1 /*
   2  * Copyright (c) 2016, 2019, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 #include "systemScale.h"
  26 #include <d2d1.h>
  27 #include <jdk_util.h>
  28 #ifndef MDT_EFFECTIVE_DPI
  29 #define MDT_EFFECTIVE_DPI 0
  30 #endif
  31 
  32 void GetScreenDpi(HMONITOR hmon, float *dpiX, float *dpiY)
  33 {
  34     unsigned x = 0;
  35     unsigned y = 0;
  36 
  37     // for debug purposes
  38     static float scale = -2.0f;
  39     if (scale == -2) {
  40         scale = -1;
  41         char *uiScale = getenv("J2D_UISCALE");
  42         if (uiScale != NULL) {
  43             scale = (float)strtod(uiScale, NULL);
  44             if (errno == ERANGE || scale <= 0) {
  45                 scale = -1;
  46             }
  47         }
  48     }
  49 
  50     if (scale > 0) {
  51         *dpiX = *dpiY = scale;
  52         return;
  53     }
  54 
  55     typedef HRESULT(WINAPI D2D1CreateFactoryFunc)
  56                    (D2D1_FACTORY_TYPE, REFIID,
  57                     CONST D2D1_FACTORY_OPTIONS*, ID2D1Factory**);
  58     typedef HRESULT(WINAPI GetDpiForMonitorFunc)(HMONITOR, int, UINT*, UINT*);
  59     static HMODULE hLibSHCoreDll = NULL;
  60     static GetDpiForMonitorFunc *lpGetDpiForMonitor = NULL;
  61 
  62     if (hLibSHCoreDll == NULL) {
  63         hLibSHCoreDll = JDK_LoadSystemLibrary("shcore.dll");
  64         if (hLibSHCoreDll != NULL) {
  65             lpGetDpiForMonitor = (GetDpiForMonitorFunc*)GetProcAddress(
  66                 hLibSHCoreDll, "GetDpiForMonitor");
  67         }
  68     }
  69 
  70     if (lpGetDpiForMonitor != NULL) {
  71         HRESULT hResult = lpGetDpiForMonitor(hmon,
  72                                              MDT_EFFECTIVE_DPI, &x, &y);
  73         if (hResult == S_OK) {
  74             *dpiX = static_cast<float>(x);
  75             *dpiY = static_cast<float>(y);
  76         }
  77     } else {
  78         static HMODULE d2dDll = NULL;
  79         static BOOL loadAttempted = FALSE;
  80         static D2D1CreateFactoryFunc *lpD2D1CreateFactory = NULL;
  81         if (!loadAttempted && d2dDll == NULL) {
  82             loadAttempted = TRUE;
  83             d2dDll = JDK_LoadSystemLibrary("d2d1.dll");
  84         }
  85         if (d2dDll != NULL && lpD2D1CreateFactory == NULL) {
  86             lpD2D1CreateFactory = (D2D1CreateFactoryFunc*)GetProcAddress(
  87                     d2dDll, "D2D1CreateFactory");
  88         }
  89         if (lpD2D1CreateFactory != NULL) {
  90             ID2D1Factory* m_pDirect2dFactory;
  91             HRESULT res = lpD2D1CreateFactory
  92                           (D2D1_FACTORY_TYPE_SINGLE_THREADED,
  93                            __uuidof(ID2D1Factory), NULL,
  94                            &m_pDirect2dFactory);
  95             if (res == S_OK) {
  96 #pragma warning(push)
  97 #pragma warning(disable : 4996) // GetDesktopDpi is deprecated.
  98                 m_pDirect2dFactory->GetDesktopDpi(dpiX, dpiY);
  99 #pragma warning(pop)
 100                 m_pDirect2dFactory->Release();
 101             }
 102         }
 103     }
 104     return;
 105 }
 106 
 107 HMONITOR WINAPI getPrimaryMonitor()
 108 {
 109     const POINT point = { 0, 0 };
 110     return MonitorFromPoint(point, MONITOR_DEFAULTTOPRIMARY);
 111 }