globalsettings: Add back a 'Paint engine' setting

- needed again to select Vulkan or OpenGL - the Qt painter is never presented as an option but can be selected via the command line again to try and get an app working (e.g. mythfrontend -O PaintEngine=Qt) when there are OpenGL/Vulkan problems - the setting is not displayed if there is no choice to be made (i.e. vulkan support is not currently compiled in by default - so only OpenGL will be available - so no setting is presented) - the setting name is PaintEngine (the old ThemePainter setting will likely have a value of 'auto' which is no longer supported) and avoids hardcoded a workaround or performing a DB updateButton - the code now builds a list of possible painters to try - with Qt as the last option (unless overriden). This allows for better future expansion.
MythTV · Aug 28, 2020 · ccf15e7 · ccf15e7
1 parent c6af3b7
commit ccf15e7
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Showing 5 changed files with 131 additions and 34 deletions.
diff --git a/mythtv/libs/libmythui/mythpainterwindow.cpp b/mythtv/libs/libmythui/mythpainterwindow.cpp
@@ -15,45 +15,111 @@
 #include "vulkan/mythpaintervulkan.h"
 #endif
 
-QString MythPainterWindow::CreatePainters(MythMainWindow *MainWindow,
+#define MYTH_PAINTER_QT QString("Qt")
+
+using TryPainter = bool(*)(MythMainWindow*, MythPainterWindow*&, MythPainter*&, bool&);
+
+QString MythPainterWindow::GetDefaultPainter()
+{
+#ifdef USING_OPENGL
+    return MYTH_PAINTER_OPENGL;
+#elif USING_VULKAN
+    return MYTH_PAINTER_VULKAN;
+#else
+    return MYTH_PAINTER_QT;
+#endif
+}
+
+const QStringList MythPainterWindow::GetPainters()
+{
+    QStringList result;
+#ifdef USING_OPENGL
+    result.append(MYTH_PAINTER_OPENGL);
+#endif
+#ifdef USING_VULKAN
+    result.append(MYTH_PAINTER_VULKAN);
+#endif
+    return result;
+}
+
+QString MythPainterWindow::CreatePainters(MythMainWindow *MainWin,
                                           MythPainterWindow *&PaintWin,
-                                          MythPainter *&Painter)
+                                          MythPainter *&Paint)
 {
     bool warn = false;
+    QString painter = GetMythDB()->GetSetting("PaintEngine", GetDefaultPainter());
 
-#ifdef USING_VULKAN
-    auto *vulkan = new MythPainterWindowVulkan(MainWindow);
-    if (vulkan && vulkan->IsValid())
+    // build a prioritised list of painters to try
+    QVector<TryPainter> painterstotry;
+
+#ifdef USING_OPENGL
+    auto TryOpenGL = [](MythMainWindow *MainWindow, MythPainterWindow *&PaintWindow,
+                        MythPainter *&Painter, bool&)
     {
-        PaintWin = vulkan;
-        auto *render = dynamic_cast<MythRenderVulkan*>(vulkan->GetRenderDevice());
-        auto *window = dynamic_cast<MythWindowVulkan*>(vulkan->GetVulkanWindow());
-        Painter = new MythPainterVulkan(render, window);
-        return QString();
-    }
-    delete vulkan;
+        auto* glwindow = new MythPainterWindowOpenGL(MainWindow);
+        if (glwindow && glwindow->IsValid())
+        {
+            PaintWindow = glwindow;
+            auto *render = dynamic_cast<MythRenderOpenGL*>(glwindow->GetRenderDevice());
+            Painter = new MythOpenGLPainter(render, MainWindow);
+            return true;
+        }
+        delete glwindow;
+        return false;
+    };
+
+    if (painter.contains(MYTH_PAINTER_OPENGL, Qt::CaseInsensitive))
+        painterstotry.prepend(TryOpenGL);
+    else
+        painterstotry.append(TryOpenGL);
 #endif
 
-    // only OpenGL provides video playback
-#ifdef USING_OPENGL
-    auto* glwindow = new MythPainterWindowOpenGL(MainWindow);
-    if (glwindow && glwindow->IsValid())
+#ifdef USING_VULKAN
+    auto TryVulkan = [](MythMainWindow *MainWindow, MythPainterWindow *&PaintWindow,
+                        MythPainter *&Painter, bool&)
     {
-        PaintWin = glwindow;
-        auto *render = dynamic_cast<MythRenderOpenGL*>(glwindow->GetRenderDevice());
-        Painter = new MythOpenGLPainter(render, MainWindow);
-        return QString();
-    }
-    delete glwindow;
+        auto *vulkan = new MythPainterWindowVulkan(MainWindow);
+        if (vulkan && vulkan->IsValid())
+        {
+            PaintWindow = vulkan;
+            auto *render = dynamic_cast<MythRenderVulkan*>(vulkan->GetRenderDevice());
+            auto *window = dynamic_cast<MythWindowVulkan*>(vulkan->GetVulkanWindow());
+            Painter = new MythPainterVulkan(render, window);
+            return true;
+        }
+        delete vulkan;
+        return false;
+    };
+
+    if (painter.contains(MYTH_PAINTER_VULKAN, Qt::CaseInsensitive))
+        painterstotry.prepend(TryVulkan);
+    else
+        painterstotry.append(TryVulkan);
 #endif
 
