From eb4d6efecd36c66c75bd2afe76d19d9534f1a261 Mon Sep 17 00:00:00 2001
From: Connor McLaughlin <stenzek@gmail.com>
Date: Tue, 23 Feb 2021 00:43:58 +1000
Subject: [PATCH] Common: Add easing.h

---
 src/common/common.vcxproj         |   1 +
 src/common/common.vcxproj.filters |   1 +
 src/common/easing.h               | 257 ++++++++++++++++++++++++++++++
 3 files changed, 259 insertions(+)
 create mode 100644 src/common/easing.h

diff --git a/src/common/common.vcxproj b/src/common/common.vcxproj
index 3f281daef..2aa989d8e 100644
--- a/src/common/common.vcxproj
+++ b/src/common/common.vcxproj
@@ -67,6 +67,7 @@
     <ClInclude Include="d3d11\stream_buffer.h" />
     <ClInclude Include="d3d11\texture.h" />
     <ClInclude Include="dimensional_array.h" />
+    <ClInclude Include="easing.h" />
     <ClInclude Include="event.h" />
     <ClInclude Include="fifo_queue.h" />
     <ClInclude Include="file_system.h" />
diff --git a/src/common/common.vcxproj.filters b/src/common/common.vcxproj.filters
index 5dd50afb0..74a1322f1 100644
--- a/src/common/common.vcxproj.filters
+++ b/src/common/common.vcxproj.filters
@@ -109,6 +109,7 @@
     </ClInclude>
     <ClInclude Include="crash_handler.h" />
     <ClInclude Include="lru_cache.h" />
+    <ClInclude Include="easing.h" />
   </ItemGroup>
   <ItemGroup>
     <ClCompile Include="jit_code_buffer.cpp" />
diff --git a/src/common/easing.h b/src/common/easing.h
new file mode 100644
index 000000000..b5d5c1d54
--- /dev/null
+++ b/src/common/easing.h
@@ -0,0 +1,257 @@
+#pragma once
+#include "types.h"
+#include <cmath>
+
+// From https://github.com/nicolausYes/easing-functions/blob/master/src/easing.cpp
+
+namespace Easing {
+static constexpr float pi = 3.1415926545f;
+
+template<typename T>
+ALWAYS_INLINE_RELEASE static T InSine(T t)
+{
+  return std::sin(1.5707963f * t);
+}
+
+template<typename T>
+ALWAYS_INLINE_RELEASE static T OutSine(T t)
+{
+  return 1 + std::sin(1.5707963f * (--t));
+}
+
+template<typename T>
+ALWAYS_INLINE_RELEASE static T InOutSine(T t)
+{
+  return 0.5f * (1 + std::sin(3.1415926f * (t - 0.5f)));
+}
+
+template<typename T>
+ALWAYS_INLINE_RELEASE static T InQuad(T t)
+{
+  return t * t;
+}
+
+template<typename T>
+ALWAYS_INLINE_RELEASE static T OutQuad(T t)
+{
+  return t * (2 - t);
+}
+
+template<typename T>
+ALWAYS_INLINE_RELEASE static T InOutQuad(T t)
+{
+  return t < 0.5f ? 2 * t * t : t * (4 - 2 * t) - 1;
+}
+
+template<typename T>
+ALWAYS_INLINE_RELEASE static T InCubic(T t)
+{
+  return t * t * t;
+}
+
+template<typename T>
+ALWAYS_INLINE_RELEASE static T OutCubic(T t)
+{
+  return 1 + (--t) * t * t;
+}
+
+template<typename T>
+ALWAYS_INLINE_RELEASE static T InOutCubic(T t)
+{
+  return t < 0.5f ? 4 * t * t * t : 1 + (--t) * (2 * (--t)) * (2 * t);
+}
+
+template<typename T>
+ALWAYS_INLINE_RELEASE static T InQuart(T t)
+{
+  t *= t;
+  return t * t;
+}
+
+template<typename T>
+ALWAYS_INLINE_RELEASE static T OutQuart(T t)
+{
+  t = (--t) * t;
+  return 1 - t * t;
+}
+
+template<typename T>
+ALWAYS_INLINE_RELEASE static T InOutQuart(T t)
+{
+  if (t < 0.5)
+  {
+    t *= t;
+    return 8 * t * t;
+  }
+  else
+  {
