27 files changed, 179 insertions, 549 deletions
diff --git a/src/model/state/zoom_info.h b/src/model/state/zoom_info.h
new file mode 100644
index 0000000..5916b3c
--- a/dev/null
+++ b/src/model/state/zoom_info.h
@@ -0,0 +1,22 @@
+#ifndef ZOOM_INFO_H
+#define ZOOM_INFO_H
+
+#include <stdbool.h>
+
+/*
+ * Maintain information for zooming.
+ */
+typedef struct
+{
+  /*
+   * A zoomed region has been selection.
+   */
+  bool active;
+
+  /*
+   * Left, right, bottom and top of zoom region in world coordinates.
+   */
+  double coords[4];
+} ZOOM_INFO;
+
+#endif // ZOOM_INFO_H