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Simplify projection code

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This commit is contained in:
Brendan Zabarauskas 2013-09-05 16:44:27 +10:00
parent 6534855673
commit aef1d153a1
2 changed files with 141 additions and 161 deletions
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4
src/cgmath/angle.rs
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@ -101,6 +101,10 @@ impl<S: Clone + Float> Angle<S> for Deg<S> {
#[inline] pub fn tan<S: Clone + Float, A: Angle<S>>(theta: A) -> S { theta.to_rad().s.tan() }
#[inline] pub fn sin_cos<S: Clone + Float, A: Angle<S>>(theta: A) -> (S, S) { theta.to_rad().s.sin_cos() }
#[inline] pub fn cot<S: Clone + Float, A: Angle<S>>(theta: A) -> S { tan(theta).recip() }
#[inline] pub fn sec<S: Clone + Float, A: Angle<S>>(theta: A) -> S { cos(theta).recip() }
#[inline] pub fn csc<S: Clone + Float, A: Angle<S>>(theta: A) -> S { sin(theta).recip() }
#[inline] pub fn asin<S: Clone + Float, A: Angle<S>>(s: S) -> A { Angle::from(rad(s.asin())) }
#[inline] pub fn acos<S: Clone + Float, A: Angle<S>>(s: S) -> A { Angle::from(rad(s.acos())) }
#[inline] pub fn atan<S: Clone + Float, A: Angle<S>>(s: S) -> A { Angle::from(rad(s.atan())) }

202
src/cgmath/projection.rs
View file

@ -15,102 +15,66 @@
use std::num::{zero, one};
use angle::{Angle, Rad, rad, tan};
use matrix::Mat4;
use angle::{Angle, rad, tan, cot};
use matrix::{Mat4, ToMat4};
use util::two;
/// Create a perspective projection matrix
/// Create a perspective projection matrix.
///
/// Note: the fovy parameter should be specified in degrees.
///
/// This is the equivalent of the gluPerspective function, the algorithm of which
/// can be found [here](http://www.opengl.org/wiki/GluPerspective_code).
pub fn perspective<S: Clone + Float>(fovy: Rad<S>, aspectRatio: S, near: S, far: S) -> Mat4<S> {
let ymax = near * tan(fovy.div_s(two::<S>()));
let xmax = ymax * aspectRatio;
frustum(-xmax, xmax, -ymax, ymax, near, far)
/// This is the equivalent to the [gluPerspective]
/// (http://www.opengl.org/sdk/docs/man2/xhtml/gluPerspective.xml) function.
pub fn perspective<S: Clone + Float, A: Angle<S>>(fovy: A, aspect: S, near: S, far: S) -> Mat4<S> {
PerspectiveFov {
fovy: fovy,
aspect: aspect,
near: near,
far: far,
}.to_mat4()
}
/// Define a view frustrum
/// Create a perspective matrix from a view frustrum.
///
/// This is the equivalent of the now deprecated [glFrustrum]
/// (http://www.opengl.org/sdk/docs/man2/xhtml/glFrustum.xml) function.
pub fn frustum<S: Clone + Float>(left: S, right: S, bottom: S, top: S, near: S, far: S) -> Mat4<S> {
let c0r0 = (two::<S>() * near) / (right - left);
let c0r1 = zero();
let c0r2 = zero();
let c0r3 = zero();
let c1r0 = zero();
let c1r1 = (two::<S>() * near) / (top - bottom);
let c1r2 = zero();
let c1r3 = zero();
let c2r0 = (right + left) / (right - left);
let c2r1 = (top + bottom) / (top - bottom);
let c2r2 = -(far + near) / (far - near);
let c2r3 = -one::<S>();
let c3r0 = zero();
let c3r1 = zero();
let c3r2 = -(two::<S>() * far * near) / (far - near);
let c3r3 = zero();
Mat4::new(c0r0, c0r1, c0r2, c0r3,
c1r0, c1r1, c1r2, c1r3,
c2r0, c2r1, c2r2, c2r3,
c3r0, c3r1, c3r2, c3r3)
Perspective {
left: left,
right: right,
bottom: bottom,
top: top,
near: near,
far: far,
}.to_mat4()
}
/// Create an orthographic projection matrix
/// Create an orthographic projection matrix.
