1 files changed, 550 insertions, 0 deletions
diff --git a/third_party/rust/metal/src/mps.rs b/third_party/rust/metal/src/mps.rs
new file mode 100644
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+++ b/third_party/rust/metal/src/mps.rs
@@ -0,0 +1,550 @@
+// Copyright 2020 GFX developers
+//
+// Licensed under the Apache License, Version 2.0, <LICENSE-APACHE or
+// http://apache.org/licenses/LICENSE-2.0> or the MIT license <LICENSE-MIT or
+// http://opensource.org/licenses/MIT>, at your option. This file may not be
+// copied, modified, or distributed except according to those terms.
+
+use super::*;
+
+use objc::runtime::{BOOL, YES};
+
+#[link(name = "MetalPerformanceShaders", kind = "framework")]
+extern "C" {
+    fn MPSSupportsMTLDevice(device: *const std::ffi::c_void) -> BOOL;
+}
+
+pub fn mps_supports_device(device: &DeviceRef) -> bool {
+    let b: BOOL = unsafe {
+        let ptr: *const DeviceRef = device;
+        MPSSupportsMTLDevice(ptr as _)
+    };
+    b == YES
+}
+
+pub enum MPSKernel {}
+
+foreign_obj_type! {
+    type CType = MPSKernel;
+    pub struct Kernel;
+    pub struct KernelRef;
+}
+
+pub enum MPSRayDataType {
+    OriginDirection = 0,
+    OriginMinDistanceDirectionMaxDistance = 1,
+    OriginMaskDirectionMaxDistance = 2,
+}
+
+bitflags! {
+    #[allow(non_upper_case_globals)]
+    pub struct MPSRayMaskOptions: NSUInteger {
+        /// Enable primitive masks
+        const Primitive = 1;
+        /// Enable instance masks
+        const Instance = 2;
+    }
+}
+
+/// Options that determine the data contained in an intersection result.
+pub enum MPSIntersectionDataType {
+    Distance = 0,
+    DistancePrimitiveIndex = 1,
+    DistancePrimitiveIndexCoordinates = 2,
+    DistancePrimitiveIndexInstanceIndex = 3,
+    DistancePrimitiveIndexInstanceIndexCoordinates = 4,
+}
+
+pub enum MPSIntersectionType {
+    /// Find the closest intersection to the ray's origin along the ray direction.
+    /// This is potentially slower than `Any` but is well suited to primary visibility rays.
+    Nearest = 0,
+    /// Find any intersection along the ray direction. This is potentially faster than `Nearest` and
+    /// is well suited to shadow and occlusion rays.
+    Any = 1,
+}
+
+pub enum MPSRayMaskOperator {
+    /// Accept the intersection if `(primitive mask & ray mask) != 0`.
+    And = 0,
+    /// Accept the intersection if `~(primitive mask & ray mask) != 0`.
+    NotAnd = 1,
+    /// Accept the intersection if `(primitive mask | ray mask) != 0`.
+    Or = 2,
+    /// Accept the intersection if `~(primitive mask | ray mask) != 0`.
+    NotOr = 3,
+    /// Accept the intersection if `(primitive mask ^ ray mask) != 0`.
+    /// Note that this is equivalent to the "!=" operator.
+    Xor = 4,
+    /// Accept the intersection if `~(primitive mask ^ ray mask) != 0`.
+    /// Note that this is equivalent to the "==" operator.
+    NotXor = 5,
+    /// Accept the intersection if `(primitive mask < ray mask) != 0`.
+    LessThan = 6,
+    /// Accept the intersection if `(primitive mask <= ray mask) != 0`.
+    LessThanOrEqualTo = 7,
+    /// Accept the intersection if `(primitive mask > ray mask) != 0`.
+    GreaterThan = 8,
+    /// Accept the intersection if `(primitive mask >= ray mask) != 0`.
+    GreaterThanOrEqualTo = 9,
+}
+
+pub enum MPSTriangleIntersectionTestType {
+    /// Use the default ray/triangle intersection test
+    Default = 0,
+    /// Use a watertight ray/triangle intersection test which avoids gaps along shared triangle edges.
+    /// Shared vertices may still have gaps.
+    /// This intersection test may be slower than `Default`.
