Add GLFW_WIN32_DPI_RESIZE

Related to #676. Related to #1115.
glfw · Aug 22, 2018 · cd89176 · cd89176
1 parent 1ad8227
commit cd89176
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Showing 7 changed files with 47 additions and 4 deletions.
diff --git a/docs/window.dox b/docs/window.dox
@@ -479,6 +479,15 @@ ASCII encoded class and instance parts of the ICCCM `WM_CLASS` window property.
 These are set with @ref glfwWindowHintString.
 
 
+@subsubsection window_hints_win32 Win32 specific window hints
+
+@anchor GLFW_WIN32_DPI_RESIZE
+__GLFW_WIN32_DPI_RESIZE__ specifies whether to scale the window content size by
+the content scale of the monitor it is placed on.  This includes scaling it at
+creation.  Possible values are `GLFW_TRUE` and `GLFW_FALSE`.  This is ignored on
+other platforms.
+
+
 @subsubsection window_hints_values Supported and default values
 
 Window hint                   | Default value               | Supported values
@@ -523,6 +532,7 @@ GLFW_COCOA_FRAME_NAME         | `""`                        | A UTF-8 encoded fr
 GLFW_COCOA_GRAPHICS_SWITCHING | `GLFW_FALSE`                | `GLFW_TRUE` or `GLFW_FALSE`
 GLFW_X11_CLASS_NAME           | `""`                        | An ASCII encoded `WM_CLASS` class name
 GLFW_X11_INSTANCE_NAME        | `""`                        | An ASCII encoded `WM_CLASS` instance name
+GLFW_WIN32_DPI_RESIZE         | `GLFW_FALSE`                | `GLFW_TRUE` or `GLFW_FALSE`
 
 
 @section window_events Window event processing

diff --git a/examples/boing.c b/examples/boing.c
@@ -627,6 +627,8 @@ int main( void )
    if( !glfwInit() )
       exit( EXIT_FAILURE );
 
+   glfwWindowHint(GLFW_WIN32_DPI_RESIZE, GLFW_TRUE);
+
    window = glfwCreateWindow( 400, 400, "Boing (classic Amiga demo)", NULL, NULL );
    if (!window)
    {

diff --git a/include/GLFW/glfw3.h b/include/GLFW/glfw3.h
@@ -980,6 +980,8 @@ extern "C" {
 
 #define GLFW_X11_CLASS_NAME         0x00024001
 #define GLFW_X11_INSTANCE_NAME      0x00024002
+
+#define GLFW_WIN32_DPI_RESIZE       0x00025001
 /*! @} */
 
 #define GLFW_NO_API                          0

diff --git a/src/internal.h b/src/internal.h
@@ -276,6 +276,9 @@ struct _GLFWwndconfig
         char      className[256];
         char      instanceName[256];
     } x11;
+    struct {
+        GLFWbool  dpiResize;
+    } win32;
 };
 
 // Context configuration

diff --git a/src/win32_platform.h b/src/win32_platform.h
@@ -306,6 +306,7 @@ typedef struct _GLFWwindowWin32
     GLFWbool            maximized;
     // Whether to enable framebuffer transparency on DWM
     GLFWbool            transparent;
+    GLFWbool            dpiResize;
 
     // The last received cursor position, regardless of source
     int                 lastCursorPosX, lastCursorPosY;

diff --git a/src/win32_window.c b/src/win32_window.c
@@ -1063,6 +1063,9 @@ static LRESULT CALLBACK windowProc(HWND hWnd, UINT uMsg,
 
         case WM_GETDPISCALEDSIZE:
         {
+            if (window->win32.dpiResize)
+                break;
+
             // Adjust the window size to keep the client area size constant
             if (_glfwIsWindows10CreatorsUpdateOrGreaterWin32())
             {
@@ -1230,15 +1233,34 @@ static int createNativeWindow(_GLFWwindow* window,
                                     WM_COPYGLOBALDATA, MSGFLT_ALLOW, NULL);
     }
 
-    // Adjust window size to account for the DPI scaled window frame
+    window->win32.dpiResize = wndconfig->win32.dpiResize;
+
+    // Adjust window size to account for DPI scaling of the window frame and
+    // optionally DPI scaling of the client area
     // This cannot be done until we know what monitor it was placed on
-    if (_glfwIsWindows10AnniversaryUpdateOrGreaterWin32() && !window->monitor)
+    if (!window->monitor)
     {
         RECT rect = { 0, 0, wndconfig->width, wndconfig->height };
+
+        if (wndconfig->win32.dpiResize)
+        {
+            float xscale, yscale;
+            _glfwPlatformGetWindowContentScale(window, &xscale, &yscale);
+            rect.right = (int) (rect.right * xscale);
+            rect.bottom = (int) (rect.bottom * yscale);
+        }
+
         ClientToScreen(window->win32.handle, (POINT*) &rect.left);
         ClientToScreen(window->win32.handle, (POINT*) &rect.right);
-        AdjustWindowRectExForDpi(&rect, style, FALSE, exStyle,
-                                 GetDpiForWindow(window->win32.handle));
+
+        if (_glfwIsWindows10AnniversaryUpdateOrGreaterWin32())
+        {
+            AdjustWindowRectExForDpi(&rect, style, FALSE, exStyle,
+                                     GetDpiForWindow(window->win32.handle));
+        }
+        else
+            AdjustWindowRectEx(&rect, style, FALSE, exStyle);
+
         SetWindowPos(window->win32.handle, NULL,
                      rect.left, rect.top,
                      rect.right - rect.left, rect.bottom - rect.top,

diff --git a/src/window.c b/src/window.c
@@ -369,6 +369,9 @@ GLFWAPI void glfwWindowHint(int hint, int value)
         case GLFW_COCOA_GRAPHICS_SWITCHING:
             _glfw.hints.context.nsgl.offline = value ? GLFW_TRUE : GLFW_FALSE;
             return;
+        case GLFW_WIN32_DPI_RESIZE:
+            _glfw.hints.window.win32.dpiResize = value ? GLFW_TRUE : GLFW_FALSE;
+            return;
         case GLFW_CENTER_CURSOR:
             _glfw.hints.window.centerCursor = value ? GLFW_TRUE : GLFW_FALSE;
             return;