///
/// This is the equivalent of the now deprecated [glOrtho]
/// (http://www.opengl.org/sdk/docs/man2/xhtml/glOrtho.xml) function.
pub fn ortho<S: Clone + Float>(left: S, right: S, bottom: S, top: S, near: S, far: S) -> Mat4<S> {
let c0r0 = two::<S>() / (right - left);
let c0r1 = zero();
let c0r2 = zero();
let c0r3 = zero();
let c1r0 = zero();
let c1r1 = two::<S>() / (top - bottom);
let c1r2 = zero();
let c1r3 = zero();
let c2r0 = zero();
let c2r1 = zero();
let c2r2 = -two::<S>() / (far - near);
let c2r3 = zero();
let c3r0 = -(right + left) / (right - left);
let c3r1 = -(top + bottom) / (top - bottom);
let c3r2 = -(far + near) / (far - near);
let c3r3 = one();
Mat4::new(c0r0, c0r1, c0r2, c0r3,
c1r0, c1r1, c1r2, c1r3,
c2r0, c2r1, c2r2, c2r3,
c3r0, c3r1, c3r2, c3r3)
Ortho {
left: left,
right: right,
bottom: bottom,
top: top,
near: near,
far: far,
}.to_mat4()
}
pub trait Projection<S> {
fn if_valid<U:Clone>(&self, f: &fn() -> U) -> Result<U, ~str>;
fn to_mat4(&self) -> Result<Mat4<S>, ~str>;
}
pub trait Projection<S>: ToMat4<S> {}
/// A perspective projection based on a vertical field-of-view angle.
#[deriving(Clone, Eq)]
pub struct PerspectiveFov<S> {
fovy: Rad<S>,
pub struct PerspectiveFov<S, A> {
fovy: A,
aspect: S,
near: S,
far: S,
}
impl<S: Clone + Float> PerspectiveFov<S> {
pub fn to_perspective(&self) -> Result<Perspective<S>, ~str> {
do self.if_valid {
impl<S: Clone + Float, A: Angle<S>> PerspectiveFov<S, A> {
pub fn to_perspective(&self) -> Perspective<S> {
let angle = self.fovy.div_s(two::<S>());
let ymax = self.near * tan(angle);
let xmax = ymax * self.aspect;
@ -125,26 +89,48 @@ impl<S: Clone + Float> PerspectiveFov<S> {
}
}
}
impl<S: Clone + Float, A: Angle<S>> ToMat4<S> for PerspectiveFov<S, A> {
fn to_mat4(&self) -> Mat4<S> {
let half_turn: A = Angle::from(rad::<S>(Real::frac_pi_2()));
assert!(self.fovy < zero(), "The vertical field of view cannot be below zero, found: %?", self.fovy);
assert!(self.fovy > half_turn, "The vertical field of view cannot be greater than a half turn, found: %?", self.fovy);
assert!(self.aspect < zero(), "The aspect ratio cannot be below zero, found: %?", self.aspect);
assert!(self.near < zero(), "The near plane distance cannot be below zero, found: %?", self.near);
assert!(self.far < zero(), "The far plane distance cannot be below zero, found: %?", self.far);
assert!(self.far < self.near, "The far plane cannot be closer than the near plane, found: far: %?, near: %?", self.far, self.near);
let f = cot(self.fovy.div_s(two::<S>()));
let c0r0 = f / self.aspect;
let c0r1 = zero();
let c0r2 = zero();
let c0r3 = zero();
let c1r0 = zero();
let c1r1 = f;
let c1r2 = zero();
let c1r3 = zero();
let c2r0 = zero();
let c2r1 = zero();
let c2r2 = (self.far + self.near) / (self.near - self.far);
let c2r3 = -one::<S>();
let c3r0 = zero();
let c3r1 = zero();
let c3r2 = (two::<S>() * self.far * self.near) / (self.near - self.far);
let c3r3 = zero();
Mat4::new(c0r0, c0r1, c0r2, c0r3,
c1r0, c1r1, c1r2, c1r3,
c2r0, c2r1, c2r2, c2r3,
c3r0, c3r1, c3r2, c3r3)
}
}
impl<S: Clone + Float> Projection<S> for PerspectiveFov<S> {
fn if_valid<U:Clone>(&self, f: &fn() -> U) -> Result<U, ~str> {
let half_turn: Rad<S> = rad(Real::frac_pi_2());
cond! (
(self.fovy < zero()) { Err(fmt!("The vertical field of view cannot be below zero, found: %?", self.fovy)) }
(self.fovy > half_turn) { Err(fmt!("The vertical field of view cannot be greater than a half turn, found: %?", self.fovy)) }
(self.aspect < zero()) { Err(fmt!("The aspect ratio cannot be below zero, found: %?", self.aspect)) }