+    Watertight = 1,
+}
+
+#[derive(Copy, Clone, Debug, Eq, PartialEq, Hash)]
+pub enum MPSAccelerationStructureStatus {
+    Unbuilt = 0,
+    Built = 1,
+}
+
+bitflags! {
+    #[allow(non_upper_case_globals)]
+    pub struct MPSAccelerationStructureUsage: NSUInteger {
+        /// No usage options specified
+        const None = 0;
+        /// Option that enables support for refitting the acceleration structure after it has been built.
+        const Refit = 1;
+        /// Option indicating that the acceleration structure will be rebuilt frequently.
+        const FrequentRebuild = 2;
+        const PreferGPUBuild = 4;
+        const PreferCPUBuild = 8;
+    }
+}
+
+/// A common bit for all floating point data types.
+const MPSDataTypeFloatBit: isize = 0x10000000;
+const MPSDataTypeSignedBit: isize = 0x20000000;
+const MPSDataTypeNormalizedBit: isize = 0x40000000;
+
+pub enum MPSDataType {
+    Invalid = 0,
+
+    Float32 = MPSDataTypeFloatBit | 32,
+    Float16 = MPSDataTypeFloatBit | 16,
+
+    // Signed integers.
+    Int8 = MPSDataTypeSignedBit | 8,
+    Int16 = MPSDataTypeSignedBit | 16,
+    Int32 = MPSDataTypeSignedBit | 32,
+
+    // Unsigned integers. Range: [0, UTYPE_MAX]
+    UInt8 = 8,
+    UInt16 = 16,
+    UInt32 = 32,
+
+    // Unsigned normalized. Range: [0, 1.0]
+    Unorm1 = MPSDataTypeNormalizedBit | 1,
+    Unorm8 = MPSDataTypeNormalizedBit | 8,
+}
+
+/// A kernel that performs intersection tests between rays and geometry.
+pub enum MPSRayIntersector {}
+
+foreign_obj_type! {
+    type CType = MPSRayIntersector;
+    pub struct RayIntersector;
+    pub struct RayIntersectorRef;
+    type ParentType = KernelRef;
+}
+
+impl RayIntersector {
+    pub fn from_device(device: &DeviceRef) -> Option<Self> {
+        unsafe {
+            let intersector: RayIntersector = msg_send![class!(MPSRayIntersector), alloc];
+            let ptr: *mut Object = msg_send![intersector.as_ref(), initWithDevice: device];
+            if ptr.is_null() {
+                None
+            } else {
+                Some(intersector)
+            }
+        }
+    }
+}
+
+impl RayIntersectorRef {
+    pub fn set_cull_mode(&self, mode: MTLCullMode) {
+        unsafe { msg_send![self, setCullMode: mode] }
+    }
+
+    pub fn set_front_facing_winding(&self, winding: MTLWinding) {
+        unsafe { msg_send![self, setFrontFacingWinding: winding] }
+    }
+
+    pub fn set_intersection_data_type(&self, options: MPSIntersectionDataType) {
+        unsafe { msg_send![self, setIntersectionDataType: options] }
+    }
+
+    pub fn set_intersection_stride(&self, stride: NSUInteger) {
+        unsafe { msg_send![self, setIntersectionStride: stride] }
+    }
+
+    pub fn set_ray_data_type(&self, ty: MPSRayDataType) {
+        unsafe { msg_send![self, setRayDataType: ty] }
+    }
+
+    pub fn set_ray_index_data_type(&self, ty: MPSDataType) {
+        unsafe { msg_send![self, setRayIndexDataType: ty] }
+    }
+
+    pub fn set_ray_mask(&self, ray_mask: u32) {
+        unsafe { msg_send![self, setRayMask: ray_mask] }
+    }
+
+    pub fn set_ray_mask_operator(&self, operator: MPSRayMaskOperator) {
+        unsafe { msg_send![self, setRayMaskOperator: operator] }
+    }
+
+    pub fn set_ray_mask_options(&self, options: MPSRayMaskOptions) {
+        unsafe { msg_send![self, setRayMaskOptions: options] }
+    }
+
+    pub fn set_ray_stride(&self, stride: NSUInteger) {
+        unsafe { msg_send![self, setRayStride: stride] }
+    }
+
+    pub fn set_triangle_intersection_test_type(&self, test_type: MPSTriangleIntersectionTestType) {
+        unsafe { msg_send![self, setTriangleIntersectionTestType: test_type] }
+    }
+
+    pub fn encode_intersection_to_command_buffer(
+        &self,
+        command_buffer: &CommandBufferRef,
+        intersection_type: MPSIntersectionType,
+        ray_buffer: &BufferRef,
+        ray_buffer_offset: NSUInteger,
+        intersection_buffer: &BufferRef,
+        intersection_buffer_offset: NSUInteger,
+        ray_count: NSUInteger,
+        acceleration_structure: &AccelerationStructureRef,
+    ) {
+        unsafe {
+            msg_send![
