CODEWITHSUNDEEP
openglframebufferglewfbo
ricãO
ricãO

Reputation: 61

Is it possible to copy the default frambuffer to a framebuffer object without showing anything on the screen?

If so, I can save the content of the FBO as an image file.

Other question: This image will have a resolution related with the screen? Or, it will have the same resolution as the input image that was texturized on the default framebuffer?

Was my question clear?

Upvotes: 0

Views: 1474

Answers (1)

dari
dari

Reputation: 2455

Copying between framebuffers: glBlitFramebuffer

see here https://www.opengl.org/sdk/docs/man3/xhtml/glBlitFramebuffer.xml

This image will have a resolution related with the screen?

The resolution can be set in the glBlitFramebuffer function. The default framebuffer has the size of your opengl window (can be different than the screen).

Is it possible to copy the default frambuffer to a framebuffer object without showing anything on the screen?

The image is usually first rendered offscreen and displayed when calling swapBuffers (double buffering). So without calling swapBuffers nothing is shown on the screen.

Keep in mind though, that you can render directly into framebuffers objects and you don't have to first render it into the default framebuffer and then copy it over. To do that just call glBindFramebuffer before your actual draw calls.

Upvotes: 1

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