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make drawing functions safe

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bendn 2023-09-22 16:50:08 +07:00
parent f74d3dc450
commit 1b5b06c36f
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3 changed files with 28 additions and 45 deletions
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2
Cargo.toml
View file

@ -1,6 +1,6 @@
[package]
name = "fimg"
version = "0.4.2"
version = "0.4.3"
authors = ["bend-n <bend.n@outlook.com>"]
license = "MIT"
edition = "2021"

54
src/drawing/box.rs
View file

@ -1,65 +1,51 @@
//! `Box<cat>`
use std::ops::Range;
use crate::Image;
impl<const CHANNELS: usize> Image<&mut [u8], CHANNELS> {
/// Draw a bordered box
///
/// # Safety
///
/// UB if the box is out of bounds
/// ```
/// # use fimg::Image;
/// let mut b = Image::alloc(10, 9);
/// unsafe { b.as_mut().r#box((1, 1), 7, 6, [255]) };
/// b.as_mut().r#box((1, 1), 7, 6, [255]);
/// # assert_eq!(b.buffer(), b"\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\xff\xff\xff\xff\xff\xff\xff\xff\x00\x00\xff\x00\x00\x00\x00\x00\x00\xff\x00\x00\xff\x00\x00\x00\x00\x00\x00\xff\x00\x00\xff\x00\x00\x00\x00\x00\x00\xff\x00\x00\xff\x00\x00\x00\x00\x00\x00\xff\x00\x00\xff\x00\x00\x00\x00\x00\x00\xff\x00\x00\xff\xff\xff\xff\xff\xff\xff\xff\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00")
/// ```
pub unsafe fn r#box(
&mut self,
(x1, y1): (u32, u32),
width: u32,
height: u32,
c: [u8; CHANNELS],
) {
pub fn r#box(&mut self, (x1, y1): (u32, u32), width: u32, height: u32, c: [u8; CHANNELS]) {
// skip sides, leave that to second loop
for x in x1 + 1..width + x1 {
for x in clamp(x1 + 1..width + x1, 0..self.width()) {
// top line
// SAFETY: responsibility is on caller
// SAFETY: clamped to bounds
unsafe { self.set_pixel(x, x1, c) };
// bottom line
// SAFETY: shift responsibility
// SAFETY: clamped to bounds
unsafe { self.set_pixel(x, x1 + height, c) };
}
for y in y1..=height + y1 {
// SAFETY: >> responsibility
for y in clamp(y1..height + y1 + 1, 0..self.height()) {
// SAFETY: clamped to bounds
unsafe { self.set_pixel(y1, y, c) };
// SAFETY: << responsibility
// SAFETY: clamped to bounds
unsafe { self.set_pixel(y1 + width, y, c) };
}
}
/// Draw a *filled* box.
///
/// # Safety
///
/// UB if box is out of bounds
/// ```
/// # use fimg::Image;
/// let mut b = Image::alloc(10, 9);
/// unsafe { b.as_mut().filled_box((1, 1), 7, 6, [255]) };
/// b.as_mut().filled_box((1, 1), 7, 6, [255]);
/// # assert_eq!(b.buffer(), b"\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\xff\xff\xff\xff\xff\xff\xff\xff\x00\x00\xff\xff\xff\xff\xff\xff\xff\xff\x00\x00\xff\xff\xff\xff\xff\xff\xff\xff\x00\x00\xff\xff\xff\xff\xff\xff\xff\xff\x00\x00\xff\xff\xff\xff\xff\xff\xff\xff\x00\x00\xff\xff\xff\xff\xff\xff\xff\xff\x00\x00\xff\xff\xff\xff\xff\xff\xff\xff\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00")
/// ```
pub unsafe fn filled_box(
&mut self,
(x1, y1): (u32, u32),
width: u32,
height: u32,
c: [u8; CHANNELS],
) {
for x in x1..=width + x1 {
for y in y1..=height + y1 {
// SAFETY: fill it
pub fn filled_box(&mut self, (x1, y1): (u32, u32), width: u32, height: u32, c: [u8; CHANNELS]) {
for x in clamp(x1..1 + width + x1, 0..self.width()) {
for y in clamp(y1..1 + height + y1, 0..self.height()) {
// SAFETY: clamped to bounds
unsafe { self.set_pixel(x, y, c) };
}
}
}
}
/// clamp a range with another range
fn clamp(r: Range<u32>, within: Range<u32>) -> Range<u32> {
r.start.clamp(within.start, within.end)..r.end.clamp(within.start, within.end)
}

17
src/drawing/tri.rs
View file

@ -3,19 +3,15 @@ use crate::Image;
impl<const CHANNELS: usize> Image<&mut [u8], CHANNELS> {
/// Draw a (filled) triangle
///
/// # Safety
///
/// UB if any point is out of bounds
/// ```
/// # use fimg::*;
/// let mut a = Image::alloc(10, 10);
/// // draw a triangle from point a v point b v point c v
/// // with color white
/// unsafe { a.as_mut().tri((3.0, 2.0), (8.0, 7.0), (1.0, 8.0), [255]) };
/// a.as_mut().tri((3.0, 2.0), (8.0, 7.0), (1.0, 8.0), [255]);
/// # assert_eq!(a.buffer(), b"\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\xff\xff\x00\x00\x00\x00\x00\x00\x00\x00\xff\xff\xff\x00\x00\x00\x00\x00\x00\x00\xff\xff\xff\xff\x00\x00\x00\x00\x00\xff\xff\xff\xff\xff\xff\x00\x00\x00\x00\xff\xff\xff\xff\xff\xff\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00");
/// ```
pub unsafe fn tri(
pub fn tri(
&mut self,
(x1, y1): (f32, f32),
(x2, y2): (f32, f32),
@ -33,10 +29,11 @@ impl<const CHANNELS: usize> Image<&mut [u8], CHANNELS> {
}
let d = (x3 - x2) * (y as f32 - y2) - (y3 - y2) * (x as f32 - x2);
if d == 0.0 || (d < 0.0) == (s + t <= 0.0) {
// SAFETY:
// caller gurantees triangle is in bounds, this loops over the
// bounding box of the triangle, therefore this is fine.
if (d == 0.0 || (d < 0.0) == (s + t <= 0.0))
&& x < self.width()
&& y < self.height()
{
// SAFETY: we just checked the bounds
unsafe { self.set_pixel(x, y, c) };
}
}