le readme

src/snapshots.cpp

@@ -0,0 +1,24 @@
+#include "undo_stack.h"
+
+void 
+undo_stack_push(Snapshots* self, Anm2* anm2)
+{
+    if (self->top >= UNDO_STACK_MAX)
+    {
+        memmove(&self->snapshots[0], &self->snapshots[1], sizeof(Anm2) * (UNDO_STACK_MAX - 1));
+        self->top = UNDO_STACK_MAX - 1;
+    }
+
+    self->snapshots[self->top++] = *anm2;
+}
+
+bool
+undo_stack_pop(Snapshots* self, Anm2* anm2)
+{
+    if (self->top == 0)
+        return false;
+
+    *anm2 = self->snapshots[--self->top];
+
+    return true;
+}