PixelPaint: Make PenTool only invalidate the modified area :^)

1 files changed, 9 insertions, 4 deletions

diff --git a/Userland/Applications/PixelPaint/PenTool.cpp b/Userland/Applications/PixelPaint/PenTool.cpp
index d26e24acef..26b48e5851 100644
--- a/Userland/Applications/PixelPaint/PenTool.cpp
+++ b/Userland/Applications/PixelPaint/PenTool.cpp
@@ -31,7 +31,7 @@ void PenTool::on_mousedown(Layer& layer, GUI::MouseEvent& event, GUI::MouseEvent
 
     GUI::Painter painter(layer.bitmap());
     painter.draw_line(event.position(), event.position(), m_editor->color_for(event), m_thickness);
-    layer.did_modify_bitmap();
+    layer.did_modify_bitmap(Gfx::IntRect::centered_on(event.position(), Gfx::IntSize { m_thickness, m_thickness }));
     m_last_drawing_event_position = event.position();
 }
 
@@ -49,11 +49,16 @@ void PenTool::on_mousemove(Layer& layer, GUI::MouseEvent& event, GUI::MouseEvent
         return;
     GUI::Painter painter(layer.bitmap());
 
-    if (m_last_drawing_event_position != Gfx::IntPoint(-1, -1))
+    Gfx::IntRect changed_rect;
+    if (m_last_drawing_event_position != Gfx::IntPoint(-1, -1)) {
         painter.draw_line(m_last_drawing_event_position, event.position(), m_editor->color_for(event), m_thickness);
-    else
+        changed_rect = Gfx::IntRect::from_two_points(m_last_drawing_event_position, event.position());
+    } else {
         painter.draw_line(event.position(), event.position(), m_editor->color_for(event), m_thickness);
-    layer.did_modify_bitmap();
+        changed_rect = Gfx::IntRect::from_two_points(event.position(), event.position());
+    }
+    changed_rect.inflate(m_thickness * 4, m_thickness * 4);
+    layer.did_modify_bitmap(changed_rect);
 
     m_last_drawing_event_position = event.position();
 }