borrwoed a lot code from https://github.com/foriequal0/devterm_keyboard in order to optimize the trackball

Code/devterm_keyboard/glider.h

@@ -0,0 +1,29 @@
+#ifndef GLIDER_H
+#define GLIDER_H
+
+#include <cstdint>
+
+
+class Glider {
+public:
+  Glider();
+  void setDirection(int8_t);
+  void update(float velocity, uint16_t sustain);
+  void updateSpeed(float velocity);
+  void stop();
+
+  struct GlideResult {
+    int8_t value;
+    bool stopped;
+  };
+  GlideResult glide(uint8_t delta);
+
+public:
+  int8_t direction;
+  float speed;
+  uint16_t sustain;
+  uint16_t release;
+  float error;
+};
+
+#endif