wiiu/render: Implement SetVSync.

GX2SetSwapInterval absolutely *does* cause the CPU to wait for
V-sync: if I set it to 2, then software runs at half speed compared
to 1.

src/render/wiiu/SDL_render_wiiu.c

@@ -28,6 +28,7 @@
 #include "SDL_render_wiiu.h"
 
 #include <gx2/event.h>
+#include <gx2/swap.h>
 #include <gx2/registers.h>
 #include <gx2/state.h>
 #include <gx2r/surface.h>
@@ -71,10 +72,13 @@ SDL_Renderer *WIIU_SDL_CreateRenderer(SDL_Window * window, Uint32 flags)
     renderer->RenderPresent = WIIU_SDL_RenderPresent;
     renderer->DestroyTexture = WIIU_SDL_DestroyTexture;
     renderer->DestroyRenderer = WIIU_SDL_DestroyRenderer;
+    renderer->SetVSync = WIIU_SDL_SetVSync;
     renderer->info = WIIU_RenderDriver.info;
     renderer->driverdata = data;
     renderer->window = window;
 
+    WIIU_SDL_SetVSync(renderer, (flags & SDL_RENDERER_PRESENTVSYNC) != 0);
+
     /* Prepare shaders */
     WIIU_SDL_CreateShaders();
 

src/render/wiiu/SDL_render_wiiu.h

@@ -127,6 +127,7 @@ int WIIU_SDL_QueueGeometry(SDL_Renderer * renderer, SDL_RenderCommand * cmd, SDL
 int WIIU_SDL_RunCommandQueue(SDL_Renderer * renderer, SDL_RenderCommand *cmd, void *vertices, size_t vertsize);
 int WIIU_SDL_RenderReadPixels(SDL_Renderer * renderer, const SDL_Rect * rect,
                           Uint32 format, void * pixels, int pitch);
+int WIIU_SDL_SetVSync(SDL_Renderer * renderer, const int vsync);
 int WIIU_SDL_RenderPresent(SDL_Renderer * renderer);
 void WIIU_SDL_DestroyTexture(SDL_Renderer * renderer, SDL_Texture * texture);
 void WIIU_SDL_DestroyRenderer(SDL_Renderer * renderer);

src/render/wiiu/SDL_rpresent_wiiu.c

@@ -36,6 +36,18 @@
 
 static SDL_bool tvDrcEnabled = SDL_FALSE;
 
+int WIIU_SDL_SetVSync(SDL_Renderer * renderer, const int vsync)
+{
+    GX2SetSwapInterval(vsync ? 1 : 0);
+
+    if (GX2GetSwapInterval() > 0) {
+        renderer->info.flags |= SDL_RENDERER_PRESENTVSYNC;
+    } else {
+        renderer->info.flags &= ~SDL_RENDERER_PRESENTVSYNC;
+    }
+    return 0;
+}
+
 int WIIU_SDL_RenderPresent(SDL_Renderer * renderer)
 {
     WIIU_RenderData *data = (WIIU_RenderData *) renderer->driverdata;