From a8b2bc2d010480544c3162daa7384a252946bda1 Mon Sep 17 00:00:00 2001
From: Brett Laptop <tri11paragon@tpgc.me>
Date: Tue, 14 May 2024 21:57:51 -0400
Subject: [PATCH] easing functions

---
 CMakeLists.txt                   |   2 +-
 include/blt/math/interpolation.h | 109 +++++++++++++++++++++++++++++++
 include/blt/math/vectors.h       |   6 --
 3 files changed, 110 insertions(+), 7 deletions(-)
 create mode 100644 include/blt/math/interpolation.h

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 62fa748..2707ed0 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,7 +1,7 @@
 cmake_minimum_required(VERSION 3.20)
 include(cmake/color.cmake)
 
-set(BLT_VERSION 0.17.9)
+set(BLT_VERSION 0.17.10)
 set(BLT_TEST_VERSION 0.0.1)
 
 set(BLT_TARGET BLT)
diff --git a/include/blt/math/interpolation.h b/include/blt/math/interpolation.h
new file mode 100644
index 0000000..1dfeb3b
--- /dev/null
+++ b/include/blt/math/interpolation.h
@@ -0,0 +1,109 @@
+#pragma once
+/*
+ *  Copyright (C) 2024  Brett Terpstra
+ *
+ *  This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef BLT_INTERPOLATION_H
+#define BLT_INTERPOLATION_H
+
+#include "vectors.h"
+
+namespace blt
+{
+    inline constexpr color4 linear_interpolate(const color4& in, const color4& desired, float factor)
+    {
+        auto diff = desired - in;
+        return in + (diff * factor);
+    }
+    
+    class easing_function
+    {
+        public:
+            easing_function() = default;
+            
+            virtual color4 apply(const color4& start, const color4& end) = 0;
+            
+            void progress(float progress)
+            {
+                total_progress += progress;
+            }
+            
+            void reset()
+            {
+                total_progress = 0;
+            }
+        
+        protected:
+            float x()
+            {
+                return total_progress;
+            }
+        
+        private:
+            float total_progress = 0;
+    };
+    
+    class quad_easing : public easing_function
+    {
+        public:
+            color4 apply(const color4& start, const color4& end) final
+            {
+                if (x() >= 1)
+                    return end;
+                auto diff = end - start;
+                return start + (diff * (x() * x()));
+            }
+    };
+    
+    class cubic_easing : public easing_function
+    {
+        public:
+            color4 apply(const color4& start, const color4& end) final
+            {
+                if (x() >= 1)
+                    return end;
+                auto diff = end - start;
+                return start + (diff * (x() * x() * x()));
+            }
+    };
+    
+    class quart_easing : public easing_function
+    {
+        public:
+            color4 apply(const color4& start, const color4& end) final
+            {
+                if (x() >= 1)
+                    return end;
+                auto diff = end - start;
+                return start + (diff * (x() * x() * x() * x()));
+            }
+    };
+    
+    class quint_easing : public easing_function
+    {
+        public:
+            color4 apply(const color4& start, const color4& end) final
+            {
+                if (x() >= 1)
+                    return end;
+                auto diff = end - start;
+                return start + (diff * (x() * x() * x() * x() * x()));
+            }
+    };
+    
+}
+
+#endif //BLT_INTERPOLATION_H
diff --git a/include/blt/math/vectors.h b/include/blt/math/vectors.h
index d83d397..ade8c32 100644
--- a/include/blt/math/vectors.h
+++ b/include/blt/math/vectors.h
@@ -433,12 +433,6 @@ namespace blt
     using color4 = vec4;
     using color3 = vec3;
     
-    inline constexpr color4 interpolate(const color4& in, const color4& desired, float factor)
-    {
-        auto diff = desired - in;
-        return in + (diff * factor);
-    }
-    
     inline constexpr color4 make_color(float r, float g, float b)
     {
         return color4{r, g, b, 1.0f};