Add flatten trait.

src/dim1/mat1.rs

@@ -4,6 +4,7 @@ use std::cmp::ApproxEq;
 use traits::dim::Dim;
 use traits::inv::Inv;
 use traits::transpose::Transpose;
+use traits::flatten::Flatten;
 use traits::workarounds::rlmul::{RMul, LMul};
 use dim1::vec1::Vec1;
 
@@ -105,3 +106,18 @@ impl<N:Rand + Copy> Rand for Mat1<N>
   fn rand<R: Rng>(rng: &mut R) -> Mat1<N>
   { Mat1::new(rng.gen()) }
 }
+
+impl<N: Copy> Flatten<N> for Mat1<N>
+{
+  fn flat_size() -> uint
+  { 1 }
+
+  fn from_flattened(l: &[N], off: uint) -> Mat1<N>
+  { Mat1::new(l[off]) }
+
+  fn to_flattened(&self) -> ~[N]
+  { ~[ self.m11 ] }
+
+  fn to_flattened_inplace(&self, l: &mut [N], off: uint)
+  { l[off] = self.m11 }
+}

src/dim1/vec1.rs

@@ -7,6 +7,7 @@ use traits::dot::Dot;
 use traits::norm::Norm;
 use traits::translation::Translation;
 use traits::sub_dot::SubDot;
+use traits::flatten::Flatten;
 use traits::workarounds::scalar_op::{ScalarMul, ScalarDiv, ScalarAdd, ScalarSub};
 
 #[deriving(Eq, ToStr)]
@@ -169,3 +170,18 @@ impl<N:Rand + Copy> Rand for Vec1<N>
   fn rand<R: Rng>(rng: &mut R) -> Vec1<N>
   { Vec1::new(rng.gen()) }
 }
+
+impl<N: Copy> Flatten<N> for Vec1<N>
+{
+  fn flat_size() -> uint
+  { 1 }
+
+  fn from_flattened(l: &[N], off: uint) -> Vec1<N>
+  { Vec1::new(l[off]) }
+
+  fn to_flattened(&self) -> ~[N]
+  { ~[ self.x ] }
+
+  fn to_flattened_inplace(&self, l: &mut [N], off: uint)
+  { l[off] = self.x }
+}

src/dim2/mat2.rs

@@ -5,6 +5,7 @@ use std::util::swap;
 use traits::dim::Dim;
 use traits::inv::Inv;
 use traits::transpose::Transpose;
+use traits::flatten::Flatten;
 use traits::workarounds::rlmul::{RMul, LMul};
 use dim2::vec2::Vec2;
 
@@ -158,3 +159,23 @@ impl<N:Rand + Copy> Rand for Mat2<N>
   fn rand<R: Rng>(rng: &mut R) -> Mat2<N>
   { Mat2::new(rng.gen(), rng.gen(), rng.gen(), rng.gen()) }
 }
+
+impl<N: Copy> Flatten<N> for Mat2<N>
+{
+  fn flat_size() -> uint
+  { 4 }
+
+  fn from_flattened(l: &[N], off: uint) -> Mat2<N>
+  { Mat2::new(l[off], l[off + 1], l[off + 2], l[off + 3]) }
+
+  fn to_flattened(&self) -> ~[N]
+  { ~[ self.m11, self.m12, self.m21, self.m22 ] }
+
+  fn to_flattened_inplace(&self, l: &mut [N], off: uint)
+  {
+    l[off]     = self.m11;
+    l[off + 1] = self.m12;
+    l[off + 2] = self.m21;
+    l[off + 3] = self.m22;
+  }
+}

src/dim2/vec2.rs

@@ -8,6 +8,7 @@ use traits::dim::Dim;
 use traits::dot::Dot;
 use traits::sub_dot::SubDot;
 use traits::norm::Norm;
+use traits::flatten::Flatten;
 use traits::translation::Translation;
 use traits::workarounds::scalar_op::{ScalarMul, ScalarDiv, ScalarAdd, ScalarSub};
 
