Struct retro_pixel::VecImage

pub struct VecImage<P> { /* fields omitted */ }

An image backed by a Vec.

Not available in no_std, obviously.

Methods

impl<P> VecImage<P>

pub fn new(width: usize, height: usize) -> Self where     P: Default + Clone,

Creates a VecImage of the given dimensions with the default value in all positions.

pub fn from_vec(width: usize, height: usize, vec: Vec<P>) -> Self

Creates a VecImage from the given vector of pixels.

Methods from Deref<Target = [P]>

pub const fn len(&self) -> usize

Returns the number of elements in the slice.

Examples

let a = [1, 2, 3];
assert_eq!(a.len(), 3);

pub const fn is_empty(&self) -> bool

Returns true if the slice has a length of 0.

Examples

let a = [1, 2, 3];
assert!(!a.is_empty());

pub fn first(&self) -> Option<&T>

Returns the first element of the slice, or None if it is empty.

Examples

let v = [10, 40, 30];
assert_eq!(Some(&10), v.first());

let w: &[i32] = &[];
assert_eq!(None, w.first());

pub fn split_first(&self) -> Option<(&T, &[T])>

Returns the first and all the rest of the elements of the slice, or None if it is empty.

Examples

let x = &[0, 1, 2];

if let Some((first, elements)) = x.split_first() {
    assert_eq!(first, &0);
    assert_eq!(elements, &[1, 2]);
}

pub fn split_last(&self) -> Option<(&T, &[T])>

Returns the last and all the rest of the elements of the slice, or None if it is empty.

Examples

let x = &[0, 1, 2];

if let Some((last, elements)) = x.split_last() {
    assert_eq!(last, &2);
    assert_eq!(elements, &[0, 1]);
}

pub fn last(&self) -> Option<&T>

Returns the last element of the slice, or None if it is empty.

Examples

let v = [10, 40, 30];
assert_eq!(Some(&30), v.last());

let w: &[i32] = &[];
assert_eq!(None, w.last());

pub fn get<I>(&self, index: I) -> Option<&<I as SliceIndex<[T]>>::Output> where     I: SliceIndex<[T]>,

Returns a reference to an element or subslice depending on the type of index.

• If given a position, returns a reference to the element at that position or None if out of bounds.
• If given a range, returns the subslice corresponding to that range, or None if out of bounds.

Examples

let v = [10, 40, 30];
assert_eq!(Some(&40), v.get(1));
assert_eq!(Some(&[10, 40][..]), v.get(0..2));
assert_eq!(None, v.get(3));
assert_eq!(None, v.get(0..4));

pub unsafe fn get_unchecked<I>(     &self,     index: I ) -> &<I as SliceIndex<[T]>>::Output where     I: SliceIndex<[T]>,

Returns a reference to an element or subslice, without doing bounds checking.

This is generally not recommended, use with caution! For a safe alternative see get.

Examples

let x = &[1, 2, 4];

unsafe {
    assert_eq!(x.get_unchecked(1), &2);
}

pub const fn as_ptr(&self) -> *const T

Returns a raw pointer to the slice's buffer.

The caller must ensure that the slice outlives the pointer this function returns, or else it will end up pointing to garbage.

Modifying the container referenced by this slice may cause its buffer to be reallocated, which would also make any pointers to it invalid.

Examples

let x = &[1, 2, 4];
let x_ptr = x.as_ptr();

unsafe {
    for i in 0..x.len() {
        assert_eq!(x.get_unchecked(i), &*x_ptr.offset(i as isize));
    }
}

pub fn iter(&self) -> Iter<T>

Returns an iterator over the slice.

Examples

let x = &[1, 2, 4];
let mut iterator = x.iter();

assert_eq!(iterator.next(), Some(&1));
assert_eq!(iterator.next(), Some(&2));
assert_eq!(iterator.next(), Some(&4));
assert_eq!(iterator.next(), None);

pub fn windows(&self, size: usize) -> Windows<T>

Returns an iterator over all contiguous windows of length size. The windows overlap. If the slice is shorter than size, the iterator returns no values.

Panics

Panics if size is 0.

