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, 6 insertions, 1 deletions

diff --git a/source/blender/gpu/opengl/gl_shader.cc b/source/blender/gpu/opengl/gl_shader.cc
index c0182306047..c76e21f9f71 100644
--- a/source/blender/gpu/opengl/gl_shader.cc
+++ b/source/blender/gpu/opengl/gl_shader.cc
@@ -24,6 +24,8 @@ using namespace blender;
 using namespace blender::gpu;
 using namespace blender::gpu::shader;
 
+extern char datatoc_glsl_shader_defines_glsl[];
+
 /* -------------------------------------------------------------------- */
 /** \name Creation / Destruction
  * \{ */
@@ -760,7 +762,7 @@ bool GLShader::do_geometry_shader_injection(const shader::ShaderCreateInfo *info
 static char *glsl_patch_default_get()
 {
   /** Used for shader patching. Init once. */
-  static char patch[1024] = "\0";
+  static char patch[2048] = "\0";
   if (patch[0] != '\0') {
     return patch;
   }
@@ -827,6 +829,9 @@ static char *glsl_patch_default_get()
   STR_CONCATF(patch, slen, "#define DFDX_SIGN %1.1f\n", GLContext::derivative_signs[0]);
   STR_CONCATF(patch, slen, "#define DFDY_SIGN %1.1f\n", GLContext::derivative_signs[1]);
 
+  /* GLSL Backend Lib. */
+  STR_CONCAT(patch, slen, datatoc_glsl_shader_defines_glsl);
+
   BLI_assert(slen < sizeof(patch));
   return patch;
 }