[Bf-blender-cvs] [fe41c1ec0b7] master: EEVEE: Fix crash on certain drivers caused by redefined constant

[Clément Foucault]

Commit: fe41c1ec0b79b2be22f7bc14c92ce94737f91800
Author: Clément Foucault
Date:   Wed Feb 26 14:59:47 2020 +0100
Branches: master
https://developer.blender.org/rBfe41c1ec0b79b2be22f7bc14c92ce94737f91800

EEVEE: Fix crash on certain drivers caused by redefined constant

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M	source/blender/draw/engines/eevee/shaders/default_world_frag.glsl

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diff --git a/source/blender/draw/engines/eevee/shaders/default_world_frag.glsl b/source/blender/draw/engines/eevee/shaders/default_world_frag.glsl
index 1faa02fd354..8c876cf582c 100644
--- a/source/blender/draw/engines/eevee/shaders/default_world_frag.glsl
+++ b/source/blender/draw/engines/eevee/shaders/default_world_frag.glsl
@@ -12,7 +12,9 @@ uniform float studioLightIntensity = 1.0;
 uniform float studioLightBlur = 0.0;
 in vec3 viewPosition;
 
-#  define M_PI 3.14159265358979323846
+#  ifndef M_PI
+#    define M_PI 3.14159265358979323846
+#  endif
 
 vec3 background_transform_to_world(vec3 viewvec)
 {