Examples

let slice = ['r', 'u', 's', 't'];
let mut iter = slice.windows(2);
assert_eq!(iter.next().unwrap(), &['r', 'u']);
assert_eq!(iter.next().unwrap(), &['u', 's']);
assert_eq!(iter.next().unwrap(), &['s', 't']);
assert!(iter.next().is_none());

If the slice is shorter than size:

let slice = ['f', 'o', 'o'];
let mut iter = slice.windows(4);
assert!(iter.next().is_none());

pub fn chunks(&self, chunk_size: usize) -> Chunks<T>

Returns an iterator over chunk_size elements of the slice at a time. The chunks are slices and do not overlap. If chunk_size does not divide the length of the slice, then the last chunk will not have length chunk_size.

See exact_chunks for a variant of this iterator that returns chunks of always exactly chunk_size elements.

Panics

Panics if chunk_size is 0.

Examples

let slice = ['l', 'o', 'r', 'e', 'm'];
let mut iter = slice.chunks(2);
assert_eq!(iter.next().unwrap(), &['l', 'o']);
assert_eq!(iter.next().unwrap(), &['r', 'e']);
assert_eq!(iter.next().unwrap(), &['m']);
assert!(iter.next().is_none());

pub fn exact_chunks(&self, chunk_size: usize) -> ExactChunks<T>

🔬 This is a nightly-only experimental API. (exact_chunks)

Returns an iterator over chunk_size elements of the slice at a time. The chunks are slices and do not overlap. If chunk_size does not divide the length of the slice, then the last up to chunk_size-1 elements will be omitted.

Due to each chunk having exactly chunk_size elements, the compiler can often optimize the resulting code better than in the case of chunks.

Panics

Panics if chunk_size is 0.

Examples

#![feature(exact_chunks)]

let slice = ['l', 'o', 'r', 'e', 'm'];
let mut iter = slice.exact_chunks(2);
assert_eq!(iter.next().unwrap(), &['l', 'o']);
assert_eq!(iter.next().unwrap(), &['r', 'e']);
assert!(iter.next().is_none());

pub fn split_at(&self, mid: usize) -> (&[T], &[T])

Divides one slice into two at an index.

The first will contain all indices from [0, mid) (excluding the index mid itself) and the second will contain all indices from [mid, len) (excluding the index len itself).

Panics

Panics if mid > len.

Examples

let v = [1, 2, 3, 4, 5, 6];

{
   let (left, right) = v.split_at(0);
   assert!(left == []);
   assert!(right == [1, 2, 3, 4, 5, 6]);
}

{
    let (left, right) = v.split_at(2);
    assert!(left == [1, 2]);
    assert!(right == [3, 4, 5, 6]);
}

{
    let (left, right) = v.split_at(6);
    assert!(left == [1, 2, 3, 4, 5, 6]);
    assert!(right == []);
}

pub fn split<F>(&self, pred: F) -> Split<T, F> where     F: FnMut(&T) -> bool,

Returns an iterator over subslices separated by elements that match pred. The matched element is not contained in the subslices.

Examples

let slice = [10, 40, 33, 20];
let mut iter = slice.split(|num| num % 3 == 0);

assert_eq!(iter.next().unwrap(), &[10, 40]);
assert_eq!(iter.next().unwrap(), &[20]);
assert!(iter.next().is_none());

If the first element is matched, an empty slice will be the first item returned by the iterator. Similarly, if the last element in the slice is matched, an empty slice will be the last item returned by the iterator:

let slice = [10, 40, 33];
let mut iter = slice.split(|num| num % 3 == 0);

assert_eq!(iter.next().unwrap(), &[10, 40]);
assert_eq!(iter.next().unwrap(), &[]);
assert!(iter.next().is_none());

If two matched elements are directly adjacent, an empty slice will be present between them:

let slice = [10, 6, 33, 20];
let mut iter = slice.split(|num| num % 3 == 0);

assert_eq!(iter.next().unwrap(), &[10]);
assert_eq!(iter.next().unwrap(), &[]);
assert_eq!(iter.next().unwrap(), &[20]);
assert!(iter.next().is_none());

pub fn rsplit<F>(&self, pred: F) -> RSplit<T, F> where     F: FnMut(&T) -> bool,

Returns an iterator over subslices separated by elements that match pred, starting at the end of the slice and working backwards. The matched element is not contained in the subslices.

