refactor layout.h into single file per Node* classes

engine/node_panel_color.cpp

@@ -0,0 +1,42 @@
+#include "pch.h"
+#include "log.h"
+#include "node_panel_color.h"
+
+Node* NodePanelColor::clone_instantiate() const
+{
+    return new NodePanelColor();
+}
+
+void NodePanelColor::clone_finalize(Node* dest) const
+{
+    NodePanelColor* n = static_cast<NodePanelColor*>(dest);
+    n->init_controls();
+}
+
+void NodePanelColor::init()
+{
+    init_template("tpl-panel-color");
+    init_controls();
+}
+
+void NodePanelColor::init_controls()
+{
+    m_quad = find<NodeColorQuad>("quad");
+    m_hue = find<NodeSliderHue>("hue");
+    m_hue->on_hue_changed = [this](Node*, glm::vec4 hue_color) {
+        m_base_color = m_quad->m_color = hue_color;
+        auto x = glm::mix(m_base_color, glm::vec4(1, 1, 1, 1), m_cursor.x);
+        m_color = glm::mix(x, glm::vec4(0, 0, 0, 1), m_cursor.y);
+        if (on_color_changed)
+            on_color_changed(this, m_color);
+    };
+    m_quad->on_value_changed = [this](Node*, glm::vec2 pos)
+    {
+        auto x = glm::mix(m_base_color, glm::vec4(1, 1, 1, 1), pos.x);
+        m_color = glm::mix(x, glm::vec4(0, 0, 0, 1), pos.y);
+        m_cursor = pos;
+        if (on_color_changed)
+            on_color_changed(this, m_color);
+    };
+    m_hue->set_value(0);
+}