Move easings_example to its proper place

examples/others/easings.h

@@ -0,0 +1,263 @@
+/*******************************************************************************************
+*
+*   raylib easings (header only file)
+*
+*   Useful easing functions for values animation
+*
+*   This header uses:
+*       #define EASINGS_STATIC_INLINE       // Inlines all functions code, so it runs faster.
+*                                           // This requires lots of memory on system.
+*   How to use:
+*   The four inputs t,b,c,d are defined as follows:
+*   t = current time (in any unit measure, but same unit as duration)
+*   b = starting value to interpolate
+*   c = the total change in value of b that needs to occur
+*   d = total time it should take to complete (duration)
+*
+*   Example:
+*
+*   int currentTime = 0;
+*   int duration = 100;
+*   float startPositionX = 0.0f;
+*   float finalPositionX = 30.0f;
+*   float currentPositionX = startPositionX;
+*
+*   while (currentPositionX < finalPositionX)
+*   {
+*       currentPositionX = EaseSineIn(currentTime, startPositionX, finalPositionX - startPositionX, duration);
+*       currentTime++;
+*   }
+*
+*   A port of Robert Penner's easing equations to C (http://robertpenner.com/easing/)
+*
+*   Robert Penner License
+*   ---------------------------------------------------------------------------------
+*   Open source under the BSD License.
+*
+*   Copyright (c) 2001 Robert Penner. All rights reserved.
+*
+*   Redistribution and use in source and binary forms, with or without modification,
+*   are permitted provided that the following conditions are met:
+*
+*       - Redistributions of source code must retain the above copyright notice,
+*         this list of conditions and the following disclaimer.
+*       - Redistributions in binary form must reproduce the above copyright notice,
+*         this list of conditions and the following disclaimer in the documentation
+*         and/or other materials provided with the distribution.
+*       - Neither the name of the author nor the names of contributors may be used
+*         to endorse or promote products derived from this software without specific
+*         prior written permission.
+*
+*   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+*   ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+*   WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+*   IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
+*   INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+*   BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+*   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+*   LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
+*   OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+*   OF THE POSSIBILITY OF SUCH DAMAGE.
+*   ---------------------------------------------------------------------------------
+*
+*   Copyright (c) 2015 Ramon Santamaria
+*
+*   This software is provided "as-is", without any express or implied warranty. In no event
+*   will the authors be held liable for any damages arising from the use of this software.
+*
+*   Permission is granted to anyone to use this software for any purpose, including commercial
+*   applications, and to alter it and redistribute it freely, subject to the following restrictions:
+*
+*     1. The origin of this software must not be misrepresented; you must not claim that you
+*     wrote the original software. If you use this software in a product, an acknowledgment
+*     in the product documentation would be appreciated but is not required.
+*
+*     2. Altered source versions must be plainly marked as such, and must not be misrepresented
+*     as being the original software.
+*
+*     3. This notice may not be removed or altered from any source distribution.
+*
+**********************************************************************************************/
+
+#ifndef EASINGS_H
+#define EASINGS_H
+
+#define EASINGS_STATIC_INLINE     // NOTE: By default, compile functions as static inline
+
+#if defined(EASINGS_STATIC_INLINE)
+    #define EASEDEF static inline
+#else
+    #define EASEDEF extern
+#endif
+
+#include <tgmath.h>       // Required for: sin(), cos(), sqrt(), pow()
+
+#ifndef PI
+    #define PI 3.14159265358979323846f //Required as PI is not always defined in math.h
+#endif
+
+#ifdef __cplusplus
+extern "C" {            // Prevents name mangling of functions
+#endif
+
+// Linear Easing functions
+EASEDEF float EaseLinearNone(float t, float b, float c, float d) { return (c*t/d + b); }
+EASEDEF float EaseLinearIn(float t, float b, float c, float d) { return (c*t/d + b); }
+EASEDEF float EaseLinearOut(float t, float b, float c, float d) { return (c*t/d + b); }
+EASEDEF float EaseLinearInOut(float t,float b, float c, float d) { return (c*t/d + b); }
+
+// Sine Easing functions
+EASEDEF float EaseSineIn(float t, float b, float c, float d) { return (-c*cos(t/d*(PI/2.0f)) + c + b); }
