PixelPaint: Draw polygonal select tool lines with two colors

This stops lines from disappearing when entering a dark area of the
image.

1 files changed, 14 insertions, 9 deletions

diff --git a/Userland/Applications/PixelPaint/Tools/PolygonalSelectTool.cpp b/Userland/Applications/PixelPaint/Tools/PolygonalSelectTool.cpp
index 49352b48d0..e3664f26b3 100644
--- a/Userland/Applications/PixelPaint/Tools/PolygonalSelectTool.cpp
+++ b/Userland/Applications/PixelPaint/Tools/PolygonalSelectTool.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2022, the SerenityOS developers.
+ * Copyright (c) 2022-2023, the SerenityOS developers.
  *
  * SPDX-License-Identifier: BSD-2-Clause
  */
@@ -139,15 +139,20 @@ void PolygonalSelectTool::on_second_paint(Layer const* layer, GUI::PaintEvent& e
 
     painter.translate(editor_layer_location(*layer));
 
-    for (size_t i = 0; i < m_polygon_points.size() - 1; i++) {
-        auto preview_start = editor_stroke_position(m_polygon_points.at(i), 1);
-        auto preview_end = editor_stroke_position(m_polygon_points.at(i + 1), 1);
-        painter.draw_line(preview_start, preview_end, Color::Black, 1);
-    }
+    auto draw_preview_lines = [&](auto color, auto thickness) {
+        for (size_t i = 0; i < m_polygon_points.size() - 1; i++) {
+            auto preview_start = editor_stroke_position(m_polygon_points.at(i), 1);
+            auto preview_end = editor_stroke_position(m_polygon_points.at(i + 1), 1);
+            painter.draw_line(preview_start, preview_end, color, thickness);
+        }
+
+        auto last_line_start = editor_stroke_position(m_polygon_points.at(m_polygon_points.size() - 1), 1);
+        auto last_line_stop = editor_stroke_position(m_last_selecting_cursor_position, 1);
+        painter.draw_line(last_line_start, last_line_stop, color, thickness);
+    };
 
-    auto last_line_start = editor_stroke_position(m_polygon_points.at(m_polygon_points.size() - 1), 1);
-    auto last_line_stop = editor_stroke_position(m_last_selecting_cursor_position, 1);
-    painter.draw_line(last_line_start, last_line_stop, Color::Black, 1);
+    draw_preview_lines(Gfx::Color::Black, 3);
+    draw_preview_lines(Gfx::Color::White, 1);
 }
 
 bool PolygonalSelectTool::on_keydown(GUI::KeyEvent& key_event)