Fix "paint brush" mode for custom brushes (fix #1587)

src/app/tools/ink.h

@@ -91,11 +91,13 @@ namespace app {
       // to a shape (e.g. pen shape)  with various scanlines.
       virtual void inkHline(int x1, int y, int x2, ToolLoop* loop) = 0;
 
-      // Returns true in case that the ink needs to update something
-      // depending on the specific stroke points (e.g. for color
-      // gradients)
-      virtual bool dependsOnStroke() const { return false; }
-      virtual void updateInk(ToolLoop* loop, Strokes& strokes) { }
+      // Called when we have to start using the ink for a new set of
+      // strokes (e.g. color gradients is adjusted depending on the
+      // first/last stroke points).
+      virtual void prepareForStrokes(ToolLoop* loop, Strokes& strokes) { }
+
+      // Called for each point shape.
+      virtual void prepareForPointShape(ToolLoop* loop, int x, int y) { }
 
     };
 

src/app/tools/ink_processing.h

@@ -34,14 +34,15 @@ namespace {
 class BaseInkProcessing {
 public:
   virtual ~BaseInkProcessing() { }
-  virtual void hline(int x1, int y, int x2, ToolLoop* loop) = 0;
-  virtual void updateInk(ToolLoop* loop, Strokes& strokes) { }
+  virtual void processScanline(int x1, int y, int x2, ToolLoop* loop) = 0;
+  virtual void prepareForStrokes(ToolLoop* loop, Strokes& strokes) { }
+  virtual void prepareForPointShape(ToolLoop* loop, int x, int y) { }
 };
 
 template<typename Derived>
 class InkProcessing : public BaseInkProcessing {
 public:
-  void hline(int x1, int y, int x2, ToolLoop* loop) override {
+  void processScanline(int x1, int y, int x2, ToolLoop* loop) override {
     int x;
 
     // Use mask
@@ -926,12 +927,12 @@ public:
   {
   }
 
-  void hline(int x1, int y, int x2, ToolLoop* loop) override {
+  void processScanline(int x1, int y, int x2, ToolLoop* loop) override {
     m_tmpAddress = (RgbTraits::address_t)m_tmpImage->getPixelAddress(x1, y);
-    base::hline(x1, y, x2, loop);
+    base::processScanline(x1, y, x2, loop);
   }
 
-  void updateInk(ToolLoop* loop, Strokes& strokes) override {
+  void prepareForStrokes(ToolLoop* loop, Strokes& strokes) override {
     // Do nothing
   }
 
@@ -948,7 +949,7 @@ private:
 };
 
 template<>
-void GradientInkProcessing<RgbTraits>::updateInk(ToolLoop* loop, Strokes& strokes)
+void GradientInkProcessing<RgbTraits>::prepareForStrokes(ToolLoop* loop, Strokes& strokes)
 {
   color_t c0 = loop->getPrimaryColor();
   color_t c1 = loop->getSecondaryColor();
@@ -966,7 +967,7 @@ void GradientInkProcessing<RgbTraits>::processPixel(int x, int y)
 }
 
 template<>
-void GradientInkProcessing<GrayscaleTraits>::updateInk(ToolLoop* loop, Strokes& strokes)
+void GradientInkProcessing<GrayscaleTraits>::prepareForStrokes(ToolLoop* loop, Strokes& strokes)
 {
   color_t c0 = loop->getPrimaryColor();
   color_t c1 = loop->getSecondaryColor();
@@ -994,7 +995,7 @@ void GradientInkProcessing<GrayscaleTraits>::processPixel(int x, int y)
 }
 
 template<>
-void GradientInkProcessing<IndexedTraits>::updateInk(ToolLoop* loop, Strokes& strokes)
+void GradientInkProcessing<IndexedTraits>::prepareForStrokes(ToolLoop* loop, Strokes& strokes)
 {
   color_t c0 = m_palette->getEntry(loop->getPrimaryColor());
   color_t c1 = m_palette->getEntry(loop->getSecondaryColor());
@@ -1094,6 +1095,13 @@ public:
     m_v = (m_brush->patternOrigin().y - loop->getCelOrigin().y) % m_height;
   }
 
+  void prepareForPointShape(ToolLoop* loop, int x, int y) override {
+    if (m_brush->pattern() == BrushPattern::PAINT_BRUSH) {
+      m_u = (m_brush->patternOrigin().x - loop->getCelOrigin().x) % m_width;
+      m_v = (m_brush->patternOrigin().y - loop->getCelOrigin().y) % m_height;
+    }
+  }
+
   void processPixel(int x, int y) {
     // Do nothing
   }

src/app/tools/inks.h

@@ -26,7 +26,12 @@ public:
 
   void inkHline(int x1, int y, int x2, ToolLoop* loop) override {
     ASSERT(m_proc);
-    m_proc->hline(x1, y, x2, loop);
+    m_proc->processScanline(x1, y, x2, loop);
+  }
+
+  void prepareForPointShape(ToolLoop* loop, int x, int y) override {
+    ASSERT(m_proc);
+    m_proc->prepareForPointShape(loop, x, y);
   }
 
 protected:
@@ -143,15 +148,14 @@ public:
 
   bool isPaint() const override { return true; }
   bool isEffect() const override { return true; }
-  bool dependsOnStroke() const override { return true; }
   bool withDitheringOptions() const override { return true; }
 
   void prepareInk(ToolLoop* loop) override {
     setProc(get_ink_proc<GradientInkProcessing>(loop));
   }
 
-  void updateInk(ToolLoop* loop, Strokes& strokes) override {
-    proc()->updateInk(loop, strokes);
+  void prepareForStrokes(ToolLoop* loop, Strokes& strokes) override {
+    proc()->prepareForStrokes(loop, strokes);
   }
 
 };

src/app/tools/point_shapes.h

@@ -66,6 +66,8 @@ public:
       }
     }
 
+    loop->getInk()->prepareForPointShape(loop, x, y);
+
     for (auto scanline : *m_compressedImage) {
       int u = x+scanline.x;
       doInkHline(u, y+scanline.y, u+scanline.w-1, loop);

src/app/tools/tool_loop_manager.cpp

@@ -175,8 +175,7 @@ void ToolLoopManager::doLoopStep(bool last_step)
     m_toolLoop->validateSrcImage(m_dirtyArea);
   }
 
-  if (m_toolLoop->getInk()->dependsOnStroke())
-    m_toolLoop->getInk()->updateInk(m_toolLoop, strokes);
+  m_toolLoop->getInk()->prepareForStrokes(m_toolLoop, strokes);
 
   // Invalidate destionation image areas.
   if (m_toolLoop->getTracePolicy() == TracePolicy::Last) {

src/app/ui/editor/brush_preview.cpp

@@ -223,6 +223,7 @@ void BrushPreview::show(const gfx::Point& screenPos)
           brushBounds.origin()));
       if (loop) {
         loop->getInk()->prepareInk(loop);
+        loop->getController()->prepareController(loop);
         loop->getIntertwine()->prepareIntertwine();
         loop->getPointShape()->preparePointShape(loop);
         loop->getPointShape()->transformPoint(