save() {
		this._colorStack.push(this.currentColor.clone());
		this._matrixStack.push(this.currentTransform.clone());

		if (this.gl.isEnabled(this.gl.SCISSOR_TEST)) {
			// FIXME avoid slice and object realloc
			this._scissorStack.push(this.currentScissor.slice());
		}

		this._blendStack.push(this.getBlendMode());
	}
saves the entire state of the renderer by pushing the current state onto a stack.
@example
// Save the current state
renderer.save();

// apply a transform and draw a rect
renderer.tranform(matrix);
renderer.fillRect(10, 10, 100, 100);

// Restore to the state saved by the most recent call to save()
renderer.restore();