asciiblaster/js/shader.js

59 lines
1.4 KiB
JavaScript

var shader = (function(){
var fn_str, fn, lex
var exports = {}
var animating = false
exports.init = function(){
lex = new Lex (0, 0)
exports.build(demo_shader.innerHTML)
}
exports.build = function (fn_str){
try {
new_fn = new Function('lex', 'x', 'y', 'w', 'h', 't', fn_str)
new_fn(lex, 0, 0, 1, 1, 0)
}
catch (e) {
throw 'Shader execution error'
}
exports.fn = fn = new_fn
return fn
}
exports.run = function(canvas){
var t = +new Date
shader.canvas = shader.canvas || canvas
var w = shader.canvas.w, h = shader.canvas.h
shader.canvas.forEach(function(lex, x, y){
fn(lex, x, y, w, h, t)
lex.build()
})
}
exports.toggle = function(state){
animating = typeof state == "boolean" ? state : ! animating
shader_fps_el.classList.toggle('hidden')
return animating
}
exports.pause = function(){
animating = false
shader_fps_el.classList.add('hidden')
shader.fps_time = 0
}
exports.play = function(){
animating = true
shader_fps_el.classList.remove('hidden')
}
exports.animate = function (t){
requestAnimationFrame(exports.animate)
if (! animating) { return }
if (shader.fps_time){
var ms = Date.now() - shader.fps_time
fps = 1000 / ms
shader_fps_el.innerHTML = (fps | 0) + ' fps'
}
shader.fps_time = Date.now()
exports.run(canvas)
}
return exports
})()