iPlug2 · olilarkin · May 7, 2024
diff --git a/IGraphics/Controls/IAttributedTextControl.h b/IGraphics/Controls/IAttributedTextControl.h
@@ -0,0 +1,123 @@
+/*
+ ==============================================================================
+
+ This file is part of the iPlug 2 library. Copyright (C) the iPlug 2 developers.
+
+ See LICENSE.txt for  more info.
+
+ ==============================================================================
+*/
+
+#pragma once
+
+/**
+ * @file
+ * @copydoc IAboutBoxControl
+ */
+
+#include "IControl.h"
+
+BEGIN_IPLUG_NAMESPACE
+BEGIN_IGRAPHICS_NAMESPACE
+
+/* An IControl for drawing attributed text to a layer using the native text routines, e.g. CoreGraphics */
+
+class IAttributedTextControl : public IEditableTextControl
+{
+public:
+  IAttributedTextControl(const IRECT& bounds, const char* str, const IText& text = DEFAULT_TEXT)
+  : IEditableTextControl(bounds, str, text)
+  {
+  }
+
+  int DrawAttributedText(IGraphics& g, const char* str, const IRECT& textArea, const IText& text)
+  {
+    auto* vg = static_cast<NVGcontext*>(g.GetDrawContext());
+
+    float w, h;
+    auto imageData = g.DrawAttributedText(str, text, w, h);
+    int imgID = nvgCreateImageRGBA(vg, ceil(w * g.GetTotalScale()), ceil(h * g.GetTotalScale()), 0, imageData.Get());
+
+    float x, y;
+
+    switch (text.mAlign)
+    {
+      case EAlign::Near:
+        x = textArea.L;
+        break;
+      case EAlign::Center:
+        x = textArea.MW() - (w / 2.0);
+        break;
+      case EAlign::Far:
+        x = textArea.R;
+        break;
+    }
+
+    switch (text.mVAlign)
+    {
+      case EVAlign::Top:
+        y = textArea.T;
+        break;
+      case EVAlign::Middle:
+        y = textArea.MH() - (h / 2.0);
+        break;
+      case EVAlign::Bottom:
+        y = textArea.B - h;
+        break;
+    }
+
+    nvgBeginPath(vg);
+    nvgRect(vg, x, y, w, h);
+    NVGpaint imgPaint = nvgImagePattern(vg, x, y, w, h, 0, imgID, 1.f);
+    nvgFillPaint(vg, imgPaint);
+    nvgFill(vg);
+
+    // Clean up
+    // nvgDeleteImage(vg, imgID);
+
+    return imgID;
+  }
+
+  void Draw(IGraphics& g) override
+  {
+    int imgID = -1;
+    if (!g.CheckLayer(mLayer))
+    {
+      g.StartLayer(this, mRECT);
+      imgID = DrawAttributedText(g, mStr.Get(), mRECT.GetPadded(-10.f), mText);
+      mLayer = g.EndLayer();
+    }
+
+    g.DrawLayer(mLayer, &mBlend);
+
+    if (imgID > -1)
+    {
+      auto* vg = static_cast<NVGcontext*>(g.GetDrawContext());
+      nvgDeleteImage(vg, imgID);
+    }
+  }
+
+  void OnRescale() override
+  {
+    if (mLayer)
+      mLayer->Invalidate();
+  }
+
+  void OnResize() override
+  {
+    if (mLayer)
+      mLayer->Invalidate();
+  }
+
+  void SetStr(const char* str) override
+  {
+    ITextControl::SetStr(str);
+    mLayer->Invalidate();
+  }
+private:
+  ILayerPtr mLayer;
+};
+
+
+END_IGRAPHICS_NAMESPACE
+END_IPLUG_NAMESPACE
diff --git a/IGraphics/IGraphics.h b/IGraphics/IGraphics.h
@@ -970,6 +970,14 @@ class IGraphics
   /** Get the app group ID on macOS and iOS, returns emtpy string on other OSs */
   virtual const char* GetAppGroupID() const { return ""; }
 
+  /** Draw text to a bitmap. May be used to render colour emojis etc. using platform text rendering
+   * @param str UTF8 encoded string to render
+   * @param text The IText style for the text
+   * @param width The width of the drawn text in pixels, without any draw or screen scaling applied
+   * @param height The height of the drawn text in pixels, without any draw or screen scaling applied 
+   * @return Bitmap data containing the rendered text */
+  virtual RawBitmapData DrawAttributedText(const char* str, const IText& text, float& width, float& height) { return RawBitmapData(); }
+
 protected:
   /* Activate the context for the view (GL only) */
   virtual void ActivateGLContext() {};

diff --git a/IGraphics/Platforms/IGraphicsIOS.h b/IGraphics/Platforms/IGraphicsIOS.h
@@ -74,6 +74,7 @@ class IGraphicsIOS final : public IGRAPHICS_DRAW_CLASS
 
