1 /*

     2 * Copyright (c) 2016, 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.

     8 *

     9 * This code is distributed in the hope that it will be useful, but WITHOUT

    10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

    11 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

    12 * version 2 for more details (a copy is included in the LICENSE file that

    13 * accompanied this code).

    14 *

    15 * You should have received a copy of the GNU General Public License version

    16 * 2 along with this work; if not, write to the Free Software Foundation,

    17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

    18 *

    19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

    20 * or visit www.oracle.com if you need additional information or have any

    21 * questions.

    22 */

    23 #include "systemScale.h"

    24 #include <d2d1.h>

    25 #pragma comment(lib, "d2d1")

    26 #include <jdk_util.h>

    27 #ifndef MDT_EFFECTIVE_DPI

    28 #define MDT_EFFECTIVE_DPI 0

    29 #endif

    30 

    31 void GetScreenDpi(HMONITOR hmon, float *dpiX, float *dpiY)

    32 {

    33     unsigned x = 0;

    34     unsigned y = 0;

    35 

    36     // for debug purposes

    37     static float scale = -2.0f;

    38     if (scale == -2) {

    39         scale = -1;

    40         char *uiScale = getenv("J2D_UISCALE");

    41         if (uiScale != NULL) {

    42             scale = (float)strtod(uiScale, NULL);

    43             if (errno == ERANGE || scale <= 0) {

    44                 scale = -1;

    45             }

    46         }

    47     }

    48 

    49     if (scale > 0) {

    50         *dpiX = *dpiY = scale;

    51         return;

    52     }

    53 

    54     typedef HRESULT(WINAPI GetDpiForMonitorFunc)(HMONITOR, int, UINT*, UINT*);

    55     static HMODULE hLibSHCoreDll = NULL;

    56     static GetDpiForMonitorFunc *lpGetDpiForMonitor = NULL;

    57 

    58     if (hLibSHCoreDll == NULL) {

    59         hLibSHCoreDll = JDK_LoadSystemLibrary("shcore.dll");

    60         if (hLibSHCoreDll != NULL) {

    61             lpGetDpiForMonitor = (GetDpiForMonitorFunc*)GetProcAddress(

    62                 hLibSHCoreDll, "GetDpiForMonitor");

    63         }

    64     }

    65 

    66     if (lpGetDpiForMonitor != NULL) {

    67         HRESULT hResult = lpGetDpiForMonitor(hmon,

    68                                              MDT_EFFECTIVE_DPI, &x, &y);

    69         if (hResult == S_OK) {

    70             *dpiX = static_cast<float>(x);

    71             *dpiY = static_cast<float>(y);

    72         }

    73     } else {

    74         ID2D1Factory* m_pDirect2dFactory;

    75         HRESULT res = D2D1CreateFactory(D2D1_FACTORY_TYPE_SINGLE_THREADED,

    76                                         &m_pDirect2dFactory);

    77         if (res == S_OK) {

    78             m_pDirect2dFactory->GetDesktopDpi(dpiX, dpiY);

    79             m_pDirect2dFactory->Release();

    80         }

    81     }

    82     return;

    83 }

    84 

    85 HMONITOR WINAPI getPrimaryMonitor()

    86 {

    87     const POINT point = { 0, 0 };

    88     return MonitorFromPoint(point, MONITOR_DEFAULTTOPRIMARY);

    89 }