simple-blit 1.2.0

use core::{
    marker::PhantomData,
    ops::{Deref, DerefMut, Index, IndexMut},
};

/// Point type.
pub type Point = mint::Point2<u32>;
/// Size type.
pub type Size = mint::Vector2<u32>;

/// Quickly construct a `Point`.
#[inline]
pub const fn point(x: u32, y: u32) -> Point {
    Point { x, y }
}

/// Quickly construct a `Size`.
#[inline]
pub const fn size(x: u32, y: u32) -> Size {
    Size { x, y }
}

/// 2D immutable surface trait.
pub trait Surface<T> {
    /// Surface size.
    fn surface_size(&self) -> Size;

    /// Get a value at (pt.x, pt.y).
    fn surface_get(&self, pt: Point) -> Option<&T>;

    /// Create a [`SubSurface`] that only uses a rectangular part of this surface.
    #[inline]
    fn sub_surface(&self, offset: Point, size: Size) -> SubSurface<&Self, T>
    where
        Self: Sized,
    {
        SubSurface::new(self, offset, size)
    }

    /// Create a [`SubSurface`] that only uses a rectangular part of this surface starting from (offset.x, offset.y).
    #[inline]
    fn offset_surface(&self, offset: Point) -> SubSurface<&Self, T>
    where
        Self: Sized,
    {
        let sur_size = self.surface_size();
        SubSurface::new(
            self,
            offset,
            size(sur_size.x - offset.x, sur_size.y - offset.y),
        )
    }

    /// Create a [`SubSurface`] that only uses a rectangular part of this surface.
    #[inline]
    fn sub_surface_mut(&mut self, offset: Point, size: Size) -> SubSurface<&mut Self, T>
    where
        Self: Sized,
    {
        SubSurface::new(self, offset, size)
    }

    /// Create a [`SubSurface`] that only uses a rectangular part of this surface starting from (offset.x, offset.y).
    #[inline]
    fn offset_surface_mut(&mut self, offset: Point) -> SubSurface<&mut Self, T>
    where
        Self: Sized,
    {
        let sur_size = self.surface_size();
        SubSurface::new(
            self,
            offset,
            size(sur_size.x - offset.x, sur_size.y - offset.y),
        )
    }

    /// Create a [`SubSurface`] that only uses a rectangular part of this surface.
    #[inline]
    fn into_sub_surface(self, offset: Point, size: Size) -> SubSurface<Self, T>
    where
        Self: Sized,
    {
        SubSurface::new(self, offset, size)
    }

    /// Create a [`SubSurface`] that only uses a rectangular part of this surface starting from (offset.x, offset.y).
    #[inline]
    fn into_offset_surface(self, offset: Point) -> SubSurface<Self, T>
    where
        Self: Sized,
    {
        let sur_size = self.surface_size();
        SubSurface::new(
            self,
            offset,
            size(sur_size.x - offset.x, sur_size.y - offset.y),
        )
    }
}

impl<S, T> Surface<T> for &S
where
    S: Surface<T>,
{
    #[inline]
    fn surface_size(&self) -> Size {
        (**self).surface_size()
    }

    #[inline]
    fn surface_get(&self, pt: Point) -> Option<&T> {
        (**self).surface_get(pt)
    }
}

impl<S, T> Surface<T> for &mut S
where
    S: Surface<T>,
{
    #[inline]
    fn surface_size(&self) -> Size {
        (**self).surface_size()
    }

    #[inline]
    fn surface_get(&self, pt: Point) -> Option<&T> {
        (**self).surface_get(pt)
    }
}

/// 2D mutable surface trait.
pub trait SurfaceMut<T>: Surface<T> {
    /// Get a mutable value at (pt.x, pt.y).
    fn surface_get_mut(&mut self, pt: Point) -> Option<&mut T>;
}

impl<S, T> SurfaceMut<T> for &mut S
where
    S: SurfaceMut<T>,
{
    #[inline]
    fn surface_get_mut(&mut self, pt: Point) -> Option<&mut T> {
        (*self).surface_get_mut(pt)
    }
}

/// Generic surface with width and height.
#[derive(Clone, Copy, Debug, PartialEq, Eq)]
#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
pub struct GenericSurface<Slice, Item> {
    slice: Slice,
    size: Size,
    ghost: PhantomData<Item>,
}

impl<Slice, Item> GenericSurface<Slice, Item>
where
    Slice: AsRef<[Item]>,
{
    /// Construct a new surface.
    ///
    /// Returns `None` if `slice.len() != size.x * size.y`.
    #[inline]
    pub fn new(slice: Slice, size: Size) -> Option<Self> {
        if slice.as_ref().len() == (size.x * size.y) as _ {
            Some(Self {
                slice,
                size,
                ghost: PhantomData,
            })
        } else {
            None
        }
    }

