hints: replace SDL_HINT_VIDEO_X11_FORCE_EGL with platform-agnostic SDL_HINT_VIDEO_FORCE_EGL

This adds support for forcing the use of EGL on Windows and MacOS. The
SDL_HINT_VIDEO_X11_FORCE_EGL hint is retained for backwards
compatibility but is now deprecated.

include/SDL_hints.h

@@ -1802,6 +1802,18 @@ extern "C" {
 */
 #define SDL_HINT_VIDEO_WIN_D3DCOMPILER              "SDL_VIDEO_WIN_D3DCOMPILER"
 
+/**
+ * \brief A variable controlling whether the OpenGL context should be created
+ * with EGL by default
+ *
+ * This variable can be set to the following values:
+ * "0" - Use platform-specific GL context creation API (GLX, WGL, CGL, etc)
+ * "1" - Use EGL
+ *
+ * By default SDL will use the platform-specific GL context API when both are present.
+ */
+#define SDL_HINT_VIDEO_FORCE_EGL "SDL_VIDEO_FORCE_EGL"
+
 /**
  * \brief A variable controlling whether X11 should use GLX or EGL by default
  *
@@ -1810,6 +1822,9 @@ extern "C" {
  * "1" - Use EGL
  *
  * By default SDL will use GLX when both are present.
+ *
+ * \deprecated Use the platform-agnostic SDL_HINT_VIDEO_FORCE_EGL hint instead.
+ *
  */
 #define SDL_HINT_VIDEO_X11_FORCE_EGL "SDL_VIDEO_X11_FORCE_EGL"
 

src/video/SDL_egl.c

@@ -506,7 +506,7 @@ SDL_EGL_LoadLibrary(_THIS, const char *egl_path, NativeDisplayType native_displa
          * Khronos doc: "EGL_BAD_DISPLAY is generated if display is not an EGL display connection, unless display is EGL_NO_DISPLAY and name is EGL_EXTENSIONS."
          * Therefore SDL_EGL_GetVersion() shouldn't work with uninitialized display.
          * - it actually doesn't work on Android that has 1.5 egl client
-         * - it works on desktop X11 (using SDL_VIDEO_X11_FORCE_EGL=1) */
+         * - it works on desktop X11 (using SDL_VIDEO_FORCE_EGL=1) */
         SDL_EGL_GetVersion(_this);
 
         if (_this->egl_data->egl_version_major == 1 && _this->egl_data->egl_version_minor == 5) {

src/video/cocoa/SDL_cocoavideo.m

@@ -139,16 +139,23 @@ Cocoa_CreateDevice(void)
     device->GL_GetSwapInterval = Cocoa_GL_GetSwapInterval;
     device->GL_SwapWindow = Cocoa_GL_SwapWindow;
     device->GL_DeleteContext = Cocoa_GL_DeleteContext;
-#elif SDL_VIDEO_OPENGL_EGL
-    device->GL_LoadLibrary = Cocoa_GLES_LoadLibrary;
-    device->GL_GetProcAddress = Cocoa_GLES_GetProcAddress;
-    device->GL_UnloadLibrary = Cocoa_GLES_UnloadLibrary;
-    device->GL_CreateContext = Cocoa_GLES_CreateContext;
-    device->GL_MakeCurrent = Cocoa_GLES_MakeCurrent;
-    device->GL_SetSwapInterval = Cocoa_GLES_SetSwapInterval;
-    device->GL_GetSwapInterval = Cocoa_GLES_GetSwapInterval;
-    device->GL_SwapWindow = Cocoa_GLES_SwapWindow;
-    device->GL_DeleteContext = Cocoa_GLES_DeleteContext;
+#endif
+#if SDL_VIDEO_OPENGL_EGL
+#if SDL_VIDEO_OPENGL_CGL
+    if (SDL_GetHintBoolean(SDL_HINT_VIDEO_FORCE_EGL, SDL_FALSE)) {
+#endif
+        device->GL_LoadLibrary = Cocoa_GLES_LoadLibrary;
+        device->GL_GetProcAddress = Cocoa_GLES_GetProcAddress;
+        device->GL_UnloadLibrary = Cocoa_GLES_UnloadLibrary;
+        device->GL_CreateContext = Cocoa_GLES_CreateContext;
+        device->GL_MakeCurrent = Cocoa_GLES_MakeCurrent;
+        device->GL_SetSwapInterval = Cocoa_GLES_SetSwapInterval;
+        device->GL_GetSwapInterval = Cocoa_GLES_GetSwapInterval;
+        device->GL_SwapWindow = Cocoa_GLES_SwapWindow;
+        device->GL_DeleteContext = Cocoa_GLES_DeleteContext;
+#if SDL_VIDEO_OPENGL_CGL
+    }
+#endif
 #endif
 
