WebGL Drawing Buffer size does not equal Canvas size

Vote count:

0

I have a webapp that uses three.js to draw multiple webgl layers, and I am sometimes getting (in Chrome) the layers with drawingBufferHeight & drawingBufferWidth that are not equal to the canvas height & width.

Each layer can be turned on and off. I have a stack of them so they are reused:

Layers.GLRendererPool = new (function() {
    this.renderers = [];
    this.getRenderer = function() {
        if(this.renderers.length == 0) {
            var r = new THREE.WebGLRenderer({ alpha: true });
            r.setClearColor(0x000000, 0);
            return r;
        } else {
            var r = this.renderers.shift();
            return r;
        }
    };
    this.saveRenderer = function(r) {
        r.setSize(0, 0); //EXPERIMENTAL
        this.renderers.push(r);
    };
    return this;
})();

They are resized after getting them using THREE.WebGLRenderer.setSize(). After calling setSize(), canvas.width == renderer.context.drawingBufferWidth and canvas.height == renderer.context.drawingBufferHeight, but not always. They are not equal even if I only have 1 renderer currently in use.

Any ideas why this happens? I was assuming that there were some limits on video card memory, and I tried calling setSize(0, 0) on every renderer that is not in use, but no luck there. Is this a Chrome + WebGL bug?

asked 42 secs ago

Charles L.

778

WebGL Drawing Buffer size does not equal Canvas size