Merge pull request #68 from ichiro-its/hotfix/fix-map-function

[Hotfix] - Fix Map Function

Author: FaaizHaikal

include/keisan/number.impl.hpp

@@ -53,7 +53,12 @@ T map(
   const T & value, const T & source_min, const T & source_max,
   const T & target_min, const T & target_max)
 {
-  return target_min + scale(value - source_min, source_max - source_min, target_max - target_min);
+  auto source_val = value;
+  source_val = std::min(source_val, std::max(source_min, source_max));
+  source_val = std::max(source_val, std::min(source_min, source_max));
+
+  return target_min +
+         scale(source_val - source_min, source_max - source_min, target_max - target_min);
 }
 
 template<typename T>

test/number_test.cpp

@@ -63,35 +63,61 @@ TEST(NumberTest, ScaleFloatingPoint)
 TEST(NumberTest, MapIntegral)
 {
   EXPECT_EQ(ksn::map(5, 2, 4, 0, 1), 1) <<
-    "5 - 2 = 3\n"
+    "min(5, max(2, 4)) = 4\n"
+    "max(4, min(2, 4)) = 4\n"
+    "4 - 2 = 2\n"
     "4 - 2 = 2\n"
     "1 - 0 = 1\n"
-    "scale(3, 2, 1) = 1\n"
+    "scale(2, 2, 1) = 1\n"
     "1 + 0 = 1";
 
-  EXPECT_EQ(ksn::map(0, -2, -4, 0, 1), -1) <<
-    "0 - (-2) = 2\n"
+  EXPECT_EQ(ksn::map(0, -2, -4, 0, 1), 0) <<
+    "min(0, max(-2, -4)) = -2\n"
+    "max(-2, min(-2, -4)) = -2\n"
+    "-2 - (-2) = 0\n"
     "-4 - (-2) = -2\n"
     "1 - 0 = 1\n"
-    "scale(2, -2, 1) = -1\n"
-    "-1 + 0 = -1";
+    "scale(0, -2, 1) = 0\n"
+    "0 + 0 = 0";
+
+  EXPECT_EQ(ksn::map(10, 3, 11, -2, 2), -2) <<
+    "min(10, max(3, 11)) = 10\n"
+    "max(10, min(3, 11)) = 10\n"
+    "10 - 3 = 7\n"
+    "11 - 3 = 8\n"
+    "2 - (-2) = 4\n"
+    "scale(7, 8, 4) = 0\n"
+    "0 + (-2) = -2";
 }
 
 TEST(NumberTest, MapFloatingPoint)
 {
   EXPECT_DOUBLE_EQ(ksn::map(0.5, 0.2, 0.8, 1.0, 3.2), 2.1) <<
+    "min(0.5, max(0.2, 0.8)) = 0.5\n"
+    "max(0.5, min(0.2, 0.8)) = 0.5\n"
     "0.5 - 0.2 = 0.3\n"
     "0.8 - 0.2 = 0.6\n"
     "3.2 - 1.0 = 2.2\n"
-    "scale(0.3, 0.6, 2.2) = 1.1\n"
+    "scale(0.5, 0.6, 2.2) = 1.1\n"
     "1.1 + 1.0 = 2.1";
 
-  EXPECT_DOUBLE_EQ(ksn::map(-0.1, 0.2, 0.8, -3.2, -1.0), -4.3) <<
-    "-0.1 - 0.2 = -0.3\n"
+  EXPECT_DOUBLE_EQ(ksn::map(-0.1, 0.2, 0.8, -3.2, -1.0), -3.2) <<
+    "min(-0.1, max(0.2, 0.8)) = -0.1\n"
+    "max(-0.1, min(0.2, 0.8)) = 0.2\n"
+    "0.2 - 0.2 = 0.0\n"
     "0.8 - 0.2 = 0.6\n"
     "-1.0 - (-3.2) = 2.2\n"
-    "scale(-0.3, 0.6, 2.2) = -1.1\n"
-    "-1.1 + (-3.2) = -4.3";
+    "scale(0.0, 0.6, 2.2) = 0.0\n"
+    "0.0 + (-3.2) = -3.2";
+
+  EXPECT_DOUBLE_EQ(ksn::map(-1.5, 5.0, -2.5, 7.0, 13.0), 12.2) <<
+    "min(-1.5, max(5.0, -2.5)) = -1.5\n"
+    "max(-1.5, min(5.0, -2.5)) = -1.5\n"
+    "-1.5 - 5.0 = -6.5\n"
+    "-2.5 - 5.0 = -7.5\n"
+    "13.0 - 7.0 = 6.0\n"
+    "scale(-6.5, -7.5, 6.0) = 5.2\n"
+    "5.2 + 7.0 = 12.2";
 }
 
 TEST(NumberTest, ClampIntegral)