RMath: implement transforms for Vector, Point, and Normal.

sub_crates/rmath/src/normal.rs

@@ -3,13 +3,14 @@
 use std::ops::{Add, Div, Mul, Neg, Sub};
 
 use crate::wide4::Float4;
+use crate::xform::XformFull;
 use crate::DotProduct;
 use crate::Vector;
 
 /// A surface normal in 3D space.
 #[derive(Debug, Copy, Clone)]
 #[repr(transparent)]
-pub struct Normal(pub(crate) Float4);
+pub struct Normal(pub Float4);
 
 impl Normal {
     #[inline(always)]
@@ -71,6 +72,25 @@ impl Normal {
     pub fn set_z(self, z: f32) -> Self {
         Self(self.0.set_c(z))
     }
+
+    //-------------
+    // Transforms.
+
+    pub fn xform(self, xform: &XformFull) -> Self {
+        Self(self.0.vec_mul_3x3(&Float4::transpose_3x3(xform.m_inv)))
+    }
+
+    pub fn xform_inv(self, xform: &XformFull) -> Self {
+        Self(self.0.vec_mul_3x3(&Float4::transpose_3x3(xform.m)))
+    }
+
+    pub fn xform_fast(self, xform: &XformFull) -> Self {
+        Self(self.0.vec_mul_3x3_fast(&Float4::transpose_3x3(xform.m_inv)))
+    }
+
+    pub fn xform_inv_fast(self, xform: &XformFull) -> Self {
+        Self(self.0.vec_mul_3x3_fast(&Float4::transpose_3x3(xform.m)))
+    }
 }
 
 impl Add for Normal {

sub_crates/rmath/src/point.rs

@@ -3,11 +3,12 @@ use std::ops::{Add, Sub};
 
 use crate::vector::Vector;
 use crate::wide4::Float4;
+use crate::xform::XformFull;
 
 /// A position in 3D space.
 #[derive(Debug, Copy, Clone)]
 #[repr(transparent)]
-pub struct Point(pub(crate) Float4);
+pub struct Point(pub Float4);
 
 impl Point {
     #[inline(always)]
@@ -62,6 +63,25 @@ impl Point {
     pub fn set_z(self, z: f32) -> Self {
         Self(self.0.set_c(z))
     }
+
+    //-------------
+    // Transforms.
+
+    pub fn xform(self, xform: &XformFull) -> Self {
+        Self(self.0.vec_mul_affine(&xform.m, xform.t))
+    }
+
+    pub fn xform_inv(self, xform: &XformFull) -> Self {
+        Self(self.0.vec_mul_affine_rev(&xform.m_inv, -xform.t))
+    }
+
+    pub fn xform_fast(self, xform: &XformFull) -> Self {
+        Self(self.0.vec_mul_affine_fast(&xform.m, xform.t))
+    }
+
+    pub fn xform_inv_fast(self, xform: &XformFull) -> Self {
+        Self(self.0.vec_mul_affine_rev_fast(&xform.m_inv, -xform.t))
+    }
 }
 
 impl Add<Vector> for Point {

sub_crates/rmath/src/vector.rs

@@ -5,12 +5,13 @@ use std::ops::{Add, Div, Mul, Neg, Sub};
 use crate::normal::Normal;
 use crate::point::Point;
 use crate::wide4::Float4;
+use crate::xform::XformFull;
 use crate::DotProduct;
 
 /// A direction vector in 3D space.
 #[derive(Debug, Copy, Clone)]
 #[repr(transparent)]
-pub struct Vector(pub(crate) Float4);
+pub struct Vector(pub Float4);
 
 impl Vector {
     #[inline(always)]
@@ -77,6 +78,25 @@ impl Vector {
     pub fn set_z(self, z: f32) -> Self {
         Self(self.0.set_c(z))
     }
+
+    //-------------
+    // Transforms.
+
+    pub fn xform(self, xform: &XformFull) -> Self {
+        Self(self.0.vec_mul_3x3(&xform.m))
+    }
+
+    pub fn xform_inv(self, xform: &XformFull) -> Self {
+        Self(self.0.vec_mul_3x3(&xform.m_inv))
+    }
+
+    pub fn xform_fast(self, xform: &XformFull) -> Self {
+        Self(self.0.vec_mul_3x3_fast(&xform.m))
+    }
+
+    pub fn xform_inv_fast(self, xform: &XformFull) -> Self {
+        Self(self.0.vec_mul_3x3_fast(&xform.m_inv))
+    }
 }
 
 impl Add for Vector {

sub_crates/rmath/src/wide4.rs

@@ -10,7 +10,6 @@ mod fallback {
 
     use crate::FMulAdd;
 
-    #[allow(non_camel_case_types)]
     #[derive(Debug, Copy, Clone)]
     #[repr(C, align(16))]
     pub struct Float4 {
@@ -463,6 +462,18 @@ impl Float4 {
         s3 + err3
     }
 
+    /// Transforms a 3d point by an affine transform.
+    ///
+    /// Faster but less precise version.
+    #[inline]
+    pub fn vec_mul_affine_fast(self, m: &[Self; 3], t: Self) -> Self {
+        let x = self.aaaa();
+        let y = self.bbbb();
+        let z = self.cccc();
+
+        (x * m[0]) + (y * m[1]) + (z * m[2]) + t
+    }
+
     /// Transforms a 3d point by an affine transform, except it applies
     /// the translation part before the 3x3 part.
     ///
@@ -499,6 +510,21 @@ impl Float4 {
         s3 + err3
     }
 
+    /// Transforms a 3d point by an affine transform, except it applies
+    /// the translation part before the 3x3 part.
+    ///
+    /// Faster but less precise version.
+    #[inline]
+    pub fn vec_mul_affine_rev_fast(self, m: &[Self; 3], t: Self) -> Self {
+        let v = self + t;
+
+        let x = v.aaaa();
+        let y = v.bbbb();
+        let z = v.cccc();
+
+        (x * m[0]) + (y * m[1]) + (z * m[2])
+    }
+
     /// Returns whether the `Float4`s are approximately equal to each
     /// other.
     ///

sub_crates/rmath/src/xform.rs

@@ -9,8 +9,8 @@ use crate::wide4::Float4;
 #[derive(Debug, Copy, Clone)]
 #[repr(C)]
 pub struct Xform {
-    pub(crate) m: [Float4; 3], // Linear matrix.
+    pub m: [Float4; 3], // Linear matrix.
-    pub(crate) t: Float4,      // Translation.
+    pub t: Float4,      // Translation.
 }
 
 impl Xform {
@@ -170,9 +170,9 @@ impl Add for Xform {
 #[derive(Debug, Copy, Clone)]
 #[repr(C)]
 pub struct XformFull {
-    pub(crate) m: [Float4; 3],     // Linear matrix.
+    pub m: [Float4; 3],     // Forward linear matrix.
-    pub(crate) m_inv: [Float4; 3], // Inverse of linear matrix.
+    pub m_inv: [Float4; 3], // Inverse linear matrix.
-    pub(crate) t: Float4,          // Forward translation.
+    pub t: Float4,          // Forward translation.
 }
 
 //-------------------------------------------------------------