Implement `{U,I}8Vec`

[andrewgazelka]

[bitshifter]

Do you have a use case for these or is this more because they aren't implemented yet?

[andrewgazelka]

Do you have a use case for these or is this more because they aren't implemented yet?

Use case. I want to use U8Vec because I want to represent chunk section coordinates in Minecraft which can be x,y,z in [0,16) so might as well use a U8Vec 🤷‍♂️

[AlessandroCanossa]

Since I too need these vectors, I've been trying to implement them but I'm having some troubles with vec4 tests, such as

error: literal out of range for `i8`
    --> tests/vec4.rs:228:58
     |
228  |             assert_eq!($new(4 as $t, 16 as $t, 64 as $t, 256 as $t), a * a);
     |                                                          ^^^
...
2145 |     impl_vec4_signed_integer_tests!(i8, i8vec4, I8Vec4, I8Vec3, I8Vec2, BVec4, bvec4);
     |     --------------------------------------------------------------------------------- in this macro invocation
     |

error: literal out of range for `i8`
    --> tests/vec4.rs:448:45
     |
448  |             assert_eq!(a.element_product(), 210 as $t);
     |                                             ^^^
...
2145 |     impl_vec4_signed_integer_tests!(i8, i8vec4, I8Vec4, I8Vec3, I8Vec2, BVec4, bvec4);
     |     --------------------------------------------------------------------------------- in this macro invocation
     |

---- i8vec4::test_ops_propagated stdout ----
thread 'i8vec4::test_ops_propagated' panicked at glam-rs/src/i8/i8vec4.rs:868:23:
attempt to multiply with overflow

In your opinion, what would be the best way to solve these problems without risking breaking all the other tests? @bitshifter

[bitshifter]

The macros are annoying to understand when they don't work.

The first one is from test_ops:

let a = $new(2 as $t, 4 as $t, 8 as $t, 16 as $t);
...
assert_eq!($new(4 as $t, 16 as $t, 64 as $t, 256 as $t), a * a);

The problem being that 16 * 16 is out of range. You could change this test to multiple by a different vector b so that the numbers don't get too large for i8,

The other failing test is test_sum_product

let a = $new(2 as $t, 3 as $t, 5 as $t, 7 as $t);
...
assert_eq!(a.element_product(), 210 as $t);

again you could change the inputs slightly to keep the result in the range of i8.

Usually I try to make sure each vector element in a test has a unique value to catch any errors where code is mistakenly referencing the same element twice by mistake or something.

Thanks for trying to implement this!

[bitshifter]

Fixed in #575 , thanks @AlessandroCanossa !