res 0.6.1

Res is a build-script dependency for managing your project's resources.
Documentation 
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
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249

//! Generate Texture Sheet.

use png_pong as png;

use heck::ShoutySnakeCase;
use sheep::{InputSprite, MaxrectsOptions, MaxrectsPacker};
use std::fs::read_dir;

pub struct Sprite {
    name: String,
    x1: f32,
    y1: f32,
    x2: f32,
    y2: f32,
}

pub struct Named {
    sprites: Vec<Sprite>,
}

impl sheep::Format for Named {
    type Data = (Named, Vec<sheep::SpriteAnchor>);
    type Options = Vec<String>;

    fn encode(
        dimensions: (u32, u32),
        in_sprites: &[sheep::SpriteAnchor],
        options: Self::Options,
    ) -> Self::Data {
        let (w, h) = dimensions;
        let (w, h) = (w as f32, h as f32);
        let mut sprites = vec![];

        for i in 0..in_sprites.len() {
            let x1 = in_sprites[i].position.0 as f32 / w;
            let y1 = in_sprites[i].position.1 as f32 / h;
            let x2 = in_sprites[i].dimensions.0 as f32 / w;
            let y2 = in_sprites[i].dimensions.1 as f32 / h;
            let name = options[in_sprites[i].id].to_string();

            sprites.push(Sprite {
                name,
                x1,
                y1,
                x2,
                y2,
            });
        }

        let named = Named { sprites };

        (named, in_sprites.to_vec())
    }
}

fn sample(pixels: &[u8], width: i32, x: i32, y: i32) -> [u8; 4] {
    [
        pixels[(x + (y * width)) as usize * 4],
        pixels[(x + (y * width)) as usize * 4 + 1],
        pixels[(x + (y * width)) as usize * 4 + 2],
        pixels[(x + (y * width)) as usize * 4 + 3],
    ]
}

fn gen_mipmaps(
    num_mipmaps: u32,
    bytes: &mut Vec<u8>,
    sprites: &mut [sheep::SpriteAnchor],
    width: u32,
) {
    let mut old_width = width as i32;
    let mut old_pixels = bytes.clone();
    let mut pixels = vec![0; old_pixels.len() / 4];

    for _ in 0..num_mipmaps {
        for sprite in sprites.iter_mut() {
            sprite.position.0 /= 2;
            sprite.position.1 /= 2;
            sprite.dimensions.0 /= 2;
            sprite.dimensions.1 /= 2;

            for k in 0..sprite.dimensions.1 {
                for j in 0..sprite.dimensions.0 {
                    let (x, y) = (
                        j as i32 + sprite.position.0 as i32,
                        k as i32 + sprite.position.1 as i32,
                    );

                    let [r00, g00, b00, a00] =
                        sample(&old_pixels, old_width, x * 2, y * 2);
                    let [r01, g01, b01, a01] =
                        sample(&old_pixels, old_width, x * 2, y * 2 + 1);
                    let [r10, g10, b10, a10] =
                        sample(&old_pixels, old_width, x * 2 + 1, y * 2);
                    let [r11, g11, b11, a11] =
                        sample(&old_pixels, old_width, x * 2 + 1, y * 2 + 1);

                    /*                    let [r, g, b, a] = if j < sprite.dimensions.0 / 2 {
                        // +X
                        if k < sprite.dimensions.1 / 2 {
                            // +X+Y
                            [r11, g11, b11, a11]
                        } else {
                            // +X-Y
                            [r10, g10, b10, a10]
                        }
                    } else {
                        // -X
                        if k < sprite.dimensions.1 / 2 {
                            // -X+Y
                            [r01, g01, b01, a01]
                        } else {
                            // -X-Y
                            [r00, g00, b00, a00]
                        }
                    };*/

                    let [red, green, blue, alpha] = [
                        ((u16::from(r00)
                            + u16::from(r01)
                            + u16::from(r10)
                            + u16::from(r11))
                            >> 2) as u8,
                        ((u16::from(g00)
                            + u16::from(g01)
                            + u16::from(g10)
                            + u16::from(g11))
                            >> 2) as u8,
                        ((u16::from(b00)
                            + u16::from(b01)
                            + u16::from(b10)
                            + u16::from(b11))
                            >> 2) as u8,
                        ((u16::from(a00)
                            + u16::from(a01)
                            + u16::from(a10)
                            + u16::from(a11))
                            >> 2) as u8,
                    ];

                    pixels[(x + y * (old_width / 2)) as usize * 4] = red;
                    pixels[(x + y * (old_width / 2)) as usize * 4 + 1] = green;
                    pixels[(x + y * (old_width / 2)) as usize * 4 + 2] = blue;
                    pixels[(x + y * (old_width / 2)) as usize * 4 + 3] = alpha;
                }
            }
        }