     // Fallback to Qt painter as the last resort.
-    LOG(VB_GENERAL, LOG_INFO, "Using the Qt painter. Video playback will not work!");
-    Painter = new MythQtPainter();
-    PaintWin = new MythPainterWindowQt(MainWindow);
-    warn = QCoreApplication::applicationName() == MYTH_APPNAME_MYTHFRONTEND;
+    auto TryQt = [](MythMainWindow *MainWindow, MythPainterWindow *&PaintWindow,
+                    MythPainter *&Painter, bool& Warn)
+    {
+        LOG(VB_GENERAL, LOG_INFO, "Using the Qt painter. Video playback will not work!");
+        Painter = new MythQtPainter();
+        PaintWindow = new MythPainterWindowQt(MainWindow);
+        Warn = QCoreApplication::applicationName() == MYTH_APPNAME_MYTHFRONTEND;
+        return true;
+    };
+
+    // N.B. this won't be selectable as a painter in the UI but can be forced
+    // from the command line again (-O ThemePainter=Qt)
+    if (painter.contains(MYTH_PAINTER_QT, Qt::CaseInsensitive))
+        painterstotry.prepend(TryQt);
+    else
+        painterstotry.append(TryQt);
+
+    for (auto & trypainter : painterstotry)
+        if (trypainter(MainWin, PaintWin, Paint, warn))
+            break;
 
-    return warn ? tr("Warning: OpenGL is not available.") : QString();
+    return warn ? tr("Warning: No GPU acceleration") : QString();
 }
 
 void MythPainterWindow::DestroyPainters(MythPainterWindow *&PaintWin, MythPainter *&Painter)
@@ -69,12 +135,12 @@ MythPainterWindow::MythPainterWindow(MythMainWindow *MainWin)
 {
 }
 
-MythRender* MythPainterWindow::GetRenderDevice(void)
+MythRender* MythPainterWindow::GetRenderDevice()
 {
     return m_render;
 }
 
-bool MythPainterWindow::RenderIsShared(void)
+bool MythPainterWindow::RenderIsShared()
 {
     return m_render && m_render->IsShared();
 }
diff --git a/mythtv/libs/libmythui/mythpainterwindow.h b/mythtv/libs/libmythui/mythpainterwindow.h
@@ -5,6 +5,7 @@
 #include <QWidget>
 
 // MythTV
+#include "mythuiexp.h"
 #include "mythrender_base.h"
 
 class MythMainWindow;
@@ -13,17 +14,19 @@ class MythPainter;
 class MythPainterWindow : public QWidget
 {
   public:
-    static QString CreatePainters(MythMainWindow* MainWindow,
+    static MUI_PUBLIC QString GetDefaultPainter();
+    static MUI_PUBLIC const QStringList GetPainters();
+    static QString CreatePainters(MythMainWindow* MainWin,
                                   MythPainterWindow*& PaintWin,
-                                  MythPainter*& Painter);
+                                  MythPainter*& Paint);
     static void    DestroyPainters(MythPainterWindow*& PaintWin,
                                    MythPainter*& Painter);
 
-    MythRender* GetRenderDevice(void);
-    bool        RenderIsShared (void);
+    MythRender* GetRenderDevice();
+    bool        RenderIsShared ();
 
   protected:
-    explicit MythPainterWindow(MythMainWindow *MainWin);
+    explicit MythPainterWindow(MythMainWindow* MainWin);
    ~MythPainterWindow() override = default;
 
     MythRender* m_render { nullptr };

diff --git a/mythtv/libs/libmythui/opengl/mythpainterwindowopengl.h b/mythtv/libs/libmythui/opengl/mythpainterwindowopengl.h
@@ -7,6 +7,8 @@
 
 class MythMainWindow;
 
+#define MYTH_PAINTER_OPENGL QString("OpenGL")
+
 class MythPainterWindowOpenGL : public MythPainterWindow
 {
     Q_OBJECT

diff --git a/mythtv/libs/libmythui/vulkan/mythpainterwindowvulkan.h b/mythtv/libs/libmythui/vulkan/mythpainterwindowvulkan.h
@@ -7,6 +7,8 @@
 class QVulkanInstance;
 class MythWindowVulkan;
 
+#define MYTH_PAINTER_VULKAN QString("Vulkan")
+
 class MythPainterWindowVulkan : public MythPainterWindow
 {
   public:

diff --git a/mythtv/programs/mythfrontend/globalsettings.cpp b/mythtv/programs/mythfrontend/globalsettings.cpp
@@ -49,6 +49,7 @@
 #include "decoders/mythvaapicontext.h"
 #endif
 #include "mythpower.h"
+#include "mythpainterwindow.h"
 
 //Use for playBackGroup, to be remove at one point
 #include "playgroup.h"
@@ -1468,6 +1469,28 @@ static HostCheckBoxSetting *FFRewReverse()
     return gc;
 }
 
+static void AddPaintEngine(GroupSetting* Group)
+{
+    if (!Group)
+        return;
+
+    const QStringList options = MythPainterWindow::GetPainters();
+
+    // Don't show an option if there is no choice. Do not offer Qt painter (but
+    // MythPainterWindow will accept 'Qt' if overriden from the command line)
+    if (options.size() <= 1)
+        return;
+
+    QString pref = GetMythDB()->GetSetting("PaintEngine", MythPainterWindow::GetDefaultPainter());
+    HostComboBoxSetting* paint = new HostComboBoxSetting("PaintEngine");
+    paint->setLabel(AppearanceSettings::tr("Paint engine"));
+    for (auto & option : options)
+        paint->addSelection(option, option, option == pref);
+
+    paint->setHelpText(AppearanceSettings::tr("This selects what MythTV uses to draw. "));
+    Group->addChild(paint);
+}
+
 static HostComboBoxSetting *MenuTheme()
 {
     auto *gc = new HostComboBoxSetting("MenuTheme");
@@ -4578,6 +4601,7 @@ AppearanceSettings::AppearanceSettings()
     screen->setLabel(tr("Theme / Screen Settings"));
     addChild(screen);
 
+    AddPaintEngine(screen);
     screen->addChild(MenuTheme());
     screen->addChild(GUIRGBLevels());