Add background/foreground UI color from host, implemented for LV2

distrho/DistrhoUI.hpp

@@ -81,6 +81,18 @@ public:
    /* --------------------------------------------------------------------------------------------------------
     * Host state */
 
+   /**
+      Get the color used for UI background (i.e. window color) in RGBA format.
+      Returns 0 by default, in case of error or lack of host support.
+    */
+    uint getBackgroundColor() const noexcept;
+
+   /**
+      Get the color used for UI foreground (i.e. text color) in RGBA format.
+      Returns 0xffffffff by default, in case of error or lack of host support.
+    */
+    uint getForegroundColor() const noexcept;
+
    /**
       Get the current sample rate used in plugin processing.
       @see sampleRateChanged(double)
@@ -92,7 +104,7 @@ public:
 
       Touch/pressed-down event.
       Lets the host know the user is tweaking a parameter.
-      Required in some hosts to record automation.      
+      Required in some hosts to record automation.
     */
     void editParameter(uint32_t index, bool started);
 

distrho/src/DistrhoPluginJack.cpp

@@ -108,8 +108,9 @@ public:
               nullptr, // send note
               setSizeCallback,
               nullptr, // file request
-              getDesktopScaleFactor(),
-              fPlugin.getInstancePointer()),
+              nullptr, // bundle
+              fPlugin.getInstancePointer(),
+              getDesktopScaleFactor()),
 #endif
           fClient(client)
     {

distrho/src/DistrhoPluginVST.cpp

@@ -178,8 +178,9 @@ public:
               sendNoteCallback,
               setSizeCallback,
               nullptr, // TODO file request
-              scaleFactor,
-              plugin->getInstancePointer()),
+              nullptr,
+              plugin->getInstancePointer(),
+              scaleFactor),
           fShouldCaptureVstKeys(false)
     {
         // FIXME only needed for windows?
@@ -593,8 +594,8 @@ public:
                 d_lastUiSampleRate = fPlugin.getSampleRate();
 
                 UIExporter tmpUI(nullptr, 0,
-                                 nullptr, nullptr, nullptr, nullptr, nullptr, nullptr,
-                                 fLastScaleFactor, fPlugin.getInstancePointer());
+                                 nullptr, nullptr, nullptr, nullptr, nullptr, nullptr, nullptr,
+                                 fPlugin.getInstancePointer(), fLastScaleFactor);
                 fVstRect.right  = tmpUI.getWidth();
                 fVstRect.bottom = tmpUI.getHeight();
                 tmpUI.quit();

distrho/src/DistrhoUI.cpp

@@ -81,6 +81,16 @@ void UI::setGeometryConstraints(uint minWidth, uint minHeight, bool keepAspectRa
 /* ------------------------------------------------------------------------------------------------------------
  * Host state */
 
+uint UI::getBackgroundColor() const noexcept
+{
+    return pData->bgColor;
+}
+
+uint UI::getForegroundColor() const noexcept
+{
+    return pData->fgColor;
+}
+
 double UI::getSampleRate() const noexcept
 {
     return pData->sampleRate;

distrho/src/DistrhoUIInternal.hpp

@@ -71,6 +71,8 @@ struct UI::PrivateData {
     bool resizeInProgress;
     uint minWidth;
     uint minHeight;
+    uint bgColor;
+    uint fgColor;
 
     // Callbacks
     void*           callbacksPtr;
@@ -91,6 +93,8 @@ struct UI::PrivateData {
           resizeInProgress(false),
           minWidth(0),
           minHeight(0),
+          bgColor(0),
+          fgColor(0),
           callbacksPtr(nullptr),
           editParamCallbackFunc(nullptr),
           setParamCallbackFunc(nullptr),
@@ -272,9 +276,11 @@ public:
                const sendNoteFunc sendNoteCall,
                const setSizeFunc setSizeCall,
                const fileRequestFunc fileRequestCall,
-               const float scaleFactor = 1.0f,
+               const char* const bundlePath = nullptr,
                void* const dspPtr = nullptr,
-               const char* const bundlePath = nullptr)
+               const float scaleFactor = 1.0f,
+               const uint32_t bgColor = 0,
+               const uint32_t fgColor = 0xffffffff)
 #if DISTRHO_PLUGIN_HAS_EXTERNAL_UI
         : fUI(createUiWrapper(dspPtr, winId, scaleFactor, bundlePath)),
 #else
@@ -288,6 +294,9 @@ public:
         DISTRHO_SAFE_ASSERT_RETURN(fUI != nullptr,);
         DISTRHO_SAFE_ASSERT_RETURN(fData != nullptr,);
 
+        fData->bgColor = bgColor;
+        fData->fgColor = fgColor;
+
         fData->callbacksPtr            = callbacksPtr;
         fData->editParamCallbackFunc   = editParamCall;
         fData->setParamCallbackFunc    = setParamCall;
@@ -356,6 +365,20 @@ public:
     }
 #endif
 
