[Feat] Expression Utilities, Arch (#8)

* expressions for eq, gt, if, lt

* move Ease class to EaseFunctions, use new expr utils

* move ease enum up one level

* remove unnecessary imports

* use enum from new location

* use enum make method

* update classes in readme

Author: ProjektGopher

README.md

@@ -39,7 +39,7 @@ For now this package can only be used within a Laravel app, but there are plans
 ```php
 use ProjektGopher\FFMpegTween\Tween;
 use ProjektGopher\FFMpegTween\Timing;
-use ProjektGopher\FFMpegTween\Enums\Ease;
+use ProjektGopher\FFMpegTween\Ease;
 
 $x = (new Tween())
     ->from("50")
@@ -54,7 +54,7 @@ $x = (new Tween())
 use ProjektGopher\FFMpegTween\Keyframe;
 use ProjektGopher\FFMpegTween\Timeline;
 use ProjektGopher\FFMpegTween\Timing;
-use ProjektGopher\FFMpegTween\Enums\Ease;
+use ProjektGopher\FFMpegTween\Ease;
 
 $x = new Timeline()
 $x->keyframe((new Keyframe)

scripts/generateEasings

@@ -3,16 +3,15 @@
 
 require_once __DIR__.'/../vendor/autoload.php';
 
-use ProjektGopher\FFMpegTween\Enums\Ease as AvailableEasings;
 use ProjektGopher\FFMpegTween\Ease;
 
 echo 'starting... (fail fast)'.PHP_EOL;
 
 $time = "X/H";
 
-foreach (AvailableEasings::cases() as $ease) {
+foreach (Ease::cases() as $ease) {
     echo "Generating snapshot for {$ease->value} easing...".PHP_EOL;
-    $easeMultiplier = Ease::{$ease->value}($time);
+    $easeMultiplier = $ease->make($time);
 
     $input = "-f lavfi -i \"color=c=black:s=256x256:d=1\"";
     $margin = '28';

scripts/generateTimeline

@@ -5,7 +5,7 @@ require_once __DIR__.'/../vendor/autoload.php';
 
 use ProjektGopher\FFMpegTween\Timeline;
 use ProjektGopher\FFMpegTween\Keyframe;
-use ProjektGopher\FFMpegTween\Enums\Ease;
+use ProjektGopher\FFMpegTween\Ease;
 use ProjektGopher\FFMpegTween\Timing;
 
 echo 'Generating video sample using Timeline...'.PHP_EOL;

src/Ease.php

@@ -2,210 +2,48 @@
 
 namespace ProjektGopher\FFMpegTween;
 
-/**
- * Ease
- *
- * Returns a string which will evaluate to a value between 0 and 1.
- * This allows us to multiply the _change_ in value by the chosen
- * easing function to get the actual value at a given time.
- *
- * (paraphrased from easings.net)
- * The argument `$time` should be a `string` which represents the absolute
- * progress of the animation in the bounds of 0 (beginning of the animation)
- * and 1 (end of animation).
- */
-class Ease
+enum Ease: string
 {
-    public static function Linear(string $time): string
-    {
-        return $time;
-    }
-
-    public static function EaseInSine(string $time): string
-    {
-        return "1-cos((({$time})*PI)/2)";
-    }
-
-    public static function EaseOutSine(string $time): string
-    {
-        return "sin((({$time})*PI)/2)";
-    }
-
-    public static function EaseInOutSine(string $time): string
-    {
-        return "-(cos(PI*({$time}))-1)/2";
-    }
-
-    public static function EaseInQuad(string $time): string
-    {
-        return "pow(({$time})\\,2)";
-    }
-
-    public static function EaseOutQuad(string $time): string
-    {
-        return "1-(1-({$time}))*(1-({$time}))";
-    }
-
-    public static function EaseInOutQuad(string $time): string
-    {
-        return "if(lt(({$time})\\,0.5)\\,2*pow(({$time})\\,2)\\,1-pow(-2*({$time})+2\\,2)/2)";
-    }
-
-    public static function EaseInCubic(string $time): string
