Thanks for the asset, the shader looks amazing! Do you have any suggestions for getting the shader to work on only a specific surface? For example, in my game I want to have the camera zoom into a TV in the room and have the scanlines only show up on the TV screen (the content of which is being drawn to a surface).
Viewing post in Advanced CRT Shader for GameMaker comments
Thank you for trying my asset! I would suggest taking a look at the "Draw GUI" events for the CRT object, where you'll see that the rendering is wrapped up in a single function call. If you call this function while your surface is the current target, the CRT screen will be drawn directly to your surface instead of the GUI surface. You'll need to ensure that crt.output_width and crt.output_height match the size of your surface, and I'd also recommend disabling the phosphor mask if your surface will be zooming or stretching around the screen.