Update README.md

Author: herace

README.md

@@ -12,7 +12,7 @@ Note: For the present, there may be incompatible changes without notice in advan
 * MSVC2015/MinGW/GCC/Clang (32-bit or 64-bit)
 
 ## Runtime Requirements
-* OpenGL4.0 CoreProfile or later
-  * On linux, you can check whether your graphics card supports OpenGL4.0 CoreProfile or not, run `glxinfo | grep "OpenGL core profile version"` on your terminal
+* OpenGL3.2 CoreProfile or later
+  * On linux, you can check whether your graphics card supports OpenGL3.2 CoreProfile or not, run `glxinfo | grep "OpenGL core profile version"` on your terminal
 * FFmpeg (Please install ffmpeg on your own for video exporting, you can also place a ffmpeg executable in /tools.)