    /// Constructs a new surface.
    ///
    /// Infers the height from slice length and width.
    #[inline]
    pub fn new_infer(slice: Slice, width: u32) -> Self {
        Self {
            size: size(width, slice.as_ref().len() as u32 / width),
            slice,
            ghost: PhantomData,
        }
    }
}

impl<Slice, Item> Deref for GenericSurface<Slice, Item>
where
    Slice: AsRef<[Item]>,
{
    type Target = [Item];

    #[inline]
    fn deref(&self) -> &Self::Target {
        self.slice.as_ref()
    }
}

impl<Slice, Item> DerefMut for GenericSurface<Slice, Item>
where
    Slice: AsRef<[Item]> + AsMut<[Item]>,
{
    #[inline]
    fn deref_mut(&mut self) -> &mut Self::Target {
        self.slice.as_mut()
    }
}

impl<Slice, Item> Surface<Item> for GenericSurface<Slice, Item>
where
    Slice: AsRef<[Item]>,
{
    #[inline]
    fn surface_size(&self) -> Size {
        self.size
    }

    #[inline]
    fn surface_get(&self, pt: Point) -> Option<&Item> {
        if pt.x < self.size.x && pt.y < self.size.y {
            Some(
                self.slice
                    .as_ref()
                    .index((pt.y * self.size.x + pt.x) as usize),
            )
        } else {
            None
        }
    }
}

impl<Slice, Item> SurfaceMut<Item> for GenericSurface<Slice, Item>
where
    Slice: AsRef<[Item]> + AsMut<[Item]>,
{
    #[inline]
    fn surface_get_mut(&mut self, pt: Point) -> Option<&mut Item> {
        if pt.x < self.size.x && pt.y < self.size.y {
            Some(
                self.slice
                    .as_mut()
                    .index_mut((pt.y * self.size.x + pt.x) as usize),
            )
        } else {
            None
        }
    }
}

/// A 'surface' that holds a single value, like a plain-colored rectangle.
#[derive(Clone, Copy, Debug, PartialEq, Eq)]
#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
pub struct SingleValueSurface<T> {
    /// Surface size.
    pub size: Size,
    /// Stored value, likely a color.
    pub value: T,
}

impl<T> SingleValueSurface<T> {
    /// Construct a new surface.
    #[inline]
    pub const fn new(value: T, size: Size) -> Self {
        Self { size, value }
    }
}

impl<T> Surface<T> for SingleValueSurface<T> {
    #[inline]
    fn surface_size(&self) -> Size {
        self.size
    }

    #[inline]
    fn surface_get(&self, _pt: Point) -> Option<&T> {
        Some(&self.value)
    }
}

impl<T> SurfaceMut<T> for SingleValueSurface<T> {
    #[inline]
    fn surface_get_mut(&mut self, _pt: Point) -> Option<&mut T> {
        Some(&mut self.value)
    }
}

/// A surface that only uses a rectangular part of another surface.
#[derive(Clone, Copy, Debug, PartialEq, Eq)]
#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
pub struct SubSurface<S, Item> {
    surface: S,
    offset: Point,
    size: Size,
    ghost: PhantomData<Item>,
}

impl<S, Item> SubSurface<S, Item> {
    /// Position of the rectangular part on the original surface.
    #[inline]
    pub fn offset(&self) -> Point {
        self.offset
    }

    /// Size of the rectangular part (size of the `SubSurface` itself).
    #[inline]
    pub fn size(&self) -> Size {
        self.size
    }

    /// Get the inner surface that was used to construct this.
    #[inline]
    pub fn inner(&self) -> &S {
        &self.surface
    }

    /// Get the inner surface that was used to construct this.
    #[inline]
    pub fn inner_mut(&mut self) -> &mut S {
        &mut self.surface
    }

    /// Get the inner surface that was used to construct this.
    #[inline]
    pub fn into_inner(self) -> S {
        self.surface
    }
}

impl<S, Item> SubSurface<S, Item>
where
    S: Surface<Item>,
{
    /// Create a new `SubSurface`.
    #[inline]
    pub fn new(surface: S, offset: Point, size: Size) -> Self {
        Self {
            surface,
            offset,
            size,
            ghost: PhantomData,
        }
    }
}

impl<S, Item> Surface<Item> for SubSurface<S, Item>
where
    S: Surface<Item>,
{
    #[inline]
    fn surface_size(&self) -> Size {
        self.size
    }

    #[inline]
    fn surface_get(&self, pt: Point) -> Option<&Item> {
        if pt.x < self.size.x && pt.y < self.size.y {
            self.surface.surface_get(point(pt.x + self.offset.x, pt.y + self.offset.y))
        } else {
            None
        }
    }
}

impl<S, Item> SurfaceMut<Item> for SubSurface<S, Item>
where
    S: SurfaceMut<Item>,
{
    #[inline]
    fn surface_get_mut(&mut self, pt: Point) -> Option<&mut Item> {
        if pt.x < self.size.x && pt.y < self.size.y {
            self.surface.surface_get_mut(point(pt.x + self.offset.x, pt.y + self.offset.y))
        } else {
            None
        }
    }
}