vo_opengl: read framebuffer depth from actual FBO used for rendering

In some cases, such as when using the libmpv opengl-cb API, or with
certain vo_opengl backends, the main framebuffer is never accessed.
Instead, rendering is done to a FBO that acts as back buffer. This meant
an incorrect/broken bit depth could be used for dithering.

Change it to read the framebuffer depth lazily on the first render call.

Also move the main FBO field out of the GL struct to MPGLContext,
because the renderer's init function does not need to access it anymore.

1 files changed, 0 insertions, 1 deletions

diff --git a/video/out/opengl/common.h b/video/out/opengl/common.h
index afb5b61f7e..e9bda4918b 100644
--- a/video/out/opengl/common.h
+++ b/video/out/opengl/common.h
@@ -94,7 +94,6 @@ struct GL {
     char *extensions;           // Equivalent to GL_EXTENSIONS
     int mpgl_caps;              // Bitfield of MPGL_CAP_* constants
     bool debug_context;         // use of e.g. GLX_CONTEXT_DEBUG_BIT_ARB
-    GLuint main_fb;             // framebuffer to render to (normally 0)
 
     void (GLAPIENTRY *Viewport)(GLint, GLint, GLsizei, GLsizei);
     void (GLAPIENTRY *Clear)(GLbitfield);