nes-sim 0.1.3

A NES (Famicom) emulator core library written in pure Rust.
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

use crate::api::VideoFrame;

const NES_RGB_PALETTE: [[u8; 3]; 64] = [
    [84, 84, 84],
    [0, 30, 116],
    [8, 16, 144],
    [48, 0, 136],
    [68, 0, 100],
    [92, 0, 48],
    [84, 4, 0],
    [60, 24, 0],
    [32, 42, 0],
    [8, 58, 0],
    [0, 64, 0],
    [0, 60, 0],
    [0, 50, 60],
    [0, 0, 0],
    [0, 0, 0],
    [0, 0, 0],
    [152, 150, 152],
    [8, 76, 196],
    [48, 50, 236],
    [92, 30, 228],
    [136, 20, 176],
    [160, 20, 100],
    [152, 34, 32],
    [120, 60, 0],
    [84, 90, 0],
    [40, 114, 0],
    [8, 124, 0],
    [0, 118, 40],
    [0, 102, 120],
    [0, 0, 0],
    [0, 0, 0],
    [0, 0, 0],
    [236, 238, 236],
    [76, 154, 236],
    [120, 124, 236],
    [176, 98, 236],
    [228, 84, 236],
    [236, 88, 180],
    [236, 106, 100],
    [212, 136, 32],
    [160, 170, 0],
    [116, 196, 0],
    [76, 208, 32],
    [56, 204, 108],
    [56, 180, 204],
    [60, 60, 60],
    [0, 0, 0],
    [0, 0, 0],
    [236, 238, 236],
    [168, 204, 236],
    [188, 188, 236],
    [212, 178, 236],
    [236, 174, 236],
    [236, 174, 212],
    [236, 180, 176],
    [228, 196, 144],
    [204, 210, 120],
    [180, 222, 120],
    [168, 226, 144],
    [152, 226, 180],
    [160, 214, 228],
    [160, 162, 160],
    [0, 0, 0],
    [0, 0, 0],
];

pub fn palette_index_to_rgb(index: u8) -> [u8; 3] {
    NES_RGB_PALETTE[(index & 0x3F) as usize]
}

pub fn frame_to_rgb(frame: VideoFrame<'_>) -> Vec<u8> {
    let mut rgb = Vec::with_capacity(frame.pixels.len() * 3);
    for &pixel in frame.pixels {
        rgb.extend_from_slice(&palette_index_to_rgb(pixel));
    }
    rgb
}

pub fn frame_to_argb32(frame: VideoFrame<'_>) -> Vec<u32> {
    let mut argb = Vec::with_capacity(frame.pixels.len());
    for &pixel in frame.pixels {
        let [r, g, b] = palette_index_to_rgb(pixel);
        argb.push((0xFF_u32 << 24) | (u32::from(r) << 16) | (u32::from(g) << 8) | u32::from(b));
    }
    argb
}

/// 预分配的视频缓冲区，避免每帧堆分配
pub struct VideoBuffer {
    buffer: Vec<u32>,
}

impl VideoBuffer {
    pub fn new(capacity: usize) -> Self {
        Self {
            buffer: vec![0; capacity],
        }
    }

    pub fn as_mut_slice(&mut self) -> &mut [u32] {
        &mut self.buffer
    }

    pub fn as_slice(&self) -> &[u32] {
        &self.buffer
    }
}

/// 将帧数据转换为 ARGB32 格式，写入预分配的缓冲区
pub fn frame_to_argb32_into(frame: VideoFrame<'_>, output: &mut [u32]) {
    for (dst, &pixel) in output.iter_mut().zip(frame.pixels) {
        let [r, g, b] = palette_index_to_rgb(pixel);
        *dst = (0xFF_u32 << 24) | (u32::from(r) << 16) | (u32::from(g) << 8) | u32::from(b);
    }
}

/// 将帧数据转换为 RGBA 字节格式（用于 Tauri IPC）
pub fn frame_to_rgba(frame: VideoFrame<'_>) -> Vec<u8> {
    let mut rgba = Vec::with_capacity(frame.pixels.len() * 4);
    for &pixel in frame.pixels {
        let [r, g, b] = palette_index_to_rgb(pixel);
        rgba.push(r);
        rgba.push(g);
        rgba.push(b);
        rgba.push(255);
    }
    rgba
}