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GREEN: Fudge fractional and integral bits to get negative numbers to work

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This commit is contained in:
Gwilym Kuiper 2021-11-18 21:05:29 +00:00
parent 413a819e64
commit 89f89803dd
1 changed files with 11 additions and 4 deletions
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15
agb/src/number.rs
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@ -454,13 +454,19 @@ fn test_rem_euclid_is_always_positive_and_sensible(_gba: &mut super::Gba) {
impl<I: FixedWidthUnsignedInteger, const N: usize> Display for Num<I, N> { impl<I: FixedWidthUnsignedInteger, const N: usize> Display for Num<I, N> {
fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result { fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
let integral = self.0 >> N; let mut integral = self.0 >> N;
let mask: I = (I::one() << N) - I::one(); let mask: I = (I::one() << N) - I::one();
let mut fractional = self.0 & mask;
if fractional != I::zero() && integral < I::zero() {
integral = integral + I::one();
fractional = (I::one() << N) - fractional;
}
write!(f, "{}", integral)?; write!(f, "{}", integral)?;
let mut fractional = self.0 & mask; if fractional != I::zero() {
if fractional & mask != I::zero() {
write!(f, ".")?; write!(f, ".")?;
} }
@ -562,7 +568,7 @@ mod formatting_tests {
use alloc::format; use alloc::format;
#[test_case] #[test_case]
fn formats_numbers_correctly(_gba: &mut crate::Gba) { fn formats_whole_numbers_correctly(_gba: &mut crate::Gba) {
let a = Num::<i32, 8>::new(-4i32); let a = Num::<i32, 8>::new(-4i32);
assert_eq!(format!("{}", a), "-4"); assert_eq!(format!("{}", a), "-4");
@ -577,6 +583,7 @@ mod formatting_tests {
let b: Num<i32, 8> = a / two; let b: Num<i32, 8> = a / two;
let c: Num<i32, 8> = b * minus_one; let c: Num<i32, 8> = b * minus_one;
assert_eq!(b + c, 0.into());
assert_eq!(format!("{}", b), "1.25"); assert_eq!(format!("{}", b), "1.25");
assert_eq!(format!("{}", c), "-1.25"); assert_eq!(format!("{}", c), "-1.25");
} }