Examples

let slice = [11, 22, 33, 0, 44, 55];
let mut iter = slice.rsplit(|num| *num == 0);

assert_eq!(iter.next().unwrap(), &[44, 55]);
assert_eq!(iter.next().unwrap(), &[11, 22, 33]);
assert_eq!(iter.next(), None);

As with split(), if the first or last element is matched, an empty slice will be the first (or last) item returned by the iterator.

let v = &[0, 1, 1, 2, 3, 5, 8];
let mut it = v.rsplit(|n| *n % 2 == 0);
assert_eq!(it.next().unwrap(), &[]);
assert_eq!(it.next().unwrap(), &[3, 5]);
assert_eq!(it.next().unwrap(), &[1, 1]);
assert_eq!(it.next().unwrap(), &[]);
assert_eq!(it.next(), None);

pub fn splitn<F>(&self, n: usize, pred: F) -> SplitN<T, F> where     F: FnMut(&T) -> bool,

Returns an iterator over subslices separated by elements that match pred, limited to returning at most n items. The matched element is not contained in the subslices.

The last element returned, if any, will contain the remainder of the slice.

Examples

Print the slice split once by numbers divisible by 3 (i.e. [10, 40], [20, 60, 50]):

let v = [10, 40, 30, 20, 60, 50];

for group in v.splitn(2, |num| *num % 3 == 0) {
    println!("{:?}", group);
}

pub fn rsplitn<F>(&self, n: usize, pred: F) -> RSplitN<T, F> where     F: FnMut(&T) -> bool,

Returns an iterator over subslices separated by elements that match pred limited to returning at most n items. This starts at the end of the slice and works backwards. The matched element is not contained in the subslices.

The last element returned, if any, will contain the remainder of the slice.

Examples

Print the slice split once, starting from the end, by numbers divisible by 3 (i.e. [50], [10, 40, 30, 20]):

let v = [10, 40, 30, 20, 60, 50];

for group in v.rsplitn(2, |num| *num % 3 == 0) {
    println!("{:?}", group);
}

pub fn contains(&self, x: &T) -> bool where     T: PartialEq<T>,

Returns true if the slice contains an element with the given value.

Examples

let v = [10, 40, 30];
assert!(v.contains(&30));
assert!(!v.contains(&50));

pub fn starts_with(&self, needle: &[T]) -> bool where     T: PartialEq<T>,

Returns true if needle is a prefix of the slice.

Examples

let v = [10, 40, 30];
assert!(v.starts_with(&[10]));
assert!(v.starts_with(&[10, 40]));
assert!(!v.starts_with(&[50]));
assert!(!v.starts_with(&[10, 50]));

Always returns true if needle is an empty slice:

let v = &[10, 40, 30];
assert!(v.starts_with(&[]));
let v: &[u8] = &[];
assert!(v.starts_with(&[]));

pub fn ends_with(&self, needle: &[T]) -> bool where     T: PartialEq<T>,

Returns true if needle is a suffix of the slice.

Examples

let v = [10, 40, 30];
assert!(v.ends_with(&[30]));
assert!(v.ends_with(&[40, 30]));
assert!(!v.ends_with(&[50]));
assert!(!v.ends_with(&[50, 30]));

Always returns true if needle is an empty slice:

let v = &[10, 40, 30];
assert!(v.ends_with(&[]));
let v: &[u8] = &[];
assert!(v.ends_with(&[]));

pub fn binary_search(&self, x: &T) -> Result<usize, usize> where     T: Ord,

Binary searches this sorted slice for a given element.

If the value is found then Ok is returned, containing the index of the matching element; if the value is not found then Err is returned, containing the index where a matching element could be inserted while maintaining sorted order.

Examples

Looks up a series of four elements. The first is found, with a uniquely determined position; the second and third are not found; the fourth could match any position in [1, 4].

let s = [0, 1, 1, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55];

assert_eq!(s.binary_search(&13),  Ok(9));
assert_eq!(s.binary_search(&4),   Err(7));
assert_eq!(s.binary_search(&100), Err(13));
let r = s.binary_search(&1);
assert!(match r { Ok(1...4) => true, _ => false, });

pub fn binary_search_by<'a, F>(&'a self, f: F) -> Result<usize, usize> where     F: FnMut(&'a T) -> Ordering,

Binary searches this sorted slice with a comparator function.