-    {
-        return "pow(({$time})\\,3)";
-    }
-
-    public static function EaseOutCubic(string $time): string
-    {
-        return "1-pow(1-({$time})\\,3)";
-    }
-
-    public static function EaseInOutCubic(string $time): string
-    {
-        return "if(lt(({$time})\\,0.5)\\,4*pow(({$time})\\,3)\\,1-pow(-2*({$time})+2\\,3)/2)";
-    }
-
-    public static function EaseInQuart(string $time): string
-    {
-        return "pow(({$time})\\,4)";
-    }
-
-    public static function EaseOutQuart(string $time): string
-    {
-        return "1-pow(1-({$time})\\,4)";
-    }
-
-    public static function EaseInOutQuart(string $time): string
-    {
-        return "if(lt(({$time})\\,0.5)\\,8*pow(({$time})\\,4)\\,1-pow(-2*({$time})+2\\,4)/2)";
-    }
-
-    public static function EaseInQuint(string $time): string
-    {
-        return "pow(({$time})\\,5)";
-    }
-
-    public static function EaseOutQuint(string $time): string
-    {
-        return "1-pow(1-({$time})\\,5)";
-    }
-
-    public static function EaseInOutQuint(string $time): string
-    {
-        return "if(lt(({$time})\\,0.5)\\,16*pow(({$time})\\,5)\\,1-pow(-2*({$time})+2\\,5)/2)";
-    }
-
-    public static function EaseInExpo(string $time): string
-    {
-        return "if(eq(({$time})\\,0)\\,0\\,pow(2\\,10*({$time})-10))";
-    }
-
-    public static function EaseOutExpo(string $time): string
-    {
-        return "if(eq(({$time})\\,1)\\,1\\,1-pow(2\\,-10*({$time})))";
-    }
-
-    public static function EaseInOutExpo(string $time): string
-    {
-        $firstExp = "pow(2\\,20*({$time})-10)/2";
-        $secondExp = "(2-pow(2\\,-20*({$time})+10))/2";
-
-        // We have to set the return value for 0 and 1 explicitly as we lose accuracy at the 4th decimal place.
-        return "if(eq(({$time})\\,0)\\,0\\,if(eq(({$time})\\,1)\\,1\\,if(lt(({$time})\\,0.5)\\,{$firstExp}\\,{$secondExp})))";
-    }
-
-    public static function EaseInCirc(string $time): string
-    {
-        return "1-sqrt(1-pow(({$time})\\,2))";
-    }
-
-    public static function EaseOutCirc(string $time): string
-    {
-        return "sqrt(1-pow(({$time})-1\\,2))";
-    }
-
-    public static function EaseInOutCirc(string $time): string
-    {
-        return "if(lt(({$time})\\,0.5)\\,(1-sqrt(1-pow(2*({$time})\\,2)))/2\\,(sqrt(1-pow(-2*({$time})+2\\,2))+1)/2)";
-    }
-
-    public static function EaseInBack(string $time): string
-    {
-        $c1 = 1.70158;
-        $c3 = $c1 + 1;
-
-        return "{$c3}*pow(({$time})\\,3)-{$c1}*pow(({$time})\\,2)";
-    }
-
-    public static function EaseOutBack(string $time): string
-    {
-        $c1 = 1.70158;
-        $c3 = $c1 + 1;
-
-        return "1+{$c3}*pow(({$time})-1\\,3)+{$c1}*pow(({$time})-1\\,2)";
-    }
-
-    public static function EaseInOutBack(string $time): string
-    {
-        $c1 = 1.70158;
-        $c2 = $c1 * 1.525;
-
-        return "if(lt(({$time})\\,0.5)\\,(pow(2*({$time})\\,2)*(({$c2}+1)*2*({$time})-{$c2}))/2\\,(pow(2*({$time})-2\\,2)*(({$c2}+1)*(({$time})*2-2)+{$c2})+2)/2)";
-    }
-
-    public static function EaseInElastic(string $time): string
-    {
-        $c4 = (2 * M_PI) / 3;
-
-        return "if(eq(({$time})\\,0)\\,0\\,if(eq(({$time})\\,1)\\,1\\,-pow(2\\,10*({$time})-10)*sin((({$time})*10-10.75)*{$c4})))";
