1 files changed, 71 insertions, 0 deletions
diff --git a/src/libjin/math/ranged_value.cpp b/src/libjin/math/ranged_value.cpp
new file mode 100644
index 0000000..1a14467
--- /dev/null
+++ b/src/libjin/math/ranged_value.cpp
@@ -0,0 +1,71 @@
+#include "ranged_value.h"
+
+namespace JinEngine
+{
+    namespace Math
+    {
+
+        RangedValue::RangedValue()
+            : mCount(0)
+        {
+        }
+
+        RangedValue::RangedValue(float* points, uint n)
+            : mCount(n)
+        {
+            for (uint i = 0; i < n; ++i)
+            {
+                float x = points[2*i];
+                float y = points[2*i + 1];
+                mXAxis.push_back(x);
+                mYAxis.push_back(y);
+            }
+        }
+
+        void RangedValue::addPoint(float x, float y)
+        {
+            mXAxis.push_back(x);
+            mYAxis.push_back(y);
+            ++mCount;
+        }
+
+        void RangedValue::removePoint(uint i)
+        {
+            mXAxis.erase(mXAxis.begin() + i);
+            mYAxis.erase(mYAxis.begin() + i);
+            --mCount;
+        }
+
+        void RangedValue::insertPoint(uint i, float x, float y)
+        {
+            mXAxis.insert(mXAxis.begin() + i, x);
+            mYAxis.insert(mYAxis.begin() + i, y);
+            ++mCount;
+        }
+
+        float RangedValue::getValue(float x)
+        {
+            int endIndex = -1;
+            int n = mCount;
+            for (int i = 1; i < n; i++) {
+                float t = mXAxis[i];
+                if (t > x) {
+                    endIndex = i;
+                    break;
+                }
+            }
+            if (endIndex == -1) return mYAxis[n - 1];
+            int startIndex = endIndex - 1;
+            float startValue = mYAxis[startIndex];
+            float startX = mXAxis[startIndex];
+            return startValue + (mYAxis[endIndex] - startValue) * ((x - startX) / (mXAxis[endIndex] - startX));
+        }
+
+        void RangedValue::clear()
+        {
+            mXAxis.clear();
+            mYAxis.clear();
+        }
+
+    }
+}
+\ No newline at end of file