Overworld render test.

src/input/input.c

@@ -108,6 +108,13 @@ bool_t inputReleased(const inputaction_t action) {
   return !inputIsDown(action) && inputWasDown(action);
 }
 
+float_t inputAxis(const inputaction_t neg, const inputaction_t pos) {
+  assertTrue(neg < INPUT_ACTION_COUNT, "Negative input action out of bounds");
+  assertTrue(pos < INPUT_ACTION_COUNT, "Positive input action out of bounds");
+
+  return inputGetCurrentValue(pos) - inputGetCurrentValue(neg);
+}
+
 void inputBind(const inputbutton_t button, const char_t *action) {
   assertNotNull(action, "Input action is null");
   assertStrLenMin(action, 1, "Input action is empty");