Add projection types
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Brendan Zabarauskas
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37826e56bc
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bf1dd601d7
1 changed files with 148 additions and 0 deletions
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@ -92,3 +92,151 @@ pub fn ortho<S: Clone + Float>(left: S, right: S, bottom: S, top: S, near: S, fa
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c2r0, c2r1, c2r2, c2r3,
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c3r0, c3r1, c3r2, c3r3)
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}
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pub trait Projection<S> {
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fn if_valid<U:Clone>(&self, f: &fn() -> U) -> Result<U, ~str>;
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fn to_mat4(&self) -> Result<Mat4<S>, ~str>;
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}
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/// A perspective projection based on a vertical field-of-view angle.
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#[deriving(Clone, Eq)]
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pub struct PerspectiveFov<S> {
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fovy: S, //radians
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aspect: S,
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near: S,
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far: S,
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}
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impl<S: Clone + Float> PerspectiveFov<S> {
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pub fn to_perspective(&self) -> Result<Perspective<S>, ~str> {
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do self.if_valid {
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let angle = self.fovy / two::<S>();
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let ymax = self.near * angle.tan();
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let xmax = ymax * self.aspect;
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Perspective {
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left: -xmax,
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right: xmax,
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bottom: -ymax,
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top: ymax,
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near: self.near.clone(),
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far: self.far.clone(),
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}
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}
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}
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}
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impl<S: Clone + Float> Projection<S> for PerspectiveFov<S> {
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fn if_valid<U:Clone>(&self, f: &fn() -> U) -> Result<U, ~str> {
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let frac_pi_2: S = Real::frac_pi_2();
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cond! (
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(self.fovy < zero()) { Err(fmt!("The vertical field of view cannot be below zero, found: %?", self.fovy)) }
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(self.fovy > frac_pi_2) { Err(fmt!("The vertical field of view cannot be greater than a half turn, found: %?", self.fovy)) }
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(self.aspect < zero()) { Err(fmt!("The aspect ratio cannot be below zero, found: %?", self.aspect)) }
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(self.near < zero()) { Err(fmt!("The near plane distance cannot be below zero, found: %?", self.near)) }
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(self.far < zero()) { Err(fmt!("The far plane distance cannot be below zero, found: %?", self.far)) }
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(self.far < self.near) { Err(fmt!("The far plane cannot be closer than the near plane, found: far: %?, near: %?", self.far, self.near)) }
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_ { Ok(f()) }
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)
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}
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fn to_mat4(&self) -> Result<Mat4<S>, ~str> {
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do self.to_perspective().chain |proj| { proj.to_mat4() }
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}
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}
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/// A perspective projection with arbitrary left/right/bottom/top distances
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#[deriving(Clone, Eq)]
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pub struct Perspective<S> {
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left: S, right: S,
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bottom: S, top: S,
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near: S, far: S,
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}
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impl<S: Clone + Float> Projection<S> for Perspective<S> {
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fn if_valid<U:Clone>(&self, f: &fn() -> U) -> Result<U, ~str> {
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cond! (
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(self.left > self.right) { Err(fmt!("`left` cannot be greater than `right`, found: left: %? right: %?", self.left, self.right)) }
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(self.bottom > self.top) { Err(fmt!("`bottom` cannot be greater than `top`, found: bottom: %? top: %?", self.bottom, self.top)) }
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(self.near > self.far) { Err(fmt!("`near` cannot be greater than `far`, found: near: %? far: %?", self.near, self.far)) }
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_ { Ok(f()) }
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)
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}
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fn to_mat4(&self) -> Result<Mat4<S>, ~str> {
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do self.if_valid {
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let c0r0 = (two::<S>() * self.near) / (self.right - self.left);
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let c0r1 = zero();
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let c0r2 = zero();
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let c0r3 = zero();
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let c1r0 = zero();
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let c1r1 = (two::<S>() * self.near) / (self.top - self.bottom);
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let c1r2 = zero();
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let c1r3 = zero();
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let c2r0 = (self.right + self.left) / (self.right - self.left);
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let c2r1 = (self.top + self.bottom) / (self.top - self.bottom);
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let c2r2 = -(self.far + self.near) / (self.far - self.near);
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let c2r3 = -one::<S>();
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let c3r0 = zero();
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let c3r1 = zero();
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let c3r2 = -(two::<S>() * self.far * self.near) / (self.far - self.near);
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let c3r3 = zero();
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Mat4::new(c0r0, c0r1, c0r2, c0r3,
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c1r0, c1r1, c1r2, c1r3,
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c2r0, c2r1, c2r2, c2r3,
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c3r0, c3r1, c3r2, c3r3)
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}
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}
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}
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/// An orthographic projection with arbitrary left/right/bottom/top distances
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#[deriving(Clone, Eq)]
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pub struct Ortho<S> {
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left: S, right: S,
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bottom: S, top: S,
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near: S, far: S,
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}
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impl<S: Clone + Float> Projection<S> for Ortho<S> {
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fn if_valid<U:Clone>(&self, f: &fn() -> U) -> Result<U, ~str> {
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cond! (
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(self.left > self.right) { Err(fmt!("`left` cannot be greater than `right`, found: left: %? right: %?", self.left, self.right)) }
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(self.bottom > self.top) { Err(fmt!("`bottom` cannot be greater than `top`, found: bottom: %? top: %?", self.bottom, self.top)) }
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(self.near > self.far) { Err(fmt!("`near` cannot be greater than `far`, found: near: %? far: %?", self.near, self.far)) }
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_ { Ok(f()) }
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)
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}
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fn to_mat4(&self) -> Result<Mat4<S>, ~str> {
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do self.if_valid {
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let c0r0 = two::<S>() / (self.right - self.left);
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let c0r1 = zero();
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let c0r2 = zero();
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let c0r3 = zero();
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let c1r0 = zero();
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let c1r1 = two::<S>() / (self.top - self.bottom);
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let c1r2 = zero();
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let c1r3 = zero();
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let c2r0 = zero();
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let c2r1 = zero();
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let c2r2 = -two::<S>() / (self.far - self.near);
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let c2r3 = -one::<S>();
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let c3r0 = -(self.right + self.left) / (self.right - self.left);
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let c3r1 = -(self.top + self.bottom) / (self.top - self.bottom);
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let c3r2 = -(self.far + self.near) / (self.far - self.near);
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let c3r3 = one::<S>();
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Mat4::new(c0r0, c0r1, c0r2, c0r3,
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c1r0, c1r1, c1r2, c1r3,
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c2r0, c2r1, c2r2, c2r3,
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c3r0, c3r1, c3r2, c3r3)
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}
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}
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}
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