Add atlas manager

This commit is contained in:
tsauerwein
2014-11-03 15:29:21 +01:00
parent 22e1159736
commit 1bd388188b
2 changed files with 522 additions and 0 deletions

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goog.provide('ol.renderer.webgl.Atlas');
goog.provide('ol.renderer.webgl.AtlasManager');
goog.require('goog.asserts');
goog.require('goog.dom');
goog.require('goog.dom.TagName');
goog.require('goog.object');
/**
* @constructor
* @struct
* @param {number} offsetX
* @param {number} offsetY
* @param {HTMLCanvasElement} image
*/
ol.renderer.webgl.AtlasInfo = function(offsetX, offsetY, image) {
/**
* @type {number}
*/
this.offsetX = offsetX;
/**
* @type {number}
*/
this.offsetY = offsetY;
/**
* @type {HTMLCanvasElement}
*/
this.image = image;
};
/**
* @constructor
* @struct
* @param {number=} opt_size The size in pixels of the sprite images
* (default: 256).
* @param {number=} opt_space The space in pixels between images
* (default: 1).
*/
ol.renderer.webgl.AtlasManager = function(opt_size, opt_space) {
/**
* The size in pixels of the sprite images.
* @private
* @type {number}
*/
this.size_ = goog.isDef(opt_size) ? opt_size : 256;
/**
* The size in pixels between images.
* @private
* @type {number}
*/
this.space_ = goog.isDef(opt_space) ? opt_space : 1;
/**
* @private
* @type {Array.<ol.renderer.webgl.Atlas>}
*/
this.atlases_ = [new ol.renderer.webgl.Atlas(this.size_, this.space_)];
};
/**
* @param {number} hash The hash of the entry to check.
* @return {ol.renderer.webgl.AtlasInfo}
*/
ol.renderer.webgl.AtlasManager.prototype.getInfo = function(hash) {
var atlas, info;
for (var i = 0, l = this.atlases_.length; i < l; i++) {
atlas = this.atlases_[i];
info = atlas.get(hash);
if (info !== null) {
return info;
}
}
return null;
};
/**
* Add an image to the atlas manager.
*
* If an entry for the given hash already exists, the entry will
* be overridden (but the space on the atlas graphic will not be freed).
*
* @param {number} hash The hash of the entry to add.
* @param {number} width The width.
* @param {number} height The height.
* @param {function(*)} renderCallback Called to render the new sprite entry
* onto the sprite image.
* @param {object=} opt_this Value to use as `this` when executing
* `renderCallback`.
* @return {ol.renderer.webgl.AtlasInfo}
*/
ol.renderer.webgl.AtlasManager.prototype.add =
function(hash, width, height, renderCallback, opt_this) {
goog.asserts.assert(width <= this.size_ && height <= this.size_,
'the entry is too big for the current atlas size');
var atlas, info;
for (var i = 0, l = this.atlases_.length; i < l; i++) {
atlas = this.atlases_[i];
info = atlas.add(hash, width, height, renderCallback, opt_this);
if (info !== null) {
return info;
}
}
// the entry could not be added to one of the existing atlases,
// create a new atlas and add to this one.
// TODO double the size and check for max. size?
atlas = new ol.renderer.webgl.Atlas(this.size_, this.space_);
this.atlases_.push(atlas);
return atlas.add(hash, width, height, renderCallback, opt_this);
};
/**
* This class facilitates the creation of texture atlases.
*
* Images added to an atlas will be rendered onto a single
* atlas canvas. The distribution of images on the canvas are
* managed with the bin packing algorithm described in:
* http://www.blackpawn.com/texts/lightmaps/
*
* @constructor
* @struct
* @param {number} size The size in pixels of the sprite images.
* @param {number} space The space in pixels between images.
*/
ol.renderer.webgl.Atlas = function(size, space) {
/**
* @private
* @type {number} The space in pixels between images.
