pixelbox

    2.1.1 • Public • Published

    pixelbox

    A sandbox framework to fast-prototype tile-based games

    Pixelbox takes inspiration from fantasy consoles like PICO8 and game creation frameworks like Unity3D.

    Install

    From version 2, the Pixelbox package no longer includes the editor. Instead, the editor is now a standalone application that can be downloaded on Itch.io.

    Use

    A Pixelbox project has the following structure:

    assets/
     ├── tilesheet.png
     ├── palette.png
     └── maps.json
    audio/
    build/
    src/
     └── main.js
    tools/
    node_modules/
    project.pixelbox
    package.json
    index.html
    
    • assets/ is where game assets go (images, text files, JSON)
    • audio/ is where sounds and music go
    • src/ is the source code folder, and main.js is the entry file of the game

    Programming with pixelbox

    Program structure

    The game entry point is the src/main.js file. If you provide an exports.update function, Pixelbox will call it every frame.

    Building is done using browserify which gives you access to require (or import) and exports to easily modularize your project.

    Assets

    Pixelbox automatically loads all assets at startup, before executing the game code. All supported files added inside the assets/ directory will be available in the assets global object. The structure follows the structure of the directory. For instance, the file located in assets/sprites/player.png will be accessible with assets.sprites.player.

    Supported files include:

    • images (.png, .jpg)
    • JSON formatted data (.json)
    • plain text files (.txt, .css, .vert, .frag)

    You have direct access to the content of JSON files.

    Because files are loaded inside the assets object and refered wthout their extension, you cannot have a file and a directory with the same name inside the same directory.

    Pixelbox API

    Pixelbox exposes the following methods directly on the global scope:

    Drawing graphics

    • cls() clear screen with paper color
    • sprite(n, x, y [,flipH [,flipV [, flipR]]]) draw sprite number n on screen at pixel position (x, y) flipH and flipV can be used to flip sprites horizontally or vertically, flipR adds a 90 degree clockwise rotation
    • draw(image, x, y [,flipH [,flipV [, flipR]]]) draw an Image, Texture or TileMap on screen at pixel position (x, y)
    • tilesheet(image) change image used as default tilesheet
    • rect(x, y, w, h) stroke a rectangle with pen color
    • rectf(x, y, w, h) fill a rectangle with paper color
    • camera(x, y) scroll add further drawing by provided position

    Printing text

    Pixelbox has a predefined "minitext" bitmap font that you can use to print text on screen or in textures. Minitext is available by default, but can be disabled in the project settings.

    • print(text, [x, y]) if x, y is provided, print text at pixel position (x, y); else print text at cursor current position
    • println(text) print text and feed new line; when the cursor reaches the bottom of the screen, vertical scroll is applied (just like it would happen in a terminal)
    • locate(i, j) set cursor position at column i line j
    • pen(colorId) set text color to colorId in color palette
    • paper(colorId) set paper color to colorId in color palette

    User controls

    • btn state of the buttons — by default, available buttons are: up, down, left, right, A, B (buttons names and binding can be configured in the project settings)
    • btnp whether button has been pressed during current frame
    • btnr whether button has been released during current frame

    Playing sound

    • sfx('sound'); play the sound.mp3 file in audio/ folder
    • music('bgm'); play the bgm.mp3 file in loop; if another music is already playing, it will cross fade to the new music; if no soundId is provided, music stops

    AudioManager is the module that handles audio loading and playback. You have access to its instance on audioManager.

    Other utility functions

    • clamp(value, min, max) clip a value between min and max
    • chr$(n) return a character from code n
    • random(n) return a random integer between 0 and n
    • inherits(Child, