Metal: Make GLSL shader source MSL compliant also

Metal shading language follows the C++ 14 standard and in some cases requires a greater level of explicitness than GLSL. There are also some small language differences:

- Explicit type-casts (C++ requirements)
- Explicit constant values (C++ requirements, e.g. floating point values using 0.0 instead of 0).
- Metal/OpenGL compatibility paths
- GLSL Function prototypes
- Explicit accessors for vector types when sampling textures.

Authored by Apple: Michael Parkin-White

Ref T96261

Reviewed By: fclem

Maniphest Tasks: T96261

Differential Revision: https://developer.blender.org/D14378

1 files changed, 1 insertions, 1 deletions

diff --git a/source/blender/draw/engines/workbench/shaders/workbench_volume_frag.glsl b/source/blender/draw/engines/workbench/shaders/workbench_volume_frag.glsl
index 076f6e80104..4ff281ccd29 100644
--- a/source/blender/draw/engines/workbench/shaders/workbench_volume_frag.glsl
+++ b/source/blender/draw/engines/workbench/shaders/workbench_volume_frag.glsl
@@ -94,7 +94,7 @@ vec4 flag_to_color(uint flag)
   if (bool(flag & uint(16))) {
     color.rgb += vec3(0.9, 0.3, 0.0); /* orange */
   }
-  if (color.rgb == vec3(0.0)) {
+  if (is_zero(color.rgb)) {
     color.rgb += vec3(0.5, 0.0, 0.0); /* medium red */
   }
   return color;