glfw version of sample app

src/map/transform.cpp

@@ -0,0 +1,21 @@
+#include <llmr/map/transform.hpp>
+
+using namespace llmr;
+
+transform::transform()
+    : x(0.0f),
+      y(0.0f),
+      scale(1.0f) {
+
+}
+
+void transform::moveBy(double dx, double dy) {
+    x += dx;
+    y += dy;
+}
+
+void transform::scaleBy(double ds, double cx, double cy) {
+    scale *= ds;
+    x = x * ds + cx * (1 - ds);
+    y = y * ds + cy * (1 - ds);
+}