public GwtRenderingContext(Panel root, GwtAppConfiguration config)
throws ParallaxRuntimeException {
this.root = root;
root.clear();
Canvas canvasWidget = Canvas.createIfSupported();
if (canvasWidget == null) throw new ParallaxRuntimeException("Canvas not supported");
int width = root.getOffsetWidth();
int height = root.getOffsetHeight();
if (width == 0 || height == 0)
new ParallaxRuntimeException("Width or Height of the Panel is 0");
lastWidth = width;
lastHeight = height;
canvas = canvasWidget.getCanvasElement();
root.add(canvasWidget);
canvas.setWidth(width);
canvas.setHeight(height);
this.config = config;
WebGLContextAttributes attributes = WebGLContextAttributes.create();
attributes.setAntialias(config.antialiasing);
attributes.setStencil(config.stencil);
attributes.setAlpha(config.alpha);
attributes.setPremultipliedAlpha(config.premultipliedAlpha);
attributes.setPreserveDrawingBuffer(config.preserveDrawingBuffer);
context = WebGLRenderingContext.getContext(canvas, attributes);
context.viewport(0, 0, width, height);
gl = new GwtGL20(context);
renderer = new GLRenderer(gl, width, height);
input = new GwtInput(canvas);
addEventListeners();
Window.addResizeHandler(this);
}
@Override
public int getWidth() {
return root.getOffsetWidth();
}