* Because texture coordinates are float values, the edges of
* texture might not be completely correct (in a way that the
* edges overlap when being rendered). To avoid this we add a
* padding around each image.
*/
this.space_ = space;
/**
* @private
* @type {Array.<ol.renderer.webgl.Atlas.Block>}
*/
this.emptyBlocks_ = [{x: 0, y: 0, width: size, height: size}];
/**
* @private
* @type {Object.<number, ol.renderer.webgl.AtlasInfo>}
*/
this.entries_ = {};
/**
* @private
* @type {HTMLCanvasElement}
*/
this.canvas_ = /** @type {HTMLCanvasElement} */
(goog.dom.createElement(goog.dom.TagName.CANVAS));
this.canvas_.width = size;
this.canvas_.height = size;
/**
* @private
* @type {CanvasRenderingContext2D}
*/
this.context_ = /** @type {CanvasRenderingContext2D} */
(this.canvas_.getContext('2d'));
};
/**
* @param {number} hash The hash of the entry to check.
* @return {ol.renderer.webgl.AtlasInfo}
*/
ol.renderer.webgl.Atlas.prototype.get = function(hash) {
return goog.object.get(this.entries_, hash, null);
};
/**
* @param {number} hash The hash of the entry to add.
* @param {number} width The width.
* @param {number} height The height.
* @param {function(*)} renderCallback Called to render the new sprite entry
* onto the sprite image.
* @param {object=} opt_this Value to use as `this` when executing
* `renderCallback`.
* @return {ol.renderer.webgl.AtlasInfo}
*/
ol.renderer.webgl.Atlas.prototype.add =
function(hash, width, height, renderCallback, opt_this) {
var block;
for (var i = 0, l = this.emptyBlocks_.length; i < l; i++) {
block = this.emptyBlocks_[i];
if (block.width >= width + this.space_ &&
block.height >= height + this.space_) {
// we found a block that is big enough for our entry
var entry = new ol.renderer.webgl.AtlasInfo(
block.x + this.space_, block.y + this.space_, this.canvas_);
this.entries_[hash] = entry;
// render the image on the atlas image
renderCallback.call(opt_this, this.context_,
block.x + this.space_, block.y + this.space_);
// split the block after the insertion, either horizontally or vertically
this.split_(i, block, width + this.space_, height + this.space_);
return entry;
}
}
// there is no space for the new entry in this atlas
return null;
};
/**
* @private
* @param {number} index The index of the block.
* @param {ol.renderer.webgl.Atlas.Block} block The block to split.
* @param {number} width The width of the entry to insert.
* @param {number} height The height of the entry to insert.
*/
ol.renderer.webgl.Atlas.prototype.split_ =
function(index, block, width, height) {
var deltaWidth = block.width - width;
var deltaHeight = block.height - height;
var newBlock1, newBlock2;
if (deltaWidth > deltaHeight) {
// split vertically
// block right of the inserted entry
newBlock1 = {
x: block.x + width,
y: block.y,
width: block.width - width,
height: block.height
};
// block below the inserted entry
newBlock2 = {
x: block.x,
y: block.y + height,
width: width,
height: block.height - height
};
this.updateBlocks_(index, newBlock1, newBlock2);
} else {
// split horizontally
// block right of the inserted entry
newBlock1 = {
x: block.x + width,
y: block.y,
width: block.width - width,
height: height
};
// block below the inserted entry
newBlock2 = {
x: block.x,
y: block.y + height,
width: block.width,
height: block.height - height
};
this.updateBlocks_(index, newBlock1, newBlock2);
}
};
/**
* Remove the old block and insert new blocks at the same array position.
* The new blocks are inserted at the same position, so that splitted
* blocks (that are potentially smaller) are filled first.
* @private
* @param {number} index The index of the block to remove.
* @param {ol.renderer.webgl.Atlas.Block} newBlock1 The 1st block to add.
