Add `SurfaceStack` class untested yet

src/Surfaces/SurfaceStack.cpp

@@ -0,0 +1,31 @@
+#include "SurfaceStack.h"
+
+namespace ofx {
+namespace piMapper {
+
+SurfaceStack::SurfaceStack(){}
+
+void SurfaceStack::push_back(ofx::piMapper::BaseSurface & s){
+	_surfaces.push_back(s);
+}
+
+void SurfaceStack::pop_back(){
+	if(_surfaces.size() > 0){
+		_surfaces.pop_back();
+	}
+}
+
+int SurfaceStack::size(){
+	return _surfaces.size();
+}
+
+void SurfaceStack::erase(int pos){
+	_surfaces.erase(_surfaces.begin() + pos);
+}
+
+void SurfaceStack::swap(ofx::piMapper::BaseSurface * a, ofx::piMapper::BaseSurface * b){
+	std::swap(a, b);
+}
+
+} // namespace piMapper
+} // namespace ofx

src/Surfaces/SurfaceStack.h

@@ -0,0 +1,29 @@
+#pragma once
+
+#include "ofMain.h"
+#include "BaseSurface.h"
+
+namespace ofx {
+namespace piMapper {
+
+// One can imagine this as a layers panel in an image editor
+class SurfaceStack {
+	public:
+		SurfaceStack();
+
+		void push_back(BaseSurface & s);
+		void pop_back();
+		void erase(int pos);
+		void swap(BaseSurface * a, BaseSurface * b);
+		void draw();
+	
+		int size();
+	
+		BaseSurface * at(int pos);
+	
+	private:
+		vector<BaseSurface> _surfaces;
+};
+
+} // namespace piMapper
+} // namespace ofx