The comparator function should implement an order consistent with the sort order of the underlying slice, returning an order code that indicates whether its argument is Less, Equal or Greater the desired target.

If a matching value is found then returns Ok, containing the index for the matched element; if no match is found then Err is returned, containing the index where a matching element could be inserted while maintaining sorted order.

Examples

Looks up a series of four elements. The first is found, with a uniquely determined position; the second and third are not found; the fourth could match any position in [1, 4].

let s = [0, 1, 1, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55];

let seek = 13;
assert_eq!(s.binary_search_by(|probe| probe.cmp(&seek)), Ok(9));
let seek = 4;
assert_eq!(s.binary_search_by(|probe| probe.cmp(&seek)), Err(7));
let seek = 100;
assert_eq!(s.binary_search_by(|probe| probe.cmp(&seek)), Err(13));
let seek = 1;
let r = s.binary_search_by(|probe| probe.cmp(&seek));
assert!(match r { Ok(1...4) => true, _ => false, });

pub fn binary_search_by_key<'a, B, F>(     &'a self,     b: &B,     f: F ) -> Result<usize, usize> where     B: Ord,     F: FnMut(&'a T) -> B,

Binary searches this sorted slice with a key extraction function.

Assumes that the slice is sorted by the key, for instance with sort_by_key using the same key extraction function.

If a matching value is found then returns Ok, containing the index for the matched element; if no match is found then Err is returned, containing the index where a matching element could be inserted while maintaining sorted order.

Examples

Looks up a series of four elements in a slice of pairs sorted by their second elements. The first is found, with a uniquely determined position; the second and third are not found; the fourth could match any position in [1, 4].

let s = [(0, 0), (2, 1), (4, 1), (5, 1), (3, 1),
         (1, 2), (2, 3), (4, 5), (5, 8), (3, 13),
         (1, 21), (2, 34), (4, 55)];

assert_eq!(s.binary_search_by_key(&13, |&(a,b)| b),  Ok(9));
assert_eq!(s.binary_search_by_key(&4, |&(a,b)| b),   Err(7));
assert_eq!(s.binary_search_by_key(&100, |&(a,b)| b), Err(13));
let r = s.binary_search_by_key(&1, |&(a,b)| b);
assert!(match r { Ok(1...4) => true, _ => false, });

pub unsafe fn align_to<U>(&self) -> (&[T], &[U], &[T])

🔬 This is a nightly-only experimental API. (slice_align_to)

Transmute the slice to a slice of another type, ensuring aligment of the types is maintained.

This method splits the slice into three distinct slices: prefix, correctly aligned middle slice of a new type, and the suffix slice. The middle slice will have the greatest length possible for a given type and input slice.

This method has no purpose when either input element T or output element U are zero-sized and will return the original slice without splitting anything.

Unsafety

This method is essentially a transmute with respect to the elements in the returned middle slice, so all the usual caveats pertaining to transmute::<T, U> also apply here.

Examples

Basic usage:

unsafe {
    let bytes: [u8; 7] = [1, 2, 3, 4, 5, 6, 7];
    let (prefix, shorts, suffix) = bytes.align_to::<u16>();
    // less_efficient_algorithm_for_bytes(prefix);
    // more_efficient_algorithm_for_aligned_shorts(shorts);
    // less_efficient_algorithm_for_bytes(suffix);
}

Trait Implementations

impl<P: Debug> Debug for VecImage<P>

fn fmt(&self, f: &mut Formatter) -> Result

Formats the value using the given formatter.

impl<P: Clone> Clone for VecImage<P>

fn clone(&self) -> VecImage<P>

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<P: PartialEq> PartialEq for VecImage<P>

fn eq(&self, other: &VecImage<P>) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &VecImage<P>) -> bool

This method tests for !=.

impl<P: Eq> Eq for VecImage<P>

impl<P: PartialOrd> PartialOrd for VecImage<P>

fn partial_cmp(&self, other: &VecImage<P>) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &VecImage<P>) -> bool

This method tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &VecImage<P>) -> bool

This method tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &VecImage<P>) -> bool

This method tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &VecImage<P>) -> bool

