Hi
On Tue, Mar 3, 2026 at 5:14 AM <[email protected]> wrote:
>
> From: Dongwon Kim <[email protected]>
>
> When egl_fb_setup_for_tex is called, we must handle cases
> where the texture ID is reused across different GL contexts.
>
> Texture Preservation - If the new texture ID matches
> the cached ID, we must skip egl_fb_delete_texture to avoid
> destroying the texture we are about to use.
>
> FBO Recreation - Because FBOs are context-local and not shared,
> a cached FBO ID from a previous context is invalid. We must
> generate a new FBO handle if we are re-validating the same
> texture ID in a potentially new context.
>
> This prevents stale FBO usage and unintended texture deletion
> during context transitions.
>
> Cc: Gerd Hoffmann <[email protected]>
> Cc: Marc-André Lureau <[email protected]>
> Signed-off-by: Vivek Kasireddy <[email protected]>
> Signed-off-by: Dongwon Kim <[email protected]>
> ---
> ui/egl-helpers.c | 16 ++++++++++++----
> 1 file changed, 12 insertions(+), 4 deletions(-)
>
> diff --git a/ui/egl-helpers.c b/ui/egl-helpers.c
> index e3f2872cc1..7ac64f3ba8 100644
> --- a/ui/egl-helpers.c
> +++ b/ui/egl-helpers.c
> @@ -111,15 +111,23 @@ void egl_fb_setup_default(egl_fb *fb, int width, int
> height, int x, int y)
> void egl_fb_setup_for_tex(egl_fb *fb, int width, int height,
> GLuint texture, bool delete)
> {
> - egl_fb_delete_texture(fb);
> + if (fb->texture != texture) {
> + egl_fb_delete_texture(fb);
> + }
That change makes sense, and prevents reusing a destroyed texture.
> +
> + /*
> + * If fb->texture == texture, the existing fb->framebuffer is tied to
> + * a previous GL context. Since FBOs are not shared across contexts,
> + * we must create a new FBO for the current context.
> + */
> + if (!fb->framebuffer || (fb->texture == texture)) {
> + glGenFramebuffers(1, &fb->framebuffer);
> + }
This, I don't understand. Assuming the framebuffer is used in a
different context, shouldn't it generate a new framebuffer regardless
of the texture?
Also, aren't these leaking framebuffers?
Can you identify cases where egl_fb_setup_for_tex() is reused in a
different context? shouldn't we prevent this instead?
thanks
>
> fb->width = width;
> fb->height = height;
> fb->texture = texture;
> fb->delete_texture = delete;
> - if (!fb->framebuffer) {
> - glGenFramebuffers(1, &fb->framebuffer);
> - }
>
> glBindFramebuffer(GL_FRAMEBUFFER_EXT, fb->framebuffer);
> glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT,
> --
> 2.43.0
>
>
--
Marc-André Lureau
