit.Renderer(document.getElementById("canvas"));
this.shader = new ShaderKit.Shader(renderer, ShaderKit.Shader.loadShader("pageCurl"));
this.easeCurl = new WebVfx.Easing.Sinusoidal(0, 1, 1);
}
PageCurl.prototype.render = function (time) {
var shader = this.shader;
shader.updateUniform("time", this.easeCurl.easeOut(time));
shader.updateUniform("sourceTex",
webvfx.getImage('sourceImage').toImageData());
shader.updateUniform("targetTex",
webvfx.getImage('targetImage').toImageData());
shader.renderer.render(shader);
}
function init() {
try {
resize();
var pageCurl = new PageCurl();
webvfx.renderRequested.connect(pageCurl, PageCurl.prototype.render);
webvfx.imageTypeMap = { "sourceImage" : webvfx.SourceImageType,
"targetImage" : webvfx.TargetImageType };
webvfx.readyRender(true);
} catch (e) {
console.warn(e);
webvfx.readyRender(false);
}
}
function resize() {
var canvas = document.getElementById("canvas");
canvas.width = window.innerWidth;
canvas.height = window.innerHeight;
}
window.addEventListener("load", init, false);
window.addEventListener("resize", resize, false);
</script>
<!--
PageCurl fragment shader is based on code from http:
Copyright (c) 2010 Calyptus Life AB <http:
Licensed under The MIT License:
http:
-->
<script id="pageCurl" type="x-shader/x-fragment">
precision mediump float;
varying vec2 texCoord;
uniform sampler2D sourceTex;
uniform sampler2D targetTex;
uniform float time;
const float MIN_AMOUNT = -0.16;
const float MAX_AMOUNT = 1.3;
float amount = time * (MAX_AMOUNT - MIN_AMOUNT) + MIN_AMOUNT;
const float PI = 3.141592653589793;
const float scale = 512.0;
const float sharpness = 3.0;
float cylinderCenter = amount;
float cylinderAngle = 2.0 * PI * amount;
const float cylinderRadius = 1.0 / PI / 2.0;
vec3 hitPoint(float hitAngle, float yc, vec3 point, mat3 rrotation) {
float hitPoint = hitAngle / (2.0 * PI);
point.y = hitPoint;
return rrotation * point;
}
vec4 antiAlias(vec4 color1, vec4 color2, float distance) {
distance *= scale;
if (distance < 0.0) return color2;
if (distance > 2.0) return color1;
float dd = pow(1.0 - distance / 2.0, sharpness);
return ((color2 - color1) * dd) + color1;
}
float distanceToEdge(vec3 point) {
float dx = abs(point.x > 0.5 ? 1.0 - point.x : point.x);
float dy = abs(point.y > 0.5 ? 1.0 - point.y : point.y);
if (point.x < 0.0) dx = -point.x;
if (point.x > 1.0) dx = point.x - 1.0;
if (point.y < 0.0) dy = -point.y;
if (point.y > 1.0) dy = point.y - 1.0;
if ((point.x < 0.0 || point.x > 1.0) && (point.y < 0.0 || point.y > 1.0)) return sqrt(dx * dx + dy * dy);
return min(dx, dy);
}
vec4 seeThrough(float yc, vec2 p, mat3 rotation, mat3 rrotation) {
float hitAngle = PI - (acos(yc / cylinderRadius) - cylinderAngle);
vec3 point = hitPoint(hitAngle, yc, rotation * vec3(p, 1.0), rrotation);
if (yc <= 0.0 && (point.x < 0.0 || point.y < 0.0 || point.x > 1.0 || point.y > 1.0)) {
return texture2D(targetTex, texCoord);
}
if (yc > 0.0) return texture2D(sourceTex, p);
vec4 color = texture2D(sourceTex, point.xy);