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl<P: Ord> Ord for VecImage<P>

fn cmp(&self, other: &VecImage<P>) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

Compares and returns the minimum of two values.

impl<P: Hash> Hash for VecImage<P>

fn hash<__HP: Hasher>(&self, state: &mut __HP)

Feeds this value into the given [Hasher].

fn hash_slice<H>(data: &[Self], state: &mut H) where     H: Hasher,

Feeds a slice of this type into the given [Hasher].

impl<P> Deref for VecImage<P>

type Target = [P]

The resulting type after dereferencing.

fn deref(&self) -> &Self::Target

Dereferences the value.

impl<P> Index<(usize, usize)> for VecImage<P>

type Output = P

The returned type after indexing.

fn index(&self, (x, y): (usize, usize)) -> &Self::Output

Performs the indexing (container[index]) operation.

impl<P> ReadableImage<P> for VecImage<P>

fn width(&self) -> usize

Can't exceed isize::MAX

fn height(&self) -> usize

Can't exceed isize::MAX

fn pitch(&self) -> isize

Offset from the start of one row to the start of the next row.

fn as_ptr(&self) -> *const P

Raw const pointer to the data.

fn get(&self, loc: (usize, usize)) -> Option<&P>

Performs an optional indexing by reference, gives None for out of bounds.

fn slice(&self, r: Range<(usize, usize)>) -> ImageSlice<P>

Grabs out a sub-slice of the data.

Important traits for ImageRefIter<'a, P>

impl<'a, P: 'a> Iterator for ImageRefIter<'a, P> type Item = (usize, usize, &'a P);

fn iter(&self) -> ImageRefIter<P>

Lets you iterate any image by reference.

fn to_vecimage(&self) -> VecImage<P> where     Self: Sized,     P: Default + Clone,

This is like to_owned, you get your own version of the data.

fn upscale(&self, scale: usize) -> VecImage<P> where     P: Copy + Default,

Scales up into a new VecImage by the given amount.

impl<P> IndexMut<(usize, usize)> for VecImage<P>

fn index_mut(&mut self, (x, y): (usize, usize)) -> &mut Self::Output

Performs the mutable indexing (container[index]) operation.

impl<P> WritableImage<P> for VecImage<P>

fn as_mut_ptr(&mut self) -> *mut P

Raw mut pointer to the data.

fn get_mut(&mut self, loc: (usize, usize)) -> Option<&mut P>

Performs an optional indexing by mut reference, gives None for out of bounds.

fn slice_mut(&mut self, r: Range<(usize, usize)>) -> ImageMutSlice<P>

Grabs out a mutable sub-slice of the data.

Important traits for ImageMutRefIter<'a, P>

impl<'a, P: 'a> Iterator for ImageMutRefIter<'a, P> type Item = (usize, usize, &'a mut P);

fn iter_mut(&mut self) -> ImageMutRefIter<P>

Lets you mutably iterate over any writable form of image.

fn set_all(&mut self, pixel: P) where     P: Clone,

Assigns all locations to be the given pixel value.

fn direct_copy<S>(&mut self, src: &S, offset: (isize, isize)) where     S: ReadableImage<P>,     P: Copy,

Directly copies the data from the source image into this image.

fn flip_vertical(&mut self)

Flips the image vertically.

fn flip_horizontal(&mut self)

Flips the image horizontally.

fn inplace_counterclockwise90_square(&mut self) -> Option<()>

Performs a 90 degrees counter-clockwise rotation, in place.

fn blit_generic<RI, F>(&mut self, src: &RI, offset: (isize, isize), op: F) where     RI: ReadableImage<P>,     F: FnMut(P, P) -> P,     P: Copy,

Modifies this image by overlaying the source image at the offset given.

impl WritableImageU16Ext for VecImage<u16>

fn blit_rgba16<RI>(&mut self, src: &RI, offset: (isize, isize)) where     RI: ReadableImage<u16>,

This copies the data from the source into the destination any time the source's alpha bit is set.

impl WritableImageU32Ext for VecImage<u32>

fn blit_blend_rectilinear<RI>(&mut self, src: &RI, offset: (isize, isize)) where     RI: ReadableImage<u32>,

Performs a rectilinear blending blit at an integral pixel offset.