From 965d4d401271e19754796aad0421aa2135d68518 Mon Sep 17 00:00:00 2001
From: Nick Gasson <nick@nickg.me.uk>
Date: Thu, 11 Jun 2009 21:14:34 +0100
Subject: [PATCH] Rename the displaced curve function

---
 include/TrackCommon.hpp |  4 ++--
 src/Points.cpp          |  4 ++--
 src/TrackCommon.cpp     | 23 ++++++-----------------
 3 files changed, 10 insertions(+), 21 deletions(-)

diff --git a/include/TrackCommon.hpp b/include/TrackCommon.hpp
index e7d7b9c..26cfda1 100644
--- a/include/TrackCommon.hpp
+++ b/include/TrackCommon.hpp
@@ -28,8 +28,8 @@ void renderReflectedHypTanRail();
 void renderCurvedTrack(int baseRadius, track::Angle startAngle,
                        track::Angle endAngle);
 void transformToOrigin(int baseRadius, track::Angle startAngle);
-float hypTanCurveFunc(float x);
-float reflectedHypTanCurveFunc(float x);
+float displacedCurveFunc(float x);
+float reflectedDisplacedCurveFunc(float x);
 
 // Track constants
 namespace track {
diff --git a/src/Points.cpp b/src/Points.cpp
index 6cfeb47..b0ad562 100644
--- a/src/Points.cpp
+++ b/src/Points.cpp
@@ -182,11 +182,11 @@ void Points::transform(const track::TravelToken& aToken, double aDelta) const
       const float curveDelta = aDelta * 3.0f / len;
 
       const float fValue = 3.0f - curveDelta;
-      const float curveValue = hypTanCurveFunc(fValue);
+      const float curveValue = displacedCurveFunc(fValue);
 
       // Calculate the angle that the tangent to the curve at this
       // point makes to (one of) the axis at this point
-      const float grad = approxGradient(hypTanCurveFunc, fValue);
+      const float grad = approxGradient(displacedCurveFunc, fValue);
       const float angle = radToDeg<float>(atanf(grad));
       
       if (myAxis == -axis::X && aToken.direction == axis::X) {
diff --git a/src/TrackCommon.cpp b/src/TrackCommon.cpp
index a205476..eae173f 100644
--- a/src/TrackCommon.cpp
+++ b/src/TrackCommon.cpp
@@ -261,26 +261,15 @@ namespace {
 }
 
 // The function that determines the curve of points and S-bends
-float hypTanCurveFunc(float x)
+float displacedCurveFunc(float x)
 {
-   const float linearAbove = 2.7f;
-   const float wantOneAt = 2.9f;
-   if (x <= linearAbove)
-      // Use the curvey function   
-      return 0.5f * (1.0f + tanh(1.8f * x - 3.5f));
-   else {
-      // Interpolate linearly
-      const float fLinearAbove = hypTanCurveFunc(linearAbove);
-      const float m = (1.0f - fLinearAbove) / (wantOneAt - linearAbove);
-      
-      return m*(x - linearAbove) + fLinearAbove;
-   }
+   return 0.5f * (1.0f + tanh(1.8f * x - 3.5f));
 }
 
 // The above function reflected about the x-axis
-float reflectedHypTanCurveFunc(float x)
+float reflectedDisplacedCurveFunc(float x)
 {
-   return -hypTanCurveFunc(x);
+   return -displacedCurveFunc(x);
 }
 
 // Draw a sleeper in the current maxtrix location
@@ -308,7 +297,7 @@ void renderStraightRail()
 void renderHypTanRail()
 {
    if (!theHypTanRailMesh)
-      theHypTanRailMesh = generateFuncRailMesh(hypTanCurveFunc);
+      theHypTanRailMesh = generateFuncRailMesh(displacedCurveFunc);
 
    glPushMatrix();
 
@@ -325,7 +314,7 @@ void renderReflectedHypTanRail()
 {
    if (!theReflectedHypTanRailMesh)
       theReflectedHypTanRailMesh =
-         generateFuncRailMesh(reflectedHypTanCurveFunc);
+         generateFuncRailMesh(reflectedDisplacedCurveFunc);
 
    glPushMatrix();
 
-- 
2.39.2