refactor layout.h into single file per Node* classes

engine/node_image.h

@@ -0,0 +1,24 @@
+#pragma once
+#include "node.h"
+#include "shape.h"
+#include "texture.h"
+
+class NodeImage : public Node
+{
+public:
+    static ui::Plane m_plane;
+    static Sampler m_sampler;
+    bool m_use_atlas = false;
+    glm::vec4 m_region;
+    glm::vec2 m_off;
+    glm::vec2 m_sz;
+    std::string m_path;
+    uint16_t m_tex_id;
+    static void static_init();
+    virtual Node* clone_instantiate() const override;
+    virtual void clone_copy(Node* dest) const override;
+    virtual void create() override;
+    virtual void restore_context() override;
+    virtual void parse_attributes(kAttribute ka, const tinyxml2::XMLAttribute* attr) override;
+    virtual void draw() override;
+};