1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147

// PNG Pong
//
// Copyright © 2019-2020 Jeron Aldaron Lau
//
// Licensed under the Apache License, Version 2.0, <LICENSE-APACHE or
// https://apache.org/licenses/LICENSE-2.0>, or the Zlib License, <LICENSE-ZLIB
// or http://opensource.org/licenses/Zlib>, at your option. This file may not be
// copied, modified, or distributed except according to those terms.

use crate::chunk::{ColorType, ImageHeader};
use pix::{
    chan::{Ch16, Ch8},
    el::Pixel,
    gray::{Gray8, SGray16, SGray8, SGraya16, SGraya8},
    rgb::{SRgb16, SRgb8, SRgba16, SRgba8},
    Palette, Raster,
};

/// A Raster of one of the PNG types (all are sRGB gamma).
/// PNGs with less than 8 bits per channel are scaled up to 8 bits per channel.
#[allow(missing_debug_implementations)]
pub enum PngRaster {
    /// 1, 2, 4, 8-bit greyscale
    Gray8(Raster<SGray8>),
    /// 16-bit grayscale
    Gray16(Raster<SGray16>),
    /// 8-bit sRGB
    Rgb8(Raster<SRgb8>),
    /// 16-bit sRGB
    Rgb16(Raster<SRgb16>),
    /// 1, 2, 4, 8-bit sRGB(A) palette
    Palette(Raster<Gray8>, Box<Palette>, Vec<u8>),
    /// 8-bit grayscale with alpha
    Graya8(Raster<SGraya8>),
    /// 16-bit grayscale with alpha
    Graya16(Raster<SGraya16>),
    /// 8-bit sRGB with alpha
    Rgba8(Raster<SRgba8>),
    /// 16-bit sRGB with alpha
    Rgba16(Raster<SRgba16>),
}

impl PngRaster {
    pub(crate) fn header(&self, interlace: bool) -> ImageHeader {
        use PngRaster::*;
        match self {
            Gray8(r) => ImageHeader {
                width: r.width(),
                height: r.height(),
                color_type: ColorType::Grey,
                bit_depth: 8,
                interlace,
            },
            Gray16(r) => ImageHeader {
                width: r.width(),
                height: r.height(),
                color_type: ColorType::Grey,
                bit_depth: 16,
                interlace,
            },
            Rgb8(r) => ImageHeader {
                width: r.width(),
                height: r.height(),
                color_type: ColorType::Rgb,
                bit_depth: 8,
                interlace,
            },
            Rgb16(r) => ImageHeader {
                width: r.width(),
                height: r.height(),
                color_type: ColorType::Rgb,
                bit_depth: 16,
                interlace,
            },
            Palette(r, _pal, _pa) => ImageHeader {
                width: r.width(),
                height: r.height(),
                color_type: ColorType::Palette,
                bit_depth: 8,
                interlace,
            },
            Graya8(r) => ImageHeader {
                width: r.width(),
                height: r.height(),
                color_type: ColorType::GreyAlpha,
                bit_depth: 8,
                interlace,
            },
            Graya16(r) => ImageHeader {
                width: r.width(),
                height: r.height(),
                color_type: ColorType::GreyAlpha,
                bit_depth: 16,
                interlace,
            },
            Rgba8(r) => ImageHeader {
                width: r.width(),
                height: r.height(),
                color_type: ColorType::Rgba,
                bit_depth: 8,
                interlace,
            },
            Rgba16(r) => ImageHeader {
                width: r.width(),
                height: r.height(),
                color_type: ColorType::Rgba,
                bit_depth: 16,
                interlace,
            },
        }
    }
}

impl<P: Pixel> From<PngRaster> for Raster<P>
where
    P::Chan: From<Ch8> + From<Ch16>,
{
    fn from(raster: PngRaster) -> Raster<P> {
        use PngRaster::*;
        match raster {
            Gray8(r) => Raster::with_raster(&r),
            Gray16(r) => Raster::with_raster(&r),
            Rgb8(r) => Raster::with_raster(&r),
            Rgb16(r) => Raster::with_raster(&r),
            Palette(raster, pal, pa) => {
                let mut pixels = Vec::with_capacity(raster.pixels().len());
                for pixel in raster.pixels() {
                    let i: u8 = pixel.one().into();
                    let i = i as usize;
                    let px: SRgb8 = pal.entry(i).unwrap();
                    let px = SRgba8::new(
                        px.one(),
                        px.two(),
                        px.three(),
                        Ch8::new(pa[i]),
                    );
                    pixels.push(px.convert());
                }
                Raster::with_pixels(raster.width(), raster.height(), pixels)
            }
            Graya8(r) => Raster::with_raster(&r),
            Graya16(r) => Raster::with_raster(&r),
            Rgba8(r) => Raster::with_raster(&r),
            Rgba16(r) => Raster::with_raster(&r),
        }
    }
}