vec4 tcolor = vec4(0.0);
return antiAlias(color, tcolor, distanceToEdge(point));
}
vec4 seeThroughWithShadow(float yc, vec2 p, vec3 point, mat3 rotation, mat3 rrotation) {
float shadow = distanceToEdge(point) * 30.0;
shadow = (1.0 - shadow) / 3.0;
if (shadow < 0.0) shadow = 0.0;
else shadow *= amount;
vec4 shadowColor = seeThrough(yc, p, rotation, rrotation);
shadowColor.r -= shadow;
shadowColor.g -= shadow;
shadowColor.b -= shadow;
return shadowColor;
}
vec4 backside(float yc, vec3 point) {
vec4 color = texture2D(sourceTex, point.xy);
float gray = (color.r + color.b + color.g) / 15.0;
gray += (8.0 / 10.0) * (pow(1.0 - abs(yc / cylinderRadius), 2.0 / 10.0) / 2.0 + (5.0 / 10.0));
color.rgb = vec3(gray);
return color;
}
vec4 behindSurface(float yc, vec3 point, mat3 rrotation) {
float shado = (1.0 - ((-cylinderRadius - yc) / amount * 7.0)) / 6.0;
shado *= 1.0 - abs(point.x - 0.5);
yc = (-cylinderRadius - cylinderRadius - yc);
float hitAngle = (acos(yc / cylinderRadius) + cylinderAngle) - PI;
point = hitPoint(hitAngle, yc, point, rrotation);
if (yc < 0.0 && point.x >= 0.0 && point.y >= 0.0 && point.x <= 1.0 && point.y <= 1.0 && (hitAngle < PI || amount > 0.5)){
shado = 1.0 - (sqrt(pow(point.x - 0.5, 2.0) + pow(point.y - 0.5, 2.0)) / (71.0 / 100.0));
shado *= pow(-yc / cylinderRadius, 3.0);
shado *= 0.5;
} else
shado = 0.0;
return vec4(texture2D(targetTex, texCoord).rgb - shado, 1.0);
}
void main(void) {
const float angle = 30.0 * PI / 180.0;
float c = cos(-angle);
float s = sin(-angle);
mat3 rotation = mat3(
c, s, 0,
-s, c, 0,
0.12, 0.258, 1
);
c = cos(angle);
s = sin(angle);
mat3 rrotation = mat3(
c, s, 0,
-s, c, 0,
0.15, -0.5, 1
);
vec3 point = rotation * vec3(texCoord, 1.0);
float yc = point.y - cylinderCenter;
if (yc < -cylinderRadius) {
gl_FragColor = behindSurface(yc, point, rrotation);
return;
}
if (yc > cylinderRadius) {
gl_FragColor = texture2D(sourceTex, texCoord);
return;
}
float hitAngle = (acos(yc / cylinderRadius) + cylinderAngle) - PI;
float hitAngleMod = mod(hitAngle, 2.0 * PI);
if ((hitAngleMod > PI && amount < 0.5) || (hitAngleMod > PI/2.0 && amount < 0.0)) {
gl_FragColor = seeThrough(yc, texCoord, rotation, rrotation);
return;
}
point = hitPoint(hitAngle, yc, point, rrotation);
if (point.x < 0.0 || point.y < 0.0 || point.x > 1.0 || point.y > 1.0) {
gl_FragColor = seeThroughWithShadow(yc, texCoord, point, rotation, rrotation);
return;
}
vec4 color = backside(yc, point);
vec4 otherColor;
if (yc < 0.0) {
float shado = 1.0 - (sqrt(pow(point.x - 0.5, 2.0) + pow(point.y - 0.5, 2.0)) / 0.71);
shado *= pow(-yc / cylinderRadius, 3.0);
shado *= 0.5;
otherColor = vec4(0.0, 0.0, 0.0, shado);
} else {
otherColor = texture2D(sourceTex, texCoord);
}
color = antiAlias(color, otherColor, cylinderRadius - abs(yc));
vec4 cl = seeThroughWithShadow(yc, texCoord, point, rotation, rrotation);
float dist = distanceToEdge(point);
gl_FragColor = antiAlias(color, cl, dist);
}
</script>
</head>
<body>
<canvas id="canvas"></canvas>
</body>
</html>