 #if SDL_VIDEO_VULKAN

src/video/windows/SDL_windowsvideo.c

@@ -226,17 +226,24 @@ WIN_CreateDevice(void)
     device->GL_GetSwapInterval = WIN_GL_GetSwapInterval;
     device->GL_SwapWindow = WIN_GL_SwapWindow;
     device->GL_DeleteContext = WIN_GL_DeleteContext;
-#elif SDL_VIDEO_OPENGL_EGL
-    /* Use EGL based functions */
-    device->GL_LoadLibrary = WIN_GLES_LoadLibrary;
-    device->GL_GetProcAddress = WIN_GLES_GetProcAddress;
-    device->GL_UnloadLibrary = WIN_GLES_UnloadLibrary;
-    device->GL_CreateContext = WIN_GLES_CreateContext;
-    device->GL_MakeCurrent = WIN_GLES_MakeCurrent;
-    device->GL_SetSwapInterval = WIN_GLES_SetSwapInterval;
-    device->GL_GetSwapInterval = WIN_GLES_GetSwapInterval;
-    device->GL_SwapWindow = WIN_GLES_SwapWindow;
-    device->GL_DeleteContext = WIN_GLES_DeleteContext;
+#endif
+#if SDL_VIDEO_OPENGL_EGL
+#if SDL_VIDEO_OPENGL_WGL
+    if (SDL_GetHintBoolean(SDL_HINT_VIDEO_FORCE_EGL, SDL_FALSE)) {
+#endif
+        /* Use EGL based functions */
+        device->GL_LoadLibrary = WIN_GLES_LoadLibrary;
+        device->GL_GetProcAddress = WIN_GLES_GetProcAddress;
+        device->GL_UnloadLibrary = WIN_GLES_UnloadLibrary;
+        device->GL_CreateContext = WIN_GLES_CreateContext;
+        device->GL_MakeCurrent = WIN_GLES_MakeCurrent;
+        device->GL_SetSwapInterval = WIN_GLES_SetSwapInterval;
+        device->GL_GetSwapInterval = WIN_GLES_GetSwapInterval;
+        device->GL_SwapWindow = WIN_GLES_SwapWindow;
+        device->GL_DeleteContext = WIN_GLES_DeleteContext;
+#if SDL_VIDEO_OPENGL_WGL
+    }
+#endif
 #endif
 #if SDL_VIDEO_VULKAN
     device->Vulkan_LoadLibrary = WIN_Vulkan_LoadLibrary;

src/video/x11/SDL_x11opengl.c

@@ -253,6 +253,7 @@ X11_GL_LoadLibrary(_THIS, const char *path)
      * GLX_EXT_create_context_es2_profile extension, switch over to X11_GLES functions  
      */
     if (((_this->gl_config.profile_mask == SDL_GL_CONTEXT_PROFILE_ES) ||
+         SDL_GetHintBoolean(SDL_HINT_VIDEO_FORCE_EGL, SDL_FALSE) ||
          SDL_GetHintBoolean(SDL_HINT_VIDEO_X11_FORCE_EGL, SDL_FALSE)) &&
         X11_GL_UseEGL(_this) ) {
 #if SDL_VIDEO_OPENGL_EGL
@@ -691,7 +692,8 @@ SDL_bool
 X11_GL_UseEGL(_THIS)
 {
     SDL_assert(_this->gl_data != NULL);
-    if (SDL_GetHintBoolean(SDL_HINT_VIDEO_X11_FORCE_EGL, SDL_FALSE))
+    if (SDL_GetHintBoolean(SDL_HINT_VIDEO_FORCE_EGL, SDL_FALSE) ||
+        SDL_GetHintBoolean(SDL_HINT_VIDEO_X11_FORCE_EGL, SDL_FALSE))
     {
         /* use of EGL has been requested, even for desktop GL */
         return SDL_TRUE;

src/video/x11/SDL_x11opengles.c

@@ -36,6 +36,7 @@ X11_GLES_LoadLibrary(_THIS, const char *path)
 
     /* If the profile requested is not GL ES, switch over to X11_GL functions  */
     if ((_this->gl_config.profile_mask != SDL_GL_CONTEXT_PROFILE_ES) &&
+        !SDL_GetHintBoolean(SDL_HINT_VIDEO_FORCE_EGL, SDL_FALSE) &&
         !SDL_GetHintBoolean(SDL_HINT_VIDEO_X11_FORCE_EGL, SDL_FALSE)) {
         #if SDL_VIDEO_OPENGL_GLX
         X11_GLES_UnloadLibrary(_this);

src/video/x11/SDL_x11video.c

@@ -282,7 +282,8 @@ X11_CreateDevice(void)
 #endif
 #if SDL_VIDEO_OPENGL_EGL
 #if SDL_VIDEO_OPENGL_GLX
-    if (SDL_GetHintBoolean(SDL_HINT_VIDEO_X11_FORCE_EGL, SDL_FALSE)) {
+    if (SDL_GetHintBoolean(SDL_HINT_VIDEO_FORCE_EGL, SDL_FALSE) ||
+        SDL_GetHintBoolean(SDL_HINT_VIDEO_X11_FORCE_EGL, SDL_FALSE)) {
 #endif
         device->GL_LoadLibrary = X11_GLES_LoadLibrary;
         device->GL_GetProcAddress = X11_GLES_GetProcAddress;

src/video/x11/SDL_x11window.c

@@ -429,6 +429,7 @@ X11_CreateWindow(_THIS, SDL_Window * window)
 
 #if SDL_VIDEO_OPENGL_EGL
         if (((_this->gl_config.profile_mask == SDL_GL_CONTEXT_PROFILE_ES) ||
+             SDL_GetHintBoolean(SDL_HINT_VIDEO_FORCE_EGL, SDL_FALSE) ||
              SDL_GetHintBoolean(SDL_HINT_VIDEO_X11_FORCE_EGL, SDL_FALSE))
 #if SDL_VIDEO_OPENGL_GLX            
             && ( !_this->gl_data || X11_GL_UseEGL(_this) )