Added #define to make MSVC see M_PI

Discussed here: #12

autodiff.hh

@@ -13,6 +13,8 @@
   that file for usage examples
  */
 
+// Apparently I need this in MSVC to get constants
+#define _USE_MATH_DEFINES
 #include <math.h>
 #include <string.h>
 #include "strides.h"

cameramodel-parser.re

@@ -8,6 +8,10 @@
 //
 //     http://www.apache.org/licenses/LICENSE-2.0
 
+
+// Apparently I need this in MSVC to get constants
+#define _USE_MATH_DEFINES
+
 #include <stdio.h>
 #include <sys/types.h>
 #include <sys/stat.h>

mrcal.c

@@ -6,6 +6,9 @@
 //
 //     http://www.apache.org/licenses/LICENSE-2.0
 
+// Apparently I need this in MSVC to get constants
+#define _USE_MATH_DEFINES
+
 #include <stdio.h>
 #include <stdlib.h>
 #include <inttypes.h>

poseutils-opencv.c

@@ -30,6 +30,9 @@
 // and on any theory of liability, whether in contract, strict liability,
 // or tort (including negligence or otherwise) arising in any way out of
 
+// Apparently I need this in MSVC to get constants
+#define _USE_MATH_DEFINES
+
 #include <math.h>
 #include <float.h>
 

poseutils.c

@@ -6,6 +6,9 @@
 //
 //     http://www.apache.org/licenses/LICENSE-2.0
 
+// Apparently I need this in MSVC to get constants
+#define _USE_MATH_DEFINES
+
 #include <stdio.h>
 #include <string.h>
 #include <math.h>

stereo.c

@@ -6,6 +6,9 @@
 //
 //     http://www.apache.org/licenses/LICENSE-2.0
 
+// Apparently I need this in MSVC to get constants
+#define _USE_MATH_DEFINES
+
 #include <math.h>
 
 #include "mrcal.h"

test/test-cahvor.c

@@ -1,3 +1,6 @@
+// Apparently I need this in MSVC to get constants
+#define _USE_MATH_DEFINES
+
 #include <stdio.h>
 #include <stdlib.h>
 #include <assert.h>

test/test-harness.h

@@ -1,5 +1,8 @@
 #pragma once
 
+// Apparently I need this in MSVC to get constants
+#define _USE_MATH_DEFINES
+
 #include <stdio.h>
 #include <stdbool.h>
 #include <math.h>