        // Add to bytes.
        bytes.extend(&pixels);

        // For next run through loop.
        old_width /= 2;
        old_pixels = pixels;
        pixels = vec![0; old_pixels.len() / 4];
    }
}

pub fn write() -> String {
    println!("cargo:rerun-if-changed=./res/texture/");

    // Find all PNG files.
    let paths = read_dir("./res/texture/").unwrap();
    let mut sprites = vec![];
    let mut names = vec![];
    let mut min_size: Option<u32> = None;

    for path in paths {
        let path = path.unwrap().path();
        let data = std::fs::read(&path).expect("Failed to open PNG");
        let data = std::io::Cursor::new(data);
        let decoder = png::Decoder::new(data).expect("Not PNG").into_steps();
        let png::Step { raster, delay: _ } = decoder
            .last()
            .expect("No frames in PNG")
            .expect("PNG parsing error");
        let raster: pix::Raster::<pix::rgb::SRgba8> = raster.into();
        let dimensions = (raster.width(), raster.height());
        let bytes: &[u8] = raster.as_u8_slice();

        if let Some(min) = min_size {
            min_size = Some(min.min(dimensions.0).min(dimensions.1));
        } else {
            min_size = Some(dimensions.0.min(dimensions.1));
        };

        sprites.push(InputSprite {
            dimensions,
            bytes: bytes.to_vec(),
        });

        println!("cargo:rerun-if-changed={}", path.to_str().unwrap());

        names.push(path.file_stem().unwrap().to_str().unwrap().to_string());
    }

    // Calculate number of mipmaps to generate.
    let mipmap_count = if let Some(min) = min_size {
        let mut full_size = 4096;
        let mut mipmap_count = 0;

        while full_size > min {
            full_size /= 2;
            mipmap_count += 1;
        }

        mipmap_count
    } else {
        0
    };

    // Set texture sheet size.
    let options = MaxrectsOptions::default().max_width(4096).max_height(4096);

    // Do the actual packing! 4 defines the stride, since we're using rgba8 we
    // have 4 bytes per pixel.
    let results = sheep::pack::<MaxrectsPacker>(sprites, 4, options);

    // MaxrectsPacker always returns a single result. Other packers can return
    // multiple sheets; should they, for example, choose to enforce a maximum
    // texture size per sheet.
    let mut sprite_sheet = results
        .into_iter()
        .next()
        .expect("Should have returned a spritesheet");
    let sheet_width = sprite_sheet.dimensions.0;

    // Now, we can encode the sprite sheet in a format of our choosing to
    // save things such as offsets, positions of the sprites and so on.
    let (meta, mut ins) = sheep::encode::<Named>(&sprite_sheet, names);

    // Generate mipmaps.
    gen_mipmaps(mipmap_count, &mut sprite_sheet.bytes, &mut ins, sheet_width);

    // Next, we save the output to a file using the image crate again.
    let mut filename = std::env::var("OUT_DIR").unwrap();
    filename.push_str("/res/texture-sheet.pix");
    std::fs::write(filename, &sprite_sheet.bytes[..])
        .expect("Failed to save image");

    let mut meta_str = format!("pub(crate) const TEXTURE_SHEET: (u16, u16, &[u8]) = ({}, {}, include_bytes!(concat!(env!(\"OUT_DIR\"), \"/res/texture-sheet.pix\")));\npub(crate) mod texture {{\n", sprite_sheet.dimensions.0, sprite_sheet.dimensions.1);

    for i in &meta.sprites {
        meta_str.push_str(&format!("\tpub(crate) const {}: ([f32; 2],[f32; 2]) = ([{}f32, {}f32], [{}f32, {}f32]);\n", i.name.to_shouty_snake_case(), i.x1, i.y1, i.x2, i.y2));
    }
    meta_str.push_str("}\n");

    meta_str
}