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

//! This is a simple crate that makes making qwac games easier.

#![cfg_attr(not(feature = "std"), no_std)]

mod ffi;

pub mod audio;
pub mod canvas;
pub mod color;
pub mod data;
pub mod event;
pub mod texture;

pub use canvas::Canvas;
pub use canvas::DrawDestination;
pub use canvas::Screen;
pub use color::Rgba;
pub use event::Event;
pub use texture::Texture;

/// Just represents the unit for euclidean transforms.
#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, PartialOrd, Ord, Hash)]
pub struct Pixels;

#[cfg(feature = "f32-canvas")]
pub type GridUnit = f32;

#[cfg(feature = "f64-canvas")]
pub type GridUnit = f64;

#[cfg(not(any(feature = "f32-canvas", feature = "f64-canvas")))]
pub type GridUnit = i32;

pub type Vector = euclid::Vector2D<GridUnit, Pixels>;
pub type Rect = euclid::Rect<GridUnit, Pixels>;
pub type Size = euclid::Size2D<GridUnit, Pixels>;
pub type Point = euclid::Point2D<GridUnit, Pixels>;

pub trait Game {
    /// Create a new Game of this type, starting at the given time in seconds.
    fn new(timestamp: f64) -> Self;

    /// Handle an input event.
    fn event(&mut self, event: event::Event);

    /// Do processing and rendering.  delta tells you the time in seconds between this frame and
    /// the last one.
    fn update(&mut self, frame_milliseconds: u32);
}

#[macro_export]
macro_rules! qwac_game {
    ($game_type:ty) => {
        #[cfg(not(feature = "std"))]
        static mut QWAC_RUST_GAME: Option<$game_type> = None;

        #[no_mangle]
        pub extern "C" fn qwac_game_create(timestamp: f64) -> *mut $game_type {
            let game = <$game_type as $crate::Game>::new(timestamp);

            #[cfg(not(feature = "std"))]
            {
                unsafe {
                    QWAC_RUST_GAME = None;
                    QWAC_RUST_GAME = Some(game);
                }
                core::ptr::null_mut()
            }

            #[cfg(feature = "std")]
            Box::new(game).into_raw()
        }

        #[no_mangle]
        pub extern "C" fn qwac_game_event_gamepad(
            _game: *mut $game_type,
            player: u8,
            button: $crate::event::GamepadButton,
            pressed: u8,
        ) {
            #[cfg(not(feature = "std"))]
            let game = unsafe { QWAC_RUST_GAME.as_mut().unwrap() };

            #[cfg(feature = "std")]
            let game = unsafe { &mut *_game };

            let state = if pressed == 0 {
                $crate::event::ButtonState::Released
            } else {
                $crate::event::ButtonState::Pressed
            };

            $crate::Game::event(
                game,
                $crate::event::Event::GamepadButton {
                    button,
                    player,
                    state,
                },
            );
        }

        #[no_mangle]
        pub extern "C" fn qwac_game_update(_game: *mut $game_type, frame_milliseconds: u32) {
            #[cfg(not(feature = "std"))]
            let game = unsafe { QWAC_RUST_GAME.as_mut().unwrap() };

            #[cfg(feature = "std")]
            let game = unsafe { &mut *_game };

            $crate::Game::update(game, frame_milliseconds);
        }

        #[no_mangle]
        pub extern "C" fn qwac_game_destroy(_game: *mut $game_type) {
            #[cfg(not(feature = "std"))]
            unsafe {
                QWAC_RUST_GAME = None;
            }

            #[cfg(feature = "std")]
            unsafe {
                Box::from_raw(game);
            }
        }
    };
}

pub fn log(string: &str) {
    let pointer = string.as_ptr();
    let len = string.len() as u32;
    unsafe {
        ffi::qwac_log(pointer, len);
    }
}