Allow disabling composition in Win Vista/7Allow disabling composition in Win Vista/7.

config.def.h

@@ -126,6 +126,9 @@ static const unsigned fullscreen_y = 0;
 // Force 16-bit colors.
 static const bool force_16bit = false;
 
+// Forcibly disable composition. Only valid on Windows Vista/7 for now.
+static const bool disable_composition = false;
+
 // Video VSYNC (recommended)
 static const bool vsync = true;
 

general.h

@@ -89,6 +89,7 @@ struct settings
       float msg_pos_y;
 
       bool force_16bit;
+      bool disable_composition;
 
       char external_driver[256];
    } video;

gfx/gfx_common.c

@@ -60,4 +60,39 @@ bool gfx_window_title(char *buf, size_t size)
    return ret;
 }
 
+#ifdef _WIN32
+#include <windows.h>
+#include "dynamic.h"
+void gfx_set_composition(void)
+{
+   if (!g_settings.video.disable_composition)
+      return;
+
+   static bool inited = false;
+   if (inited)
+      return;
+   inited = true;
+
+   dylib_t lib = dylib_load("dwmapi.dll");
+   if (!lib)
+   {
+      SSNES_ERR("Did not find dwmapi.dll");
+      return;
+   }
+
+   HRESULT (WINAPI *composition_enable)(UINT) = (HRESULT (WINAPI*)(UINT))dylib_proc(lib, "DwmEnableComposition");
+   if (!composition_enable)
+   {
+      SSNES_ERR("Did not find DwmEnableComposition ...\n");
+      dylib_close(lib);
+      return;
+   }
+
+   HRESULT ret = composition_enable(0);
+   if (FAILED(ret))
+      SSNES_ERR("Failed to set composition state ...\n");
+
+   dylib_close(lib);
+}
+#endif
 

gfx/gfx_common.h

@@ -24,4 +24,8 @@
 bool gfx_window_title(char *buf, size_t size);
 void gfx_window_title_reset(void);
 
+#ifdef _WIN32
+void gfx_set_composition(void);
+#endif
+
 #endif

gfx/gl.c

@@ -1036,6 +1036,10 @@ static void gl_set_nonblock_state(void *data, bool state)
 
 static void* gl_init(const video_info_t *video, const input_driver_t **input, void **input_data)
 {
+#ifdef _WIN32
+   gfx_set_composition();
+#endif
+
    if (SDL_Init(SDL_INIT_VIDEO) < 0)
       return NULL;
 

settings.c

@@ -118,6 +118,7 @@ static void set_defaults(void)
    g_settings.video.fullscreen_x = fullscreen_x;
    g_settings.video.fullscreen_y = fullscreen_y;
    g_settings.video.force_16bit = force_16bit;
+   g_settings.video.disable_composition = disable_composition;
    g_settings.video.vsync = vsync;
    g_settings.video.smooth = video_smooth;
    g_settings.video.force_aspect = force_aspect;
@@ -299,6 +300,7 @@ static void parse_config_file(void)
    }
 
    CONFIG_GET_BOOL(video.force_16bit, "video_force_16bit");
+   CONFIG_GET_BOOL(video.disable_composition, "video_disable_composition");
    CONFIG_GET_BOOL(video.vsync, "video_vsync");
    CONFIG_GET_BOOL(video.smooth, "video_smooth");
    CONFIG_GET_BOOL(video.force_aspect, "video_force_aspect");

ssnes.cfg

@@ -25,6 +25,9 @@
 # Force 16-bit colors. Apparently some video cards in use today have troubles with 32-bit ...
 # video_force_16bit = false
 
+# Forcibly disable composition. Only works in Windows Vista/7 for now.
+# video_disable_composition = false
+
 # Video vsync.
 # video_vsync = true