use super::Color;
use std::fs::File;
use std::io::Read;
use std::ops::Deref;
pub struct BmpFile {
w: usize,
h: usize,
data: Vec<Color>,
}
impl BmpFile {
pub fn new(width: usize, height: usize) -> Self {
BmpFile {
w: width,
h: height,
data: Vec::new(),
}
}
pub fn default() -> Self {
Self::new(0, 0)
}
pub fn from_path(path: &str) -> Self {
let mut data: Vec<u8> = Vec::new();
if let Ok(mut file) = File::open(path) {
let _ = file.read_to_end(&mut data); }
Self::from_data(&data)
}
pub fn from_data(file_data: &[u8]) -> Self {
let get = |i: usize| -> u8 {
match file_data.get(i) {
Some(byte) => *byte,
None => 0,
}
};
let getw = |i: usize| -> u16 { (get(i) as u16) + ((get(i + 1) as u16) << 8) };
let getd = |i: usize| -> u32 {
(get(i) as u32) + ((get(i + 1) as u32) << 8) + ((get(i + 2) as u32) << 16) +
((get(i + 3) as u32) << 24)
};
let gets = |start: usize, len: usize| -> String {
(start..start + len).map(|i| get(i) as char).collect::<String>()
};
let mut ret: BmpFile;
if gets(0, 2) == "BM" {
let offset = getd(0xA);
let width = getd(0x12);
let height = getd(0x16);
let depth = getw(0x1C) as u32;
let bytes = (depth + 7) / 8;
let row_bytes = (depth * width + 31) / 32 * 4;
let mut blue_mask = 0xFF;
let mut green_mask = 0xFF00;
let mut red_mask = 0xFF0000;
let mut alpha_mask = 0xFF000000;
if getd(0x1E) == 3 {
red_mask = getd(0x36);
green_mask = getd(0x3A);
blue_mask = getd(0x3E);
alpha_mask = getd(0x42);
}
let mut blue_shift = 0;
while blue_mask > 0 && blue_shift < 32 && (blue_mask >> blue_shift) & 1 == 0 {
blue_shift += 1;
}
let mut green_shift = 0;
while green_mask > 0 && green_shift < 32 && (green_mask >> green_shift) & 1 == 0 {
green_shift += 1;
}
let mut red_shift = 0;
while red_mask > 0 && red_shift < 32 && (red_mask >> red_shift) & 1 == 0 {
red_shift += 1;
}
let mut alpha_shift = 0;
while alpha_mask > 0 && alpha_shift < 32 && (alpha_mask >> alpha_shift) & 1 == 0 {
alpha_shift += 1;
}
ret = Self::new(width as usize, height as usize);
for y in 0..height {
for x in 0..width {
let pixel_offset = offset + (height - y - 1) * row_bytes + x * bytes;
let pixel_data = getd(pixel_offset as usize);
let red = ((pixel_data & red_mask) >> red_shift) as u8;
let green = ((pixel_data & green_mask) >> green_shift) as u8;
let blue = ((pixel_data & blue_mask) >> blue_shift) as u8;
let alpha = ((pixel_data & alpha_mask) >> alpha_shift) as u8;
if bytes == 3 {
ret.data.push(Color::rgb(red, green, blue));
} else if bytes == 4 {
ret.data.push(Color::rgba(red, green, blue, alpha));
}
}
}
} else {
ret = Self::default();
}
ret
}
pub fn has_data(&self) -> bool {
!self.data.is_empty()
}
pub fn width(&self) -> usize {
self.w
}
pub fn height(&self) -> usize {
self.h
}
}
impl Deref for BmpFile {
type Target = [Color];
fn deref(&self) -> &Self::Target {
&self.data
}
}