Driver performance warnings after recent shader unbinding change

The commit 01ea5b1 (#5944) has caused performance warnings to appear, and sometimes spam, when drawing. A minimal reproducible example is shown below which can be fixed by reverting to any previous commit, or unbinding the shader yourself.

These warnings show when using an Nvidia card. I have not yet tested any AMD cards. I am unsure which specific GL state is causing the shader to be recompiled, but it could be various combined.

This also occurs when using SpriteBatch, SpriteCache, and other drawing classes.

[LWJGL] OpenGL debug message
	ID: 0x20092
	Source: API
	Type: PERFORMANCE
	Severity: MEDIUM
	Message: Program/shader state performance warning: Vertex shader in program 3 is being recompiled based on GL state.

Lwjgl3ApplicationConfiguration options = new Lwjgl3ApplicationConfiguration();

options.enableGLDebugOutput(true, System.err);

new Lwjgl3Application(new ApplicationAdapter() {

    private ShapeRenderer shapeRenderer;

    @Override
    public void create() {
        shapeRenderer = new ShapeRenderer();
    }

    @Override
    public void render() {
        Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);

        shapeRenderer.begin(ShapeRenderer.ShapeType.Line);
        shapeRenderer.line(0.0f, 0.0f, 1.0f, 1.0f);
        shapeRenderer.end();
    }

    @Override
    public void dispose() {
        shapeRenderer.dispose();
    }
}, options);

[AndEditor7]

I decided to visit this issue because I got this same message when I recently updated my project to 1.9.11 and LWJGL 3.2.3. Even tho I got a new Geforce GTX 1660 SUPER graphic card with a lastest driver update (451.67 - July 9th, 2020), and the message appears in my console log with enabled GL debug output. But good news, I found what causes it, and fix it. (may not work on every GPU and drivers). How I found it? I traced the log by adding a breakpoint in System.err.println() to found what triggers it. From what I found, it caused from Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);. I added Gdx.gl.glUseProgram(0); before the Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);. And what you know, the debug message is gone! 🦀🦀🦀

[WickedShell]

@mgsx-dev I just reproduced this here: ArchLinux using 5.5.7-arch1-1 kernel Java: 1.8.0_242 GTX 1070 NVIDIA 440.64 drivers

I get it without using the shaperenderer, I just took my existing application and told it to use the 1.9.11-SNAPSHOT. I’d actually suggest you might be getting away with it due to the older driver version you are on. (You also have to actually enable the GLDebug output on LWJGL3 which I hadn’t realized was a thing before now, but this is the only message I’ve seen come out it so far.)