Removed Angle type.

Everything that used to take `Angle` now takes `f32` in radians. The
only exception is functions that take FOV for creating perspective
functions, these expect angles in degrees.

Fixes #22.

Author: bitshifter

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "glam"
-version = "0.7.3" # remember to update html_root_url
+version = "0.8.0" # remember to update html_root_url
 edition = "2018"
 authors = ["Cameron Hart <cameron.hart@gmail.com>"]
 description = "A simple and fast 3D math library for games and graphics"

README.md

@@ -16,7 +16,6 @@ and the look and feel of the API has solidified.
 * vectors: `Vec3`, `Vec3`, `Vec4`
 * square matrices: `Mat2`, `Mat3`, `Mat4`
 * a quaternion type: `Quat`
-* an angle type: `Angle`
 * SSE2 opimized `sin_cos`
 
 ### SIMD

benches/support/mod.rs

@@ -1,6 +1,6 @@
 #![allow(dead_code)]
 use core::f32;
-use glam::f32::{rad, Mat2, Mat3, Mat4, Quat, Vec2, Vec3, Vec4};
+use glam::f32::{Mat2, Mat3, Mat4, Quat, Vec2, Vec3, Vec4};
 
 pub struct PCG32 {
     state: u64,
@@ -72,7 +72,7 @@ pub fn random_quat(rng: &mut PCG32) -> Quat {
     let yaw = random_radians(rng);
     let pitch = random_radians(rng);
     let roll = random_radians(rng);
-    Quat::from_rotation_ypr(rad(yaw), rad(pitch), rad(roll))
+    Quat::from_rotation_ypr(yaw, pitch, roll)
 }
 
 pub fn random_mat2(rng: &mut PCG32) -> Mat2 {

src/f32/angle.rs

@@ -139,3 +139,36 @@ pub unsafe fn sin_cos_sse2(x: __m128) -> (__m128, __m128) {
         _mm_xor_ps(xmm2, sign_bit_cos),
     )
 }
+
+#[inline]
+pub fn scalar_acos(value: f32) -> f32 {
+    // from DirectXMath XMScalarAcos
+    // Clamp input to [-1,1].
+    let nonnegative = value >= 0.0;
+    let x = value.abs();
+    let mut omx = 1.0 - x;
+    if omx < 0.0 {
+        omx = 0.0;
+    }
+    let root = omx.sqrt();
+
+    // 7-degree minimax approximation
+    #[allow(clippy::approx_constant)]
+    let mut result =
+        ((((((-0.001_262_491_1 * x + 0.006_670_09) * x - 0.017_088_126) * x + 0.030_891_88) * x
+            - 0.050_174_303)
+            * x
+            + 0.088_978_99)
+            * x
+            - 0.214_598_8)
+            * x
+            + 1.570_796_3;
+    result *= root;
+
+    // acos(x) = pi - acos(-x) when x < 0
+    if nonnegative {
+        result
+    } else {
+        std::f32::consts::PI - result
+    }
+}

src/f32/funcs.rs

@@ -1,45 +1,6 @@
-use crate::f32::{Angle, Mat2, Mat3, Mat4, Quat, Vec2, Vec3, Vec4};
+use crate::f32::{Mat2, Mat3, Mat4, Quat, Vec2, Vec3, Vec4};
 use approx::{AbsDiffEq, RelativeEq, UlpsEq};
 
-impl AbsDiffEq for Angle {
-    type Epsilon = <f32 as AbsDiffEq>::Epsilon;
-    fn default_epsilon() -> Self::Epsilon {
-        f32::default_epsilon()
-    }
-    fn abs_diff_eq(&self, other: &Self, epsilon: Self::Epsilon) -> bool {
-        let a1 = self.radians();
-        let a2 = other.radians();
-        a1.abs_diff_eq(&a2, epsilon)
-    }
-}
-
-impl RelativeEq for Angle {
-    fn default_max_relative() -> Self::Epsilon {
-        f32::default_max_relative()
-    }
-    fn relative_eq(
-        &self,
-        other: &Self,
-        epsilon: Self::Epsilon,
-        max_relative: Self::Epsilon,
-    ) -> bool {
-        let a1 = self.radians();
-        let a2 = other.radians();
-        a1.relative_eq(&a2, epsilon, max_relative)
-    }
-}
-
-impl UlpsEq for Angle {
-    fn default_max_ulps() -> u32 {
-        f32::default_max_ulps()
-    }
-    fn ulps_eq(&self, other: &Self, epsilon: Self::Epsilon, max_ulps: u32) -> bool {
-        let a1 = self.radians();
-        let a2 = other.radians();
-        a1.ulps_eq(&a2, epsilon, max_ulps)
-    }
-}
-
 impl AbsDiffEq for Quat {
     type Epsilon = <f32 as AbsDiffEq>::Epsilon;
     fn default_epsilon() -> Self::Epsilon {

src/f32/glam_approx.rs

@@ -1,4 +1,4 @@
-use super::{super::Angle, Vec2, Vec4};
+use super::{scalar_sin_cos, Vec2, Vec4};
 
 #[cfg(feature = "rand")]
 use rand::{
@@ -40,9 +40,10 @@ impl Mat2 {
         Self(Vec4::new(x_axis.x(), x_axis.y(), y_axis.x(), y_axis.y()))
     }
 
+    /// Create a 2x2 matrix containing scale and rotation (in radians).
     #[inline]
-    pub fn from_scale_angle(scale: Vec2, angle: Angle) -> Self {
-        let (sin, cos) = angle.sin_cos();
+    pub fn from_scale_angle(scale: Vec2, angle: f32) -> Self {
+        let (sin, cos) = scalar_sin_cos(angle);
         let (scale_x, scale_y) = scale.into();
         Self(Vec4::new(
             cos * scale_x,
@@ -52,9 +53,10 @@ impl Mat2 {
         ))
     }
 
+    /// Create a 2x2 matrix containing a rotation (in radians).
     #[inline]
-    pub fn from_angle(angle: Angle) -> Self {
-        let (sin, cos) = angle.sin_cos();
+    pub fn from_angle(angle: f32) -> Self {
+        let (sin, cos) = scalar_sin_cos(angle);
         Self(Vec4::new(cos, sin, -sin, cos))
     }