Move Win32 async context ownership and trim canvas draw setup

src/node_canvas.cpp

@@ -385,32 +385,14 @@ void NodeCanvas::draw()
                     }),
             });
 
-        const auto draw_merged_texture_plane = [&](int plane_index) {
-            pp::panopainter::execute_legacy_canvas_draw_merge_layer_texture(
-                {
-                    .mvp = proj * camera *
-                        m_canvas->m_plane_transform[plane_index] *
-                        glm::translate(glm::vec3(0, 0, -1)),
-                    .texture_slot = 0,
-                    .alpha = 1.f,
-                    .highlight = false,
-                },
-                {
-                    .bind_sampler = [&] {
-                        m_sampler.bind(0);
-                        set_active_texture_unit(0);
-                    },
-                    .bind_layer_texture = [&] {
-                        m_canvas->m_layers_merge.rtt(plane_index).bindTexture();
-                    },
-                    .draw = [&] {
-                        m_face_plane.draw_fill();
-                    },
-                    .unbind_layer_texture = [&] {
-                        m_canvas->m_layers_merge.rtt(plane_index).unbindTexture();
-                    },
-                });
-        };
+        const auto draw_merged_texture_plane = pp::panopainter::make_legacy_canvas_draw_merge_layer_texture_draw(
+            &m_canvas->m_layers_merge,
+            &m_sampler,
+            &m_face_plane,
+            set_active_texture_unit,
+            proj,
+            camera,
+            m_canvas->m_plane_transform);
 
         for (int plane_index = 0; plane_index < 6; plane_index++)
         {