sokol_gfx.h: validation for sg_shader_desc.mtl_threads_per_threadgroup

sokol_gfx.h

@@ -3855,6 +3855,7 @@ typedef struct sg_frame_stats {
     _SG_LOGITEM_XMACRO(VALIDATE_SHADERDESC_COMPUTE_SOURCE_OR_BYTECODE, "compute shader source or byte code expected") \
     _SG_LOGITEM_XMACRO(VALIDATE_SHADERDESC_INVALID_SHADER_COMBO, "cannot combine compute shaders with vertex or fragment shaders") \
     _SG_LOGITEM_XMACRO(VALIDATE_SHADERDESC_NO_BYTECODE_SIZE, "shader byte code length (in bytes) required") \
+    _SG_LOGITEM_XMACRO(VALIDATE_SHADERDESC_METAL_THREADS_PER_THREADGROUP, "sg_shader_desc.mtl_threads_per_threadgroup must be initialized for compute shaders (metal)") \
     _SG_LOGITEM_XMACRO(VALIDATE_SHADERDESC_UNIFORMBLOCK_NO_CONT_MEMBERS, "uniform block members must occupy continuous slots") \
     _SG_LOGITEM_XMACRO(VALIDATE_SHADERDESC_UNIFORMBLOCK_SIZE_IS_ZERO, "bound uniform block size cannot be zero") \
     _SG_LOGITEM_XMACRO(VALIDATE_SHADERDESC_UNIFORMBLOCK_METAL_BUFFER_SLOT_OUT_OF_RANGE, "uniform block 'msl_buffer_n' is out of range (must be 0..7)") \
@@ -17708,6 +17709,13 @@ _SOKOL_PRIVATE bool _sg_validate_shader_desc(const sg_shader_desc* desc) {
         } else {
             _SG_VALIDATE((0 == desc->compute_func.source) && (0 == desc->compute_func.bytecode.ptr), VALIDATE_SHADERDESC_INVALID_SHADER_COMBO);
         }
+        #if defined(SOKOL_METAL)
+        if (is_compute_shader) {
+            _SG_VALIDATE(desc->mtl_threads_per_threadgroup.x > 0, VALIDATE_SHADERDESC_METAL_THREADS_PER_THREADGROUP);
+            _SG_VALIDATE(desc->mtl_threads_per_threadgroup.y > 0, VALIDATE_SHADERDESC_METAL_THREADS_PER_THREADGROUP);
+            _SG_VALIDATE(desc->mtl_threads_per_threadgroup.z > 0, VALIDATE_SHADERDESC_METAL_THREADS_PER_THREADGROUP);
+        }
+        #endif
         for (size_t i = 0; i < SG_MAX_VERTEX_ATTRIBUTES; i++) {
             if (desc->attrs[i].glsl_name) {
                 _SG_VALIDATE(strlen(desc->attrs[i].glsl_name) < _SG_STRING_SIZE, VALIDATE_SHADERDESC_ATTR_STRING_TOO_LONG);
@@ -18610,7 +18618,6 @@ _SOKOL_PRIVATE sg_shader_desc _sg_shader_desc_defaults(const sg_shader_desc* des
             def.compute_func.d3d11_target = _sg_def(def.fragment_func.d3d11_target,"cs_5_0");
         }
     #endif
-    def.mtl_threads_per_threadgroup.x = _sg_def(desc->mtl_threads_per_threadgroup.x, 1);
     def.mtl_threads_per_threadgroup.y = _sg_def(desc->mtl_threads_per_threadgroup.y, 1);
     def.mtl_threads_per_threadgroup.z = _sg_def(desc->mtl_threads_per_threadgroup.z, 1);
     for (size_t ub_index = 0; ub_index < SG_MAX_UNIFORMBLOCK_BINDSLOTS; ub_index++) {