Use explicit methods to convert between arrays and matrices.

Removed `From` trait implementations converting between 1D and 2D arrays
and matrix types to avoid any potential confusion about data being
loaded and stored in column major order. New function names hopefully
make it clear that column major ordering is being used.

Fixes #21.

src/f32/mat2.rs

@@ -10,7 +10,7 @@ use std::ops::{Add, Mul, Sub};
 
 #[inline]
 pub fn mat2(x_axis: Vec2, y_axis: Vec2) -> Mat2 {
-    Mat2::new(x_axis, y_axis)
+    Mat2::from_cols(x_axis, y_axis)
 }
 
 /// A 2x2 column major matrix.
@@ -35,11 +35,47 @@ impl Mat2 {
         Self(Vec4::new(1.0, 0.0, 0.0, 1.0))
     }
 
+    #[deprecated(since = "0.7.2", note = "please use `Mat4::from_cols` instead")]
     #[inline]
     pub fn new(x_axis: Vec2, y_axis: Vec2) -> Self {
+        Self::from_cols(x_axis, y_axis)
+    }
+
+    /// Creates a new `Mat2` from four column vectors.
+    #[inline]
+    pub fn from_cols(x_axis: Vec2, y_axis: Vec2) -> Self {
         Self(Vec4::new(x_axis.x(), x_axis.y(), y_axis.x(), y_axis.y()))
     }
 
+    /// Creates a new `Mat2` from a `[f32; 4]` stored in column major order.
+    /// If your data is stored in row major you will need to `transpose` the resulting `Mat2`.
+    #[inline]
+    pub fn from_cols_array(m: &[f32; 4]) -> Self {
+        Mat2(Vec4::new(m[0], m[1], m[2], m[3]))
+    }
+
+    /// Creates a new `[f32; 4]` storing data in column major order.
+    /// If you require data in row major order `transpose` the `Mat2` first.
+    #[inline]
+    pub fn into_cols_array(&self) -> [f32; 4] {
+        self.0.into()
+    }
+
+    /// Creates a new `Mat2` from a `[[f32; 2]; 2]` stored in column major order.
+    /// If your data is in row major order you will need to `transpose` the resulting `Mat2`.
+    #[inline]
+    pub fn from_cols_array_2d(m: &[[f32; 2]; 2]) -> Self {
+        Mat2(Vec4::new(m[0][0], m[0][1], m[1][0], m[1][1]))
+    }
+
+    /// Creates a new `[[f32; 2]; 2]` storing data in column major order.
+    /// If you require data in row major order `transpose` the `Mat2` first.
+    #[inline]
+    pub fn into_cols_array_2d(&self) -> [[f32; 2]; 2] {
+        let (x0, y0, x1, y1) = self.0.into();
+        [[x0, y0], [x1, y1]]
+    }
+
     /// Create a 2x2 matrix containing scale and rotation (in radians).
     #[inline]
     pub fn from_scale_angle(scale: Vec2, angle: f32) -> Self {
@@ -128,7 +164,7 @@ impl Mat2 {
     pub fn mul_mat2(&self, rhs: &Self) -> Self {
         // TODO: SSE2
         let (x0, y0, x1, y1) = rhs.0.into();
-        Mat2::new(
+        Mat2::from_cols(
             self.mul_vec2(Vec2::new(x0, y0)),
             self.mul_vec2(Vec2::new(x1, y1)),
         )
@@ -220,34 +256,3 @@ impl Mul<f32> for Mat2 {
         self.mul_scalar(rhs)
     }
 }
-
-impl From<[[f32; 2]; 2]> for Mat2 {
-    #[inline]
-    fn from(m: [[f32; 2]; 2]) -> Self {
-        Mat2(Vec4::new(m[0][0], m[0][1], m[1][0], m[1][1]))
-    }
-}
-
-impl From<Mat2> for [[f32; 2]; 2] {
-    #[inline]
-    fn from(m: Mat2) -> Self {
-        let (x0, y0, x1, y1) = m.0.into();
-        [[x0, y0], [x1, y1]]
-    }
-}
-
-impl From<[f32; 4]> for Mat2 {
-    #[inline]
-    /// Load from array in column major order.
-    fn from(m: [f32; 4]) -> Self {
-        Mat2(m.into())
-    }
-}
-
-impl From<Mat2> for [f32; 4] {
-    #[inline]
-    /// Store to array in column major order.
-    fn from(m: Mat2) -> Self {
-        m.0.into()
-    }
-}

src/f32/mat3.rs

@@ -76,16 +76,62 @@ impl Mat3 {
         }
     }
 
+    #[deprecated(since = "0.7.2", note = "please use `Mat3::from_cols` instead")]
     #[inline]
     pub fn new(x_axis: Vec3, y_axis: Vec3, z_axis: Vec3) -> Self {
+        Self::from_cols(x_axis, y_axis, z_axis)
+    }
+
+    /// Creates a new `Mat3` from three column vectors.
+    #[inline]
+    pub fn from_cols(x_axis: Vec3, y_axis: Vec3, z_axis: Vec3) -> Self {
         Self {
             x_axis,
             y_axis,
             z_axis,
         }
     }
 