+    uint getBackgroundColor() const noexcept
+    {
+        DISTRHO_SAFE_ASSERT_RETURN(fData != nullptr, 0);
+
+        return fData->bgColor;
+    }
+
+    uint getForegroundColor() const noexcept
+    {
+        DISTRHO_SAFE_ASSERT_RETURN(fData != nullptr, 0xffffffff);
+
+        return fData->fgColor;
+    }
+
     // -------------------------------------------------------------------
 
     uint32_t getParameterOffset() const noexcept

distrho/src/DistrhoUILV2.cpp

@@ -70,9 +70,11 @@ public:
           const LV2_Feature* const* const features,
           const LV2UI_Controller controller,
           const LV2UI_Write_Function writeFunc,
-          const float scaleFactor,
           LV2UI_Widget* const widget,
-          void* const dspPtr)
+          void* const dspPtr,
+          const float scaleFactor,
+          const uint32_t bgColor,
+          const uint32_t fgColor)
         : fUI(this, winId,
               editParameterCallback,
               setParameterCallback,
@@ -80,7 +82,11 @@ public:
               sendNoteCallback,
               setSizeCallback,
               fileRequestCallback,
-              scaleFactor, dspPtr, bundlePath),
+              bundlePath,
+              dspPtr,
+              scaleFactor,
+              bgColor,
+              fgColor),
           fUridMap(uridMap),
           fUiRequestValue(getLv2Feature<LV2UI_Request_Value>(features, LV2_UI__requestValue)),
           fUiResize(getLv2Feature<LV2UI_Resize>(features, LV2_UI__resize)),
@@ -515,13 +521,18 @@ static LV2UI_Handle lv2ui_instantiate(const LV2UI_Descriptor*,
     }
 #endif
 
+    const intptr_t winId = (intptr_t)parentId;
     float scaleFactor = 1.0f;
-    const intptr_t winId((intptr_t)parentId);
+    uint32_t bgColor = 0;
+    uint32_t fgColor = 0xffffffff;
 
     if (options != nullptr)
     {
+        const LV2_URID uridAtomInt     = uridMap->map(uridMap->handle, LV2_ATOM__Int);
         const LV2_URID uridAtomFloat   = uridMap->map(uridMap->handle, LV2_ATOM__Float);
         const LV2_URID uridSampleRate  = uridMap->map(uridMap->handle, LV2_PARAMETERS__sampleRate);
+        const LV2_URID uridBgColor     = uridMap->map(uridMap->handle, LV2_UI__backgroundColor);
+        const LV2_URID uridFgColor     = uridMap->map(uridMap->handle, LV2_UI__foregroundColor);
         const LV2_URID uridScaleFactor = uridMap->map(uridMap->handle, LV2_UI__scaleFactor);
 
         for (int i=0; options[i].key != 0; ++i)
@@ -540,6 +551,20 @@ static LV2UI_Handle lv2ui_instantiate(const LV2UI_Descriptor*,
                 else
                     d_stderr("Host provides UI scale factor but has wrong value type");
             }
+            else if (options[i].key == uridBgColor)
+            {
+                if (options[i].type == uridAtomInt)
+                    bgColor = (uint32_t)*(const int32_t*)options[i].value;
+                else
+                    d_stderr("Host provides UI background color but has wrong value type");
+            }
+            else if (options[i].key == uridFgColor)
+            {
+                if (options[i].type == uridAtomInt)
+                    fgColor = (uint32_t)*(const int32_t*)options[i].value;
+                else
+                    d_stderr("Host provides UI foreground color but has wrong value type");
+            }
         }
     }
 
@@ -550,7 +575,8 @@ static LV2UI_Handle lv2ui_instantiate(const LV2UI_Descriptor*,
     }
 
     return new UiLv2(bundlePath, winId, options, uridMap, features,
-                     controller, writeFunction, scaleFactor, widget, instance);
+                     controller, writeFunction, widget, instance,
+                     scaleFactor, bgColor, fgColor);
 }
 
 #define uiPtr ((UiLv2*)ui)

examples/Parameters/ExampleUIParameters.cpp

@@ -105,9 +105,32 @@ protected:
         const uint width = getWidth();
         const uint height = getHeight();
         const uint minwh = std::min(width, height);
+        const uint bgColor = getBackgroundColor();
 
         Rectangle<int> r;
 
+        // if host doesn't respect aspect-ratio but supports ui background, draw out-of-bounds color from it
+        if (width != height && bgColor != 0)
+        {
+            const GLubyte red   = (bgColor >> 24) & 0xff;
+            const GLubyte green = (bgColor >> 16) & 0xff;
+            const GLubyte blue  = (bgColor >>  8) & 0xff;
+            glColor3ub(red, green, blue);
+
+            if (width > height)
+            {
+                r.setPos(height, 0);
+                r.setSize(width-height, height);
+            }
+            else
+            {
+                r.setPos(0, width);
+                r.setSize(width, height-width);
+            }
+
+            r.draw();
+        }
+
         r.setWidth(minwh/3 - 6);
         r.setHeight(minwh/3 - 6);