   EUIAppearance GetUIAppearance() const override;
 
+  RawBitmapData DrawAttributedText(const char* str, const IText& text, float& width, float& height) override;
 protected:
   PlatformFontPtr LoadPlatformFont(const char* fontID, const char* fileNameOrResID) override;
   PlatformFontPtr LoadPlatformFont(const char* fontID, const char* fontName, ETextStyle style) override;

diff --git a/IGraphics/Platforms/IGraphicsIOS.mm b/IGraphics/Platforms/IGraphicsIOS.mm
@@ -367,6 +367,61 @@ float GetScaleForScreen(int plugWidth, int plugHeight)
   }
 }
 
+RawBitmapData IGraphicsIOS::DrawAttributedText(const char* str, const IText& text, float& width, float& height)
+{
+  auto scaleFactor = GetTotalScale();
+  CFStringRef string = CFStringCreateWithCString(NULL, str, kCFStringEncodingUTF8);
+  CFMutableAttributedStringRef attrString = CFAttributedStringCreateMutable(kCFAllocatorDefault, 0);
+  CFAttributedStringReplaceString(attrString, CFRangeMake(0, 0), string);
+  CFRelease(string);
+
+  CFStringRef fontName = CFStringCreateWithCString(NULL, text.mFont, kCFStringEncodingUTF8);
+  CoreTextFontDescriptor* CTFontDescriptor = CoreTextHelpers::GetCTFontDescriptor(text, sFontDescriptorCache);
+  double ratio = CTFontDescriptor->GetEMRatio()/* * GetDrawScale()*/;
+  CTFontRef font = CTFontCreateWithName(fontName, text.mSize * ratio, NULL);
+  CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
+  CGFloat components[] = {text.mFGColor.R / 255.0, text.mFGColor.G / 255.0, text.mFGColor.B / 255.0, text.mFGColor.A / 255.0}; // RGBA
+  CGColorRef color = CGColorCreate(colorSpace, components);
+  CFAttributedStringSetAttribute(attrString, CFRangeMake(0, CFAttributedStringGetLength(attrString)), kCTFontAttributeName, font);
+  CFAttributedStringSetAttribute(attrString, CFRangeMake(0, CFAttributedStringGetLength(attrString)), kCTForegroundColorAttributeName, color);
+  CFRelease(color);
+  CGColorSpaceRelease(colorSpace);
+  CFRelease(font);
+  CFRelease(fontName);
+
+  CTFramesetterRef framesetter = CTFramesetterCreateWithAttributedString(attrString);
+  CGSize textSize = CTFramesetterSuggestFrameSizeWithConstraints(framesetter, CFRangeMake(0, CFAttributedStringGetLength(attrString)), NULL, CGSizeMake(CGFLOAT_MAX, CGFLOAT_MAX), NULL);
+
+  CGMutablePathRef path = CGPathCreateMutable();
+  CGRect bounds = CGRectMake(0, 0, textSize.width, textSize.height); // Create bounds according to the text size
+  CGPathAddRect(path, NULL, bounds);
+
+  CTFrameRef frame = CTFramesetterCreateFrame(framesetter, CFRangeMake(0, CFAttributedStringGetLength(attrString)), path, NULL);
+
+  CFRelease(framesetter);
+  CFRelease(attrString);
+
+  width = textSize.width;
+  height = textSize.height;
+  int bitmapWidth = ceil(width * scaleFactor);
+  int bitmapHeight = ceil(height * scaleFactor);
+
+  RawBitmapData imageData;
+  imageData.Resize(4 * bitmapWidth * bitmapHeight);
+  imageData.SetToZero();
+  CGContextRef bitmapContext = CGBitmapContextCreate(imageData.Get(), bitmapWidth, bitmapHeight, 8, bitmapWidth * 4, CGColorSpaceCreateDeviceRGB(), kCGImageAlphaPremultipliedLast);
+  CGContextScaleCTM(bitmapContext, scaleFactor, scaleFactor);
+  CTFrameDraw(frame, bitmapContext);
+  CGContextFlush(bitmapContext);
+
+  CFRelease(frame);
+  CGPathRelease(path);
+  CGContextRelease(bitmapContext);
+
+  return imageData;
+}
+
+
 #if defined IGRAPHICS_NANOVG
   #include "IGraphicsNanoVG.cpp"
 #elif defined IGRAPHICS_SKIA

diff --git a/IGraphics/Platforms/IGraphicsMac.h b/IGraphics/Platforms/IGraphicsMac.h
@@ -74,6 +74,9 @@ class IGraphicsMac final : public IGRAPHICS_DRAW_CLASS
   float MeasureText(const IText& text, const char* str, IRECT& bounds) const override;
 
