Make it possible to disable rounded corners on Windows 11

Makefile

@@ -272,7 +272,7 @@ endif
 
 ifeq ($(PLATFORM),windows32)
 CFLAGS += -IWindows -Drandom=rand --target=x86_64-pc-windows
-LDFLAGS += -lmsvcrt -lcomdlg32 -luser32 -lshell32 -lole32 -ladvapi32 -lSDL2main -Wl,/MANIFESTFILE:NUL --target=x86_64-pc-windows
+LDFLAGS += -lmsvcrt -lkernel32 -lcomdlg32 -luser32 -lshell32 -lole32 -ladvapi32 -ldwmapi -lSDL2main -Wl,/MANIFESTFILE:NUL --target=x86_64-pc-windows -v
 
 SDL_LDFLAGS := -lSDL2
 GL_LDFLAGS := -lopengl32
@@ -692,7 +692,7 @@ ifeq ($(CONF), release)
 	$(CODESIGN) $@
 endif
 
-$(BIN)/tester/sameboy_tester.exe: $(CORE_OBJECTS) $(SDL_OBJECTS)
+$(BIN)/tester/sameboy_tester.exe: $(CORE_OBJECTS)
 	-@$(MKDIR) -p $(dir $@)
 	$(CC) $^ -o $@ $(LDFLAGS) -Wl,/subsystem:console
 

SDL/configuration.h

@@ -157,6 +157,9 @@ typedef struct {
         
         /* v1.0 */
         bool windows_associations_prompted; // Windows only
+        
+        /* v1.0.1 */
+        bool disable_rounded_corners; // Windows only
     };
 } configuration_t;
 

SDL/gui.c

@@ -13,7 +13,9 @@
 #include "audio/audio.h"
 
 #ifdef _WIN32
+#include <dwmapi.h>
 #include <associations.h>
+#include <SDL_syswm.h>
 #endif
 
 static const SDL_Color gui_palette[4] = {{8, 24, 16,}, {57, 97, 57,}, {132, 165, 99}, {198, 222, 140}};
@@ -1591,6 +1593,50 @@ static const char *current_osd_mode(unsigned index)
     return configuration.osd? "Enabled" : "Disabled";
 }
 
+#ifdef _WIN32
+
+// Don't use the standard header definitions because we might not have the newest headers
+typedef enum {
+    DWM_CORNER_DEFAULT = 0,
+    DWM_CORNER_SQUARE = 1,
+    DWM_CORNER_ROUND = 2,
+    DWM_CORNER_ROUNDSMALL = 3
+} DMW_corner_settings_t;
+
+#define DWM_CORNER_PREFERENCE 33
+
+void configure_window_corners(void)
+{
+    SDL_SysWMinfo wmInfo;
+    SDL_VERSION(&wmInfo.version);
+    SDL_GetWindowWMInfo(window, &wmInfo);
+    HWND hwnd = wmInfo.info.win.window;
+    DMW_corner_settings_t pref = configuration.disable_rounded_corners? DWM_CORNER_SQUARE : DWM_CORNER_DEFAULT;
+    DwmSetWindowAttribute(hwnd, DWM_CORNER_PREFERENCE, &pref, sizeof(pref));
+}
+
+static void toggle_corners(unsigned index)
+{
+    configuration.disable_rounded_corners = !configuration.disable_rounded_corners;
+    configure_window_corners();
+}
+
+static const char *current_corner_mode(unsigned index)
+{
+    SDL_SysWMinfo wmInfo;
+    SDL_VERSION(&wmInfo.version);
+    SDL_GetWindowWMInfo(window, &wmInfo);
+    HWND hwnd = wmInfo.info.win.window;
+    DMW_corner_settings_t pref;
+    
+    if (DwmGetWindowAttribute(hwnd, DWM_CORNER_PREFERENCE, &pref, sizeof(pref)) ||
+        pref == DWM_CORNER_SQUARE) {
+        return "Square";
+    }
+    return "Rounded";
+}
+#endif
+
 static const struct menu_item graphics_menu[] = {
     {"Scaling Mode:", cycle_scaling, current_scaling_mode, cycle_scaling_backwards},
     {"Default Window Scale:", cycle_default_scale, current_default_scale, cycle_default_scale_backwards},
@@ -1601,6 +1647,9 @@ static const struct menu_item graphics_menu[] = {
     {"Mono Palette:", cycle_palette, current_palette, cycle_palette_backwards},
     {"Display Border:", cycle_border_mode, current_border_mode, cycle_border_mode_backwards},
     {"On-Screen Display:", toggle_osd, current_osd_mode, toggle_osd},
+#ifdef _WIN32
+    {"Window Corners:", toggle_corners, current_corner_mode, toggle_corners},
+#endif
     {"Back", enter_options_menu},
     {NULL,}
 };

SDL/gui.h

@@ -67,3 +67,7 @@ extern unsigned osd_text_lines;
 void convert_mouse_coordinates(signed *x, signed *y);
 const GB_palette_t *current_dmg_palette(void);
 void update_swap_interval(void);
+
+#ifdef _WIN32
+void configure_window_corners(void);
+#endif

SDL/main.c

@@ -1221,6 +1221,10 @@ int main(int argc, char **argv)
     if (fullscreen) {
         SDL_SetWindowFullscreen(window, SDL_WINDOW_FULLSCREEN_DESKTOP);
     }
+
+#ifdef _WIN32
+    configure_window_corners();
+#endif
     
     gl_context = nogl? NULL : SDL_GL_CreateContext(window);