Size = 2;
shouldBeTrue("fboSize < canvas.width");
var fbo = gl.createFramebuffer();
gl.bindFramebuffer(gl.FRAMEBUFFER, fbo);
var fboTex = gl.createTexture();
gl.activeTexture(gl.TEXTURE1);
gl.bindTexture(gl.TEXTURE_2D, fboTex);
gl.framebufferTexture2D(gl.FRAMEBUFFER, gl.COLOR_ATTACHMENT0, gl.TEXTURE_2D, fboTex, 0);
gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA, fboSize, fboSize, 0, gl.RGBA, gl.UNSIGNED_BYTE, null);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR);
gl.texParameteri(gl.TEXTURE_2D, 