Win: Add launcher to hide the console window flash

This patch fixes a long-standing complaint from users:
the console window shortly flashing when they start
blender.

This is done by adding a new executable called
blender-launcher.exe which starts blender.exe while
hiding the console.

Any command line parameters given to blender-launcher
will be passed on to blender.exe so it'll be a drop
in replacement.

Starting blender.exe on its own will still function as
a proper console app so no changes required here for
users that use blender for batch processing.

Notable changes:

Registering blender (-R switch) will now register
blender-launcher as the preferred executable.

This patch updates the installer and updates the
shortcuts to start blender-launcher.exe rather
than blender.exe

Differential Revision: https://developer.blender.org/D11094

Reviewed by: brecht, harley

2 files changed, 102 insertions, 1 deletions

diff --git a/source/creator/CMakeLists.txt b/source/creator/CMakeLists.txt
index c2893317924..baea3ad1f9b 100644
--- a/source/creator/CMakeLists.txt
+++ b/source/creator/CMakeLists.txt
@@ -285,6 +285,15 @@ if(WITH_PYTHON_MODULE)
 
 else()
   add_executable(blender ${EXETYPE} ${SRC})
+  if(WIN32)
+      add_executable(blender-launcher WIN32
+        blender-launcher.c
+        ${CMAKE_SOURCE_DIR}/release/windows/icons/winblender.rc
+        ${CMAKE_BINARY_DIR}/blender.exe.manifest
+      )
+      target_compile_definitions (blender-launcher PRIVATE -D_UNICODE -DUNICODE)
+      target_link_libraries(blender-launcher Pathcch.lib)
+  endif()
 endif()
 
 if(WITH_BUILDINFO)
@@ -1212,7 +1221,7 @@ endif()
 
 if(WIN32 AND NOT WITH_PYTHON_MODULE)
   install(
-    TARGETS blender
+    TARGETS blender blender-launcher
     COMPONENT Blender
     DESTINATION "."
   )
diff --git a/source/creator/blender-launcher.c b/source/creator/blender-launcher.c
new file mode 100644
index 00000000000..86b0f4f3b97
--- /dev/null
+++ b/source/creator/blender-launcher.c
@@ -0,0 +1,92 @@
+/*
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ */
+
+#include <Windows.h>
+#include <strsafe.h>
+
+#include <PathCch.h>
+
+int WINAPI wWinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, PWSTR pCmdLine, int nCmdShow)
+{
+  STARTUPINFO siStartInfo = {0};
+  PROCESS_INFORMATION procInfo;
+  wchar_t path[MAX_PATH];
+
+  siStartInfo.wShowWindow = SW_HIDE;
+  siStartInfo.dwFlags = STARTF_USESHOWWINDOW;
+
+  /* Get the path to the currently running executable (blender-launcher.exe) */
+
+  DWORD nSize = GetModuleFileName(NULL, path, MAX_PATH);
+  if (!nSize) {
+    return -1;
+  }
+
+  /* GetModuleFileName returns the number of characters written, but GetLastError needs to be
+   * called to see if it ran out of space or not. However where would we be without exceptions
+   * to the rule: "If the buffer is too small to hold the module name, the function returns nSize.
+   * The last error code remains ERROR_SUCCESS." - source: MSDN. */
+
+  if (GetLastError() == ERROR_SUCCESS && nSize == MAX_PATH) {
+    return -1;
+  }
+
+  /* Remove the filename (blender-launcher.exe) from path. */
+  if (PathCchRemoveFileSpec(path, MAX_PATH) != S_OK) {
+    return -1;
+  }
+
+  /* Add blender.exe to path, resulting in the full path to the blender executable. */
+  if (PathCchCombine(path, MAX_PATH, path, L"blender.exe") != S_OK) {
+    return -1;
+  }
+
+  int required_size_chars = lstrlenW(path) +     /* Module name */
+                            3 +                  /* 2 quotes + Space */
+                            lstrlenW(pCmdLine) + /* Original command line */
+                            1;                   /* Zero terminator */
+  size_t required_size_bytes = required_size_chars * sizeof(wchar_t);
+  wchar_t *buffer = (wchar_t *)malloc(required_size_bytes);
+  if (!buffer) {
+    return -1;
+  }
+
+  if (StringCbPrintfEx(buffer,
+                       required_size_bytes,
+                       NULL,
+                       NULL,
+                       STRSAFE_NULL_ON_FAILURE,
+                       L"\"%s\" %s",
+                       path,
+                       pCmdLine) != S_OK) {
+    free(buffer);
+    return -1;
+  }
+
+  BOOL success = CreateProcess(
+      path, buffer, NULL, NULL, TRUE, CREATE_NEW_CONSOLE, NULL, NULL, &siStartInfo, &procInfo);
+
+  if (success) {
+    /* Handles in PROCESS_INFORMATION must be closed with CloseHandle when they are no longer
+     * needed - MSDN. Closing the handles will NOT terminate the thread/process that we just
+     * started. */
+    CloseHandle(procInfo.hThread);
+    CloseHandle(procInfo.hProcess);
+  }
+
+  free(buffer);
+  return success ? 0 : -1;
+}