Extract canvas object draw and brush panel services

src/legacy_canvas_object_draw_services.h

@@ -0,0 +1,22 @@
+#pragma once
+
+#include "canvas.h"
+
+#include <functional>
+
+namespace pp::panopainter {
+
+void legacy_canvas_draw_objects_direct(
+    Canvas& canvas,
+    std::function<void(const glm::mat4& camera, const glm::mat4& proj, int i)> observer,
+    Layer& layer,
+    int frame);
+
+void legacy_canvas_draw_objects(
+    Canvas& canvas,
+    std::function<void(const glm::mat4& camera, const glm::mat4& proj, int i)> observer,
+    Layer& layer,
+    int frame,
+    bool save_history);
+
+} // namespace pp::panopainter