58 lines
1.7 KiB
Rust
58 lines
1.7 KiB
Rust
use core::num::{Zero, One};
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use numeric::*;
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use std::cmp::FuzzyEq;
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use mat::{Mat4, Matrix4};
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/**
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* Create a perspective projection matrix
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*
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* This is the equivalent of the gluPerspective function, the algorithm of which
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* can be found [here](http://www.opengl.org/wiki/GluPerspective_code).
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*/
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#[inline(always)]
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pub fn perspective<T:Copy + Float + Zero + One + FuzzyEq<T> + Add<T,T> + Sub<T,T> + Mul<T,T> + Div<T,T> + Neg<T>>(fovy: T, aspectRatio: T, near: T, far: T) -> Mat4<T> {
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let ymax = near * tan(radians(fovy));
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let xmax = ymax * aspectRatio;
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frustum(-xmax, xmax, -ymax, ymax, near, far)
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}
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/**
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* Define a view frustrum
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*
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* This is the equivalent of the now deprecated [glFrustrum]
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* (http://www.opengl.org/sdk/docs/man2/xhtml/glFrustum.xml) function.
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*/
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#[inline(always)]
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pub fn frustum<T:Copy + Float + Zero + One + FuzzyEq<T> + Add<T,T> + Sub<T,T> + Mul<T,T> + Div<T,T> + Neg<T>>(left: T, right: T, bottom: T, top: T, near: T, far: T) -> Mat4<T> {
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let _0: T = num::cast(0);
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let _1: T = num::cast(1);
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let _2: T = num::cast(2);
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let c0r0 = (_2 * near) / (right - left);
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let c0r1 = _0;
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let c0r2 = _0;
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let c0r3 = _0;
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let c1r0 = _0;
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let c1r1 = (_2 * near) / (top - bottom);
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let c1r2 = _0;
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let c1r3 = _0;
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let c2r0 = (right + left) / (right - left);
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let c2r1 = (top + bottom) / (top - bottom);
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let c2r2 = -(far + near) / (far - near);
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let c2r3 = -_1;
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let c3r0 = _0;
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let c3r1 = _0;
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let c3r2 = -(_2 * far * near) / (far - near);
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let c3r3 = _0;
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Matrix4::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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} |