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-rw-r--r--vendor/image/src/math/utils.rs123
1 files changed, 0 insertions, 123 deletions
diff --git a/vendor/image/src/math/utils.rs b/vendor/image/src/math/utils.rs
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index 3a1f121..0000000
--- a/vendor/image/src/math/utils.rs
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-//! 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));
- }
-}