   EUIAppearance GetUIAppearance() const override;
+
+  RawBitmapData DrawAttributedText(const char* str, const IText& text, float& width, float& height) override;
+
 protected:
 
   IPopupMenu* CreatePlatformPopupMenu(IPopupMenu& menu, const IRECT bounds, bool& isAsync) override;

diff --git a/IGraphics/Platforms/IGraphicsMac.mm b/IGraphics/Platforms/IGraphicsMac.mm
@@ -725,6 +725,60 @@ static int GetSystemVersion()
   return EUIAppearance::Light;
 }
 
+RawBitmapData IGraphicsMac::DrawAttributedText(const char* str, const IText& text, float& width, float& height)
+{
+  auto scaleFactor = GetTotalScale();
+  CFStringRef string = CFStringCreateWithCString(NULL, str, kCFStringEncodingUTF8);
+  CFMutableAttributedStringRef attrString = CFAttributedStringCreateMutable(kCFAllocatorDefault, 0);
+  CFAttributedStringReplaceString(attrString, CFRangeMake(0, 0), string);
+  CFRelease(string);
+
+  CFStringRef fontName = CFStringCreateWithCString(NULL, text.mFont, kCFStringEncodingUTF8);
+  CoreTextFontDescriptor* CTFontDescriptor = CoreTextHelpers::GetCTFontDescriptor(text, sFontDescriptorCache);
+  double ratio = CTFontDescriptor->GetEMRatio()/* * GetDrawScale()*/;
+  CTFontRef font = CTFontCreateWithName(fontName, text.mSize * ratio, NULL);
+  CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
+  CGFloat components[] = {text.mFGColor.R / 255.0, text.mFGColor.G / 255.0, text.mFGColor.B / 255.0, text.mFGColor.A / 255.0}; // RGBA
+  CGColorRef color = CGColorCreate(colorSpace, components);
+  CFAttributedStringSetAttribute(attrString, CFRangeMake(0, CFAttributedStringGetLength(attrString)), kCTFontAttributeName, font);
+  CFAttributedStringSetAttribute(attrString, CFRangeMake(0, CFAttributedStringGetLength(attrString)), kCTForegroundColorAttributeName, color);
+  CFRelease(color);
+  CGColorSpaceRelease(colorSpace);
+  CFRelease(font);
+  CFRelease(fontName);
+
+  CTFramesetterRef framesetter = CTFramesetterCreateWithAttributedString(attrString);
+  CGSize textSize = CTFramesetterSuggestFrameSizeWithConstraints(framesetter, CFRangeMake(0, CFAttributedStringGetLength(attrString)), NULL, CGSizeMake(CGFLOAT_MAX, CGFLOAT_MAX), NULL);
+
+  CGMutablePathRef path = CGPathCreateMutable();
+  CGRect bounds = CGRectMake(0, 0, textSize.width, textSize.height); // Create bounds according to the text size
+  CGPathAddRect(path, NULL, bounds);
+
+  CTFrameRef frame = CTFramesetterCreateFrame(framesetter, CFRangeMake(0, CFAttributedStringGetLength(attrString)), path, NULL);
+
+  CFRelease(framesetter);
+  CFRelease(attrString);
+
+  width = textSize.width;
+  height = textSize.height;
+  int bitmapWidth = ceil(width * scaleFactor);
+  int bitmapHeight = ceil(height * scaleFactor);
+
+  RawBitmapData imageData;
+  imageData.Resize(4 * bitmapWidth * bitmapHeight);
+  imageData.SetToZero();
+  CGContextRef bitmapContext = CGBitmapContextCreate(imageData.Get(), bitmapWidth, bitmapHeight, 8, bitmapWidth * 4, CGColorSpaceCreateDeviceRGB(), kCGImageAlphaPremultipliedLast);
+  CGContextScaleCTM(bitmapContext, scaleFactor, scaleFactor);
+  CTFrameDraw(frame, bitmapContext);
+  CGContextFlush(bitmapContext);
+
+  CFRelease(frame);
+  CGPathRelease(path);
+  CGContextRelease(bitmapContext);
+
+  return imageData;
+}
+
 void IGraphicsMac::ActivateGLContext()
 {
 #ifdef IGRAPHICS_GL