import BoundingRectangle from '../Core/BoundingRectangle.js';
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import Color from '../Core/Color.js';
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import defaultValue from '../Core/defaultValue.js';
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import defined from '../Core/defined.js';
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import destroyObject from '../Core/destroyObject.js';
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import Framebuffer from '../Renderer/Framebuffer.js';
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import PassState from '../Renderer/PassState.js';
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import Renderbuffer from '../Renderer/Renderbuffer.js';
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import RenderbufferFormat from '../Renderer/RenderbufferFormat.js';
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import Texture from '../Renderer/Texture.js';
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/**
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* @private
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*/
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function PickFramebuffer(context) {
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// Override per-command states
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var passState = new PassState(context);
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passState.blendingEnabled = false;
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passState.scissorTest = {
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enabled : true,
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rectangle : new BoundingRectangle()
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};
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passState.viewport = new BoundingRectangle();
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this._context = context;
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this._fb = undefined;
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this._passState = passState;
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this._width = 0;
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this._height = 0;
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}
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PickFramebuffer.prototype.begin = function(screenSpaceRectangle, viewport) {
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var context = this._context;
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var width = viewport.width;
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var height = viewport.height;
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BoundingRectangle.clone(screenSpaceRectangle, this._passState.scissorTest.rectangle);
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// Initially create or recreate renderbuffers and framebuffer used for picking
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if ((!defined(this._fb)) || (this._width !== width) || (this._height !== height)) {
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this._width = width;
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this._height = height;
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this._fb = this._fb && this._fb.destroy();
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this._fb = new Framebuffer({
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context : context,
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colorTextures : [new Texture({
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context : context,
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width : width,
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height : height
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})],
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depthStencilRenderbuffer : new Renderbuffer({
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context : context,
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width : width,
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height : height,
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format : RenderbufferFormat.DEPTH_STENCIL
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})
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});
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this._passState.framebuffer = this._fb;
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}
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this._passState.viewport.width = width;
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this._passState.viewport.height = height;
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return this._passState;
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};
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var colorScratch = new Color();
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PickFramebuffer.prototype.end = function(screenSpaceRectangle) {
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var width = defaultValue(screenSpaceRectangle.width, 1.0);
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var height = defaultValue(screenSpaceRectangle.height, 1.0);
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var context = this._context;
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var pixels = context.readPixels({
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x : screenSpaceRectangle.x,
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y : screenSpaceRectangle.y,
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width : width,
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height : height,
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framebuffer : this._fb
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});
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var max = Math.max(width, height);
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var length = max * max;
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var halfWidth = Math.floor(width * 0.5);
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var halfHeight = Math.floor(height * 0.5);
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var x = 0;
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var y = 0;
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var dx = 0;
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var dy = -1;
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// Spiral around the center pixel, this is a workaround until
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// we can access the depth buffer on all browsers.
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// The region does not have to square and the dimensions do not have to be odd, but
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// loop iterations would be wasted. Prefer square regions where the size is odd.
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for (var i = 0; i < length; ++i) {
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if (-halfWidth <= x && x <= halfWidth && -halfHeight <= y && y <= halfHeight) {
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var index = 4 * ((halfHeight - y) * width + x + halfWidth);
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colorScratch.red = Color.byteToFloat(pixels[index]);
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colorScratch.green = Color.byteToFloat(pixels[index + 1]);
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colorScratch.blue = Color.byteToFloat(pixels[index + 2]);
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colorScratch.alpha = Color.byteToFloat(pixels[index + 3]);
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var object = context.getObjectByPickColor(colorScratch);
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if (defined(object)) {
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return object;
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}
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}
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// if (top right || bottom left corners) || (top left corner) || (bottom right corner + (1, 0))
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// change spiral direction
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if (x === y || (x < 0 && -x === y) || (x > 0 && x === 1 - y)) {
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var temp = dx;
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dx = -dy;
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dy = temp;
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}
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x += dx;
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y += dy;
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}
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return undefined;
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};
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PickFramebuffer.prototype.isDestroyed = function() {
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return false;
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};
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PickFramebuffer.prototype.destroy = function() {
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this._fb = this._fb && this._fb.destroy();
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return destroyObject(this);
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};
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export default PickFramebuffer;
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