Improve default window size on Skia/Win port (fix #693)

src/app/modules/gui.cpp

@@ -212,8 +212,10 @@ void exit_module_gui()
 static void load_gui_config(int& w, int& h, bool& maximized,
                             std::string& windowLayout)
 {
-  w = get_config_int("GfxMode", "Width", 0);
-  h = get_config_int("GfxMode", "Height", 0);
+  gfx::Size defSize = she::instance()->defaultNewDisplaySize();
+
+  w = get_config_int("GfxMode", "Width", defSize.w);
+  h = get_config_int("GfxMode", "Height", defSize.h);
   maximized = get_config_bool("GfxMode", "Maximized", false);
   windowLayout = get_config_string("GfxMode", "WindowLayout", "");
 }

src/she/alleg4/she.cpp

@@ -163,6 +163,10 @@ public:
     // Do nothing
   }
 
+  gfx::Size defaultNewDisplaySize() override {
+    return gfx::Size(0, 0);
+  }
+
   Display* defaultDisplay() override {
     return unique_display;
   }

src/she/skia/skia_system.h

@@ -67,6 +67,19 @@ public:
     m_gpuAcceleration = state;
   }
 
+  gfx::Size defaultNewDisplaySize() override {
+    gfx::Size sz;
+#ifdef _WIN32
+    sz.w = GetSystemMetrics(SM_CXMAXIMIZED);
+    sz.h = GetSystemMetrics(SM_CYMAXIMIZED);
+    sz.w -= GetSystemMetrics(SM_CXSIZEFRAME)*4;
+    sz.h -= GetSystemMetrics(SM_CYSIZEFRAME)*4;
+    sz.w = MAX(0, sz.w);
+    sz.h = MAX(0, sz.h);
+#endif
+    return sz;
+  }
+
   Display* defaultDisplay() override {
     return m_defaultDisplay;
   }

src/she/system.h

@@ -38,6 +38,7 @@ namespace she {
     virtual EventQueue* eventQueue() = 0;
     virtual bool gpuAcceleration() const = 0;
     virtual void setGpuAcceleration(bool state) = 0;
+    virtual gfx::Size defaultNewDisplaySize() = 0;
     virtual Display* defaultDisplay() = 0;
     virtual Display* createDisplay(int width, int height, int scale) = 0;
     virtual Surface* createSurface(int width, int height) = 0;

src/she/win/window.h

@@ -598,6 +598,19 @@ namespace she {
 
       SetWindowLongPtr(hwnd, GWLP_USERDATA, LONG_PTR(self));
 
+      // Center the window
+      RECT workarea;
+      if (SystemParametersInfo(SPI_GETWORKAREA, 0, (PVOID)&workarea, 0)) {
+        SetWindowPos(hwnd, nullptr,
+                     (workarea.right-workarea.left)/2-width/2,
+                     (workarea.bottom-workarea.top)/2-height/2, 0, 0,
+                     SWP_NOSIZE |
+                     SWP_NOSENDCHANGING |
+                     SWP_NOOWNERZORDER |
+                     SWP_NOZORDER |
+                     SWP_NOREDRAW);
+      }
+
       // Set scroll info to receive WM_HSCROLL/VSCROLL events (events
       // generated by some trackpad drivers).
       SCROLLINFO si;