Fixed bug 4882 - Fix build for iOS when disabling OpenGL

Aaron Barany

Since OpenGL is deprecated on iOS, it is advantageous to be able to remove all OpenGL related code when building SDL for iOS. This patch adds the necessary #if checks to compile in this case.
diff --git a/src/video/uikit/SDL_uikitevents.m b/src/video/uikit/SDL_uikitevents.m
index 278e2e6..e99be38 100644
--- a/src/video/uikit/SDL_uikitevents.m
+++ b/src/video/uikit/SDL_uikitevents.m
@@ -65,7 +65,9 @@
     } while(result == kCFRunLoopRunHandledSource);
 
     /* See the comment in the function definition. */
+#if SDL_VIDEO_OPENGL_ES || SDL_VIDEO_OPENGL_ES2
     UIKit_GL_RestoreCurrentContext();
+#endif
 }
 
 #endif /* SDL_VIDEO_DRIVER_UIKIT */
diff --git a/src/video/uikit/SDL_uikitopengles.h b/src/video/uikit/SDL_uikitopengles.h
index d08f4ac..d20f447 100644
--- a/src/video/uikit/SDL_uikitopengles.h
+++ b/src/video/uikit/SDL_uikitopengles.h
@@ -21,6 +21,8 @@
 #ifndef SDL_uikitopengles_
 #define SDL_uikitopengles_
 
+#if SDL_VIDEO_OPENGL_ES || SDL_VIDEO_OPENGL_ES2
+
 #include "../SDL_sysvideo.h"
 
 extern int UIKit_GL_MakeCurrent(_THIS, SDL_Window * window,
@@ -35,6 +37,8 @@
 
 extern void UIKit_GL_RestoreCurrentContext(void);
 
+#endif // SDL_VIDEO_OPENGL_ES || SDL_VIDEO_OPENGL_ES2
+
 #endif /* SDL_uikitopengles_ */
 
 /* vi: set ts=4 sw=4 expandtab: */
diff --git a/src/video/uikit/SDL_uikitopengles.m b/src/video/uikit/SDL_uikitopengles.m
index 68d8f1d..aedc142 100644
--- a/src/video/uikit/SDL_uikitopengles.m
+++ b/src/video/uikit/SDL_uikitopengles.m
@@ -20,7 +20,7 @@
 */
 #include "../../SDL_internal.h"
 
-#if SDL_VIDEO_DRIVER_UIKIT
+#if SDL_VIDEO_DRIVER_UIKIT && (SDL_VIDEO_OPENGL_ES || SDL_VIDEO_OPENGL_ES2)
 
 #include "SDL_uikitopengles.h"
 #import "SDL_uikitopenglview.h"
diff --git a/src/video/uikit/SDL_uikitopenglview.h b/src/video/uikit/SDL_uikitopenglview.h
index a2657a3..1848a70 100644
--- a/src/video/uikit/SDL_uikitopenglview.h
+++ b/src/video/uikit/SDL_uikitopenglview.h
@@ -19,6 +19,8 @@
   3. This notice may not be removed or altered from any source distribution.
 */
 
+#if SDL_VIDEO_OPENGL_ES || SDL_VIDEO_OPENGL_ES2
+
 #import <UIKit/UIKit.h>
 #import <OpenGLES/EAGL.h>
 #import <OpenGLES/ES3/gl.h>
@@ -57,4 +59,6 @@
 
 @end
 
+#endif // SDL_VIDEO_OPENGL_ES || SDL_VIDEO_OPENGL_ES2
+
 /* vi: set ts=4 sw=4 expandtab: */
diff --git a/src/video/uikit/SDL_uikitopenglview.m b/src/video/uikit/SDL_uikitopenglview.m
index b3ffbe8..64361b8 100644
--- a/src/video/uikit/SDL_uikitopenglview.m
+++ b/src/video/uikit/SDL_uikitopenglview.m
@@ -20,7 +20,7 @@
 */
 #include "../../SDL_internal.h"
 
-#if SDL_VIDEO_DRIVER_UIKIT
+#if SDL_VIDEO_DRIVER_UIKIT && (SDL_VIDEO_OPENGL_ES || SDL_VIDEO_OPENGL_ES2)
 
 #include <OpenGLES/EAGLDrawable.h>
 #include <OpenGLES/ES2/glext.h>
diff --git a/src/video/uikit/SDL_uikitvideo.m b/src/video/uikit/SDL_uikitvideo.m
index 46d6059..d7b0caf 100644
--- a/src/video/uikit/SDL_uikitvideo.m
+++ b/src/video/uikit/SDL_uikitvideo.m
@@ -116,6 +116,7 @@
         device->HasClipboardText = UIKit_HasClipboardText;
 
         /* OpenGL (ES) functions */
+#if SDL_VIDEO_OPENGL_ES || SDL_VIDEO_OPENGL_ES2
         device->GL_MakeCurrent      = UIKit_GL_MakeCurrent;
         device->GL_GetDrawableSize  = UIKit_GL_GetDrawableSize;
         device->GL_SwapWindow       = UIKit_GL_SwapWindow;
@@ -123,6 +124,7 @@
         device->GL_DeleteContext    = UIKit_GL_DeleteContext;
         device->GL_GetProcAddress   = UIKit_GL_GetProcAddress;
         device->GL_LoadLibrary      = UIKit_GL_LoadLibrary;
+#endif
         device->free = UIKit_DeleteDevice;
 
 #if SDL_VIDEO_VULKAN
diff --git a/src/video/uikit/SDL_uikitviewcontroller.m b/src/video/uikit/SDL_uikitviewcontroller.m
index d45ac06..d568d04 100644
--- a/src/video/uikit/SDL_uikitviewcontroller.m
+++ b/src/video/uikit/SDL_uikitviewcontroller.m
@@ -180,7 +180,9 @@
     /* Don't run the game loop while a messagebox is up */
     if (!UIKit_ShowingMessageBox()) {
         /* See the comment in the function definition. */
+#if SDL_VIDEO_OPENGL_ES || SDL_VIDEO_OPENGL_ES2
         UIKit_GL_RestoreCurrentContext();
+#endif
 
         animationCallback(animationCallbackParam);
     }
diff --git a/src/video/uikit/SDL_uikitwindow.m b/src/video/uikit/SDL_uikitwindow.m
index 4561223..7524305 100644
--- a/src/video/uikit/SDL_uikitwindow.m
+++ b/src/video/uikit/SDL_uikitwindow.m
@@ -364,12 +364,16 @@
 
             /* These struct members were added in SDL 2.0.4. */
             if (versionnum >= SDL_VERSIONNUM(2,0,4)) {
+#if SDL_VIDEO_OPENGL_ES || SDL_VIDEO_OPENGL_ES2
                 if ([data.viewcontroller.view isKindOfClass:[SDL_uikitopenglview class]]) {
                     SDL_uikitopenglview *glview = (SDL_uikitopenglview *)data.viewcontroller.view;
                     info->info.uikit.framebuffer = glview.drawableFramebuffer;
                     info->info.uikit.colorbuffer = glview.drawableRenderbuffer;
                     info->info.uikit.resolveFramebuffer = glview.msaaResolveFramebuffer;
                 } else {
+#else
+                {
+#endif
                     info->info.uikit.framebuffer = 0;
                     info->info.uikit.colorbuffer = 0;
                     info->info.uikit.resolveFramebuffer = 0;