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author | Valentin Popov <valentin@popov.link> | 2024-01-08 00:21:28 +0300 |
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committer | Valentin Popov <valentin@popov.link> | 2024-01-08 00:21:28 +0300 |
commit | 1b6a04ca5504955c571d1c97504fb45ea0befee4 (patch) | |
tree | 7579f518b23313e8a9748a88ab6173d5e030b227 /vendor/image/src/math | |
parent | 5ecd8cf2cba827454317368b68571df0d13d7842 (diff) | |
download | fparkan-1b6a04ca5504955c571d1c97504fb45ea0befee4.tar.xz fparkan-1b6a04ca5504955c571d1c97504fb45ea0befee4.zip |
Initial vendor packages
Signed-off-by: Valentin Popov <valentin@popov.link>
Diffstat (limited to 'vendor/image/src/math')
-rw-r--r-- | vendor/image/src/math/mod.rs | 6 | ||||
-rw-r--r-- | vendor/image/src/math/rect.rs | 12 | ||||
-rw-r--r-- | vendor/image/src/math/utils.rs | 123 |
3 files changed, 141 insertions, 0 deletions
diff --git a/vendor/image/src/math/mod.rs b/vendor/image/src/math/mod.rs new file mode 100644 index 0000000..43b5b82 --- /dev/null +++ b/vendor/image/src/math/mod.rs @@ -0,0 +1,6 @@ +//! Mathematical helper functions and types. +mod rect; +mod utils; + +pub use self::rect::Rect; +pub(super) use utils::resize_dimensions; diff --git a/vendor/image/src/math/rect.rs b/vendor/image/src/math/rect.rs new file mode 100644 index 0000000..74696be --- /dev/null +++ b/vendor/image/src/math/rect.rs @@ -0,0 +1,12 @@ +/// A Rectangle defined by its top left corner, width and height. +#[derive(Copy, Clone, Debug, PartialEq, Eq, Hash)] +pub struct Rect { + /// The x coordinate of the top left corner. + pub x: u32, + /// The y coordinate of the top left corner. + pub y: u32, + /// The rectangle's width. + pub width: u32, + /// The rectangle's height. + pub height: u32, +} diff --git a/vendor/image/src/math/utils.rs b/vendor/image/src/math/utils.rs new file mode 100644 index 0000000..3a1f121 --- /dev/null +++ b/vendor/image/src/math/utils.rs @@ -0,0 +1,123 @@ +//! Shared mathematical utility functions. + +use std::cmp::max; + +/// Calculates the width and height an image should be resized to. +/// This preserves aspect ratio, and based on the `fill` parameter +/// will either fill the dimensions to fit inside the smaller constraint +/// (will overflow the specified bounds on one axis to preserve +/// aspect ratio), or will shrink so that both dimensions are +/// completely contained within the given `width` and `height`, +/// with empty space on one axis. +pub(crate) fn resize_dimensions( + width: u32, + height: u32, + nwidth: u32, + nheight: u32, + fill: bool, +) -> (u32, u32) { + let wratio = nwidth as f64 / width as f64; + let hratio = nheight as f64 / height as f64; + + let ratio = if fill { + f64::max(wratio, hratio) + } else { + f64::min(wratio, hratio) + }; + + let nw = max((width as f64 * ratio).round() as u64, 1); + let nh = max((height as f64 * ratio).round() as u64, 1); + + if nw > u64::from(u32::MAX) { + let ratio = u32::MAX as f64 / width as f64; + (u32::MAX, max((height as f64 * ratio).round() as u32, 1)) + } else if nh > u64::from(u32::MAX) { + let ratio = u32::MAX as f64 / height as f64; + (max((width as f64 * ratio).round() as u32, 1), u32::MAX) + } else { + (nw as u32, nh as u32) + } +} + +#[cfg(test)] +mod test { + quickcheck! { + fn resize_bounds_correctly_width(old_w: u32, new_w: u32) -> bool { + if old_w == 0 || new_w == 0 { return true; } + // In this case, the scaling is limited by scaling of height. + // We could check that case separately but it does not conform to the same expectation. + if new_w as u64 * 400u64 >= old_w as u64 * u64::from(u32::MAX) { return true; } + + let result = super::resize_dimensions(old_w, 400, new_w, ::std::u32::MAX, false); + let exact = (400 as f64 * new_w as f64 / old_w as f64).round() as u32; + result.0 == new_w && result.1 == exact.max(1) + } + } + + quickcheck! { + fn resize_bounds_correctly_height(old_h: u32, new_h: u32) -> bool { + if old_h == 0 || new_h == 0 { return true; } + // In this case, the scaling is limited by scaling of width. + // We could check that case separately but it does not conform to the same expectation. + if 400u64 * new_h as u64 >= old_h as u64 * u64::from(u32::MAX) { return true; } + + let result = super::resize_dimensions(400, old_h, ::std::u32::MAX, new_h, false); + let exact = (400 as f64 * new_h as f64 / old_h as f64).round() as u32; + result.1 == new_h && result.0 == exact.max(1) + } + } + + #[test] + fn resize_handles_fill() { + let result = super::resize_dimensions(100, 200, 200, 500, true); + assert!(result.0 == 250); + assert!(result.1 == 500); + + let result = super::resize_dimensions(200, 100, 500, 200, true); + assert!(result.0 == 500); + assert!(result.1 == 250); + } + + #[test] + fn resize_never_rounds_to_zero() { + let result = super::resize_dimensions(1, 150, 128, 128, false); + assert!(result.0 > 0); + assert!(result.1 > 0); + } + + #[test] + fn resize_handles_overflow() { + let result = super::resize_dimensions(100, ::std::u32::MAX, 200, ::std::u32::MAX, true); + assert!(result.0 == 100); + assert!(result.1 == ::std::u32::MAX); + + let result = super::resize_dimensions(::std::u32::MAX, 100, ::std::u32::MAX, 200, true); + assert!(result.0 == ::std::u32::MAX); + assert!(result.1 == 100); + } + + #[test] + fn resize_rounds() { + // Only truncation will result in (3840, 2229) and (2160, 3719) + let result = super::resize_dimensions(4264, 2476, 3840, 2160, true); + assert_eq!(result, (3840, 2230)); + + let result = super::resize_dimensions(2476, 4264, 2160, 3840, false); + assert_eq!(result, (2160, 3720)); + } + + #[test] + fn resize_handles_zero() { + let result = super::resize_dimensions(0, 100, 100, 100, false); + assert_eq!(result, (1, 100)); + + let result = super::resize_dimensions(100, 0, 100, 100, false); + assert_eq!(result, (100, 1)); + + let result = super::resize_dimensions(100, 100, 0, 100, false); + assert_eq!(result, (1, 1)); + + let result = super::resize_dimensions(100, 100, 100, 0, false); + assert_eq!(result, (1, 1)); + } +} |