rust/land2d/src/lib.rs
branchui-scaling
changeset 15288 c4fd2813b127
parent 14707 29dbe9ce8b7d
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/rust/land2d/src/lib.rs	Wed Jul 31 23:14:27 2019 +0200
@@ -0,0 +1,342 @@
+use std::{
+    cmp,
+    ops::Index
+};
+
+use integral_geometry::{ArcPoints, EquidistantPoints, Line, Point, Rect, Size, SizeMask};
+
+pub struct Land2D<T> {
+    pixels: vec2d::Vec2D<T>,
+    play_box: Rect,
+    mask: SizeMask,
+}
+
+impl<T: Copy + PartialEq> Land2D<T> {
+    pub fn new(play_size: Size, fill_value: T) -> Self {
+        let real_size = play_size.next_power_of_two();
+        let top_left = Point::new(
+            ((real_size.width - play_size.width) / 2) as i32,
+            (real_size.height - play_size.height) as i32,
+        );
+        let play_box = Rect::from_size(top_left, play_size);
+        Self {
+            play_box,
+            pixels: vec2d::Vec2D::new(real_size, fill_value),
+            mask: real_size.to_mask(),
+        }
+    }
+
+    pub fn raw_pixels(&self) -> &[T] {
+        &self.pixels.as_slice()
+    }
+
+    pub fn raw_pixel_bytes(&self) -> &[u8] {
+        unsafe {
+            self.pixels.as_bytes()
+        }
+    }
+
+    #[inline]
+    pub fn width(&self) -> usize {
+        self.pixels.width()
+    }
+
+    #[inline]
+    pub fn height(&self) -> usize {
+        self.pixels.height()
+    }
+
+    #[inline]
+    pub fn size(&self) -> Size {
+        self.pixels.size()
+    }
+
+    #[inline]
+    pub fn play_width(&self) -> usize {
+        self.play_box.width()
+    }
+
+    #[inline]
+    pub fn play_height(&self) -> usize {
+        self.play_box.height()
+    }
+
+    #[inline]
+    pub fn play_size(&self) -> Size {
+        self.play_box.size()
+    }
+
+    #[inline]
+    pub fn play_box(&self) -> Rect {
+        self.play_box
+    }
+
+    #[inline]
+    pub fn is_valid_x(&self, x: i32) -> bool {
+        self.mask.contains_x(x as usize)
+    }
+
+    #[inline]
+    pub fn is_valid_y(&self, y: i32) -> bool {
+        self.mask.contains_y(y as usize)
+    }
+
+    #[inline]
+    pub fn is_valid_coordinate(&self, x: i32, y: i32) -> bool {
+        self.is_valid_x(x) && self.is_valid_y(y)
+    }
+
+    #[inline]
+    pub fn rows(&self) -> impl DoubleEndedIterator<Item = &[T]> {
+        self.pixels.rows()
+    }
+
+    #[inline]
+    pub fn map<U: Default, F: FnOnce(&mut T) -> U>(&mut self, y: i32, x: i32, f: F) -> U {
+        if self.is_valid_coordinate(x, y) {
+            unsafe {
+                // hey, I just checked that coordinates are valid!
+                f(self.pixels.get_unchecked_mut(y as usize, x as usize))
+            }
+        } else {
+            U::default()
+        }
+    }
+
+    #[inline]
+    pub fn map_point<U: Default, F: FnOnce(&mut T) -> U>(&mut self, point: Point, f: F) -> U {
+        self.map(point.y, point.x, f)
+    }
+
+    pub fn fill_from_iter<I>(&mut self, i: I, value: T) -> usize
+    where
+        I: std::iter::Iterator<Item = Point>,
+    {
+        i.map(|p| {
+            self.map(p.y, p.x, |v| {
+                *v = value;
+                1
+            })
+        }).count()
+    }
+
+    pub fn draw_line(&mut self, line: Line, value: T) -> usize {
+        self.fill_from_iter(line.into_iter(), value)
+    }
+
+    pub fn fill(&mut self, start_point: Point, border_value: T, fill_value: T) {
+        assert!(self.is_valid_coordinate(start_point.x - 1, start_point.y));
+        assert!(self.is_valid_coordinate(start_point.x, start_point.y));
+
+        let mask = self.mask;
+        let width = self.width();
+
+        let mut stack: Vec<(usize, usize, usize, isize)> = Vec::new();
+        fn push(
+            mask: SizeMask,
+            stack: &mut Vec<(usize, usize, usize, isize)>,
+            xl: usize,
+            xr: usize,
+            y: usize,
+            dir: isize,
+        ) {
+            let yd = y as isize + dir;
+            if mask.contains_y(yd as usize) {
+                stack.push((xl, xr, yd as usize, dir));
+            }
+        };
+
+        let start_x_l = (start_point.x - 1) as usize;
+        let start_x_r = start_point.x as usize;
+        for dir in [-1, 1].iter().cloned() {
+            push(mask, &mut stack, start_x_l, start_x_r, start_point.y as usize, dir);
+        }
+
+        while let Some((mut xl, mut xr, y, dir)) = stack.pop() {
+            let row = &mut self.pixels[y][..];
+            while xl > 0 && row[xl] != border_value && row[xl] != fill_value
+            {
+                xl -= 1;
+            }
+
+            while xr < width - 1 && row[xr] != border_value && row[xr] != fill_value
+            {
+                xr += 1;
+            }
+
+            while xl < xr {
+                while xl <= xr && (row[xl] == border_value || row[xl] == fill_value)
+                {
+                    xl += 1;
+                }
+
+                let x = xl;
+
+                while xl <= xr && row[xl] != border_value && row[xl] != fill_value
+                {
+                    row[xl] = fill_value;
