83 lines
1.8 KiB
Zig
83 lines
1.8 KiB
Zig
const math = @import("std").math;
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pub const Vec3 = packed struct {
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x: f32 = 0.0,
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y: f32 = 0.0,
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z: f32 = 0.0,
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pub fn add(u: Vec3, v: Vec3) Vec3 {
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return Vec3{
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.x = u.x + v.x,
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.y = u.y + v.y,
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.z = u.z + v.z,
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};
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}
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pub fn sub(u: Vec3, v: Vec3) Vec3 {
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return Vec3{
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.x = u.x - v.x,
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.y = u.y - v.y,
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.z = u.z - v.z,
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};
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}
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pub fn mul(self: Vec3, scalar: f32) Vec3 {
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return Vec3{
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.x = self.x * scalar,
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.y = self.y * scalar,
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.z = self.z * scalar,
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};
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}
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pub fn div(self: Vec3, scalar: f32) Vec3 {
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return Vec3{
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.x = self.x / scalar,
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.y = self.y / scalar,
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.z = self.z / scalar,
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};
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}
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pub fn length(self: Vec3) f32 {
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return math.sqrt(self.x * self.x + self.y * self.y + self.z * self.z);
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}
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pub fn length_squared(self: Vec3) f32 {
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return self.x * self.x + self.y * self.y + self.z * self.z;
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}
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pub fn dot(u: Vec3, v: Vec3) f32 {
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return u.x * v.x + u.y * v.y + u.z * v.z;
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}
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pub fn cross(u: Vec3, v: Vec3) Vec3 {
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return Vec3{
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.x = u.y * v.z - u.z * v.y,
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.y = u.z * v.x - u.x * v.z,
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.z = u.x * v.y - u.y * v.x,
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};
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}
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// pub fn unit_vector() Vec3 {
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// return
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// }
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};
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pub fn unitVector(vec: Vec3) Vec3 {
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return vec.div(vec.length());
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}
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pub const Point3 = Vec3;
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pub const Color = Vec3;
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const assert = @import("std").debug.assert;
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fn assert_cmp(actual: f32, expected: f32) void {
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const epsilon: f32 = 1e-5;
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assert(math.fabs(actual - expected) < epsilon);
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}
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test "Vec3.length" {
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const v = Vec3{ .x = 1.0, .y = 1.0, .z = 1.0 };
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assert_cmp(v.length(), 1.7320508);
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}
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