From c988a8e36ef102a53489bdc897800f2a48e4c2df Mon Sep 17 00:00:00 2001
From: Luca Bacci <luca.bacci982@gmail.com>
Date: Fri, 27 Mar 2026 10:34:33 +0100
Subject: [PATCH] MSVC: Define _USE_MATH_DEFINES via meson.build

This way M_PI and other constants are available everywhere.
The constants are behind a preprocessor macro because they
aren't part of standard C.
---
 meson.build                                | 1 +
 perf/micro/pythagoras-tree.c               | 2 +-
 src/cairoint.h                             | 3 ---
 test/cairo-test.h                          | 1 -
 util/cairo-script/cairo-script-operators.c | 4 ----
 5 files changed, 2 insertions(+), 9 deletions(-)

diff --git a/meson.build b/meson.build
index 0251a88ed..98e007bca 100644
--- a/meson.build
+++ b/meson.build
@@ -102,6 +102,7 @@ if cc.get_id() == 'msvc'
                         language : ['c', 'cpp'])
   add_project_arguments(['-D_CRT_SECURE_NO_WARNINGS',
                          '-D_CRT_NONSTDC_NO_WARNINGS',
+                         '-D_USE_MATH_DEFINES',
                         ], language : ['c', 'cpp'])
 endif
 
diff --git a/perf/micro/pythagoras-tree.c b/perf/micro/pythagoras-tree.c
index 9d3ca1155..6581e4ed6 100644
--- a/perf/micro/pythagoras-tree.c
+++ b/perf/micro/pythagoras-tree.c
@@ -24,7 +24,7 @@
  */
 
 #include "cairo-perf.h"
-#define _USE_MATH_DEFINES /* for M_SQRT2 on win32 */
+
 #include <math.h>
 
 static void
diff --git a/src/cairoint.h b/src/cairoint.h
index b18a579be..fa8f5d395 100644
--- a/src/cairoint.h
+++ b/src/cairoint.h
@@ -55,9 +55,6 @@
 #include <stdarg.h>
 #include <stddef.h>
 
-#ifdef _MSC_VER
-#define _USE_MATH_DEFINES
-#endif
 #include <math.h>
 #include <limits.h>
 #include <stdio.h>
diff --git a/test/cairo-test.h b/test/cairo-test.h
index 4a853c0d1..0a36cd7a3 100644
--- a/test/cairo-test.h
+++ b/test/cairo-test.h
@@ -55,7 +55,6 @@ typedef unsigned __int64 uint64_t;
 #endif
 
 #ifdef _MSC_VER
-#define _USE_MATH_DEFINES
 #include <float.h>
 #endif
 
diff --git a/util/cairo-script/cairo-script-operators.c b/util/cairo-script/cairo-script-operators.c
index 27116ca6d..301080b31 100644
--- a/util/cairo-script/cairo-script-operators.c
+++ b/util/cairo-script/cairo-script-operators.c
@@ -46,10 +46,6 @@
 #include <stdlib.h> /* mkstemp */
 #include <string.h>
 
-#ifdef _MSC_VER
-#define _USE_MATH_DEFINES /* for M_LN2, M_PI and M_SQRT2 on win32 */
-#endif
-
 #include <math.h>
 #include <limits.h> /* INT_MAX */
 #include <assert.h>