+                    xl += 1;
+                }
+
+                if x < xl {
+                    push(mask, &mut stack, x, xl - 1, y, dir);
+                    push(mask, &mut stack, x, xl - 1, y, -dir);
+                }
+            }
+        }
+    }
+
+    #[inline]
+    fn fill_circle_line<F: Fn(&mut T) -> usize>(
+        &mut self,
+        y: i32,
+        x_from: i32,
+        x_to: i32,
+        f: &F,
+    ) -> usize {
+        let mut result = 0;
+
+        if self.is_valid_y(y) {
+            for i in cmp::min(x_from, 0) as usize..cmp::max(x_to as usize, self.width() - 1) {
+                unsafe {
+                    // coordinates are valid at this point
+                    result += f(self.pixels.get_unchecked_mut(y as usize, i));
+                }
+            }
+        }
+
+        result
+    }
+
+    #[inline]
+    fn fill_circle_lines<F: Fn(&mut T) -> usize>(
+        &mut self,
+        x: i32,
+        y: i32,
+        dx: i32,
+        dy: i32,
+        f: &F,
+    ) -> usize {
+        self.fill_circle_line(y + dy, x - dx, x + dx, f)
+            + self.fill_circle_line(y - dy, x - dx, x + dx, f)
+            + self.fill_circle_line(y + dx, x - dy, x + dy, f)
+            + self.fill_circle_line(y - dx, x - dy, x + dy, f)
+    }
+
+    pub fn change_round<F: Fn(&mut T) -> usize>(
+        &mut self,
+        x: i32,
+        y: i32,
+        radius: i32,
+        f: F,
+    ) -> usize {
+        ArcPoints::new(radius)
+            .map(&mut |p: Point| self.fill_circle_lines(x, y, p.x, p.y, &f))
+            .sum()
+    }
+
+    fn fill_row(&mut self, center: Point, offset: Point, value: T) -> usize {
+        let row_index = center.y + offset.y;
+        if self.is_valid_y(row_index) {
+            let from_x = cmp::max(0, center.x - offset.x) as usize;
+            let to_x = cmp::min(self.width() - 1, (center.x + offset.x) as usize);
+            self.pixels[row_index as usize][from_x..=to_x]
+                .iter_mut()
+                .for_each(|v| *v = value);
+            to_x - from_x + 1
+        } else {
+            0
+        }
+    }
+
+    pub fn fill_circle(&mut self, center: Point, radius: i32, value: T) -> usize {
+        let transforms = [[0, 1, 1, 0], [0, 1, -1, 0], [1, 0, 0, 1], [1, 0, 0, -1]];
+        ArcPoints::new(radius)
+            .map(|vector| {
+                transforms
+                    .iter()
+                    .map(|m| self.fill_row(center, vector.transform(m), value))
+                    .sum::<usize>()
+            }).sum()
+    }
+
+    pub fn draw_thick_line(&mut self, line: Line, radius: i32, value: T) -> usize {
+        let mut result = 0;
+
+        for vector in ArcPoints::new(radius) {
+            for delta in EquidistantPoints::new(vector) {
+                for point in line.into_iter() {
+                    self.map_point(point + delta, |p| {
+                        if *p != value {
+                            *p = value;
+                            result += 1;
+                        }
+                    })
+                }
+            }
+        }
+
+        result
+    }
+}
+
+impl<T> Index<usize> for Land2D<T> {
+    type Output = [T];
+    #[inline]
+    fn index(&self, row: usize) -> &[T] {
+        &self.pixels[row]
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn basics() {
+        let l: Land2D<u8> = Land2D::new(Size::new(30, 50), 0);
+
+        assert_eq!(l.play_width(), 30);
+        assert_eq!(l.play_height(), 50);
+        assert_eq!(l.width(), 32);
+        assert_eq!(l.height(), 64);
+
+        assert!(l.is_valid_coordinate(0, 0));
+        assert!(!l.is_valid_coordinate(-1, -1));
+
+        assert!(l.is_valid_coordinate(31, 63));
+        assert!(!l.is_valid_coordinate(32, 63));
+        assert!(!l.is_valid_coordinate(31, 64));
+    }
+
+    #[test]
+    fn fill() {
+        let mut l: Land2D<u8> = Land2D::new(Size::square(128), 0);
+
+        l.draw_line(Line::new(Point::new(0, 0), Point::new(32, 96)), 1);
+        l.draw_line(Line::new(Point::new(32, 96), Point::new(64, 32)), 1);
+        l.draw_line(Line::new(Point::new(64, 32), Point::new(96, 80)), 1);
+        l.draw_line(Line::new(Point::new(96, 80), Point::new(128, 0)), 1);
+
+        l.draw_line(Line::new(Point::new(0, 128), Point::new(64, 96)), 1);
+        l.draw_line(Line::new(Point::new(128, 128), Point::new(64, 96)), 1);
+
+        l.fill(Point::new(32, 32), 1, 2);
+        l.fill(Point::new(16, 96), 1, 3);
+        l.fill(Point::new(60, 100), 1, 4);
+
+        assert_eq!(l.pixels[0][0], 1);
+        assert_eq!(l.pixels[96][64], 1);
+
+        assert_eq!(l.pixels[40][32], 2);
+        assert_eq!(l.pixels[40][96], 2);
+        assert_eq!(l.pixels[5][0], 3);
+        assert_eq!(l.pixels[120][0], 3);
+        assert_eq!(l.pixels[5][127], 3);
+        assert_eq!(l.pixels[120][127], 3);
+        assert_eq!(l.pixels[35][64], 3);
+        assert_eq!(l.pixels[120][20], 4);
+        assert_eq!(l.pixels[120][100], 4);
+        assert_eq!(l.pixels[100][64], 4);
+    }
+}