Collapse draw merge layer composite shell

src/canvas.cpp

@@ -555,6 +555,19 @@ std::array<std::vector<vertex_t>, 6> Canvas::stroke_draw_project(std::array<vert
     return ret;
 }
 
+static void execute_canvas_draw_merge_layer_composite(
+    bool is_temporary_erase,
+    bool is_temporary_paint,
+    bool use_blend,
+    const pp::panopainter::LegacyCanvasDrawMergeLayerCompositeExecution& execution)
+{
+    pp::panopainter::execute_legacy_canvas_draw_merge_layer_composite(
+        is_temporary_erase,
+        is_temporary_paint,
+        use_blend,
+        execution);
+}
+
 glm::vec4 Canvas::stroke_draw_samples(
     int i,
     std::vector<vertex_t>& P,
@@ -1429,7 +1442,7 @@ void Canvas::draw_merge(bool draw_checkerboard, std::array<bool, 6> faces /*= SI
                 m_merge_rtt.clear();
             }
 
-                pp::panopainter::execute_legacy_canvas_draw_merge_layer_composite(
+                execute_canvas_draw_merge_layer_composite(
             m_current_stroke && m_current_mode == kCanvasMode::Erase && m_show_tmp && m_current_layer_idx == layer_index,
             m_current_stroke && m_show_tmp && m_current_layer_idx == layer_index,
             use_blend,