Mason Wheeler to sdl I updated SDL, and suddenly my SDL frames stopped working. They'd "initialize" full of gibberish, and I couldn't render anything to them. After a bit of digging, I found a problem: the renderer initialization routine in my SDL frame code wasn't getting called anymore. procedure TSdlFrame.Paint; begin if SDL_SelectRenderer(FWindowID) = -1 then CreateRenderer; SDL_RenderPresent; end; function TSdlFrame.CreateRenderer: boolean; const pf: tagPIXELFORMATDESCRIPTOR = (nSize: sizeof(pf); nVersion: 1; dwFlags: PFD_DRAW_TO_WINDOW or PFD_SUPPORT_OPENGL or PFD_DOUBLEBUFFER; iPixelType: PFD_TYPE_RGBA; cColorBits: 24; cAlphaBits: 8; iLayerType: PFD_MAIN_PLANE); RENDERERS: array[TRendererType] of AnsiString = ('software', 'gdi', 'opengl', 'd3d'); var pFormat: integer; begin if (SDL_SelectRenderer(FWindowID) = 0) then begin result := true; Exit; end; if FRendererType = rtOpenGL then begin pFormat := ChoosePixelFormat(canvas.Handle, @pf); if not SetPixelFormat(canvas.Handle, pFormat, @pf) then outputDebugString(PChar(SysErrorMessage(GetLastError))); if wglCreateContext(canvas.Handle) = 0 then outputDebugString(PChar(SysErrorMessage(GetLastError))); end; if (SDL_CreateRenderer(FWindowID, SDL_RendererIndex(RENDERERS[FRendererType]), [sdlrPresentFlip3, sdlrAccelerated]) = 0) then begin SDL_ShowWindow(FWindowID); assert(SDL_SetRenderDrawColor(0, 0, 0, 255) = 0); FFlags := SDL_GetWindowFlags(FWindowID); if assigned(FOnAvailable) then FOnAvailable(self); end else outputDebugString(pChar(format('SDL_CreateRenderer failed: %s', [sdl_GetError]))); result := SDL_SelectRenderer(FWindowID) = 0; end; This is a critical issue. The Paint method gets called when the control receives a WM_PAINT message from Windows. I can't create the renderer before then, or it will fail and cause trouble. And when I do create it, it needs to be created with certain parameters. So imagine my surprise when I started debugging into the DLL and found that SDL_SelectRenderer was trying to be "helpful" by creating the renderer for me if it didn't already exist! Now not only does my initialization code not get called, I end up with the wrong renderer and so things don't render as expected when I try to use the window.

#include "testnative.h"

#ifdef TEST_NATIVE_X11

static void *CreateWindowX11(int w, int h);
static void DestroyWindowX11(void *window);

NativeWindowFactory X11WindowFactory = {
    "x11",
    CreateWindowX11,
    DestroyWindowX11
};

static Display *dpy;

static void *
CreateWindowX11(int w, int h)
{
    Window window = 0;

    dpy = XOpenDisplay(NULL);
    if (dpy) {
        window =
            XCreateSimpleWindow(dpy, DefaultRootWindow(dpy), 0, 0, w, h, 0, 0,
                                0);
        XMapRaised(dpy, window);
        XSync(dpy, False);
    }
    return (void *) window;
}

static void
DestroyWindowX11(void *window)
{
    if (dpy) {
        XDestroyWindow(dpy, (Window) window);
        XCloseDisplay(dpy);
    }
}

#endif