+                self,
+                encodeIntersectionToCommandBuffer: command_buffer
+                intersectionType: intersection_type
+                rayBuffer: ray_buffer
+                rayBufferOffset: ray_buffer_offset
+                intersectionBuffer: intersection_buffer
+                intersectionBufferOffset: intersection_buffer_offset
+                rayCount: ray_count
+                accelerationStructure: acceleration_structure
+            ]
+        }
+    }
+
+    pub fn recommended_minimum_ray_batch_size_for_ray_count(
+        &self,
+        ray_count: NSUInteger,
+    ) -> NSUInteger {
+        unsafe { msg_send![self, recommendedMinimumRayBatchSizeForRayCount: ray_count] }
+    }
+}
+
+/// A group of acceleration structures which may be used together in an instance acceleration structure
+pub enum MPSAccelerationStructureGroup {}
+
+foreign_obj_type! {
+    type CType = MPSAccelerationStructureGroup;
+    pub struct AccelerationStructureGroup;
+    pub struct AccelerationStructureGroupRef;
+}
+
+impl AccelerationStructureGroup {
+    pub fn new_with_device(device: &DeviceRef) -> Option<Self> {
+        unsafe {
+            let group: AccelerationStructureGroup =
+                msg_send![class!(MPSAccelerationStructureGroup), alloc];
+            let ptr: *mut Object = msg_send![group.as_ref(), initWithDevice: device];
+            if ptr.is_null() {
+                None
+            } else {
+                Some(group)
+            }
+        }
+    }
+}
+
+impl AccelerationStructureGroupRef {
+    pub fn device(&self) -> &DeviceRef {
+        unsafe { msg_send![self, device] }
+    }
+}
+
+/// The base class for data structures that are built over geometry and used to accelerate ray tracing.
+pub enum MPSAccelerationStructure {}
+
+foreign_obj_type! {
+    type CType = MPSAccelerationStructure;
+    pub struct AccelerationStructure;
+    pub struct AccelerationStructureRef;
+}
+
+impl AccelerationStructureRef {
+    pub fn status(&self) -> MPSAccelerationStructureStatus {
+        unsafe { msg_send![self, status] }
+    }
+
+    pub fn usage(&self) -> MPSAccelerationStructureUsage {
+        unsafe { msg_send![self, usage] }
+    }
+
+    pub fn set_usage(&self, usage: MPSAccelerationStructureUsage) {
+        unsafe { msg_send![self, setUsage: usage] }
+    }
+
+    pub fn group(&self) -> &AccelerationStructureGroupRef {
+        unsafe { msg_send![self, group] }
+    }
+
+    pub fn encode_refit_to_command_buffer(&self, buffer: &CommandBufferRef) {
+        unsafe { msg_send![self, encodeRefitToCommandBuffer: buffer] }
+    }
+
+    pub fn rebuild(&self) {
+        unsafe { msg_send![self, rebuild] }
+    }
+}
+
+pub enum MPSPolygonAccelerationStructure {}
+
+foreign_obj_type! {
+    type CType = MPSPolygonAccelerationStructure;
+    pub struct PolygonAccelerationStructure;
+    pub struct PolygonAccelerationStructureRef;
+    type ParentType = AccelerationStructureRef;
+}
+
+impl PolygonAccelerationStructureRef {
+    pub fn set_index_buffer(&self, buffer: Option<&BufferRef>) {
+        unsafe { msg_send![self, setIndexBuffer: buffer] }
+    }
+
+    pub fn set_index_buffer_offset(&self, offset: NSUInteger) {
+        unsafe { msg_send![self, setIndexBufferOffset: offset] }
+    }
+
+    pub fn set_index_type(&self, data_type: MPSDataType) {
+        unsafe { msg_send![self, setIndexType: data_type] }
+    }
+
+    pub fn set_mask_buffer(&self, buffer: Option<&BufferRef>) {
+        unsafe { msg_send![self, setMaskBuffer: buffer] }
+    }
+
+    pub fn set_mask_buffer_offset(&self, offset: NSUInteger) {
+        unsafe { msg_send![self, setMaskBufferOffset: offset] }
+    }
+
+    pub fn set_vertex_buffer(&self, buffer: Option<&BufferRef>) {
+        unsafe { msg_send![self, setVertexBuffer: buffer] }
+    }
+
+    pub fn set_vertex_buffer_offset(&self, offset: NSUInteger) {
+        unsafe { msg_send![self, setVertexBufferOffset: offset] }
+    }
+
+    pub fn set_vertex_stride(&self, stride: NSUInteger) {
+        unsafe { msg_send![self, setVertexStride: stride] }
+    }
+}
+
+/// An acceleration structure built over triangles.