* @param {ol.renderer.webgl.Atlas.Block} newBlock2 The 2nd block to add.
*/
ol.renderer.webgl.Atlas.prototype.updateBlocks_ =
function(index, newBlock1, newBlock2) {
var args = [index, 1];
if (newBlock1.width > 0 && newBlock1.height > 0) {
args.push(newBlock1);
}
if (newBlock2.width > 0 && newBlock2.height > 0) {
args.push(newBlock2);
}
this.emptyBlocks_.splice.apply(this.emptyBlocks_, args);
};
/**
* @typedef{{x: number, y: number, width: number, height: number}}
*/
ol.renderer.webgl.Atlas.Block;

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goog.provide('ol.test.renderer.webgl.AtlasManager');
describe('ol.renderer.webgl.Atlas', function() {
var defaultRender = function(context, x, y) {
};
describe('#constructor', function() {
it('inits the atlas', function() {
var atlas = new ol.renderer.webgl.Atlas(256, 1);
expect(atlas.emptyBlocks_).to.eql(
[{x: 0, y: 0, width: 256, height: 256}]);
});
});
describe('#add (squares with same size)', function() {
it('adds one entry', function() {
var atlas = new ol.renderer.webgl.Atlas(128, 1);
var info = atlas.add(1, 32, 32, defaultRender);
expect(info).to.eql(
{offsetX: 1, offsetY: 1, image: atlas.canvas_});
expect(atlas.get(1)).to.eql(info);
});
it('adds two entries', function() {
var atlas = new ol.renderer.webgl.Atlas(128, 1);
atlas.add(1, 32, 32, defaultRender);
var info = atlas.add(2, 32, 32, defaultRender);
expect(info).to.eql(
{offsetX: 34, offsetY: 1, image: atlas.canvas_});
expect(atlas.get(2)).to.eql(info);
});
it('adds three entries', function() {
var atlas = new ol.renderer.webgl.Atlas(128, 1);
atlas.add(1, 32, 32, defaultRender);
atlas.add(2, 32, 32, defaultRender);
var info = atlas.add(3, 32, 32, defaultRender);
expect(info).to.eql(
{offsetX: 67, offsetY: 1, image: atlas.canvas_});
expect(atlas.get(3)).to.eql(info);
});
it('adds four entries (new row)', function() {
var atlas = new ol.renderer.webgl.Atlas(128, 1);
atlas.add(1, 32, 32, defaultRender);
atlas.add(2, 32, 32, defaultRender);
atlas.add(3, 32, 32, defaultRender);
var info = atlas.add(4, 32, 32, defaultRender);
expect(info).to.eql(
{offsetX: 1, offsetY: 34, image: atlas.canvas_});
expect(atlas.get(4)).to.eql(info);
});
it('returns null when an entry is too big', function() {
var atlas = new ol.renderer.webgl.Atlas(128, 1);
atlas.add(1, 32, 32, defaultRender);
atlas.add(2, 32, 32, defaultRender);
atlas.add(3, 32, 32, defaultRender);
var info = atlas.add(4, 100, 100, defaultRender);
expect(info).to.eql(null);
});
it('fills up the whole atlas', function() {
var atlas = new ol.renderer.webgl.Atlas(128, 1);
for (var i = 1; i <= 16; i++) {
expect(atlas.add(i, 28, 28, defaultRender)).to.be.ok();
}
// there is no more space for items of this size, the next one will fail
expect(atlas.add(17, 28, 28, defaultRender)).to.eql(null);
});
});
describe('#add (rectangles with different sizes)', function() {
it('adds a bunch of rectangles', function() {
var atlas = new ol.renderer.webgl.Atlas(128, 1);
expect(atlas.add(1, 64, 32, defaultRender)).to.eql(
{offsetX: 1, offsetY: 1, image: atlas.canvas_});
expect(atlas.add(2, 64, 32, defaultRender)).to.eql(
{offsetX: 1, offsetY: 34, image: atlas.canvas_});
expect(atlas.add(3, 64, 32, defaultRender)).to.eql(
