Replace manual intrinsics with spirv_std functions

Cargo.toml

@@ -32,8 +32,8 @@ spirv-builder.workspace = true
 members = ["shaders", "shared"]
 
 [workspace.dependencies]
-spirv-builder = { git = "https://github.com/Rust-GPU/rust-gpu", rev = "ac0c7035d53ae0bf87fbff12cc8ad4e6f6628834", default-features = false }
-spirv-std = { git = "https://github.com/Rust-GPU/rust-gpu", rev = "ac0c7035d53ae0bf87fbff12cc8ad4e6f6628834" }
+spirv-builder = { git = "https://github.com/Rust-GPU/rust-gpu", rev = "0b37696e9f5edde8fa0c1363a88e6c8cb8e6ff68", default-features = false }
+spirv-std = { git = "https://github.com/Rust-GPU/rust-gpu", rev = "0b37696e9f5edde8fa0c1363a88e6c8cb8e6ff68" }
 
 # Compile build-dependencies in release mode with
 # the same settings as regular dependencies.

shaders/src/filtering_procedurals.rs

@@ -19,6 +19,7 @@
 //! */
 //! ```
 
+use spirv_std::arch::Derivative;
 use shared::*;
 use spirv_std::glam::{vec2, vec3, vec4, Vec2, Vec3, Vec3Swizzles, Vec4, Vec4Swizzles};
 
@@ -400,8 +401,8 @@ impl Inputs {
                 uvw = tex_coords(pos);
 
                 // calc texture sampling footprint
-                ddx_uvw = uvw + uvw.ddx();
-                ddy_uvw = uvw + uvw.ddy();
+                ddx_uvw = uvw + uvw.dfdx();
+                ddy_uvw = uvw + uvw.dfdy();
             }
             // shading
             let mate: Vec3;

shaders/src/skyline.rs

@@ -11,6 +11,7 @@
 //! */
 //! ```
 
+use spirv_std::arch::Derivative;
 use crate::SampleCube;
 use shared::*;
 use spirv_std::glam::{vec2, vec3, Vec2, Vec2Swizzles, Vec3, Vec3Swizzles, Vec4, Vec4Swizzles};
@@ -770,8 +771,8 @@ impl<C0: SampleCube> State<C0> {
             let mut window_ref: f32 = 0.0;
             // texture map the sides of buildings
             if (normal.y < 0.1) && (dist_and_mat.y == 0.0) {
-                let posdx: Vec3 = pos.ddx();
-                let posdy: Vec3 = pos.ddy();
+                let posdx: Vec3 = pos.dfdx();
+                let posdy: Vec3 = pos.dfdy();
                 let _pos_grad: Vec3 = posdx * hash21(uv) + posdy * hash21(uv * 7.6543);
 
                 // Quincunx antialias the building texture and normal map.
@@ -930,7 +931,7 @@ impl<C0: SampleCube> State<C0> {
             if dist_and_mat.y >= 100.0 {
                 let mut yfade: f32 = 0.01_f32.max(1.0_f32.min(ref_.y * 100.0));
                 // low-res way of making lines at the edges of car windows. Not sure I like it.
-                yfade *= saturate(1.0 - (window_mask.ddx() * window_mask.ddy()).abs() * 250.995);
+                yfade *= saturate(1.0 - (window_mask.dfdx() * window_mask.dfdy()).abs() * 250.995);
                 final_color += self.get_env_map_skyline(ref_, self.sun_dir, pos.y - 1.5)
                     * 0.3
                     * yfade

shared/src/lib.rs

@@ -6,7 +6,7 @@
 use bytemuck::{Pod, Zeroable};
 use core::f32::consts::PI;
 use core::ops::{Add, Mul, Sub};
-use spirv_std::glam::{vec2, vec3, vec4, Vec2, Vec3, Vec3A, Vec4};
+use spirv_std::glam::{vec2, vec3, vec4, Vec2, Vec3, Vec4};
 
 // Note: This cfg is incorrect on its surface, it really should be "are we compiling with std", but
 // we tie #[no_std] above to the same condition, so it's fine.
@@ -350,107 +350,6 @@ impl VecExt for Vec4 {
     }
 }
 
