merged from 0.6.7 codebase

1 files changed, 43 insertions, 0 deletions

diff --git a/api/logic/ExponentialSeries.h b/api/logic/ExponentialSeries.h
new file mode 100644
index 00000000..a9487f0a
--- /dev/null
+++ b/api/logic/ExponentialSeries.h
@@ -0,0 +1,43 @@
+
+#pragma once
+
+template <typename T>
+inline void clamp(T& current, T min, T max)
+{
+    if (current < min)
+    {
+        current = min;
+    }
+    else if(current > max)
+    {
+        current = max;
+    }
+}
+
+// List of numbers from min to max. Next is exponent times bigger than previous.
+
+class ExponentialSeries
+{
+public:
+    ExponentialSeries(unsigned min, unsigned max, unsigned exponent = 2)
+    {
+        m_current = m_min = min;
+        m_max = max;
+        m_exponent = exponent;
+    }
+    void reset()
+    {
+        m_current = m_min;
+    }
+    unsigned operator()()
+    {
+        unsigned retval = m_current;
+        m_current *= m_exponent;
+        clamp(m_current, m_min, m_max);
+        return retval;
+    }
+    unsigned m_current;
+    unsigned m_min;
+    unsigned m_max;
+    unsigned m_exponent;
+};