2D - Possible To Read Pixel Colors Displayed On The Screen?

JeZxLee

Hi,

Does Godot have an ability to read pixel colors displayed on the screen? Let us know, thanks!

Jesse

Megalomaniak

I think you should be able to read the main viewport, but I've never tried this myself. Note that every godot runtime(i.e. running game) features at least 1 viewport at the very top of the scene-graph/node tree. It should be the root node.

JeZxLee

Is there a function to read pixel colors? Like: "ReadPixelColor(x, y)" ?

TwistedTwigleg

You can get the root viewport using get_tree().root, get it’s ViewportTexture by calling get_texture(). From there, you can convert the ViewportTexture to an Image by calling get_data(), and then the pixel data by calling get_pixel. Altogether, it would look something like this:

func _ready():
	var root_view = get_tree().root
	var root_view_tex = root_view.get_texture()
	var root_view_image = root_view_tex.get_data()
	# then to access pixels
	print (root_view_image.get_pixel(20, 20)

I haven’t tested the code though, so I don’t know if it will work.

JeZxLee

Hi,

Thanks for the code...Have not tried it yet. If I ran above code every frame would that be very CPU expensive?

Making a vertical 2D shooter and need a method to check for collision between player and land. Thanks again!

Jesse

Calinou

Reading the viewport's contents every frame is definitely too expensive. On desktop machines, it can generally only be done between 5 and 20 times per second depending on the window size.

TwistedTwigleg

Instead of reading the contents of the viewport, what you probably want to do is have a StaticBody2D or a RigidBody2D node for the land and then have a collision shape or collision polygon that encompasses the terrain, and then just use the normal physics callbacks to tell if the player has collided with the land. That would probably be a more performance friendly way to detect collision with the land and then it won’t require reading the Viewport texture.