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Diffstat (limited to 'docs')
| -rw-r--r-- | docs/cuda-target.md | 21 |
1 files changed, 20 insertions, 1 deletions
diff --git a/docs/cuda-target.md b/docs/cuda-target.md index 01803c145..9c82b1dc9 100644 --- a/docs/cuda-target.md +++ b/docs/cuda-target.md @@ -97,7 +97,26 @@ The UniformState and UniformEntryPointParams struct typically vary by shader. Un ## Unsized arrays -WIP: Not implemented yet. +Unsized arrays can be used, which are indicated by an array with no size as in `[]`. For example + +``` + RWStructuredBuffer<int> arrayOfArrays[]; +``` + +With normal 'sized' arrays, the elements are just stored contiguously within wherever they are defined. With an unsized array they map to `Array<T>` which is... + +``` + T* data; + size_t count; +``` + +Note that there is no method in the shader source to get the `count`, even though on the CUDA target it is stored and easily available. This is because of the behavior on GPU targets + +* That the count has to be stored elsewhere (unlike with CUDA) +* On some GPU targets there is no bounds checking - accessing outside the bound values can cause *undefined behavior* +* The elements may be laid out *contiguously* on GPU + +In practice this means if you want to access the `count` in shader code it will need to be passed by another mechanism - such as within a constant buffer. It is possible in the future support may be added to allow direct access of `count` work across targets transparently. ## Prelude |