@@ -203,3 +204,21 @@ impl<N:Rand + Copy> Rand for Vec2<N>
   fn rand<R: Rng>(rng: &mut R) -> Vec2<N>
   { Vec2::new(rng.gen(), rng.gen()) }
 }
+
+impl<N: Copy> Flatten<N> for Vec2<N>
+{
+  fn flat_size() -> uint
+  { 2 }
+
+  fn from_flattened(l: &[N], off: uint) -> Vec2<N>
+  { Vec2::new(l[off], l[off + 1]) }
+
+  fn to_flattened(&self) -> ~[N]
+  { ~[ self.x, self.y ] }
+
+  fn to_flattened_inplace(&self, l: &mut [N], off: uint)
+  {
+    l[off]     = self.x;
+    l[off + 1] = self.y;
+  }
+}

src/dim3/mat3.rs

@@ -5,6 +5,7 @@ use std::util::swap;
 use traits::dim::Dim;
 use traits::inv::Inv;
 use traits::transpose::Transpose;
+use traits::flatten::Flatten;
 use traits::workarounds::rlmul::{RMul, LMul};
 use dim3::vec3::Vec3;
 
@@ -212,3 +213,36 @@ impl<N:Rand + Copy> Rand for Mat3<N>
               rng.gen(), rng.gen(), rng.gen())
   }
 }
+
+impl<N: Copy> Flatten<N> for Mat3<N>
+{
+  fn flat_size() -> uint
+  { 9 }
+
+  fn from_flattened(l: &[N], off: uint) -> Mat3<N>
+  { Mat3::new(l[off + 0], l[off + 1], l[off + 2],
+              l[off + 3], l[off + 4], l[off + 5],
+              l[off + 6], l[off + 7], l[off + 8]) }
+
+  fn to_flattened(&self) -> ~[N]
+  {
+    ~[
+      self.m11, self.m12, self.m13,
+      self.m21, self.m22, self.m23,
+      self.m31, self.m32, self.m33
+    ]
+  }
+
+  fn to_flattened_inplace(&self, l: &mut [N], off: uint)
+  {
+    l[off + 0] = self.m11;
+    l[off + 1] = self.m12;
+    l[off + 2] = self.m13;
+    l[off + 3] = self.m21;
+    l[off + 4] = self.m22;
+    l[off + 5] = self.m23;
+    l[off + 6] = self.m31;
+    l[off + 7] = self.m32;
+    l[off + 8] = self.m33;
+  }
+}

src/dim3/vec3.rs

@@ -7,6 +7,7 @@ use traits::dim::Dim;
 use traits::dot::Dot;
 use traits::sub_dot::SubDot;
 use traits::norm::Norm;
+use traits::flatten::Flatten;
 use traits::translation::Translation;
 use traits::workarounds::scalar_op::{ScalarMul, ScalarDiv, ScalarAdd, ScalarSub};
 
@@ -232,3 +233,22 @@ impl<N:Copy + Rand> Rand for Vec3<N>
   fn rand<R: Rng>(rng: &mut R) -> Vec3<N>
   { Vec3::new(rng.gen(), rng.gen(), rng.gen()) }
 }
+
+impl<N: Copy> Flatten<N> for Vec3<N>
+{
+  fn flat_size() -> uint
+  { 3 }
+
+  fn from_flattened(l: &[N], off: uint) -> Vec3<N>
+  { Vec3::new(l[off], l[off + 1], l[off + 2]) }
+
+  fn to_flattened(&self) -> ~[N]
+  { ~[ self.x, self.y, self.z ] }
+
+  fn to_flattened_inplace(&self, l: &mut [N], off: uint)
+  {
+    l[off]     = self.x;
+    l[off + 1] = self.y;
+    l[off + 2] = self.z;
+  }
+}

src/nalgebra.rc

@@ -69,6 +69,7 @@ pub mod traits
   pub mod ring;
   pub mod division_ring;
   pub mod sub_dot;
+  pub mod flatten;
 
   /// This package contains everything done because the current compiler either
   /// crashes or miss features.

