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

Code/devterm_keyboard/math.h

@@ -0,0 +1,56 @@
+#ifndef MATH_H
+#define MATH_H
+
+#include <cstdint>
+#include <limits>
+#include <cmath>
+
+uint32_t getDelta(uint32_t prev, uint32_t now);
+uint32_t getDelta(uint32_t prev, uint32_t now, uint32_t max);
+
+template<typename T>
+T sign(T value) {
+  if (value > 0) {
+    return 1;
+  }
+  if (value < 0) {
+    return -1;
+  }
+  return 0;
+}
+
+template<typename T, typename U>
+T clamp(U value) {
+  if (value >= std::numeric_limits<T>().max()) {
+    return std::numeric_limits<T>().max();
+  }
+
+  if (value <= std::numeric_limits<T>().min()) {
+    return std::numeric_limits<T>().min();
+  }
+
+  return value;
+}
+
+template<typename T>
+T min(T x, T y) {
+  if (x < y) {
+      return x;
+  }
+  return y;
+}
+
+template<typename T>
+T max(T x, T y) {
+  if (x > y) {
+      return x;
+  }
+  return y;
+}
+
+template<typename T>
+T hypot(T x, T y) {
+  return std::sqrt(x * x + y * y);
+}
+
+#endif