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

//! Gamepad related functions and structures.

use crate::{mmu::BusComponent, warnln};

#[cfg(feature = "wasm")]
use wasm_bindgen::prelude::*;

#[derive(Clone, Copy, PartialEq, Eq)]
pub enum PadSelection {
    None,
    Action,
    Direction,
}

#[cfg_attr(feature = "wasm", wasm_bindgen)]
pub enum PadKey {
    Up,
    Down,
    Left,
    Right,
    Start,
    Select,
    A,
    B,
}

impl PadKey {
    pub fn from_u8(value: u8) -> Self {
        match value {
            1 => PadKey::Up,
            2 => PadKey::Down,
            3 => PadKey::Left,
            4 => PadKey::Right,
            5 => PadKey::Start,
            6 => PadKey::Select,
            7 => PadKey::A,
            8 => PadKey::B,
            _ => panic!("Invalid pad key value: {}", value),
        }
    }
}

pub struct Pad {
    down: bool,
    up: bool,
    left: bool,
    right: bool,
    start: bool,
    select: bool,
    b: bool,
    a: bool,
    selection: PadSelection,
    int_pad: bool,
}

impl Pad {
    pub fn new() -> Self {
        Self {
            down: false,
            up: false,
            left: false,
            right: false,
            start: false,
            select: false,
            b: false,
            a: false,
            selection: PadSelection::None,
            int_pad: false,
        }
    }

    pub fn read(&mut self, addr: u16) -> u8 {
        match addr {
            // 0xFF00 — P1/JOYP: Joypad
            0xff00 => {
                let mut value = match self.selection {
                    PadSelection::Action =>
                    {
                        #[allow(clippy::bool_to_int_with_if)]
                        (if self.a { 0x00 } else { 0x01 }
                            | if self.b { 0x00 } else { 0x02 }
                            | if self.select { 0x00 } else { 0x04 }
                            | if self.start { 0x00 } else { 0x08 })
                    }
                    PadSelection::Direction =>
                    {
                        #[allow(clippy::bool_to_int_with_if)]
                        (if self.right { 0x00 } else { 0x01 }
                            | if self.left { 0x00 } else { 0x02 }
                            | if self.up { 0x00 } else { 0x04 }
                            | if self.down { 0x00 } else { 0x08 })
                    }
                    PadSelection::None => 0x0f,
                };
                value |= match self.selection {
                    PadSelection::Action => 0x10,
                    PadSelection::Direction => 0x20,
                    PadSelection::None => 0x30,
                };
                value
            }
            _ => {
                warnln!("Reading from unknown Pad location 0x{:04x}", addr);
                0xff
            }
        }
    }

    pub fn write(&mut self, addr: u16, value: u8) {
        match addr {
            // 0xFF00 — P1/JOYP: Joypad
            0xff00 => {
                self.selection = match value & 0x30 {
                    0x10 => PadSelection::Action,
                    0x20 => PadSelection::Direction,
                    0x30 => PadSelection::None,
                    _ => PadSelection::None,
                };
            }
            _ => warnln!("Writing to unknown Pad location 0x{:04x}", addr),
        }
    }

    pub fn key_press(&mut self, key: PadKey) {
        match key {
            PadKey::Up => self.up = true,
            PadKey::Down => self.down = true,
            PadKey::Left => self.left = true,
            PadKey::Right => self.right = true,
            PadKey::Start => self.start = true,
            PadKey::Select => self.select = true,
            PadKey::A => self.a = true,
            PadKey::B => self.b = true,
        }

        // signals that a JoyPad interrupt is pending to be
        // handled as a key press has been performed
        self.int_pad = true;
    }

    pub fn key_lift(&mut self, key: PadKey) {
        match key {
            PadKey::Up => self.up = false,
            PadKey::Down => self.down = false,
            PadKey::Left => self.left = false,
            PadKey::Right => self.right = false,
            PadKey::Start => self.start = false,
            PadKey::Select => self.select = false,
            PadKey::A => self.a = false,
            PadKey::B => self.b = false,
        }
    }

    #[inline(always)]
    pub fn int_pad(&self) -> bool {
        self.int_pad
    }

    #[inline(always)]
    pub fn set_int_pad(&mut self, value: bool) {
        self.int_pad = value;
    }

    #[inline(always)]
    pub fn ack_pad(&mut self) {
        self.set_int_pad(false);
    }
}

impl BusComponent for Pad {
    fn read(&mut self, addr: u16) -> u8 {
        self.read(addr)
    }

    fn write(&mut self, addr: u16, value: u8) {
        self.write(addr, value);
    }
}

impl Default for Pad {
    fn default() -> Self {
        Self::new()
    }
}