cmake, main: work toward introducing alternative UI

We're going to base opentrack derivatives on the same branch. Previously
merges were a living hell. Modularizing the UI code and having
continuously-built executables will do a lot.

First opentrack variant in progress is a TrackHat device for mouse and
scrolling control for people with spine and hand/arm disabilities.

1 files changed, 222 insertions, 0 deletions

diff --git a/gui/init.cpp b/gui/init.cpp
new file mode 100644
index 00000000..7ccc67fe
--- /dev/null
+++ b/gui/init.cpp
@@ -0,0 +1,222 @@
+#include "init.hpp"
+
+#if defined(Q_CREATOR_RUN)
+#   pragma clang diagnostic ignored "-Wmain"
+#endif
+
+#include "migration/migration.hpp"
+#include "gui/main-window.hpp"
+#include "options/options.hpp"
+using namespace options;
+#include "opentrack-library-path.h"
+
+#include <memory>
+#include <cstring>
+#include <cstdio>
+#include <cstdlib>
+
+#include <QApplication>
+#include <QStyleFactory>
+#include <QLocale>
+#include <QTranslator>
+#include <QApplication>
+#include <QDir>
+#include <QFile>
+#include <QFileDialog>
+#include <QString>
+#include <QSysInfo>
+
+#include <QDebug>
+
+#if /* denormal control */ \
+    /* GNU */   defined __x86_64__  || defined __SSE2__ || \
+    /* MSVC */  defined _M_AMD64    || (defined _M_IX86_FP && _M_IX86_FP >= 2)
+#   include <xmmintrin.h>
+#   include <pmmintrin.h>
+#   include <cfloat>
+
+#define OTR_HAS_DENORM_CONTROL
+void set_fp_mask()
+{
+    _MM_SET_FLUSH_ZERO_MODE(_MM_FLUSH_ZERO_ON);
+    _MM_SET_DENORMALS_ZERO_MODE(_MM_DENORMALS_ZERO_ON);
+    _MM_SET_ROUNDING_MODE(_MM_ROUND_NEAREST);
+    _MM_SET_EXCEPTION_MASK(_MM_MASK_MASK);
+}
+#endif
+
+void set_qt_style()
+{
+#if defined _WIN32
+    if (QSysInfo::WindowsVersion == QSysInfo::WV_XP)
+        return;
+#endif
+
+#if defined _WIN32 || defined __APPLE__
+    // our layouts on OSX make some control wrongly sized -sh 20160908
+    {
+        const char* preferred[] { "fusion", "windowsvista", "macintosh" };
+        for (const char* style_name : preferred)
+        {
+            QStyle* s = QStyleFactory::create(style_name);
+            if (s)
+            {
+                QApplication::setStyle(s);
+                break;
+            }
+        }
+    }
+#endif
+}
+
+#ifdef _WIN32
+
+void qdebug_to_console(QtMsgType, const QMessageLogContext& ctx, const QString &msg)
+{
+    const unsigned short* const str_ = msg.utf16();
+    auto str = reinterpret_cast<const wchar_t* const>(str_);
+    static_assert(sizeof(*str_) == sizeof(*str), "");
+
+    std::fflush(stderr);
+    if (ctx.function)
+        std::fprintf(stderr, "[%s:%d%s]: %ls\n", ctx.file, ctx.line, ctx.function, str);
+    else if (ctx.file)
+        std::fprintf(stderr, "[%s:%d]: %ls\n", ctx.file, ctx.line, str);
+    else
+        std::fprintf(stderr, "%ls\n", str);
+    std::fflush(stderr);
+}
+
+void attach_parent_console()
+{
+    if (AttachConsole(ATTACH_PARENT_PROCESS))
+    {
+        // XXX c++ iostreams aren't reopened
+
+        _wfreopen(L"CON", L"w", stdout);
+        _wfreopen(L"CON", L"w", stderr);
+        _wfreopen(L"CON", L"r", stdin);
+    }
+    (void)qInstallMessageHandler(qdebug_to_console);
+}
+
+void add_win32_path()
+{
+    // see https://software.intel.com/en-us/articles/limitation-to-the-length-of-the-system-path-variable
+    static char env_path[4096] { '\0', };
+    {
+        QString lib_path = OPENTRACK_BASE_PATH;
+        lib_path.replace("/", "\\");
+        const QByteArray lib_path_ = QFile::encodeName(lib_path);
+
+        QString mod_path = OPENTRACK_BASE_PATH + OPENTRACK_LIBRARY_PATH;
+        mod_path.replace("/", "\\");
+        const QByteArray mod_path_ = QFile::encodeName(mod_path);
+
+        const char* contents[] {
+            "PATH=",
+            lib_path_.constData(),
+            ";",
+            mod_path_.constData(),
+            ";",
+            getenv("PATH"),
+        };
+
+        bool ok = true;
+
+        for (const char* ptr : contents)
+        {
+            if (ptr)
+                strcat_s(env_path, sizeof(env_path), ptr);
+
+            if (!ptr || ptr[0] == '\0' || env_path[0] == '\0')
+            {
+                qDebug() << "bad path element"
+                         << (ptr == nullptr ? "<null>" : ptr);
+                ok = false;
+                break;
+            }
+        }
+
+        if (ok)
+        {
+            const int error = _putenv(env_path);
+
+            if (error)
+                qDebug() << "can't _putenv win32 path";
+        }
+        else
+            qDebug() << "can't set win32 path";
+    }
+}
+
+#endif
+
+int run_window(QApplication& app, std::unique_ptr<QWidget> main_window)
+{
+    if (!main_window->isEnabled())
+    {
+        qDebug() << "exit before window created";
+        return 2;
+    }
+
+    app.setQuitOnLastWindowClosed(false);
+
+    int ret = app.exec();
+    qDebug() << "exit" << ret;
+
+    return ret;
+}
+
+int otr_main(int argc, char** argv, std::function<QWidget*()> make_main_window)
+{
+#ifdef _WIN32
+    attach_parent_console();
+#endif
+
+#if defined OTR_HAS_DENORM_CONTROL
+    set_fp_mask();
+#endif
+
+    QCoreApplication::setAttribute(Qt::AA_EnableHighDpiScaling);
+    QCoreApplication::setAttribute(Qt::AA_X11InitThreads, true);
+
+    QApplication app(argc, argv);
+
+#ifdef _WIN32
+    add_win32_path();
+#endif
+
+    QDir::setCurrent(OPENTRACK_BASE_PATH);
+
+#if 0
+#if !defined(__linux) && !defined _WIN32
+    // workaround QTBUG-38598
+    QCoreApplication::addLibraryPath(".");
+#endif
+#endif
+
+    set_qt_style();
+    QTranslator t;
+
+    // QLocale::setDefault(QLocale("ru_RU")); // force i18n for testing
+
+    if (group::with_global_settings_object([&](QSettings& s) {
+        return !s.value("disable-translation", false).toBool();
+    }))
+    {
+        (void) t.load(QLocale(), "", "", OPENTRACK_BASE_PATH + "/" OPENTRACK_I18N_PATH, ".qm");
+        (void) QCoreApplication::installTranslator(&t);
+    }
+
+    int ret = run_window(app, std::unique_ptr<QWidget>(make_main_window()));
+
+    // msvc crashes in Qt plugin system's dtor
+    // Note: QLibrary::PreventUnloadHint seems to workaround it
+#if defined(_MSC_VER) && 0
+    qDebug() << "exit: terminating";
+    TerminateProcess(GetCurrentProcess(), 0);
+#endif
+
+    return ret;
+}