[Mesa-dev] [RFC 1/7] eglplatform.h: introduce and use EGL_USE_PLATFORM_*_KHR

[Eric Engestrom]

On Thu, Sep 22, 2016 at 09:38:06AM +0100, Emil Velikov wrote:
> From: Emil Velikov <emil.velikov at collabora.com>
> 
> In order to avoid the current, somewhat fragile detection in
> eglplatform.h introduce explicit platform selection.
> 
> The approach is based on the one used in Vulkan and allows one to
> explicitly "request" the platform they will be using without the need of
> local hacks.
> 
> ---
> XXX: Strictly speaking the default/else case would be the None/native
> one, but since we still have the "autodetection" heuristics...
> 
> Admittedly some of the names can be improved, plus there's a limited
> about of Symbian users still in the wild. The latter kept for
> compatibility reasons.
> ---
>  include/EGL/eglplatform.h | 56 +++++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 56 insertions(+)
> 
> diff --git a/include/EGL/eglplatform.h b/include/EGL/eglplatform.h
> index b376e64..923b5f6 100644
> --- a/include/EGL/eglplatform.h
> +++ b/include/EGL/eglplatform.h
> @@ -67,6 +67,62 @@
>   * implementations.
>   */
>  
> +#if defined(EGL_USE_PLATFORM_ANDROID_KHR)
> +#include <android/native_window.h>
> +
> +struct egl_native_pixmap_t;
> +
> +typedef struct ANativeWindow*           EGLNativeWindowType;
> +typedef struct egl_native_pixmap_t*     EGLNativePixmapType;
> +typedef void*                           EGLNativeDisplayType;
> +
> +#elif defined(EGL_USE_PLATFORM_GBM_KHR) // XXX: Name GBM vs DRM vs other
> +
> +typedef struct gbm_device  *EGLNativeDisplayType;
> +typedef struct gbm_bo      *EGLNativePixmapType;
> +typedef void               *EGLNativeWindowType;
> +
> +#elif defined(EGL_USE_PLATFORM_NONE_KHR) // XXX: Name NONE vs Native vs other
> +
> +typedef void            *EGLNativeDisplayType;
> +typedef khronos_uintptr_t EGLNativePixmapType;
> +typedef khronos_uintptr_t EGLNativeWindowType;
> +
> +#elif defined(EGL_USE_PLATFORM_SYMBIAN_KHR)
> +
> +typedef int   EGLNativeDisplayType;
> +typedef void *EGLNativeWindowType;
> +typedef void *EGLNativePixmapType;
> +
> +#elif defined(EGL_USE_PLATFORM_WAYLAND_KHR)
> +
> +typedef struct wl_display     *EGLNativeDisplayType;
> +typedef struct wl_egl_pixmap  *EGLNativePixmapType;
> +typedef struct wl_egl_window  *EGLNativeWindowType;
> +
> +#elif defined(EGL_USE_PLATFORM_WIN32_KHR)
> +
> +#ifndef WIN32_LEAN_AND_MEAN
> +#define WIN32_LEAN_AND_MEAN 1
> +#endif

Isn't that fragile too?  I'm not familiar with Windows and what this
#define does, but presumably if someone where to `#include <windows.h>`
first, the behaviour would change?
If that's the case, maybe we could add an `#else #warning "Don't include
<windows.h> before this file"`?

> +#include <windows.h>
> +
> +typedef HDC     EGLNativeDisplayType;
> +typedef HBITMAP EGLNativePixmapType;
> +typedef HWND    EGLNativeWindowType;
> +
> +#elif defined(EGL_USE_PLATFORM_XLIB_KHR)
> +#include <X11/Xlib.h>
> +#include <X11/Xutil.h>
> +
> +typedef Display *EGLNativeDisplayType;
> +typedef Pixmap   EGLNativePixmapType;
> +typedef Window   EGLNativeWindowType;
> +
> +#else

That `+#else` is missing its matching `+#endif` :)

-------8<-------
@@ -134,6 +190,7 @@ typedef khronos_uintptr_t    EGLNativeWindowType;
 #else
 #error "Platform not recognized"
 #endif
+#endif
 
 /* EGL 1.2 types, renamed for consistency in EGL 1.3 */
 typedef EGLNativeDisplayType NativeDisplayType;
------->8-------

Overall, I think this series is a good idea, although #7 will probably
have to wait for a while...

Cheers,
  Eric

> +
> +/* Fallback to autodetection of the current platform */
> +
>  #if defined(_WIN32) || defined(__VC32__) && !defined(__CYGWIN__) && !defined(__SCITECH_SNAP__) /* Win32 and WinCE */
>  #ifndef WIN32_LEAN_AND_MEAN
>  #define WIN32_LEAN_AND_MEAN 1
> -- 
> 2.9.3