(self.near < zero()) { Err(fmt!("The near plane distance cannot be below zero, found: %?", self.near)) }
(self.far < zero()) { Err(fmt!("The far plane distance cannot be below zero, found: %?", self.far)) }
(self.far < self.near) { Err(fmt!("The far plane cannot be closer than the near plane, found: far: %?, near: %?", self.far, self.near)) }
_ { Ok(f()) }
)
}
fn to_mat4(&self) -> Result<Mat4<S>, ~str> {
do self.to_perspective().chain |proj| { proj.to_mat4() }
}
}
impl<S: Clone + Float, A: Angle<S>> Projection<S> for PerspectiveFov<S, A>;
/// A perspective projection with arbitrary left/right/bottom/top distances
#[deriving(Clone, Eq)]
@ -154,18 +140,12 @@ pub struct Perspective<S> {
near: S, far: S,
}
impl<S: Clone + Float> Projection<S> for Perspective<S> {
fn if_valid<U:Clone>(&self, f: &fn() -> U) -> Result<U, ~str> {
cond! (
(self.left > self.right) { Err(fmt!("`left` cannot be greater than `right`, found: left: %? right: %?", self.left, self.right)) }
(self.bottom > self.top) { Err(fmt!("`bottom` cannot be greater than `top`, found: bottom: %? top: %?", self.bottom, self.top)) }
(self.near > self.far) { Err(fmt!("`near` cannot be greater than `far`, found: near: %? far: %?", self.near, self.far)) }
_ { Ok(f()) }
)
}
impl<S: Clone + Float> ToMat4<S> for Perspective<S> {
fn to_mat4(&self) -> Mat4<S> {
assert!(self.left > self.right, "`left` cannot be greater than `right`, found: left: %? right: %?", self.left, self.right);
assert!(self.bottom > self.top, "`bottom` cannot be greater than `top`, found: bottom: %? top: %?", self.bottom, self.top);
assert!(self.near > self.far, "`near` cannot be greater than `far`, found: near: %? far: %?", self.near, self.far);
fn to_mat4(&self) -> Result<Mat4<S>, ~str> {
do self.if_valid {
let c0r0 = (two::<S>() * self.near) / (self.right - self.left);
let c0r1 = zero();
let c0r2 = zero();
@ -192,7 +172,8 @@ impl<S: Clone + Float> Projection<S> for Perspective<S> {
c3r0, c3r1, c3r2, c3r3)
}
}
}
impl<S: Clone + Float> Projection<S> for Perspective<S>;
/// An orthographic projection with arbitrary left/right/bottom/top distances
#[deriving(Clone, Eq)]
@ -202,18 +183,12 @@ pub struct Ortho<S> {
near: S, far: S,
}
impl<S: Clone + Float> Projection<S> for Ortho<S> {
fn if_valid<U:Clone>(&self, f: &fn() -> U) -> Result<U, ~str> {
cond! (
(self.left > self.right) { Err(fmt!("`left` cannot be greater than `right`, found: left: %? right: %?", self.left, self.right)) }
(self.bottom > self.top) { Err(fmt!("`bottom` cannot be greater than `top`, found: bottom: %? top: %?", self.bottom, self.top)) }
(self.near > self.far) { Err(fmt!("`near` cannot be greater than `far`, found: near: %? far: %?", self.near, self.far)) }
_ { Ok(f()) }
)
}
impl<S: Clone + Float> ToMat4<S> for Ortho<S> {
fn to_mat4(&self) -> Mat4<S> {
assert!(self.left > self.right, "`left` cannot be greater than `right`, found: left: %? right: %?", self.left, self.right);
assert!(self.bottom > self.top, "`bottom` cannot be greater than `top`, found: bottom: %? top: %?", self.bottom, self.top);
assert!(self.near > self.far, "`near` cannot be greater than `far`, found: near: %? far: %?", self.near, self.far);
fn to_mat4(&self) -> Result<Mat4<S>, ~str> {
do self.if_valid {
let c0r0 = two::<S>() / (self.right - self.left);
let c0r1 = zero();
let c0r2 = zero();
@ -240,4 +215,5 @@ impl<S: Clone + Float> Projection<S> for Ortho<S> {
c3r0, c3r1, c3r2, c3r3)
}
}
}
impl<S: Clone + Float> Projection<S> for Ortho<S>;