Preventing terminal windows in Windows

.gitignore

@@ -11,6 +11,7 @@ tools/iop_deps.pdf
 cscope.out
 .*.swp
 .vscode/
+.vs/
 .clangd/
 .cache
 tags
@@ -25,3 +26,5 @@ output*png
 Brewfile.lock.json
 CMakeLists.txt.user
 workspace/
+
+CMakeUserPresets.json

data/luarc

@@ -20,6 +20,29 @@ ipairs = function(t)
   end
 end
 
+
+local dt = require "darktable"
+if dt.configuration.running_os == "windows" then
+  -- Lua on Windows opens a cmd terminal window whenver
+  -- a subprocess is started. We need to use Win32 APIs
+  -- which do not do this, and replace the standard Lua functions.
+
+  -- os.execute = dt.windows.os_execute
+
+  io.close = dt.windows.close
+  io.flush = dt.windows.flush
+  io.input = dt.windows.input
+  io.lines = dt.windows.lines
+  io.open = dt.windows.open
+  io.output = dt.windows.output
+  io.popen = dt.windows.popen
+  io.read = dt.windows.read
+  io.tmpfile = dt.windows.tmpfile
+  io.type = dt.windows.type
+  io.write = dt.windows.write
+  end
+
+
 -- script installer
 
 local _scripts_install = {}

packaging/windows/README.md

@@ -2,17 +2,26 @@ The steps to build darktable Windows executable and make installer (Windows 8.1
 [UCRT installed](https://support.microsoft.com/en-us/topic/update-for-universal-c-runtime-in-windows-c0514201-7fe6-95a3-b0a5-287930f3560c))
 are as follows:
 
-* Install MSYS2 (instructions and prerequisites can be found on the official website: https://www.msys2.org)
+A short summary about the installation environment: The compilation is done by MSYS2 (For more background, see the documentation at https://www.msys2.org). In short, MSYS2 provides a Unix development environmnent (binaries, libraries, compilers etc) on Windows. In contrast to WSL, it does not run in a virtual machine. Instead, the binaries are native Windows binaries. 
 
-* Start the MSYS terminal and update the base system until no further updates are available by repeating:
+We will use the Universal C Runtime (UCRT), which is a newer runtime (in comparison with MSVCRT). See the information about the environments on MSYS at https://www.msys2.org/docs/environments.
+
+Note that there are two terminals. The MSYS terminal is for "normal" system work, and the UCRT64 terminal is for building (this is achived by prepending the MSYS64's `bin` directory to the PATH, thus giving precedence to the UCRT64 toolchain).
+
+
+* Install MSYS2 (instructions and prerequisites can be found on the official website: https://www.msys2.org). For additional convenience, 
+  configure the Windows terminal (https://www.msys2.org/docs/terminals/#windows-terminal) appropriately.
+
+
+* Start the MSYS (not UCRT64) terminal and update the base system until no further updates are available by repeating:
     ```bash
     pacman -Syu
     ```
 
 * From the MSYS terminal, install the toolchain (assuming x64), developer tools and git:
     ```bash
     pacman -S --needed base-devel git intltool po4a
-    pacman -S --needed mingw-w64-ucrt-x86_64-{cc,cmake,gcc-libs,ninja,omp}
+    pacman -S --needed mingw-w64-ucrt-x86_64-{cc,cmake,gcc-libs,ninja,omp} #Install the UCRT64 toolchain
     ```
 
 * Install required and recommended dependencies for darktable:
@@ -93,3 +102,15 @@ If you like experimenting you could also install `mingw-w64-ucrt-x86_64-{clang,l
 Windows on Arm (WoA) users should use the `mingw-w64-clang-aarch64-` prefix when installing packages above and build within the CLANGARM64 environment instead (note that it is not currently possible to build the installer image because of missing `nsis`).
 
 Have fun with this, report back your findings.
+
+
+## Development with Visual Studio Code
+
+After installing and configuring MSYS2 from above, create a `CMakeUserPresets.json` in the root directory of this repository.
+
+
+
+https://cadhut.com/2020/08/02/how-to-set-up-and-use-msys2/
+https://www.msys2.org/docs/environments/
+
+https://dominikberner.ch/cmake-presets-best-practices/#:~:text=The%20command%20to%20configure%20a%20project%20using%20a,CMake%20with%20cmake%20--build%20--preset%20%3Cpreset-name%3E%20--target%20test.

src/CMakeLists.txt

@@ -157,6 +157,9 @@ FILE(GLOB SOURCE_FILES
   "imageio/imageio_tiff.c"
   "libs/lib.c"
   "views/view.c"
+  if(WIN32)
+    "lua/windows.c"
+  endif(WIN32)
   )
 
 FILE(GLOB HEADER_FILES "*.h" "common/*.h" "external/OpenCL/CL/*.h" "control/*.h" "iop/*.h" "libs/*.h" "views/*.h")

src/external/lua/src/lapi.c

@@ -175,7 +175,7 @@ LUA_API int lua_absindex (lua_State *L, int idx) {
 
 LUA_API int lua_gettop (lua_State *L) {
   return cast_int(L->top.p - (L->ci->func.p + 1));
-}
+}°
 
 
 LUA_API void lua_settop (lua_State *L, int idx) {

src/lua/init.c

@@ -45,6 +45,7 @@
 #include "lua/types.h"
 #include "lua/util.h"
 #include "lua/view.h"
+#include "lua/windows.h"
 #include "lua/widget/widget.h"
 
 static int _lua_fully_initialized = false;
@@ -136,14 +137,23 @@ static int run_early_script(lua_State* L)
 }
 
 
+#ifndef WIN32
 static lua_CFunction init_funcs[]
     = { dt_lua_init_glist,         dt_lua_init_image,       dt_lua_init_styles,   dt_lua_init_print,
         dt_lua_init_configuration, dt_lua_init_preferences, dt_lua_init_database, dt_lua_init_gui,
         dt_lua_init_luastorages,   dt_lua_init_tags,        dt_lua_init_film,     dt_lua_init_call,
         dt_lua_init_view,          dt_lua_init_events,      dt_lua_init_init,     dt_lua_init_widget,
         dt_lua_init_lualib,        dt_lua_init_gettext,     dt_lua_init_guides,   dt_lua_init_cairo,
-        dt_lua_init_password,      dt_lua_init_util,        NULL };
-
+        dt_lua_init_password,      NULL };
+#else
+static lua_CFunction init_funcs[]
+    = { dt_lua_init_glist,         dt_lua_init_image,       dt_lua_init_styles,   dt_lua_init_print,
+        dt_lua_init_configuration, dt_lua_init_preferences, dt_lua_init_database, dt_lua_init_gui,
+        dt_lua_init_luastorages,   dt_lua_init_tags,        dt_lua_init_film,     dt_lua_init_call,
+        dt_lua_init_view,          dt_lua_init_events,      dt_lua_init_init,     dt_lua_init_widget,
+        dt_lua_init_lualib,        dt_lua_init_gettext,     dt_lua_init_guides,   dt_lua_init_cairo,
+        dt_lua_init_password,      dt_lua_init_windows,     NULL };
+#endif
 
 void dt_lua_init(lua_State *L, const char *lua_command)
 {