From fc2fd1343f0eadbf5e39b0a7a8e8a1c7dc9afeab Mon Sep 17 00:00:00 2001
From: Dennis Eichhorn <spl1nnes.com@googlemail.com>
Date: Thu, 25 May 2023 12:19:24 +0000
Subject: [PATCH] Improve performance

---
 Image/Skew.php                             | 17 +++++++------
 Math/Geometry/ConvexHull/MonotoneChain.php | 28 ++++++++--------------
 2 files changed, 20 insertions(+), 25 deletions(-)

diff --git a/Image/Skew.php b/Image/Skew.php
index 4ae1f3051..092477a84 100755
--- a/Image/Skew.php
+++ b/Image/Skew.php
@@ -132,12 +132,15 @@ final class Skew
 
         $rotated = [[]];
 
+        $cXArr = [];
+        for ($j = 0; $j < $dim[1]; ++$j) {
+            $cXArr[] = $j - $dim[1] / 2.0; // center
+        }
+
         for ($i = 0; $i < $dim[0]; ++$i) {
             $cY = $i - $dim[0] / 2.0; // center
 
-            for ($j = 0; $j < $dim[1]; ++$j) {
-                $cX = $j - $dim[1] / 2.0; // center
-
+            foreach ($cXArr as $j => $cX) {
                 $x = $cos * $cX + $sin * $cY + $dim[1] / 2.0;
                 $y = -$sin * $cX + $cos * $cY + $dim[0] / 2.0;
 
@@ -162,11 +165,11 @@ final class Skew
      */
     private static function getNearestValue(array $pixel, array $dim, float $x, float $y) : int
     {
-        $xLow  = \min((int) $x, $dim[1] - 1);
-        $xHigh = \min((int) \ceil($x), $dim[1] - 1);
+        $xLow  = ($x < 0) ? 0 : (($x > ($dim[1] - 1)) ? ($dim[1] - 1) : (int) $x);
+        $xHigh = ($xLow == ($dim[1] - 1)) ? $xLow : ($xLow + 1);
 
-        $yLow  = \min((int) $y, $dim[0] - 1);
-        $yHigh = \min((int) \ceil($y), $dim[0] - 1);
+        $yLow  = ($y < 0) ? 0 : (($y > ($dim[0] - 1)) ? ($dim[0] - 1) : (int) $y);
+        $yHigh = ($yLow == ($dim[0] - 1)) ? $yLow : ($yLow + 1);
 
         $points = [
             [$xLow, $yLow],
diff --git a/Math/Geometry/ConvexHull/MonotoneChain.php b/Math/Geometry/ConvexHull/MonotoneChain.php
index ae0460657..e82d0902d 100755
--- a/Math/Geometry/ConvexHull/MonotoneChain.php
+++ b/Math/Geometry/ConvexHull/MonotoneChain.php
@@ -56,7 +56,11 @@ final class MonotoneChain
 
         // Lower hull
         for ($i = 0; $i < $n; ++$i) {
-            while ($k >= 2 && self::cross($result[$k - 2], $result[$k - 1], $points[$i]) <= 0) {
+            while ($k >= 2
+                && ($result[$k - 1]['x'] - $result[$k - 2]['x']) * ($points[$i]['y'] - $result[$k - 2]['y'])
+                    - ($result[$k - 1]['y'] - $result[$k - 2]['y']) * ($points[$i]['x'] - $result[$k - 2]['x']
+                ) <= 0
+            ) {
                 --$k;
             }
 
@@ -65,7 +69,11 @@ final class MonotoneChain
 
         // Upper hull
         for ($i = $n - 2, $t = $k + 1; $i >= 0; --$i) {
-            while ($k >= $t && self::cross($result[$k - 2], $result[$k - 1], $points[$i]) <= 0) {
+            while ($k >= $t
+                && ($result[$k - 1]['x'] - $result[$k - 2]['x']) * ($points[$i]['y'] - $result[$k - 2]['y'])
+                    - ($result[$k - 1]['y'] - $result[$k - 2]['y']) * ($points[$i]['x'] - $result[$k - 2]['x']
+                ) <= 0
+            ) {
                 --$k;
             }
 
@@ -78,22 +86,6 @@ final class MonotoneChain
         return \array_slice($result, 0, $k - 1);
     }
 
-    /**
-     * Counter clock wise turn?
-     *
-     * @param array{x:int|float, y:int|float} $a Point a
-     * @param array{x:int|float, y:int|float} $b Point b
-     * @param array{x:int|float, y:int|float} $c Point c
-     *
-     * @return float
-     *
-     * @since 1.0.0
-     */
-    private static function cross(array $a, array $b, array $c) : float
-    {
-        return ($b['x'] - $a['x']) * ($c['y'] - $a['y']) - ($b['y'] - $a['y']) * ($c['x'] - $a['x']);
-    }
-
     /**
      * Sort by x coordinate then by z coordinate
      *