zig/mach
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

math: Fix Ray and Ray.Hit type adaptations

Browse source
This commit is contained in:
Joel D. Schüller 2023-10-07 16:26:03 +02:00 • committed by Stephen Gutekanst
parent 1c32ae83a7
commit 8ddb9ade70
1 changed files with 20 additions and 11 deletions
Download patch file Download diff file Expand all files Collapse all files

31
src/math/ray.zig
View file

@ -20,13 +20,21 @@ pub fn Ray(comptime Vec3P: type) type {
@typeName(P) ++ "'"),
};
const Vec4P = switch (Vec3P) {
math.Vec3 => math.Vec4,
math.Vec3h => math.Vec4h,
math.Vec3d => math.Vec4d,
else => @compileError("Expected Vec3, Vec3h, Vec3d, found '" ++
@typeName(Vec3P) ++ "'"),
};
return extern struct {
origin: Vec3P,
direction: Vec3P,
/// A ray hit for which xyz represent the barycentric coordinates
/// and w represents hit distance t
pub const Hit = math.Vec4;
pub const Hit = Vec4P;
pub usingnamespace switch (Vec3P) {
math.Vec3, math.Vec3h, math.Vec3d => struct {
@ -55,17 +63,17 @@ pub fn Ray(comptime Vec3P: type) type {
/// On hit, will return a RayHit which contains distance t
/// and barycentric coordinates.
pub inline fn triangleIntersect(
ray: *const math.Ray,
ray: *const Ray(Vec3P),
va: *const Vec3P,
vb: *const Vec3P,
vc: *const Vec3P,
backface_culling: bool,
) ?Hit {
var kz: u8 = maxDim(math.vec3(
var kz: u8 = maxDim([3]P{
@abs(ray.direction.v[0]),
@abs(ray.direction.v[1]),
@abs(ray.direction.v[2]),
));
});
var kx: u8 = kz + 1;
if (kx == 3)
kx = 0;
@ -132,18 +140,19 @@ pub fn Ray(comptime Vec3P: type) type {
if (det == 0.0)
return null; // no hit
// Calculate scaled z-coordinates of vertices and use them to calculate
// the hit distance
// Calculate scaled z-coordinates of vertices and use them
// to calculate the hit distance
const az: P = sz * a[kz];
const bz: P = sz * b[kz];
const cz: P = sz * c[kz];
var t: P = u * az + v * bz + w * cz;
// hit.t counts as a previous hit for backface culling, in which
// case triangle behind will no longer be considered a hit
// Since Ray.Hit is represented by a Vec4, t is the last element
// of that vector
var hit: Hit = math.vec4(
// hit.t counts as a previous hit for backface culling,
// in which case triangle behind will no longer be
// considered a hit.
// Since Ray.Hit is represented by a Vec4, t is the last
// element of that vector
var hit: Hit = Vec4P.init(
undefined,
undefined,
undefined,