Problems with openfl_TextureCoordv in shader

DaveBMurtagh

Hey everyone,
I'm having a problem with the openfl_TextureCoordv call on a Shader in HaxeFlixel 4.5.1 (OpenFL 8.5.0 and Lime 7.1.1). I know I had this same problem in 4.4.1 also. I'm not sure if it is a bug or if I'm just not understanding something. This happens in HTML5 and CPP targets.

I have a simple shader that I'm trying to get to work:
import flixel.system.FlxAssets.FlxShader;

class TestShader extends FlxShader
{
	@:glFragmentSource('
		#pragma header
			
		void main()
		{
			if (openfl_TextureCoordv.y > 0.5)
				gl_FragColor = vec4(1.0,0.0,0.0,1.0);
			else
				gl_FragColor =vec4(0.0,0.0,1.0,1.0);
		}'
	)
	public function new() 
	{
		super();
	}	
}

Here's my simple PlayState:

import flixel.FlxG;
import flixel.FlxSprite;
import flixel.FlxState;
import openfl.filters.ShaderFilter;

class PlayState extends FlxState
{
	override public function create():Void
	{
		super.create();
		var filter = new ShaderFilter(new TestShader());
		FlxG.game.setFilters([filter]);
	}

	override public function update(elapsed:Float):Void
	{
		super.update(elapsed);
	}
}

I set the window size in the Project.xml to 128 x 128 to get the screenshots.
I would expect the shader to color the bottom of my game screen red (after flipping the Y) and the top half blue. Instead, I get this: Weird, right?

Then I wait about 7 seconds, and it suddenly turns to this all by itself:

Now it is slightly less than half the screen.

If I use the same shader on a sprite it works correctly.

Am I just missing something about how the ShaderFilters work? If this is an actual problem I'm happy to raise an issue on GitHub but I wanted to make sure I'm not just being dense before I did that.

Joleeee

Did you figure it out?