SDL3: SDL_render_gl(render name: opengl) dose not support transparent on Linux/X11:
Create SDL window with SDL_WINDOW_TRANSPARENT flag;
Create "opengl" renderer for the window;
The window can't shown with errors:
X Error of failed request: BadMatch (invalid parameter attributes)
Major opcode of failed request: 130 (MIT-SHM)
Minor opcode of failed request: 3 (X_ShmPutImage)
Bug reason:
SDL_x11window.c:490 : bool X11_CreateWindow(SDL_VideoDevice *_this, SDL_Window *window, SDL_PropertiesID create_props)
SDL_x11window.c:566 : vinfo = X11_GL_GetVisual(_this, display, screen, transparent);[XVisualInfo *vinfo]
the X11_GL_GetVisual function returns a vinfo dose not support transparent.
Fix:
SDL_x11opengl.c:637 : XVisualInfo *X11_GL_GetVisual(SDL_VideoDevice *_this, Display *display, int screen, bool transparent)
X11_GL_GetVisual should returns a vinfo support transparent when transparent is true.
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