Input handling "library" in Zig for WASM-4

input.zig

const w4 = @import("wasm4.zig");

pub const Input = struct {
    previous_frame_gamepad: u8,
    current_frame_gamepad: u8,

    previous_frame_mouse: u8,
    current_frame_mouse: u8,

    previous_frame_mouse_x: i16,
    current_frame_mouse_x: i16,
    previous_frame_mouse_y: i16,
    current_frame_mouse_y: i16,

    pub fn init() Input {
        return Input{
            .previous_frame_gamepad = 0,
            .current_frame_gamepad = 0,
            .previous_frame_mouse = 0,
            .current_frame_mouse = 0,
            .previous_frame_mouse_x = 0,
            .current_frame_mouse_x = 0,
            .previous_frame_mouse_y = 0,
            .current_frame_mouse_y = 0,
        };
    }

    pub fn update(self: *Input) void {
        self.previous_frame_gamepad = self.current_frame_gamepad;
        self.current_frame_gamepad = w4.GAMEPAD1.*;

        self.previous_frame_mouse = self.current_frame_mouse;
        self.current_frame_mouse = w4.MOUSE_BUTTONS.*;

        self.previous_frame_mouse_x = self.current_frame_mouse_x;
        self.current_frame_mouse_x = w4.MOUSE_X.*;
        self.previous_frame_mouse_y = self.current_frame_mouse_y;
        self.current_frame_mouse_y = w4.MOUSE_Y.*;
    }

    pub fn getMouseX(self: Input) i16 {
        return self.current_frame_mouse_x;
    }
    pub fn getMouseY(self: Input) i16 {
        return self.current_frame_mouse_y;
    }
    pub fn getMouseDx(self: Input) i16 {
        return -(self.previous_frame_mouse_x - self.current_frame_mouse_x);
    }
    pub fn getMouseDy(self: Input) i16 {
        return -(self.previous_frame_mouse_y - self.current_frame_mouse_y);
    }

    pub fn isLeftMousePressed(self: Input) bool {
        return (self.current_frame_mouse & w4.MOUSE_LEFT) != 0;
    }
    pub fn isRightMousePressed(self: Input) bool {
        return (self.current_frame_mouse & w4.MOUSE_RIGHT) != 0;
    }
    pub fn isMiddleMousePressed(self: Input) bool {
        return (self.current_frame_mouse & w4.MOUSE_MIDDLE) != 0;
    }
    pub fn isLeftMouseJustPressed(self: Input) bool {
        return ((self.previous_frame_mouse & w4.MOUSE_LEFT) == 0) and self.isLeftMousePressed();
    }
    pub fn isRightMouseJustPressed(self: Input) bool {
        return ((self.previous_frame_mouse & w4.MOUSE_RIGHT) == 0) and self.isRightMousePressed();
    }
    pub fn isMiddleMouseJustPressed(self: Input) bool {
        return ((self.previous_frame_mouse & w4.MOUSE_MIDDLE) == 0) and self.isMiddleMousePressed();
    }
    pub fn isLeftMouseJustReleased(self: Input) bool {
        return ((self.previous_frame_mouse & w4.MOUSE_LEFT) != 0) and !self.isLeftMousePressed();
    }
    pub fn isRightMouseJustReleased(self: Input) bool {
        return ((self.previous_frame_mouse & w4.MOUSE_RIGHT) != 0) and !self.isRightMousePressed();
    }
    pub fn isMiddleMouseJustReleased(self: Input) bool {
        return ((self.previous_frame_mouse & w4.MOUSE_MIDDLE) != 0) and !self.isMiddleMousePressed();
    }

    pub fn isUpPressed(self: Input) bool {
        return (self.current_frame_gamepad & w4.BUTTON_UP) != 0;
    }
    pub fn isDownPressed(self: Input) bool {
        return (self.current_frame_gamepad & w4.BUTTON_DOWN) != 0;
    }
    pub fn isLeftPressed(self: Input) bool {
        return (self.current_frame_gamepad & w4.BUTTON_LEFT) != 0;
    }
    pub fn isRightPressed(self: Input) bool {
        return (self.current_frame_gamepad & w4.BUTTON_RIGHT) != 0;
    }
    pub fn isXPressed(self: Input) bool {
        return (self.current_frame_gamepad & w4.BUTTON_1) != 0;
    }
    pub fn isZPressed(self: Input) bool {
        return (self.current_frame_gamepad & w4.BUTTON_2) != 0;
    }
    pub fn isUpJustPressed(self: Input) bool {
        return ((self.previous_frame_gamepad & w4.BUTTON_UP) == 0) and self.isUpPressed();
    }
    pub fn isDownJustPressed(self: Input) bool {
        return ((self.previous_frame_gamepad & w4.BUTTON_DOWN) == 0) and self.isDownPressed();
    }
    pub fn isLeftJustPressed(self: Input) bool {
        return ((self.previous_frame_gamepad & w4.BUTTON_LEFT) == 0) and self.isLeftPressed();
    }
    pub fn isRightJustPressed(self: Input) bool {
        return ((self.previous_frame_gamepad & w4.BUTTON_RIGHT) == 0) and self.isRightPressed();
    }
    pub fn isXJustPressed(self: Input) bool {
        return ((self.previous_frame_gamepad & w4.BUTTON_1) == 0) and self.isXPressed();
    }
    pub fn isZJustPressed(self: Input) bool {
        return ((self.previous_frame_gamepad & w4.BUTTON_2) == 0) and self.isZPressed();
    }
    pub fn isUpJustReleased(self: Input) bool {
        return ((self.previous_frame_gamepad & w4.BUTTON_UP) != 0) and !self.isUpPressed();
    }
    pub fn isDownJustReleased(self: Input) bool {
        return ((self.previous_frame_gamepad & w4.BUTTON_DOWN) != 0) and !self.isDownPressed();
    }
    pub fn isLeftJustReleased(self: Input) bool {
        return ((self.previous_frame_gamepad & w4.BUTTON_LEFT) != 0) and !self.isLeftPressed();
    }
    pub fn isRightJustReleased(self: Input) bool {
        return ((self.previous_frame_gamepad & w4.BUTTON_RIGHT) != 0) and !self.isRightPressed();
    }
    pub fn isXJustReleased(self: Input) bool {
        return ((self.previous_frame_gamepad & w4.BUTTON_1) != 0) and !self.isXPressed();
    }
    pub fn isZJustReleased(self: Input) bool {
        return ((self.previous_frame_gamepad & w4.BUTTON_2) != 0) and !self.isZPressed();
    }
};

main.zig

const w4 = @import("wasm4.zig");
const Input = @import("input.zig").Input;

const smiley = [8]u8{
    0b11000011,
    0b10000001,
    0b00100100,
    0b00100100,
    0b00000000,
    0b00100100,
    0b10011001,
    0b11000011,
};

export fn start() void {}

var input = Input.init();

export fn update() void {
    input.update();

    w4.DRAW_COLORS.* = 2;
    w4.text("Hello from Zig!", 10, 10);
    if (input.isXPressed()) {
        w4.DRAW_COLORS.* = 4;
    }
    w4.blit(&smiley, 76, 76, 8, 8, w4.BLIT_1BPP);
    w4.text("Press X to blink", 16, 90);
}