From e3047956229d3ed90885801463ef19affeeaa630 Mon Sep 17 00:00:00 2001
From: Alexander Alekhin <alexander.alekhin@intel.com>
Date: Thu, 12 Jan 2017 19:14:51 +0300
Subject: [PATCH] cmake: add defines to enable useful macroses

---
 cmake/OpenCVModule.cmake | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/cmake/OpenCVModule.cmake b/cmake/OpenCVModule.cmake
index 925731b7c6..c5a81b2422 100644
--- a/cmake/OpenCVModule.cmake
+++ b/cmake/OpenCVModule.cmake
@@ -170,6 +170,10 @@ macro(ocv_add_module _name)
       return() # extra protection from redefinition
     endif()
     project(${the_module})
+    add_definitions(
+        -D_USE_MATH_DEFINES  # M_PI constant in MSVS
+        -D__STDC_CONSTANT_MACROS -D__STDC_LIMIT_MACROS  # to use C libraries from C++ code (ffmpeg)
+    )
   endif(OPENCV_INITIAL_PASS)
 endmacro()