src/ndim/nmat.rs

@@ -6,6 +6,7 @@ use traits::dim::Dim;
 use traits::inv::Inv;
 use traits::division_ring::DivisionRing;
 use traits::transpose::Transpose;
+use traits::flatten::Flatten;
 use traits::workarounds::rlmul::{RMul, LMul};
 use ndim::dmat::{DMat, one_mat_with_dim, zero_mat_with_dim, is_zero_mat};
 use ndim::nvec::NVec;
@@ -168,3 +169,39 @@ impl<D: Dim, N: Rand + Zero + Copy> Rand for NMat<D, N>
     res
   }
 }
+
+impl<D: Dim, N: Zero + Copy> Flatten<N> for NMat<D, N>
+{
+  fn flat_size() -> uint
+  { Dim::dim::<D>() * Dim::dim::<D>() }
+
+  fn from_flattened(l: &[N], off: uint) -> NMat<D, N>
+  {
+    let     dim = Dim::dim::<D>();
+    let mut res = Zero::zero::<NMat<D, N>>();
+
+    for iterate(0u, dim * dim) |i|
+    { res.mij.mij[i] = l[off + i] }
+
+    res
+  }
+
+  fn to_flattened(&self) -> ~[N]
+  {
+    let     dim = Dim::dim::<D>();
+    let mut res = ~[];
+
+    for iterate(0u, dim * dim) |i|
+    { res.push(self.mij.mij[i]) }
+
+    res
+  }
+
+  fn to_flattened_inplace(&self, l: &mut [N], off: uint)
+  {
+    let dim = Dim::dim::<D>();
+
+    for iterate(0u, dim * dim) |i|
+    { l[off + i] = self.mij.mij[i] }
+  }
+}

src/ndim/nvec.rs

@@ -12,6 +12,7 @@ use traits::dot::Dot;
 use traits::sub_dot::SubDot;
 use traits::norm::Norm;
 use traits::translation::Translation;
+use traits::flatten::Flatten;
 use traits::workarounds::scalar_op::{ScalarMul, ScalarDiv, ScalarAdd, ScalarSub};
 
 // D is a phantom parameter, used only as a dimensional token.
@@ -196,3 +197,39 @@ impl<D: Dim, N: Rand + Zero + Copy> Rand for NVec<D, N>
     res
   }
 }
+
+impl<D: Dim, N: Zero + Copy> Flatten<N> for NVec<D, N>
+{
+  fn flat_size() -> uint
+  { Dim::dim::<D>() }
+
+  fn from_flattened(l: &[N], off: uint) -> NVec<D, N>
+  {
+    let     dim = Dim::dim::<D>();
+    let mut res = Zero::zero::<NVec<D, N>>();
+
+    for iterate(0u, dim) |i|
+    { res.at.at[i] = l[off + i] }
+
+    res
+  }
+
+  fn to_flattened(&self) -> ~[N]
+  {
+    let     dim = Dim::dim::<D>();
+    let mut res = ~[];
+
+    for iterate(0u, dim) |i|
+    { res.push(self.at.at[i]) }
+
+    res
+  }
+
+  fn to_flattened_inplace(&self, l: &mut [N], off: uint)
+  {
+    let dim = Dim::dim::<D>();
+
+    for iterate(0u, dim) |i|
+    { l[off + i] = self.at.at[i] }
+  }
+}

src/tests/mat.rs

@@ -1,5 +1,7 @@
 #[test]
-use std::num::{Real, One, abs};
+use std::vec;
+#[test]
+use std::num::{Real, Zero, One, abs};
 #[test]
 use std::rand::{random};
 #[test]
@@ -8,8 +10,8 @@ use std::cmp::ApproxEq;
 use traits::inv::Inv;
 #[test]
 use traits::rotation::Rotation;
-// #[test]
-// use traits::dim::d7;
+#[test]
+use traits::dim::d7;
 #[test]
 use dim1::vec1::Vec1;
 #[test]
@@ -18,10 +20,12 @@ use dim1::mat1::Mat1;
 use dim2::mat2::Mat2;
 #[test]
 use dim3::mat3::Mat3;
-// #[test]
-// use ndim::nmat::NMat;
+#[test]
+use ndim::nmat::NMat;
 #[test]
 use adaptors::rotmat::Rotmat;
+#[test]
+use traits::flatten::Flatten;
 
 macro_rules! test_inv_mat_impl(
   ($t: ty) => (
@@ -34,6 +38,21 @@ macro_rules! test_inv_mat_impl(
   );
 )
 
+macro_rules! test_flatten_impl(
+  ($t: ty, $n: ty) => (
+    for 10000.times
+    {
+      let v:     $t    = random();
+      let mut l: ~[$n] = vec::from_elem(42 + Flatten::flat_size::<$n, $t>(), Zero::zero::<$n>());
+
+      v.to_flattened_inplace(l, 42);
+
+      assert!(Flatten::from_flattened::<$n, $t>(v.to_flattened(), 0) == v);
+      assert!(Flatten::from_flattened::<$n, $t>(l, 42) == v);
+    }
+  )
+)
+
 #[test]
 fn test_inv_mat1()
 { test_inv_mat_impl!(Mat1<f64>); }
@@ -51,6 +70,22 @@ fn test_inv_mat3()
 // fn test_inv_nmat()
 // { test_inv_mat_impl!(NMat<d7, f64>); }
 