-    /// Create a 3x3 matrix that can scale, rotate and translate a 2D vector.
+    /// Creates a new `Mat3` from a `[f32; 9]` stored in column major order.
+    /// If your data is stored in row major you will need to `transpose` the resulting `Mat3`.
+    #[inline]
+    pub fn from_cols_array(m: &[f32; 9]) -> Self {
+        Mat3 {
+            x_axis: Vec3::new(m[0], m[1], m[2]),
+            y_axis: Vec3::new(m[3], m[4], m[5]),
+            z_axis: Vec3::new(m[6], m[7], m[8]),
+        }
+    }
+
+    /// Creates a new `[f32; 9]` storing data in column major order.
+    /// If you require data in row major order `transpose` the `Mat3` first.
+    #[inline]
+    pub fn into_cols_array(&self) -> [f32; 9] {
+        let (m00, m01, m02) = self.x_axis.into();
+        let (m10, m11, m12) = self.y_axis.into();
+        let (m20, m21, m22) = self.z_axis.into();
+        [m00, m01, m02, m10, m11, m12, m20, m21, m22]
+    }
+
+    /// Creates a new `Mat3` from a `[[f32; 3]; 3]` stored in column major order.
+    /// If your data is in row major order you will need to `transpose` the resulting `Mat3`.
+    #[inline]
+    pub fn from_cols_array_2d(m: &[[f32; 3]; 3]) -> Self {
+        Mat3 {
+            x_axis: m[0].into(),
+            y_axis: m[1].into(),
+            z_axis: m[2].into(),
+        }
+    }
+
+    /// Creates a new `[[f32; 3]; 3]` storing data in column major order.
+    /// If you require data in row major order `transpose` the `Mat3` first.
+    #[inline]
+    pub fn into_cols_array_2d(&self) -> [[f32; 3]; 3] {
+        [self.x_axis.into(), self.y_axis.into(), self.z_axis.into()]
+    }
+
+    /// Creates a new `Mat3` that can scale, rotate and translate a 2D vector.
     /// `angle` is in radians.
     #[inline]
     pub fn from_scale_angle_translation(scale: Vec2, angle: f32, translation: Vec2) -> Self {
@@ -235,7 +281,7 @@ impl Mat3 {
         glam_assert!(det.cmpne(Vec3::zero()).all());
         let inv_det = det.reciprocal();
         // TODO: Work out if it's possible to get rid of the transpose
-        Mat3::new(tmp0 * inv_det, tmp1 * inv_det, tmp2 * inv_det).transpose()
+        Mat3::from_cols(tmp0 * inv_det, tmp1 * inv_det, tmp2 * inv_det).transpose()
     }
 
     #[inline]
@@ -352,44 +398,3 @@ impl Mul<f32> for Mat3 {
         self.mul_scalar(rhs)
     }
 }
-
-impl From<[[f32; 3]; 3]> for Mat3 {
-    #[inline]
-    fn from(m: [[f32; 3]; 3]) -> Self {
-        Mat3 {
-            x_axis: m[0].into(),
-            y_axis: m[1].into(),
-            z_axis: m[2].into(),
-        }
-    }
-}
-
-impl From<Mat3> for [[f32; 3]; 3] {
-    #[inline]
-    fn from(m: Mat3) -> Self {
-        [m.x_axis.into(), m.y_axis.into(), m.z_axis.into()]
-    }
-}
-
-impl From<[f32; 9]> for Mat3 {
-    #[inline]
-    /// Load from array in column major order.
-    fn from(m: [f32; 9]) -> Self {
-        Mat3 {
-            x_axis: Vec3::new(m[0], m[1], m[2]),
-            y_axis: Vec3::new(m[3], m[4], m[5]),
-            z_axis: Vec3::new(m[6], m[7], m[8]),
-        }
-    }
-}
-
-impl From<Mat3> for [f32; 9] {
-    #[inline]
-    /// Store to array in column major order.
-    fn from(m: Mat3) -> Self {
-        let (m00, m01, m02) = m.x_axis.into();
-        let (m10, m11, m12) = m.y_axis.into();
-        let (m20, m21, m22) = m.z_axis.into();
-        [m00, m01, m02, m10, m11, m12, m20, m21, m22]
-    }
-}