+    t = (--t) * t;
+    return 1 - 8 * t * t;
+  }
+}
+
+template<typename T>
+ALWAYS_INLINE_RELEASE static T InQuint(T t)
+{
+  T t2 = t * t;
+  return t * t2 * t2;
+}
+
+template<typename T>
+ALWAYS_INLINE_RELEASE static T OutQuint(T t)
+{
+  T t2 = (--t) * t;
+  return 1 + t * t2 * t2;
+}
+
+template<typename T>
+ALWAYS_INLINE_RELEASE static T InOutQuint(T t)
+{
+  T t2;
+  if (t < 0.5)
+  {
+    t2 = t * t;
+    return 16 * t * t2 * t2;
+  }
+  else
+  {
+    t2 = (--t) * t;
+    return 1 + 16 * t * t2 * t2;
+  }
+}
+
+template<typename T>
+ALWAYS_INLINE_RELEASE static T InExpo(T t)
+{
+  return (std::pow(2, 8 * t) - 1) / 255;
+}
+
+template<typename T>
+ALWAYS_INLINE_RELEASE static T OutExpo(T t)
+{
+  return 1 - std::pow(2, -8 * t);
+}
+
+template<typename T>
+ALWAYS_INLINE_RELEASE static T InOutExpo(T t)
+{
+  if (t < 0.5f)
+  {
+    return (std::pow(2, 16 * t) - 1) / 510;
+  }
+  else
+  {
+    return 1 - 0.5f * std::pow(2, -16 * (t - 0.5f));
+  }
+}
+
+template<typename T>
+ALWAYS_INLINE_RELEASE static T InCirc(T t)
+{
+  return 1 - std::sqrt(1 - t);
+}
+
+template<typename T>
+ALWAYS_INLINE_RELEASE static T OutCirc(T t)
+{
+  return std::sqrt(t);
+}
+
+template<typename T>
+ALWAYS_INLINE_RELEASE static T InOutCirc(T t)
+{
+  if (t < 0.5f)
+  {
+    return (1 - std::sqrt(1 - 2 * t)) * 0.5f;
+  }
+  else
+  {
+    return (1 + std::sqrt(2 * t - 1)) * 0.5f;
+  }
+}
+
+template<typename T>
+ALWAYS_INLINE_RELEASE static T InBack(T t)
+{
+  return t * t * (2.70158f * t - 1.70158f);
+}
+
+template<typename T>
+ALWAYS_INLINE_RELEASE static T OutBack(T t)
+{
+  return 1 + (--t) * t * (2.70158f * t + 1.70158f);
+}
+
+template<typename T>
+ALWAYS_INLINE_RELEASE static T InOutBack(T t)
+{
+  if (t < 0.5f)
+  {
+    return t * t * (7 * t - 2.5f) * 2;
+  }
+  else
+  {
+    return 1 + (--t) * t * 2 * (7 * t + 2.5f);
+  }
+}
+
+template<typename T>
+ALWAYS_INLINE_RELEASE static T InElastic(T t)
+{
+  T t2 = t * t;
+  return t2 * t2 * std::sin(t * pi * 4.5f);
+}
+
+template<typename T>
+ALWAYS_INLINE_RELEASE static T OutElastic(T t)
+{
+  T t2 = (t - 1) * (t - 1);
+  return 1 - t2 * t2 * std::cos(t * pi * 4.5f);
+}
+
+template<typename T>
+ALWAYS_INLINE_RELEASE static T InOutElastic(T t)
+{
+  T t2;
+  if (t < 0.45f)
+  {
+    t2 = t * t;
+    return 8 * t2 * t2 * std::sin(t * pi * 9);
+  }
+  else if (t < 0.55f)
+  {
+    return 0.5f + 0.75f * std::sin(t * pi * 4);
+  }
+  else
+  {
+    t2 = (t - 1) * (t - 1);
+    return 1 - 8 * t2 * t2 * std::sin(t * pi * 9);
+  }
+}
+
+template<typename T>
+ALWAYS_INLINE_RELEASE static T InBounce(T t)
+{
+  return std::pow(2, 6 * (t - 1)) * std::abs(sin(t * pi * 3.5f));
+}
+
+template<typename T>
+ALWAYS_INLINE_RELEASE static T OutBounce(T t)
+{
+  return 1 - std::pow(2, -6 * t) * std::abs(std::cos(t * pi * 3.5f));
+}
+
+template<typename T>
+ALWAYS_INLINE_RELEASE static T InOutBounce(T t)
+{
+  if (t < 0.5f)
+  {
+    return 8 * std::pow(2, 8 * (t - 1)) * std::abs(std::sin(t * pi * 7));
+  }
+  else
+  {
+    return 1 - 8 * std::pow(2, -8 * t) * std::abs(std::sin(t * pi * 7));
+  }
+}
+
+} // namespace Easing
\ No newline at end of file