Extract merged texture pass through helper

src/node_canvas.cpp

@@ -392,28 +392,36 @@ void NodeCanvas::draw()
                 .draw_checkerboard_plane = draw_background_plane,
             });
 
-        for (int plane_index = 0; plane_index < 6; plane_index++)
+        const auto draw_merged_texture_plane = [&](int plane_index) {
+            pp::panopainter::execute_legacy_canvas_draw_merge_layer_texture(
                 {
-            int z = 1;
+                    .mvp = proj * camera *
-            auto plane_mvp_z = proj * camera *
-                //glm::scale(glm::vec3(z + 1)) *
-                //glm::eulerAngleYXZ(yaw, pitch, roll) *
                         m_canvas->m_plane_transform[plane_index] *
-                glm::translate(glm::vec3(0, 0, -1));
+                        glm::translate(glm::vec3(0, 0, -1)),
-
-            m_sampler.bind(0);
-            pp::panopainter::setup_legacy_canvas_draw_merge_texture_alpha_shader(
-                pp::panopainter::LegacyCanvasDrawMergeTextureAlphaUniforms {
-                    .mvp = plane_mvp_z,
                     .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();
+                    },
+                });
+        };
+
+        for (int plane_index = 0; plane_index < 6; plane_index++)
+        {
+            draw_merged_texture_plane(plane_index);
         }
     }
     else