+#[test]
+fn test_flatten_mat1()
+{ test_flatten_impl!(Mat1<f64>, f64); }
+
+#[test]
+fn test_flatten_mat2()
+{ test_flatten_impl!(Mat2<f64>, f64); }
+
+#[test]
+fn test_flatten_mat3()
+{ test_flatten_impl!(Mat3<f64>, f64); }
+
+#[test]
+fn test_flatten_nmat()
+{ test_flatten_impl!(NMat<d7, f64>, f64); }
+
 #[test]
 fn test_rotation2()
 {

src/tests/vec.rs

@@ -1,4 +1,6 @@
 #[test]
+use std::vec;
+#[test]
 use std::iterator::IteratorUtil;
 #[test]
 use std::num::{Zero, One};
@@ -24,6 +26,8 @@ use traits::cross::Cross;
 use traits::dot::Dot;
 #[test]
 use traits::norm::Norm;
+#[test]
+use traits::flatten::Flatten;
 
 macro_rules! test_commut_dot_impl(
   ($t: ty) => (
@@ -75,6 +79,21 @@ macro_rules! test_subspace_basis_impl(
   );
 )
 
+macro_rules! test_flatten_impl(
+  ($t: ty, $n: ty) => (
+    for 10000.times
+    {
+      let v:     $t    = random();
+      let mut l: ~[$n] = vec::from_elem(42 + Flatten::flat_size::<$n, $t>(), Zero::zero::<$n>());
+
+      v.to_flattened_inplace(l, 42);
+
+      assert!(Flatten::from_flattened::<$n, $t>(v.to_flattened(), 0) == v);
+      assert!(Flatten::from_flattened::<$n, $t>(l, 42) == v);
+    }
+  )
+)
+
 #[test]
 fn test_cross_vec3()
 {
@@ -136,3 +155,19 @@ fn test_subspace_basis_vec3()
 #[test]
 fn test_subspace_basis_nvec()
 { test_subspace_basis_impl!(NVec<d7, f64>); }
+
+#[test]
+fn test_flatten_vec1()
+{ test_flatten_impl!(Vec1<f64>, f64); }
+
+#[test]
+fn test_flatten_vec2()
+{ test_flatten_impl!(Vec2<f64>, f64); }
+
+#[test]
+fn test_flatten_vec3()
+{ test_flatten_impl!(Vec3<f64>, f64); }
+
+#[test]
+fn test_flatten_nvec()
+{ test_flatten_impl!(NVec<d7, f64>, f64); }

src/traits/flatten.rs

@@ -0,0 +1,34 @@
+/// Trait of objects which can be written as a list of values, and read from
+/// that list.
+pub trait Flatten<N>
+{
+  /// The number of elements needed to flatten this object.
+  fn flat_size() -> uint;
+
+  /**
+   * Creates a new object from its flattened version. Its flattened version is
+   * a continuous list of values. It is assumet that `flat_size` elements will
+   * be read.
+   *
+   *   - `l`: list from which the flat version must be read.
+   *   - `off`: index from which (included) the flat version read must begin.
+   *            It is assumed that the caller gives a valid input.
+   */
+  fn from_flattened(l: &[N], off: uint) -> Self; // FIXME: keep (vector + index) or use an iterator?
+
+  /**
+   * Creates a flattened version of `self`. The result vector must be of size
+   * `flat_size`.
+   */
+  fn to_flattened(&self) -> ~[N];
+
+  /**
+   * Creates a flattened version of `self` on a vector. It is assumed that
+   * `flat_size` elements will be written contiguously.
+   *
+   *   - `l`: list to which the flat version must be written.
+   *   - `off`: index from which (included) the flat version write must begin.
+   *            It is assumed that the caller allocated a long enough list.
+   */
+  fn to_flattened_inplace(&self, l: &mut [N], off: uint); // FIXME: keep (vector + index) or use an iterator (to a mutable value…)?
+}