CODEWITHSUNDEEP
opengl
James Nguyen
James Nguyen

Reputation: 1171

OpenGL Framebuffer not complete on Nvidia when using Cube Map Textures

Edit: I narrowed down the cause and simplified the problem

I noticed, when playing around with OpenGL layered rendering, that Nvidia drivers/GPUs have trouble with framebuffers that have cube map textures bound to them. Intel IGPUs has no problem with this but when I switch over to my dedicated GPU, I get an error

The code below recreates the error:

GLuint environment = 0; glCreateTextures(GL_TEXTURE_CUBE_MAP, 1, &environment);

constexpr GLsizei resolution = 512;
glTextureStorage2D(environment, 1, GL_RGB32F, resolution, resolution);
glTextureParameteri(environment, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTextureParameteri(environment, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
glTextureParameteri(environment, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
glTextureParameteri(environment, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
glTextureParameteri(environment, GL_TEXTURE_WRAP_R, GL_CLAMP_TO_EDGE);
glTextureParameteri(environment, GL_TEXTURE_BASE_LEVEL, 0);
glTextureParameteri(environment, GL_TEXTURE_MAX_LEVEL, 0);

GLuint capture_fbo = 0; glCreateFramebuffers(1, &capture_fbo);
GLuint capture_rbo = 0; glCreateRenderbuffers(1, &capture_rbo);
glNamedRenderbufferStorage(capture_rbo, GL_DEPTH_COMPONENT32F, resolution, resolution);

glNamedFramebufferTexture(capture_fbo, GL_COLOR_ATTACHMENT0, environment, 0);
glNamedFramebufferRenderbuffer(capture_fbo, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, capture_rbo);

if (glCheckNamedFramebufferStatus(capture_fbo, GL_DRAW_FRAMEBUFFER) == GL_FRAMEBUFFER_COMPLETE)
{
    fmt::print("Framebuffer Complete!\n");

    glBindFramebuffer(GL_DRAW_FRAMEBUFFER, capture_fbo);
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
}
else fmt::print("Framebuffer Not Complete!\n");

When I query the framebuffer after trying to run the code above, it says it isn't complete until I unbind/rebind the framebuffer. After which it says it's complete again, even though nothing has changed.

The console output on Nvidia:

Manufacturer: NVIDIA Corporation
GPU: GeForce GTX 1060 with Max-Q Design/PCIe/SSE2
OpenGL Version: 4.5.0 NVIDIA 416.34
GLSL Version: 4.50 NVIDIA
Framebuffer Complete!
OpenGL [API Error 1286] (High): GL_INVALID_FRAMEBUFFER_OPERATION error generated. Operation is not valid because a bound framebuffer is not framebuffer complete.

Console output on Intel:

Manufacturer: Intel
GPU: Intel(R) UHD Graphics 630
OpenGL Version: 4.5.0 - Build 23.20.16.4973
GLSL Version: 4.50 - Build 23.20.16.4973
Framebuffer Complete!

Am I encountering a bug? Since it works on one vendor but not another, is there some special specification for Nvidia framebuffers?

Upvotes: 1

Views: 1153

Answers (1)

Nicol Bolas
Nicol Bolas

Reputation: 474126

Cubemap textures effectively have 6 layers. So calling glNamedFramebufferTexture will attach the cubemap as a layered image. And for framebuffers to be complete, either all attached images are layered, or none of them are. Renderbuffer images are never layered, so you have a framebuffer which should not be complete.

So while glCheckNamedFramebufferStatus should not have returned "complete", NVIDIA is closer to being correct than Intel (not a surprise).

Upvotes: 2

Related Questions