Adding performance measurement tool.

README.md

@@ -25,6 +25,12 @@ The cross-platform fenster-based single-source bitmap renderer can be compiled w
 
 ````g++ -std=c++20 -mavx -mwindows -O3 tiny_bvh_fenster.cpp -o tiny_bvh_fenster```` (on windows)
 
+```g++ -std=c++20 -mavx -O3 -framework Cocoa tiny_bvh_fenster.cpp -o tiny_bvh_fenster``` (on macOS)
+
+The performance measurements use OpenMP and can be compiled with:
+
+````g++ -std=c++20 -mavx -fopenmp tiny_bvh_speedtest.cpp -o tiny_bvh_speedtest````
+
 # Version
 The current version of the library is a 'prototype'; please expect changes to the interface. Once the interface has settled, more functionality will follow. Plans:
 * Spatial Splits (SBVH)

tiny_bvh_fenster.cpp

@@ -82,4 +82,4 @@ void Tick( uint32_t* buf )
 		int c = (int)(15.9f * avg);
 		buf[x + y * SCRWIDTH] = c + (c << 8) + (c << 16);
 	}
-}
+}