Fixes #2308, recreate window if GL requirements for the renderer are not met

If the window has been created with values for SDL_GL_CONTEXT_PROFILE_MASK,
SDL_GL_CONTEXT_MAJOR_VERSION and SDL_GL_CONTEXT_MINOR_VERSION not matching those
required by the renderer, attempt to recreate the window.
This is needed on platforms where both GL and GLES 1/2 surfaces are supported
by the video backend, requiring that the window be recreated when switching
between context types.

src/render/opengl/SDL_render_gl.c

@@ -32,6 +32,8 @@
 #include <OpenGL/OpenGL.h>
 #endif
 
+#define RENDERER_CONTEXT_MAJOR 2
+#define RENDERER_CONTEXT_MINOR 0
 
 /* OpenGL renderer implementation */
 
@@ -381,11 +383,24 @@ GL_CreateRenderer(SDL_Window * window, Uint32 flags)
     const char *hint;
     GLint value;
     Uint32 window_flags;
+    int profile_mask, major, minor;
+
+    SDL_GL_GetAttribute(SDL_GL_CONTEXT_PROFILE_MASK, &profile_mask);
+    SDL_GL_GetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, &major);
+    SDL_GL_GetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, &minor);
+    
+    SDL_GL_SetAttribute(SDL_GL_CONTEXT_PROFILE_MASK, SDL_GL_CONTEXT_PROFILE_CORE);
+    SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, RENDERER_CONTEXT_MAJOR);
+    SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, RENDERER_CONTEXT_MINOR);
 
     window_flags = SDL_GetWindowFlags(window);
-    if (!(window_flags & SDL_WINDOW_OPENGL)) {
+    if (!(window_flags & SDL_WINDOW_OPENGL) ||
+        profile_mask != SDL_GL_CONTEXT_PROFILE_CORE || major != RENDERER_CONTEXT_MAJOR || minor != RENDERER_CONTEXT_MINOR) {
         if (SDL_RecreateWindow(window, window_flags | SDL_WINDOW_OPENGL) < 0) {
             /* Uh oh, better try to put it back... */
+            SDL_GL_SetAttribute(SDL_GL_CONTEXT_PROFILE_MASK, profile_mask);
+            SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, major);
+            SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, minor);
             SDL_RecreateWindow(window, window_flags);
             return NULL;
         }

src/render/opengles/SDL_render_gles.c

@@ -26,6 +26,9 @@
 #include "SDL_opengles.h"
 #include "../SDL_sysrender.h"
 
+#define RENDERER_CONTEXT_MAJOR 1
+#define RENDERER_CONTEXT_MINOR 1
+
 #if defined(SDL_VIDEO_DRIVER_PANDORA)
 
 /* Empty function stub to get OpenGL ES 1.x support without  */
@@ -279,24 +282,24 @@ GLES_CreateRenderer(SDL_Window * window, Uint32 flags)
     GLES_RenderData *data;
     GLint value;
     Uint32 windowFlags;
-    int profileMask, majorVersion, minorVersion;
+    int profile_mask, major, minor;
 
-    SDL_GL_GetAttribute(SDL_GL_CONTEXT_PROFILE_MASK, &profileMask);
-    SDL_GL_GetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, &majorVersion);
-    SDL_GL_GetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, &minorVersion);
+    SDL_GL_GetAttribute(SDL_GL_CONTEXT_PROFILE_MASK, &profile_mask);
+    SDL_GL_GetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, &major);
+    SDL_GL_GetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, &minor);
 
     SDL_GL_SetAttribute(SDL_GL_CONTEXT_PROFILE_MASK, SDL_GL_CONTEXT_PROFILE_ES);
-    SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 1);
-    SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 1);
+    SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, RENDERER_CONTEXT_MAJOR);
+    SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, RENDERER_CONTEXT_MINOR);
 
     windowFlags = SDL_GetWindowFlags(window);
     if (!(windowFlags & SDL_WINDOW_OPENGL) ||
-        profileMask != SDL_GL_CONTEXT_PROFILE_ES || majorVersion != 1 || minorVersion != 1) {
+        profile_mask != SDL_GL_CONTEXT_PROFILE_ES || major != RENDERER_CONTEXT_MAJOR || minor != RENDERER_CONTEXT_MINOR) {
         if (SDL_RecreateWindow(window, windowFlags | SDL_WINDOW_OPENGL) < 0) {
             /* Uh oh, better try to put it back... */
-            SDL_GL_SetAttribute(SDL_GL_CONTEXT_PROFILE_MASK, profileMask);
-            SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, majorVersion);
-            SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, minorVersion);
+            SDL_GL_SetAttribute(SDL_GL_CONTEXT_PROFILE_MASK, profile_mask);
+            SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, major);
+            SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, minor);
             SDL_RecreateWindow(window, windowFlags);
             return NULL;
         }

src/render/opengles2/SDL_render_gles2.c

@@ -28,6 +28,9 @@
 #include "../../video/SDL_blit.h"
 #include "SDL_shaders_gles2.h"
 
+#define RENDERER_CONTEXT_MAJOR 2
+#define RENDERER_CONTEXT_MINOR 0
+
 /* Used to re-create the window with OpenGL ES capability */
 extern int SDL_RecreateWindow(SDL_Window * window, Uint32 flags);
 
@@ -1740,24 +1743,24 @@ GLES2_CreateRenderer(SDL_Window *window, Uint32 flags)
     Uint32 windowFlags;
     GLint window_framebuffer;
     GLint value;
-    int profileMask, majorVersion, minorVersion;
+    int profile_mask, major, minor;
 
-    SDL_GL_GetAttribute(SDL_GL_CONTEXT_PROFILE_MASK, &profileMask);
-    SDL_GL_GetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, &majorVersion);
-    SDL_GL_GetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, &minorVersion);
+    SDL_GL_GetAttribute(SDL_GL_CONTEXT_PROFILE_MASK, &profile_mask);
+    SDL_GL_GetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, &major);
+    SDL_GL_GetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, &minor);
 
     SDL_GL_SetAttribute(SDL_GL_CONTEXT_PROFILE_MASK, SDL_GL_CONTEXT_PROFILE_ES);
-    SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 2);
-    SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 0);
+    SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, RENDERER_CONTEXT_MAJOR);
+    SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, RENDERER_CONTEXT_MINOR);
 
     windowFlags = SDL_GetWindowFlags(window);
     if (!(windowFlags & SDL_WINDOW_OPENGL) ||
-        profileMask != SDL_GL_CONTEXT_PROFILE_ES || majorVersion != 2 || minorVersion != 0) {
+        profile_mask != SDL_GL_CONTEXT_PROFILE_ES || major != RENDERER_CONTEXT_MAJOR || minor != RENDERER_CONTEXT_MINOR) {
         if (SDL_RecreateWindow(window, windowFlags | SDL_WINDOW_OPENGL) < 0) {
             /* Uh oh, better try to put it back... */
-            SDL_GL_SetAttribute(SDL_GL_CONTEXT_PROFILE_MASK, profileMask);
-            SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, majorVersion);
-            SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, minorVersion);
+            SDL_GL_SetAttribute(SDL_GL_CONTEXT_PROFILE_MASK, profile_mask);
+            SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, major);
+            SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, minor);
             SDL_RecreateWindow(window, windowFlags);
             return NULL;
         }