Implement CairoImageKnob rotation

dgl/src/Cairo.cpp

@@ -413,8 +413,26 @@ void CairoImage::loadFromMemory(const char* const rdata, const Size<uint>& s, co
         }
         break;
     case kImageFormatBGRA:
-        // RGB8 to CAIRO_FORMAT_ARGB32
-        // TODO
+        // BGRA8 to CAIRO_FORMAT_ARGB32
+        // FIXME something is wrong here...
+        for (uint h = 0, t; h < height; ++h)
+        {
+            for (uint w = 0; w < width; ++w)
+            {
+                if ((t = rdata[h*width*4+w*4+3]) != 0)
+                {
+                    newdata[h*width*4+w*4+0] = rdata[h*width*4+w*4+0];
+                    newdata[h*width*4+w*4+1] = rdata[h*width*4+w*4+1];
+                    newdata[h*width*4+w*4+2] = rdata[h*width*4+w*4+2];
+                    newdata[h*width*4+w*4+3] = t;
+                }
+                else
+                {
+                    // make all pixels zero, cairo does not render full transparency otherwise
+                    memset(&newdata[h*width*4+w*4], 0, 4);
+                }
+            }
+        }
         break;
     case kImageFormatRGB:
         // RGB8 to CAIRO_FORMAT_RGB24
@@ -564,14 +582,13 @@ template class ImageBaseButton<CairoImage>;
 template <>
 void ImageBaseKnob<CairoImage>::PrivateData::init()
 {
-    // new (&cairoDisplayImage) CairoImage();
+    alwaysRepaint = true;
     cairoSurface = nullptr;
 }
 
 template <>
 void ImageBaseKnob<CairoImage>::PrivateData::cleanup()
 {
-    // cairoDisplayImage.~CairoImage();
     cairo_surface_destroy((cairo_surface_t*)cairoSurface);
     cairoSurface = nullptr;
 }
@@ -644,24 +661,25 @@ void ImageBaseKnob<CairoImage>::onDisplay()
         const uint layerX = pData->isImgVertical ? 0 : layerNum * layerW;
         const uint layerY = !pData->isImgVertical ? 0 : layerNum * layerH;
 
-        cairo_surface_t* const newsurface = getRegion(pData->image.getSurface(), layerX, layerY, layerW, layerH);
-        DISTRHO_SAFE_ASSERT_RETURN(newsurface != nullptr,);
+        cairo_surface_t* newsurface;
 
-        if (pData->rotationAngle != 0)
+        if (pData->rotationAngle == 0)
+        {
+            newsurface = getRegion(pData->image.getSurface(), layerX, layerY, layerW, layerH);
+        }
+        else
         {
-            // TODO
-            /*
-            CairoImage rotated(cairo_image_surface_create(CAIRO_FORMAT_ARGB32, layerW, layerH), false);
-            cairo_t* cr = cairo_create(rotated.getSurface());
+            newsurface = cairo_image_surface_create(CAIRO_FORMAT_ARGB32, layerW, layerH);
+            cairo_t* const cr = cairo_create(newsurface);
             cairo_translate(cr, 0.5 * layerW, 0.5 * layerH);
-            cairo_rotate(cr, normValue * angle * (float)(M_PI / 180));
-            cairo_set_source_surface(cr, displayImage.getSurface(), -0.5f * layerW, -0.5f * layerH);
+            cairo_rotate(cr, normValue * pData->rotationAngle * (float)(M_PI / 180));
+            cairo_set_source_surface(cr, pData->image.getSurface(), -0.5f * layerW, -0.5f * layerH);
             cairo_paint(cr);
             cairo_destroy(cr);
-            pData->cairoDisplayImage = rotated;
-            */
         }
 
+        DISTRHO_SAFE_ASSERT_RETURN(newsurface != nullptr,);
+
         cairo_surface_destroy(surface);
         pData->cairoSurface = surface = newsurface;
         pData->isReady = true;

dgl/src/Common.hpp

@@ -140,6 +140,7 @@ struct ImageBaseKnob<ImageType>::PrivateData {
 
     Callback* callback;
 
+    bool alwaysRepaint;
     bool isImgVertical;
     uint imgLayerWidth;
     uint imgLayerHeight;
@@ -148,7 +149,6 @@ struct ImageBaseKnob<ImageType>::PrivateData {
 
     union {
         uint glTextureId;
-        // ImageType cairoDisplayImage;
         void* cairoSurface;
     };
 

dgl/src/ImageBaseWidgets.cpp

@@ -204,6 +204,7 @@ ImageBaseKnob<ImageType>::PrivateData::PrivateData(const ImageType& img, const O
         lastX(0),
         lastY(0),
         callback(nullptr),
+        alwaysRepaint(false),
         isImgVertical(img.getHeight() > img.getWidth()),
         imgLayerWidth(isImgVertical ? img.getWidth() : img.getHeight()),
         imgLayerHeight(imgLayerWidth),
@@ -230,6 +231,7 @@ ImageBaseKnob<ImageType>::PrivateData::PrivateData(PrivateData* const other)
         lastX(0),
         lastY(0),
         callback(other->callback),
+        alwaysRepaint(other->alwaysRepaint),
         isImgVertical(other->isImgVertical),
         imgLayerWidth(other->imgLayerWidth),
         imgLayerHeight(other->imgLayerHeight),
@@ -258,11 +260,12 @@ void ImageBaseKnob<ImageType>::PrivateData::assignFrom(PrivateData* const other)
     lastX    = 0;
     lastY    = 0;
     callback = other->callback;
+    alwaysRepaint  = other->alwaysRepaint;
     isImgVertical  = other->isImgVertical;
     imgLayerWidth  = other->imgLayerWidth;
     imgLayerHeight = other->imgLayerHeight;
     imgLayerCount  = other->imgLayerCount;
-    isReady  = false;
+    isReady        = false;
     init();
 }
 
@@ -364,7 +367,7 @@ void ImageBaseKnob<ImageType>::setValue(float value, bool sendCallback) noexcept
     if (d_isZero(pData->step))
         pData->valueTmp = value;
 
-    if (pData->rotationAngle == 0)
+    if (pData->rotationAngle == 0 || pData->alwaysRepaint)
         pData->isReady = false;
 
     repaint();
@@ -755,8 +758,8 @@ void ImageBaseSlider<ImageType>::onDisplay()
 {
     const GraphicsContext& context(getGraphicsContext());
 
-#if 1 // DEBUG, paints slider area
-    Color(0.4f, 0.5f, 0.1f).setFor(context);
+#if 0 // DEBUG, paints slider area
+    Color(1.0f, 1.0f, 1.0f, 0.5f).setFor(context, true);
     Rectangle<int>(pData->sliderArea.getX(),
                    pData->sliderArea.getY(),
                    pData->sliderArea.getX()+pData->sliderArea.getWidth(),