+EASEDEF float EaseSineOut(float t, float b, float c, float d) { return (c*sin(t/d*(PI/2.0f)) + b); }
+EASEDEF float EaseSineInOut(float t, float b, float c, float d) { return (-c/2.0f*(cos(PI*t/d) - 1.0f) + b); }
+
+// Circular Easing functions
+EASEDEF float EaseCircIn(float t, float b, float c, float d) { t /= d; return (-c*(sqrt(1.0f - t*t) - 1.0f) + b); }
+EASEDEF float EaseCircOut(float t, float b, float c, float d) { t = t/d - 1.0f; return (c*sqrt(1.0f - t*t) + b); }
+EASEDEF float EaseCircInOut(float t, float b, float c, float d)
+{
+    if ((t/=d/2.0f) < 1.0f) return (-c/2.0f*(sqrt(1.0f - t*t) - 1.0f) + b);
+    t -= 2.0f; return (c/2.0f*(sqrt(1.0f - t*t) + 1.0f) + b);
+}
+
+// Cubic Easing functions
+EASEDEF float EaseCubicIn(float t, float b, float c, float d) { t /= d; return (c*t*t*t + b); }
+EASEDEF float EaseCubicOut(float t, float b, float c, float d) { t = t/d - 1.0f; return (c*(t*t*t + 1.0f) + b); }
+EASEDEF float EaseCubicInOut(float t, float b, float c, float d)
+{
+    if ((t/=d/2.0f) < 1.0f) return (c/2.0f*t*t*t + b);
+    t -= 2.0f; return (c/2.0f*(t*t*t + 2.0f) + b);
+}
+
+// Quadratic Easing functions
+EASEDEF float EaseQuadIn(float t, float b, float c, float d) { t /= d; return (c*t*t + b); }
+EASEDEF float EaseQuadOut(float t, float b, float c, float d) { t /= d; return (-c*t*(t - 2.0f) + b); }
+EASEDEF float EaseQuadInOut(float t, float b, float c, float d)
+{
+    if ((t/=d/2) < 1) return (((c/2)*(t*t)) + b);
+	return (-c/2.0f*(((t - 1.0f)*(t - 3.0f)) - 1.0f) + b);
+}
+
+// Exponential Easing functions
+EASEDEF float EaseExpoIn(float t, float b, float c, float d) { return (t == 0.0f) ? b : (c*pow(2.0f, 10.0f*(t/d - 1.0f)) + b); }
+EASEDEF float EaseExpoOut(float t, float b, float c, float d) { return (t == d) ? (b + c) : (c*(-pow(2.0f, -10.0f*t/d) + 1.0f) + b);    }
+EASEDEF float EaseExpoInOut(float t, float b, float c, float d)
+{
+    if (t == 0.0f) return b;
+    if (t == d) return (b + c);
+    if ((t/=d/2.0f) < 1.0f) return (c/2.0f*pow(2.0f, 10.0f*(t - 1.0f)) + b);
+
+	return (c/2.0f*(-pow(2.0f, -10.0f*(t - 1.0f)) + 2.0f) + b);
+}
+
+// Back Easing functions
+EASEDEF float EaseBackIn(float t, float b, float c, float d)
+{
+    float s = 1.70158f;
+    float postFix = t/=d;
+    return (c*(postFix)*t*((s + 1.0f)*t - s) + b);
+}
+
+EASEDEF float EaseBackOut(float t, float b, float c, float d)
+{
+    float s = 1.70158f;
+    t = t/d - 1.0f;
+    return (c*(t*t*((s + 1.0f)*t + s) + 1.0f) + b);
+}
+
+EASEDEF float EaseBackInOut(float t, float b, float c, float d)
+{
+    float s = 1.70158f;
+    if ((t/=d/2.0f) < 1.0f)
+    {
+        s *= 1.525f;
+        return (c/2.0f*(t*t*((s + 1.0f)*t - s)) + b);
+    }
+
+    float postFix = t-=2.0f;
+    s *= 1.525f;
+    return (c/2.0f*((postFix)*t*((s + 1.0f)*t + s) + 2.0f) + b);
+}
+
+// Bounce Easing functions
+EASEDEF float EaseBounceOut(float t, float b, float c, float d)
+{
+    if ((t/=d) < (1.0f/2.75f))
+    {
+        return (c*(7.5625f*t*t) + b);
+    }
+    else if (t < (2.0f/2.75f))
+    {
+        float postFix = t-=(1.5f/2.75f);
+        return (c*(7.5625f*(postFix)*t + 0.75f) + b);
+    }
+    else if (t < (2.5/2.75))
+    {
+        float postFix = t-=(2.25f/2.75f);
+        return (c*(7.5625f*(postFix)*t + 0.9375f) + b);
+    }
+    else
+    {
+        float postFix = t-=(2.625f/2.75f);
+        return (c*(7.5625f*(postFix)*t + 0.984375f) + b);
+    }
+}
+
+EASEDEF float EaseBounceIn(float t, float b, float c, float d) { return (c - EaseBounceOut(d - t, 0.0f, c, d) + b); }
+EASEDEF float EaseBounceInOut(float t, float b, float c, float d)
+{
+    if (t < d/2.0f) return (EaseBounceIn(t*2.0f, 0.0f, c, d)*0.5f + b);
+    else return (EaseBounceOut(t*2.0f - d, 0.0f, c, d)*0.5f + c*0.5f + b);
+}
+
+// Elastic Easing functions
+EASEDEF float EaseElasticIn(float t, float b, float c, float d)
+{
+    if (t == 0.0f) return b;
+    if ((t/=d) == 1.0f) return (b + c);
+
+    float p = d*0.3f;
+    float a = c;
+    float s = p/4.0f;
+    float postFix = a*pow(2.0f, 10.0f*(t-=1.0f));
+
+    return (-(postFix*sin((t*d-s)*(2.0f*PI)/p )) + b);
+}
+
+EASEDEF float EaseElasticOut(float t, float b, float c, float d)
+{
+    if (t == 0.0f) return b;
+    if ((t/=d) == 1.0f) return (b + c);
+
+    float p = d*0.3f;
+    float a = c;
+    float s = p/4.0f;
+
+    return (a*pow(2.0f,-10.0f*t)*sin((t*d-s)*(2.0f*PI)/p) + c + b);
+}
+
+EASEDEF float EaseElasticInOut(float t, float b, float c, float d)
+{
+    if (t == 0.0f) return b;
+    if ((t/=d/2.0f) == 2.0f) return (b + c);
+
+    float p = d*(0.3f*1.5f);
+    float a = c;
+    float s = p/4.0f;
+
+    if (t < 1.0f)
+    {
+        float postFix = a*pow(2.0f, 10.0f*(t-=1.0f));
+        return -0.5f*(postFix*sin((t*d-s)*(2.0f*PI)/p)) + b;
+    }
+
+    float postFix = a*pow(2.0f, -10.0f*(t-=1.0f));
+
+    return (postFix*sin((t*d-s)*(2.0f*PI)/p)*0.5f + c + b);
+}
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // EASINGS_H