Fix MinGW build and add instruction

CMakeLists.txt

@@ -81,7 +81,7 @@ include(GNUInstallDirs)
 include(CheckIncludeFiles)
 include(rpath)
 include(install_to_extras_subdir)
-if (NOT MSVC)
+if (NOT MSVC AND NOT MINGW)
   include(cotire)
 else()
   macro(cotire _target)
@@ -189,17 +189,30 @@ set(FULL_DATADIR "${CMAKE_INSTALL_FULL_DATADIR}/${PROJECT_NAME}")
 if (NOT GIT_COMMIT)
   find_program(GIT_FOUND git)
   if (GIT_FOUND)
-    execute_process(
-      COMMAND git log --pretty=format:"%h" -1
-      WORKING_DIRECTORY "${CMAKE_SOURCE_DIR}"
-      OUTPUT_VARIABLE GIT_COMMIT
-    )
+    if (NOT MINGW)
+      execute_process(
+        COMMAND git log --pretty=format:"%h" -1
+        WORKING_DIRECTORY "${CMAKE_SOURCE_DIR}"
+        OUTPUT_VARIABLE GIT_COMMIT
+      )
+    endif()
+    if (MINGW)
+      execute_process(
+        COMMAND git log --pretty=format:'%h' -1
+        WORKING_DIRECTORY "${CMAKE_SOURCE_DIR}"
+        OUTPUT_VARIABLE GIT_COMMIT
+      )
+    endif()
     if ("${GIT_COMMIT}" STREQUAL "")
       set(GIT_COMMIT "unknown")
     endif()
   else()
     set(GIT_COMMIT "unknown")
   endif()
+  
+  if (MINGW)
+    set(GIT_COMMIT "\"${GIT_COMMIT}\"")
+  endif()
 endif()
 
 add_definitions(

INSTALL

@@ -9,6 +9,8 @@ official 32/64 bit development snapshots for Windows.
 
 To build from sources please follow instructions below.
 
+
+
 Common building instructions
 ----------------------------
 
@@ -24,6 +26,8 @@ If you have fmtlib and Eigen3 installed from other sources (OS repository or
 vcpg) or don't want to build Celestia with SPICE support then you can skip the
 2nd step.
 
+
+
 Celestia Install instructions for UNIX
 --------------------------------------
 
@@ -85,8 +89,8 @@ following option to cmake: -DCMAKE_INSTALL_PREFIX=/another/path.
 
 
 
-Celestia Install instructions for Windows
------------------------------------------
+Celestia Install instructions for Windows (MSVC)
+------------------------------------------------
 
 Currently to build on Windows you need a Visual Studio 2015 or later, CMake
 and vcpkg (*).
@@ -123,7 +127,6 @@ CMAKE_PREFIX_PATH to cmake call used to configure Celestia, e.g.
 
 Not supported yet:
 - automatic installation using cmake
-- building using GNU toolchain (Mingw32), currently Work-In-Progress
 - using Ninja instead of MSBuild
 
 Notes:
@@ -132,6 +135,41 @@ Notes:
 
 
 
+Celestia Install instructions for Windows (MINGW64), qt-only
+------------------------------------------------------------
+
+It is recommended to build the source with MSYS2
+https://www.msys2.org/ .
+
+Do the following in the MINGW64 shell (mingw64.exe).
+
+Install required packages:
+
+  pacman -S mingw-w64-x86_64-toolchain
+  pacman -S base-devel
+  pacman -S git
+  pacman -S mingw-w64-x86_64-cmake
+  pacman -S mingw-w64-x86_64-qt5
+  pacman -S mingw-w64-x86_64-freeglut mingw-w64-x86_64-glew mingw-w64-x86_64-lua
+  pacman -S mingw-w64-x86_64-libtheora mingw-w64-x86_64-mesa
+
+Install optional packages:
+
+  pacman -S mingw-w64-x86_64-fmt mingw-w64-x86_64-eigen3 mingw-w64-x86_64-luajit
+
+Clone the source and go to the source directory.
+
+Configure and build:
+
+  mkdir build
+  cd build
+  cmake .. -G"MSYS Makefiles" -DENABLE_WIN=OFF
+  mingw32-make.exe -jN
+
+Instead of N, pass a number of CPU cores you want to use during a build.
+
+
+
 Celestia Install instructions for OS X
 --------------------------------------
 

src/celutil/winutil.cpp

@@ -22,15 +22,15 @@ void CenterWindow(HWND hParent, HWND hWnd)
     //Center window with hWnd handle relative to hParent.
     if (hParent && hWnd)
     {
-        RECT or, ir;
-        if (GetWindowRect(hParent, &or))
+        RECT ort, irt;
+        if (GetWindowRect(hParent, &ort))
         {
-            if (GetWindowRect(hWnd, &ir))
+            if (GetWindowRect(hWnd, &irt))
             {
                 int x, y;
 
-                x = or.left + (or.right - or.left - (ir.right - ir.left)) / 2;
-                y = or.top + (or.bottom - or.top - (ir.bottom - ir.top)) / 2;;
+                x = ort.left + (ort.right - ort.left - (irt.right - irt.left)) / 2;
+                y = ort.top + (ort.bottom - ort.top - (irt.bottom - irt.top)) / 2;;
                 SetWindowPos(hWnd, HWND_TOP, x, y, 0, 0, SWP_NOSIZE | SWP_NOZORDER);
             }
         }