{offsetX: 1, offsetY: 67, image: atlas.canvas_});
// this one can not be added anymore
expect(atlas.add(4, 64, 32, defaultRender)).to.eql(null);
// but there is still room for smaller ones
expect(atlas.add(5, 40, 32, defaultRender)).to.eql(
{offsetX: 66, offsetY: 1, image: atlas.canvas_});
expect(atlas.add(6, 40, 32, defaultRender)).to.eql(
{offsetX: 66, offsetY: 34, image: atlas.canvas_});
});
it('fills up the whole atlas (rectangles in portrait format)', function() {
var atlas = new ol.renderer.webgl.Atlas(128, 1);
for (var i = 1; i <= 32; i++) {
expect(atlas.add(i, 28, 14, defaultRender)).to.be.ok();
}
// there is no more space for items of this size, the next one will fail
expect(atlas.add(33, 28, 14, defaultRender)).to.eql(null);
});
it('fills up the whole atlas (rectangles in landscape format)', function() {
var atlas = new ol.renderer.webgl.Atlas(128, 1);
for (var i = 1; i <= 32; i++) {
expect(atlas.add(i, 14, 28, defaultRender)).to.be.ok();
}
// there is no more space for items of this size, the next one will fail
expect(atlas.add(33, 14, 28, defaultRender)).to.eql(null);
});
});
describe('#add (rendering)', function() {
it('calls the render callback with the right values', function() {
var atlas = new ol.renderer.webgl.Atlas(128, 1);
var rendererCallback = sinon.spy();
atlas.add(1, 32, 32, rendererCallback);
expect(rendererCallback.calledOnce).to.be.ok();
expect(rendererCallback.calledWith(atlas.context_, 1, 1)).to.be.ok();
rendererCallback = sinon.spy();
atlas.add(2, 32, 32, rendererCallback);
expect(rendererCallback.calledOnce).to.be.ok();
expect(rendererCallback.calledWith(atlas.context_, 34, 1)).to.be.ok();
});
it('is possible to actually draw on the canvas', function() {
var atlas = new ol.renderer.webgl.Atlas(128, 1);
var rendererCallback = function(context, x, y) {
context.fillStyle = '#FFA500';
context.fillRect(x, y, 32, 32);
};
expect(atlas.add(1, 32, 32, rendererCallback)).to.be.ok();
expect(atlas.add(2, 32, 32, rendererCallback)).to.be.ok();
// no error, ok
});
});
});
describe('ol.renderer.webgl.AtlasManager', function() {
var defaultRender = function(context, x, y) {
};
describe('#constructor', function() {
it('inits the atlas manager', function() {
var manager = new ol.renderer.webgl.AtlasManager();
expect(manager.atlases_).to.not.be.empty();
});
});
describe('#add', function() {
it('adds one entry', function() {
var manager = new ol.renderer.webgl.AtlasManager(128);
var info = manager.add(1, 32, 32, defaultRender);
expect(info).to.eql(
{offsetX: 1, offsetY: 1, image: manager.atlases_[0].canvas_});
expect(manager.getInfo(1)).to.eql(info);
});
it('creates a new atlas if needed', function() {
var manager = new ol.renderer.webgl.AtlasManager(128);
expect(manager.add(1, 100, 100, defaultRender)).to.be.ok();
expect(manager.add(2, 100, 100, defaultRender)).to.be.ok();
expect(manager.atlases_).to.have.length(2);
});
});
describe('#getInfo', function() {
it('returns null if no entry for the given hash', function() {
var manager = new ol.renderer.webgl.AtlasManager(128);
expect(manager.getInfo(123456)).to.eql(null);
});
});
});
goog.require('ol.renderer.webgl.Atlas');
goog.require('ol.renderer.webgl.AtlasManager');