-pub trait Derivative {
-    fn ddx(self) -> Self;
-    fn ddx_fine(self) -> Self;
-    fn ddx_coarse(self) -> Self;
-    fn ddy(self) -> Self;
-    fn ddy_fine(self) -> Self;
-    fn ddy_coarse(self) -> Self;
-    fn fwidth(self) -> Self;
-    fn fwidth_fine(self) -> Self;
-    fn fwidth_coarse(self) -> Self;
-}
-
-#[cfg(target_arch = "spirv")]
-macro_rules! deriv_caps {
-    (true) => {
-        core::arch::asm!("OpCapability DerivativeControl")
-    };
-    (false) => {};
-}
-
-macro_rules! deriv_fn {
-    ($name:ident, $inst:ident, $needs_caps:tt) => {
-        fn $name(self) -> Self {
-            #[cfg(not(target_arch = "spirv"))]
-            panic!(concat!(stringify!($name), " is not supported on the CPU"));
-            #[cfg(target_arch = "spirv")]
-            unsafe {
-                let mut result = Default::default();
-                deriv_caps!($needs_caps);
-                core::arch::asm!(
-                    "%input = OpLoad typeof*{1} {1}",
-                    concat!("%result = ", stringify!($inst), " typeof*{1} %input"),
-                    "OpStore {0} %result",
-                    in(reg) &mut result,
-                    in(reg) &self,
-                );
-                result
-            }
-        }
-    };
-}
-macro_rules! deriv_impl {
-    ($ty:ty) => {
-        impl Derivative for $ty {
-            deriv_fn!(ddx, OpDPdx, false);
-            deriv_fn!(ddx_fine, OpDPdxFine, true);
-            deriv_fn!(ddx_coarse, OpDPdxCoarse, true);
-            deriv_fn!(ddy, OpDPdy, false);
-            deriv_fn!(ddy_fine, OpDPdyFine, true);
-            deriv_fn!(ddy_coarse, OpDPdyCoarse, true);
-            deriv_fn!(fwidth, OpFwidth, false);
-            deriv_fn!(fwidth_fine, OpFwidthFine, true);
-            deriv_fn!(fwidth_coarse, OpFwidthCoarse, true);
-        }
-    };
-}
-
-// "must be a scalar or vector of floating-point type. The component width must be 32 bits."
-deriv_impl!(f32);
-deriv_impl!(Vec2);
-deriv_impl!(Vec3A);
-deriv_impl!(Vec4);
-
-impl Derivative for Vec3 {
-    fn ddx(self) -> Self {
-        Vec3A::from(self).ddx().into()
-    }
-    fn ddx_fine(self) -> Self {
-        Vec3A::from(self).ddx_fine().into()
-    }
-    fn ddx_coarse(self) -> Self {
-        Vec3A::from(self).ddx_coarse().into()
-    }
-    fn ddy(self) -> Self {
-        Vec3A::from(self).ddy().into()
-    }
-    fn ddy_fine(self) -> Self {
-        Vec3A::from(self).ddy_fine().into()
-    }
-    fn ddy_coarse(self) -> Self {
-        Vec3A::from(self).ddy_coarse().into()
-    }
-    fn fwidth(self) -> Self {
-        Vec3A::from(self).fwidth().into()
-    }
-    fn fwidth_fine(self) -> Self {
-        Vec3A::from(self).fwidth_fine().into()
-    }
-    fn fwidth_coarse(self) -> Self {
-        Vec3A::from(self).fwidth_coarse().into()
-    }
-}
-
 pub fn discard() {
-    #[cfg(target_arch = "spirv")]
-    unsafe {
-        use core::arch::asm;
-        asm!(
-            "OpExtension \"SPV_EXT_demote_to_helper_invocation\"",
-            "OpCapability DemoteToHelperInvocationEXT",
-            "OpDemoteToHelperInvocationEXT"
-        );
-    }
+    unsafe { spirv_std::arch::demote_to_helper_invocation() }
 }