+pub enum MPSTriangleAccelerationStructure {}
+
+foreign_obj_type! {
+    type CType = MPSTriangleAccelerationStructure;
+    pub struct TriangleAccelerationStructure;
+    pub struct TriangleAccelerationStructureRef;
+    type ParentType = PolygonAccelerationStructureRef;
+}
+
+impl TriangleAccelerationStructure {
+    pub fn from_device(device: &DeviceRef) -> Option<Self> {
+        unsafe {
+            let structure: TriangleAccelerationStructure =
+                msg_send![class!(MPSTriangleAccelerationStructure), alloc];
+            let ptr: *mut Object = msg_send![structure.as_ref(), initWithDevice: device];
+            if ptr.is_null() {
+                None
+            } else {
+                Some(structure)
+            }
+        }
+    }
+}
+
+impl TriangleAccelerationStructureRef {
+    pub fn triangle_count(&self) -> NSUInteger {
+        unsafe { msg_send![self, triangleCount] }
+    }
+
+    pub fn set_triangle_count(&self, count: NSUInteger) {
+        unsafe { msg_send![self, setTriangleCount: count] }
+    }
+}
+
+#[repr(u64)]
+#[derive(Clone, Copy, PartialEq, Eq, Hash, Debug)]
+pub enum MPSTransformType {
+    Float4x4 = 0,
+    Identity = 1,
+}
+
+/// An acceleration structure built over instances of other acceleration structures
+pub enum MPSInstanceAccelerationStructure {}
+
+foreign_obj_type! {
+    type CType = MPSInstanceAccelerationStructure;
+    pub struct InstanceAccelerationStructure;
+    pub struct InstanceAccelerationStructureRef;
+    type ParentType = AccelerationStructureRef;
+}
+
+impl InstanceAccelerationStructure {
+    pub fn init_with_group(group: &AccelerationStructureGroupRef) -> Option<Self> {
+        unsafe {
+            let structure: InstanceAccelerationStructure =
+                msg_send![class!(MPSInstanceAccelerationStructure), alloc];
+            let ptr: *mut Object = msg_send![structure.as_ref(), initWithGroup: group];
+            if ptr.is_null() {
+                None
+            } else {
+                Some(structure)
+            }
+        }
+    }
+}
+
+impl InstanceAccelerationStructureRef {
+    /// Marshal to Rust Vec
+    pub fn acceleration_structures(&self) -> Vec<PolygonAccelerationStructure> {
+        unsafe {
+            let acs: *mut Object = msg_send![self, accelerationStructures];
+            let count: NSUInteger = msg_send![acs, count];
+            let ret = (0..count)
+                .map(|i| {
+                    let ac = msg_send![acs, objectAtIndex: i];
+                    PolygonAccelerationStructure::from_ptr(ac)
+                })
+                .collect();
+            ret
+        }
+    }
+
+    /// Marshal from Rust slice
+    pub fn set_acceleration_structures(&self, acs: &[&PolygonAccelerationStructureRef]) {
+        let ns_array = Array::<PolygonAccelerationStructure>::from_slice(acs);
+        unsafe { msg_send![self, setAccelerationStructures: ns_array] }
+    }
+
+    pub fn instance_buffer(&self) -> &BufferRef {
+        unsafe { msg_send![self, instanceBuffer] }
+    }
+
+    pub fn set_instance_buffer(&self, buffer: &BufferRef) {
+        unsafe { msg_send![self, setInstanceBuffer: buffer] }
+    }
+
+    pub fn instance_buffer_offset(&self) -> NSUInteger {
+        unsafe { msg_send![self, instanceBufferOffset] }
+    }
+
+    pub fn set_instance_buffer_offset(&self, offset: NSUInteger) {
+        unsafe { msg_send![self, setInstanceBufferOffset: offset] }
+    }
+
+    pub fn transform_buffer(&self) -> &BufferRef {
+        unsafe { msg_send![self, transformBuffer] }
+    }
+
+    pub fn set_transform_buffer(&self, buffer: &BufferRef) {