-    }
-
-    public static function EaseOutElastic(string $time): string
-    {
-        $c4 = (2 * M_PI) / 3;
-
-        return "if(eq(({$time})\\,0)\\,0\\,if(eq(({$time})\\,1)\\,1\\,pow(2\\,-10*({$time}))*sin((({$time})*10-0.75)*{$c4})+1))";
-    }
-
-    public static function EaseInOutElastic(string $time): string
-    {
-        $c5 = (2 * M_PI) / 4.5;
-        $ltExpr = "-(pow(2\\,20*({$time})-10)*sin((20*({$time})-11.125)*{$c5}))/2";
-        $gtExpr = "(pow(2\\,-20*({$time})+10)*sin((20*({$time})-11.125)*{$c5}))/2+1";
-
-        return "if(eq(({$time})\\,0)\\,0\\,if(eq(({$time})\\,1)\\,1\\,if(lt(({$time})\\,0.5)\\,{$ltExpr}\\,{$gtExpr})))";
-    }
-
-    public static function EaseInBounce(string $time): string
-    {
-        $x = self::EaseOutBounce("1-({$time})");
-
-        return "1-({$x})";
-    }
-
-    public static function EaseOutBounce(string $time): string
-    {
-        $n1 = 7.5625;
-        $d1 = 2.75;
-        $firstExpr = "{$n1}*pow(({$time})\\,2)";
-        $secondTime = "(({$time})-1.5/{$d1})";
-        $secondExpr = "{$n1}*{$secondTime}*{$secondTime}+0.75";
-        $thirdTime = "(({$time})-2.25/{$d1})";
-        $thirdExpr = "{$n1}*{$thirdTime}*{$thirdTime}+0.9375";
-        $fourthTime = "(({$time})-2.65/{$d1})";
-        $fourthExpr = "{$n1}*{$fourthTime}*{$fourthTime}+0.984375";
-
-        return "if(lt(({$time})\\, 1/{$d1})\\,{$firstExpr}\\,if(lt(({$time})\\,2/{$d1})\\,{$secondExpr}\\,if(lt(({$time})\\,2.5/{$d1})\\,{$thirdExpr}\\,{$fourthExpr})))";
-    }
-
-    public static function EaseInOutBounce(string $time): string
-    {
-        $x1 = self::EaseOutBounce("1-2*({$time})");
-        $x2 = self::EaseOutBounce("2*({$time})-1");
-        $ltExpr = "(1-({$x1}))/2";
-        $gtExpr = "(1+({$x2}))/2";
-
-        return "if(lt(({$time})\\,0.5)\\,{$ltExpr}\\,{$gtExpr})";
+    case Linear = 'Linear';
+    case InSine = 'EaseInSine';
+    case OutSine = 'EaseOutSine';
+    case InOutSine = 'EaseInOutSine';
+    case InQuad = 'EaseInQuad';
+    case OutQuad = 'EaseOutQuad';
+    case InOutQuad = 'EaseInOutQuad';
+    case InCubic = 'EaseInCubic';
+    case OutCubic = 'EaseOutCubic';
+    case InOutCubic = 'EaseInOutCubic';
+    case InQuart = 'EaseInQuart';
+    case OutQuart = 'EaseOutQuart';
+    case InOutQuart = 'EaseInOutQuart';
+    case InQuint = 'EaseInQuint';
+    case OutQuint = 'EaseOutQuint';
+    case InOutQuint = 'EaseInOutQuint';
+    case InExpo = 'EaseInExpo';
+    case OutExpo = 'EaseOutExpo';
+    case InOutExpo = 'EaseInOutExpo';
+    case InCirc = 'EaseInCirc';
+    case OutCirc = 'EaseOutCirc';
+    case InOutCirc = 'EaseInOutCirc';
+    case InBack = 'EaseInBack';
+    case OutBack = 'EaseOutBack';
+    case InOutBack = 'EaseInOutBack';
+    case InElastic = 'EaseInElastic';
+    case OutElastic = 'EaseOutElastic';
+    case InOutElastic = 'EaseInOutElastic';
+    case InBounce = 'EaseInBounce';
+    case OutBounce = 'EaseOutBounce';
+    case InOutBounce = 'EaseInOutBounce';
+
+    public function make(string $time): string
+    {
+        // Wrap the result in parentheses to ensure that it
+        // doesn't interfere with surrounding expressions
+        return implode([
+            '(',
+            EaseFunctions::{$this->value}($time),
+            ')',
+        ]);
     }
 }