Allow DPF_SCALE_FACTOR env var for quickly testing scale factors

Signed-off-by: falkTX <falktx@falktx.com>

dgl/TopLevelWidget.hpp

@@ -67,6 +67,7 @@ public:
     Window& getWindow() const noexcept;
 
     // TODO group stuff after here, convenience functions present in Window class
+    double getScaleFactor() const noexcept;
     void repaint() noexcept;
     void repaint(const Rectangle<uint>& rect) noexcept;
     void setGeometryConstraints(uint minimumWidth,

dgl/Window.hpp

@@ -61,7 +61,7 @@ public:
     */
     explicit Window(Application& app,
                     uintptr_t parentWindowHandle,
-                    double scaling,
+                    double scaleFactor,
                     bool resizable);
 
    /**
@@ -72,7 +72,7 @@ public:
                     uintptr_t parentWindowHandle,
                     uint width,
                     uint height,
-                    double scaling,
+                    double scaleFactor,
                     bool resizable);
 
    /**

dgl/src/TopLevelWidget.cpp

@@ -40,6 +40,11 @@ Window& TopLevelWidget::getWindow() const noexcept
     return pData->window;
 }
 
+double TopLevelWidget::getScaleFactor() const noexcept
+{
+    return pData->window.getScaleFactor();
+}
+
 void TopLevelWidget::repaint() noexcept
 {
     pData->window.repaint();

dgl/src/Window.cpp

@@ -31,17 +31,17 @@ Window::Window(Application& app)
 
 Window::Window(Application& app,
                const uintptr_t parentWindowHandle,
-               const double scaling,
+               const double scaleFactor,
                const bool resizable)
-    : pData(new PrivateData(app, this, parentWindowHandle, scaling, resizable)) {}
+    : pData(new PrivateData(app, this, parentWindowHandle, scaleFactor, resizable)) {}
 
 Window::Window(Application& app,
                const uintptr_t parentWindowHandle,
                const uint width,
                const uint height,
-               const double scaling,
+               const double scaleFactor,
                const bool resizable)
-    : pData(new PrivateData(app, this, parentWindowHandle, width, height, scaling, resizable)) {}
+    : pData(new PrivateData(app, this, parentWindowHandle, width, height, scaleFactor, resizable)) {}
 
 Window::~Window()
 {

dgl/src/WindowPrivateData.cpp

@@ -40,6 +40,16 @@ START_NAMESPACE_DGL
 
 // -----------------------------------------------------------------------
 
+static double getDesktopScaleFactor()
+{
+    if (const char* const scale = getenv("DPF_SCALE_FACTOR"))
+        return std::max(1.0, std::atof(scale));
+
+    return 1.0;
+}
+
+// -----------------------------------------------------------------------
+
 Window::PrivateData::PrivateData(Application& a, Window* const s)
     : app(a),
       appData(a.pData),
@@ -49,7 +59,7 @@ Window::PrivateData::PrivateData(Application& a, Window* const s)
       isClosed(true),
       isVisible(false),
       isEmbed(false),
-      scaleFactor(1.0),
+      scaleFactor(getDesktopScaleFactor()),
       autoScaling(false),
       autoScaleFactor(1.0),
       minWidth(0),
@@ -68,7 +78,7 @@ Window::PrivateData::PrivateData(Application& a, Window* const s, Window& transi
       isClosed(true),
       isVisible(false),
       isEmbed(false),
-      scaleFactor(1.0),
+      scaleFactor(getDesktopScaleFactor()),
       autoScaling(false),
       autoScaleFactor(1.0),
       minWidth(0),
@@ -91,7 +101,7 @@ Window::PrivateData::PrivateData(Application& a, Window* const s,
       isClosed(parentWindowHandle == 0),
       isVisible(parentWindowHandle != 0),
       isEmbed(parentWindowHandle != 0),
-      scaleFactor(scale),
+      scaleFactor(scale != 0.0 ? scale : getDesktopScaleFactor()),
       autoScaling(false),
       autoScaleFactor(1.0),
       minWidth(0),
@@ -125,7 +135,7 @@ Window::PrivateData::PrivateData(Application& a, Window* const s,
       isClosed(parentWindowHandle == 0),
       isVisible(parentWindowHandle != 0),
       isEmbed(parentWindowHandle != 0),
-      scaleFactor(scale),
+      scaleFactor(scale != 0.0 ? scale : getDesktopScaleFactor()),
       autoScaling(false),
       autoScaleFactor(1.0),
       minWidth(0),

distrho/src/DistrhoPluginJack.cpp

@@ -82,16 +82,6 @@ static void initSignalHandler()
 
 // -----------------------------------------------------------------------
 
-#if DISTRHO_PLUGIN_HAS_UI
-// TODO
-static double getDesktopScaleFactor() noexcept
-{
-    return 1.0;
-}
-#endif
-
-// -----------------------------------------------------------------------
-
 #if DISTRHO_PLUGIN_HAS_UI
 class PluginJack : public IdleCallback
 #else
@@ -111,7 +101,7 @@ public:
               nullptr, // file request
               nullptr, // bundle
               fPlugin.getInstancePointer(),
-              getDesktopScaleFactor()),
+              0.0),
 #endif
           fClient(client)
     {

distrho/src/DistrhoUIInternal.hpp

@@ -137,7 +137,7 @@ public:
                const fileRequestFunc fileRequestCall,
                const char* const bundlePath = nullptr,
                void* const dspPtr = nullptr,
-               const float scaleFactor = 1.0f,
+               const double scaleFactor = 1.0,
                const uint32_t bgColor = 0,
                const uint32_t fgColor = 0xffffffff)
 #if DISTRHO_PLUGIN_HAS_EXTERNAL_UI