From 5fe7c1a926d159ecc9d36f4033609dabafd5a8ac Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Miloslav=20=C4=8C=C3=AD=C5=BE?= <tastyfish@seznam.cz>
Date: Sun, 9 Sep 2018 19:56:12 +0200
Subject: [PATCH] Use Chebyshew instead Euclid

---
 demo1.cpp | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/demo1.cpp b/demo1.cpp
index 11181e9..d4b2e11 100644
--- a/demo1.cpp
+++ b/demo1.cpp
@@ -7,6 +7,7 @@
   license: CC0 1.0
 */
 
+// redefine player's height
 #define CAMERA_COLL_HEIGHT_BELOW ((3 * UNITS_PER_SQUARE) / 2)
 
 #include "general.hpp"
@@ -665,7 +666,11 @@ void draw()
 
   for (uint8_t i = 0; i < SPRITES; ++i)
   {
-    if (dist(sprites[i].mPosition,player.mCamera.position) > SPRITE_MAX_DISTANCE)
+    // use Chebyshew distance instead Euclidean, it's faster
+    if (absVal(sprites[i].mPosition.x - player.mCamera.position.x) > SPRITE_MAX_DISTANCE)
+      continue;
+
+    if (absVal(sprites[i].mPosition.y - player.mCamera.position.y) > SPRITE_MAX_DISTANCE)
       continue;
 
     PixelInfo pos = mapToScreen(sprites[i].mPosition,sprites[i].mHeight,player.mCamera);