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
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
//! Decoding of netpbm image formats (pbm, pgm, ppm and pam).
//!
//! The formats pbm, pgm and ppm are fully supported. The pam decoder recognizes the tuple types
//! `BLACKANDWHITE`, `GRAYSCALE` and `RGB` and explicitly recognizes but rejects their `_ALPHA`
//! variants for now as alpha color types are unsupported.
use self::autobreak::AutoBreak;
pub use self::decoder::PnmDecoder;
pub use self::encoder::PnmEncoder;
use self::header::HeaderRecord;
pub use self::header::{
    ArbitraryHeader, ArbitraryTuplType, BitmapHeader, GraymapHeader, PixmapHeader,
};
pub use self::header::{PnmHeader, PnmSubtype, SampleEncoding};

mod autobreak;
mod decoder;
mod encoder;
mod header;

#[cfg(test)]
mod tests {
    use super::*;
    use crate::color::ColorType;
    use crate::image::ImageDecoder;
    use byteorder::{ByteOrder, NativeEndian};

    fn execute_roundtrip_default(buffer: &[u8], width: u32, height: u32, color: ColorType) {
        let mut encoded_buffer = Vec::new();

        {
            let mut encoder = PnmEncoder::new(&mut encoded_buffer);
            encoder
                .encode(buffer, width, height, color)
                .expect("Failed to encode the image buffer");
        }

        let (header, loaded_color, loaded_image) = {
            let decoder = PnmDecoder::new(&encoded_buffer[..]).unwrap();
            let color_type = decoder.color_type();
            let mut image = vec![0; decoder.total_bytes() as usize];
            decoder
                .read_image(&mut image)
                .expect("Failed to decode the image");
            let (_, header) = PnmDecoder::new(&encoded_buffer[..]).unwrap().into_inner();
            (header, color_type, image)
        };

        assert_eq!(header.width(), width);
        assert_eq!(header.height(), height);
        assert_eq!(loaded_color, color);
        assert_eq!(loaded_image.as_slice(), buffer);
    }

    fn execute_roundtrip_with_subtype(
        buffer: &[u8],
        width: u32,
        height: u32,
        color: ColorType,
        subtype: PnmSubtype,
    ) {
        let mut encoded_buffer = Vec::new();

        {
            let mut encoder = PnmEncoder::new(&mut encoded_buffer).with_subtype(subtype);
            encoder
                .encode(buffer, width, height, color)
                .expect("Failed to encode the image buffer");
        }

        let (header, loaded_color, loaded_image) = {
            let decoder = PnmDecoder::new(&encoded_buffer[..]).unwrap();
            let color_type = decoder.color_type();
            let mut image = vec![0; decoder.total_bytes() as usize];
            decoder
                .read_image(&mut image)
                .expect("Failed to decode the image");
            let (_, header) = PnmDecoder::new(&encoded_buffer[..]).unwrap().into_inner();
            (header, color_type, image)
        };

        assert_eq!(header.width(), width);
        assert_eq!(header.height(), height);
        assert_eq!(header.subtype(), subtype);
        assert_eq!(loaded_color, color);
        assert_eq!(loaded_image.as_slice(), buffer);
    }

    fn execute_roundtrip_u16(buffer: &[u16], width: u32, height: u32, color: ColorType) {
        let mut encoded_buffer = Vec::new();

        {
            let mut encoder = PnmEncoder::new(&mut encoded_buffer);
            encoder
                .encode(buffer, width, height, color)
                .expect("Failed to encode the image buffer");
        }

        let (header, loaded_color, loaded_image) = {
            let decoder = PnmDecoder::new(&encoded_buffer[..]).unwrap();
            let color_type = decoder.color_type();
            let mut image = vec![0; decoder.total_bytes() as usize];
            decoder
                .read_image(&mut image)
                .expect("Failed to decode the image");
            let (_, header) = PnmDecoder::new(&encoded_buffer[..]).unwrap().into_inner();
            (header, color_type, image)
        };

        let mut buffer_u8 = vec![0; buffer.len() * 2];
        NativeEndian::write_u16_into(buffer, &mut buffer_u8[..]);

        assert_eq!(header.width(), width);
        assert_eq!(header.height(), height);
        assert_eq!(loaded_color, color);
        assert_eq!(loaded_image, buffer_u8);
    }

    #[test]
    fn roundtrip_gray() {
        #[rustfmt::skip]
        let buf: [u8; 16] = [
            0, 0, 0, 255,
            255, 255, 255, 255,
            255, 0, 255, 0,
            255, 0, 0, 0,
        ];

        execute_roundtrip_default(&buf, 4, 4, ColorType::L8);
        execute_roundtrip_with_subtype(&buf, 4, 4, ColorType::L8, PnmSubtype::ArbitraryMap);
        execute_roundtrip_with_subtype(
            &buf,
            4,
            4,
            ColorType::L8,
            PnmSubtype::Graymap(SampleEncoding::Ascii),
        );
        execute_roundtrip_with_subtype(
            &buf,
            4,
            4,
            ColorType::L8,
            PnmSubtype::Graymap(SampleEncoding::Binary),
        );
    }

    #[test]
    fn roundtrip_rgb() {
        #[rustfmt::skip]
        let buf: [u8; 27] = [
              0,   0,   0,
              0,   0, 255,
              0, 255,   0,
              0, 255, 255,
            255,   0,   0,
            255,   0, 255,
            255, 255,   0,
            255, 255, 255,
            255, 255, 255,
        ];
        execute_roundtrip_default(&buf, 3, 3, ColorType::Rgb8);
        execute_roundtrip_with_subtype(&buf, 3, 3, ColorType::Rgb8, PnmSubtype::ArbitraryMap);
        execute_roundtrip_with_subtype(
            &buf,
            3,
            3,
            ColorType::Rgb8,
            PnmSubtype::Pixmap(SampleEncoding::Binary),
        );
        execute_roundtrip_with_subtype(
            &buf,
            3,
            3,
            ColorType::Rgb8,
            PnmSubtype::Pixmap(SampleEncoding::Ascii),
        );
    }

    #[test]
    fn roundtrip_u16() {
        let buf: [u16; 6] = [0, 1, 0xFFFF, 0x1234, 0x3412, 0xBEAF];

        execute_roundtrip_u16(&buf, 6, 1, ColorType::L16);
    }
}