canvas-based-HTML5-Comic-Bo.../scripts.js
2010-07-06 10:19:24 +01:00

88 lines
No EOL
2.1 KiB
JavaScript

var book;
window.onload = function() {
book = new ComicBook();
var srcs = {
1: "http://dev.justforcomics.com/get/image/?f=comics/extracted/oni_whiteout_melt_1/00.jpg",
2: "http://dev.justforcomics.com/get/image/?f=comics/extracted/oni_whiteout_melt_1/01.jpg",
3: "http://dev.justforcomics.com/get/image/?f=comics/extracted/oni_whiteout_melt_1/02.jpg",
4: "http://dev.justforcomics.com/get/image/?f=comics/extracted/oni_whiteout_melt_1/03.jpg",
5: "http://dev.justforcomics.com/get/image/?f=comics/extracted/oni_whiteout_melt_1/04.jpg",
6: "http://dev.justforcomics.com/get/image/?f=comics/extracted/oni_whiteout_melt_1/05.jpg",
7: "http://dev.justforcomics.com/get/image/?f=comics/extracted/oni_whiteout_melt_1/06.jpg",
8: "http://dev.justforcomics.com/get/image/?f=comics/extracted/oni_whiteout_melt_1/07.jpg"
};
book.draw("comic", srcs);
}
function ComicBook() {
var srcs = [];
var pages = [];
var canvas;
var context;
var buffer = 4;
var pointer = 0;
/*
* @param {String} id The canvas ID to draw the comic on.
* @param {Array} srcs An array of all the comic page srcs, in order
*/
this.draw = function(id, srcs) {
// setup canvas
canvas = document.getElementById(id);
context = canvas.getContext("2d");
preload(srcs);
}
function preload(srcs) {
var loaded = 0;
if (srcs.length < buffer) buffer = srcs.length; // don't get stuck if the buffer level is higher than the number of pages
for (i in srcs) {
var page = new Image();
page.src = srcs[i];
page.onload = function() {
pages[loaded] = this; loaded++;
if (loaded == buffer) drawPage();
}
};
}
/**
* TODO: break this down into drawSinglePage() & drawDoublePage()
* TODO: if the current browser doesn't have canvas support, use img tags
*/
function drawPage() {
console.log(pointer, pages);
var page = pages[pointer];
canvas.width = page.width;
canvas.height = page.height;
context.drawImage(page, 0, 0);
}
this.drawNextPage = function() {
if (pointer < pointer + 1) pointer++;
drawPage();
}
this.drawPrevPage = function() {
if (pointer > 0) pointer--;
drawPage();
}
}