+        unsafe { msg_send![self, setTransformBuffer: buffer] }
+    }
+
+    pub fn transform_buffer_offset(&self) -> NSUInteger {
+        unsafe { msg_send![self, transformBufferOffset] }
+    }
+
+    pub fn set_transform_buffer_offset(&self, offset: NSUInteger) {
+        unsafe { msg_send![self, setTransformBufferOffset: offset] }
+    }
+
+    pub fn transform_type(&self) -> MPSTransformType {
+        unsafe { msg_send![self, transformType] }
+    }
+
+    pub fn set_transform_type(&self, transform_type: MPSTransformType) {
+        unsafe { msg_send![self, setTransformType: transform_type] }
+    }
+
+    pub fn mask_buffer(&self) -> &BufferRef {
+        unsafe { msg_send![self, maskBuffer] }
+    }
+
+    pub fn set_mask_buffer(&self, buffer: &BufferRef) {
+        unsafe { msg_send![self, setMaskBuffer: buffer] }
+    }
+
+    pub fn mask_buffer_offset(&self) -> NSUInteger {
+        unsafe { msg_send![self, maskBufferOffset] }
+    }
+
+    pub fn set_mask_buffer_offset(&self, offset: NSUInteger) {
+        unsafe { msg_send![self, setMaskBufferOffset: offset] }
+    }
+
+    pub fn instance_count(&self) -> NSUInteger {
+        unsafe { msg_send![self, instanceCount] }
+    }
+
+    pub fn set_instance_count(&self, count: NSUInteger) {
+        unsafe { msg_send![self, setInstanceCount: count] }
+    }
+}
+
+#[repr(C)]
+pub struct MPSPackedFloat3 {
+    pub elements: [f32; 3],
+}
+
+/// Represents a 3D ray with an origin, a direction, and an intersection distance range from the origin.
+#[repr(C)]
+pub struct MPSRayOriginMinDistanceDirectionMaxDistance {
+    /// Ray origin. The intersection test will be skipped if the origin contains NaNs or infinities.
+    pub origin: MPSPackedFloat3,
+    /// Minimum intersection distance from the origin along the ray direction.
+    /// The intersection test will be skipped if the minimum distance is equal to positive infinity or NaN.
+    pub min_distance: f32,
+    /// Ray direction. Does not need to be normalized. The intersection test will be skipped if
+    /// the direction has length zero or contains NaNs or infinities.
+    pub direction: MPSPackedFloat3,
+    /// Maximum intersection distance from the origin along the ray direction. May be infinite.
+    /// The intersection test will be skipped if the maximum distance is less than zero, NaN, or
+    /// less than the minimum intersection distance.
+    pub max_distance: f32,
+}
+
+/// Intersection result which contains the distance from the ray origin to the intersection point,
+/// the index of the intersected primitive, and the first two barycentric coordinates of the intersection point.
+#[repr(C)]
+pub struct MPSIntersectionDistancePrimitiveIndexCoordinates {
+    /// Distance from the ray origin to the intersection point along the ray direction vector such
+    /// that `intersection = ray.origin + ray.direction * distance`.
+    /// Is negative if there is no intersection. If the intersection type is `MPSIntersectionTypeAny`,
+    /// is a positive value for a hit or a negative value for a miss.
+    pub distance: f32,
+    /// Index of the intersected primitive. Undefined if the ray does not intersect a primitive or
+    /// if the intersection type is `MPSIntersectionTypeAny`.
+    pub primitive_index: u32,
+    /// The first two barycentric coordinates `U` and `V` of the intersection point.
+    /// The third coordinate `W = 1 - U - V`. Undefined if the ray does not intersect a primitive or
+    /// if the intersection type is `MPSIntersectionTypeAny`.
+    pub coordinates: [f32; 2],
+}