Always getting GL_FRAMEBUFFER_UNSUPPORTED as soon as I try to add a depth buffer

[escamoteur]

I'm trying to create a Framebuffer that uses RBOs.

The code that works on Windows results on my Mac in GL_FRAMEBUFFER_UNSUPPORTED when I check the framebuffer status.

Here is how I create everything:

        glGenRenderbuffers(1, &_rbo);
        glBindRenderbuffer(GL_RENDERBUFFER, _rbo);

        glRenderbufferStorage(GL_RENDERBUFFER, GL_RGBA8, width, height);

In Dart I use that RBO to connect it to a framebuffer:

    rawOpenGl.glGenFramebuffers(1, fbo);
    rawOpenGl.glBindFramebuffer(GL_FRAMEBUFFER, fbo.value);

    final newTexture = FlutterGLTexture.fromMap(result, fbo.value, width, height);

    print(rawOpenGl.glGetError());
    rawOpenGl.glBindRenderbuffer(GL_RENDERBUFFER, newTexture.rboId);

    rawOpenGl.glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_RENDERBUFFER, newTexture.rboId);
    var frameBufferCheck = rawOpenGl.glCheckFramebufferStatus(GL_FRAMEBUFFER);
    if (frameBufferCheck != GL_FRAMEBUFFER_COMPLETE) {
      print("Framebuffer (color) check failed: ${frameBufferCheck.toRadixString(16)}");
    }

    Pointer<Int32> depthBuffer = calloc();
    rawOpenGl.glGenRenderbuffers(1, depthBuffer.cast());
    rawOpenGl.glBindRenderbuffer(GL_RENDERBUFFER, depthBuffer.value);
    if (Platform.isMacOS || Platform.isIOS) {
      rawOpenGl.glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT16, width, height);
    } else {
      rawOpenGl.glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT16, width, height);
    }

    rawOpenGl.glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, depthBuffer.value);
    frameBufferCheck = rawOpenGl.glCheckFramebufferStatus(GL_FRAMEBUFFER);
    if (frameBufferCheck != GL_FRAMEBUFFER_COMPLETE) {
      print("Framebuffer (depth) check failed: ${frameBufferCheck.toRadixString(16)}");
    }

Attaching the ColorAttachment works, but as soon as I try to attach a depth attachment I get this error.
I tried different values for glRenderbufferStorage but without any success.

Any idea what could be wrong?

Thanks a lot!

[kakashidinho]

One possibility is that your FlutterGLTexture.fromMap(result, fbo.value, width, height) doesn't actually return a texture with size exactly = width, height. Hence, when creating depth buffer with size = width, height and attach to FBO, it throws this error.
Other ANGLE backends might support framebuffer's attachments having different size. However, Metal backend currently doesn't.

[escamoteur]

Awesome, you had the right hunch, it wasn't the fromMap but I had still some constants for width and size in the objetive C part with different dimensions!
Thanks a lot!