From 1a37504b0956ee428516c67383ebb21ce504d32d Mon Sep 17 00:00:00 2001
From: Simon Detheridge <simon@highlyillogical.org>
Date: Mon, 22 Jun 2015 14:50:43 +0100
Subject: [PATCH] Add 'saw' motion function

---
 Source/Ember/EmberDefines.h | 2 +-
 Source/Ember/EmberToXml.h   | 2 ++
 Source/Ember/Interpolate.h  | 6 +++++-
 Source/Ember/XmlToEmber.h   | 2 ++
 4 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/Source/Ember/EmberDefines.h b/Source/Ember/EmberDefines.h
index 534f3a6..cd619be 100644
--- a/Source/Ember/EmberDefines.h
+++ b/Source/Ember/EmberDefines.h
@@ -114,7 +114,7 @@ enum eInterp : uint { EMBER_INTERP_LINEAR = 0, EMBER_INTERP_SMOOTH = 1 };
 enum eAffineInterp : uint { INTERP_LINEAR = 0, INTERP_LOG = 1, INTERP_COMPAT = 2, INTERP_OLDER = 3 };
 enum ePaletteMode : uint { PALETTE_STEP = 0, PALETTE_LINEAR = 1 };
 enum ePaletteInterp : uint { INTERP_HSV = 0, INTERP_SWEEP = 1 };
-enum eMotion : uint { MOTION_SIN = 1, MOTION_TRIANGLE = 2, MOTION_HILL = 3 };
+enum eMotion : uint { MOTION_SIN = 1, MOTION_TRIANGLE = 2, MOTION_HILL = 3, MOTION_SAW = 4 };
 enum eProcessAction : uint { NOTHING = 0, ACCUM_ONLY = 1, FILTER_AND_ACCUM = 2, KEEP_ITERATING = 3, FULL_RENDER = 4 };
 enum eProcessState : uint { NONE = 0, ITER_STARTED = 1, ITER_DONE = 2, FILTER_DONE = 3, ACCUM_DONE = 4 };
 enum eInteractiveFilter : uint { FILTER_LOG = 0, FILTER_DE = 1 };
diff --git a/Source/Ember/EmberToXml.h b/Source/Ember/EmberToXml.h
index 9d6cbf1..b1febdd 100644
--- a/Source/Ember/EmberToXml.h
+++ b/Source/Ember/EmberToXml.h
@@ -488,6 +488,8 @@ private:
 				os << "motion_function=\"triangle\" ";
 			else if (xform.m_MotionFunc== MOTION_HILL)
 				os << "motion_function=\"hill\" ";
+			else if (xform.m_MotionFunc== MOTION_SAW)
+				os << "motion_function=\"saw\" ";
 		}
 		else
 		{
diff --git a/Source/Ember/Interpolate.h b/Source/Ember/Interpolate.h
index 23b16d2..950ca86 100644
--- a/Source/Ember/Interpolate.h
+++ b/Source/Ember/Interpolate.h
@@ -883,10 +883,14 @@ public:
 
 			return fr;
 		}
-		else//MOTION_HILL
+		else if (funcNum == MOTION_HILL)
 		{
 			return ((1 - cos(T(2.0) * T(M_PI) * timeVal)) * T(0.5));
 		}
+		else //MOTION_SAW
+		{
+			return (T(2.0) * fmod(timeVal - T(0.5), T(1.0)) - T(1.0));
+		}
 	}
 
 	/*
diff --git a/Source/Ember/XmlToEmber.h b/Source/Ember/XmlToEmber.h
index 07ea62f..0a92ab4 100644
--- a/Source/Ember/XmlToEmber.h
+++ b/Source/Ember/XmlToEmber.h
@@ -1073,6 +1073,8 @@ private:
 					xform.m_MotionFunc = MOTION_TRIANGLE;
 				else if (!_stricmp("hill", attStr))
 					xform.m_MotionFunc = MOTION_HILL;
+				else if (!_stricmp("saw", attStr))
+					xform.m_MotionFunc = MOTION_SAW;
 				else
 				{
 					xform.m_MotionFunc = MOTION_SIN;