src/tint/lang/msl/writer/common/options.h

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#ifndef SRC_TINT_LANG_MSL_WRITER_COMMON_OPTIONS_H_
#define SRC_TINT_LANG_MSL_WRITER_COMMON_OPTIONS_H_

#include <unordered_map>

#include "src/tint/api/common/binding_point.h"
#include "src/tint/utils/reflection/reflection.h"

namespace tint::msl::writer {
namespace binding {

/// Generic binding point
struct BindingInfo {
    /// The binding
    uint32_t binding = 0;

    /// Equality operator
    /// @param rhs the BindingInfo to compare against
    /// /// @returns true if this BindingInfo is equal to `rhs`
    inline bool operator==(const BindingInfo& rhs) const { return binding == rhs.binding; }
    /// Inequality operator
    /// @param rhs the BindingInfo to compare against
    /// @returns true if this BindingInfo is not equal to `rhs`
    inline bool operator!=(const BindingInfo& rhs) const { return !(*this == rhs); }

    /// @returns the hash code of the BindingInfo
    tint::HashCode HashCode() const { return Hash(binding); }

    /// Reflect the fields of this class so taht it can be used by tint::ForeachField()
    TINT_REFLECT(BindingInfo, binding);
};

using Uniform = BindingInfo;
using Storage = BindingInfo;
using Texture = BindingInfo;
using StorageTexture = BindingInfo;
using Sampler = BindingInfo;

/// An external texture
struct ExternalTexture {
    /// Metadata
    BindingInfo metadata{};
    /// Plane0 binding data
    BindingInfo plane0{};
    /// Plane1 binding data;
    BindingInfo plane1{};

    /// Reflect the fields of this class so that it can be used by tint::ForeachField()
    TINT_REFLECT(ExternalTexture, metadata, plane0, plane1);
};

}  // namespace binding

/// Maps the WGSL binding point to the SPIR-V group,binding for uniforms
using UniformBindings = std::unordered_map<BindingPoint, binding::Uniform>;
/// Maps the WGSL binding point to the SPIR-V group,binding for storage
using StorageBindings = std::unordered_map<BindingPoint, binding::Storage>;
/// Maps the WGSL binding point to the SPIR-V group,binding for textures
using TextureBindings = std::unordered_map<BindingPoint, binding::Texture>;
/// Maps the WGSL binding point to the SPIR-V group,binding for storage textures
using StorageTextureBindings = std::unordered_map<BindingPoint, binding::StorageTexture>;
/// Maps the WGSL binding point to the SPIR-V group,binding for samplers
using SamplerBindings = std::unordered_map<BindingPoint, binding::Sampler>;
/// Maps the WGSL binding point to the plane0, plane1, and metadata for external textures
using ExternalTextureBindings = std::unordered_map<BindingPoint, binding::ExternalTexture>;

/// Binding information
struct Bindings {
    /// Uniform bindings
    UniformBindings uniform{};
    /// Storage bindings
    StorageBindings storage{};
    /// Texture bindings
    TextureBindings texture{};
    /// Storage texture bindings
    StorageTextureBindings storage_texture{};
    /// Sampler bindings
    SamplerBindings sampler{};
    /// External bindings
    ExternalTextureBindings external_texture{};

    /// Reflect the fields of this class so that it can be used by tint::ForeachField()
    TINT_REFLECT(Bindings, uniform, storage, texture, storage_texture, sampler, external_texture);
};

/// Options used to specify a mapping of binding points to indices into a UBO
/// from which to load buffer sizes.
struct ArrayLengthFromUniformOptions {
    /// The MSL binding point to use to generate a uniform buffer from which to read buffer sizes.
    uint32_t ubo_binding;
    /// The mapping from the storage buffer binding points in WGSL binding-point space to the index
    /// into the uniform buffer where the length of the buffer is stored.
    std::unordered_map<BindingPoint, uint32_t> bindpoint_to_size_index;

    /// Reflect the fields of this class so that it can be used by tint::ForeachField()
    TINT_REFLECT(ArrayLengthFromUniformOptions, ubo_binding, bindpoint_to_size_index);
};

/// Configuration options used for generating MSL.
struct Options {
    /// Constructor
    Options();
    /// Destructor
    ~Options();
    /// Copy constructor
    Options(const Options&);
    /// Copy assignment
    /// @returns this Options
    Options& operator=(const Options&);

    /// Set to `true` to disable software robustness that prevents out-of-bounds accesses.
    bool disable_robustness = false;

    /// Set to `true` to disable workgroup memory zero initialization
    bool disable_workgroup_init = false;

    /// Set to `true` to generate a [[point_size]] attribute which is set to 1.0
    /// for all vertex shaders in the module.
    bool emit_vertex_point_size = false;

    /// Set to `true` to disable the polyfills on integer division and modulo.
    bool disable_polyfill_integer_div_mod = false;

    /// The index to use when generating a UBO to receive storage buffer sizes.
    /// Defaults to 30, which is the last valid buffer slot.
    uint32_t buffer_size_ubo_index = 30;

    /// The fixed sample mask to combine with fragment shader outputs.
    /// Defaults to 0xFFFFFFFF.
    uint32_t fixed_sample_mask = 0xFFFFFFFF;

    /// Index of pixel_local structure member index to attachment index
    std::unordered_map<uint32_t, uint32_t> pixel_local_attachments;

    /// Options used to specify a mapping of binding points to indices into a UBO
    /// from which to load buffer sizes.
    ArrayLengthFromUniformOptions array_length_from_uniform = {};

    /// The bindings
    Bindings bindings;

    /// Reflect the fields of this class so that it can be used by tint::ForeachField()
    TINT_REFLECT(Options,
                 disable_robustness,
                 disable_workgroup_init,
                 emit_vertex_point_size,
                 disable_polyfill_integer_div_mod,
                 buffer_size_ubo_index,
                 fixed_sample_mask,
                 pixel_local_attachments,
                 array_length_from_uniform,
                 bindings);
};

}  // namespace tint::msl::writer

#endif  // SRC_TINT_LANG_MSL_WRITER_COMMON_OPTIONS_H_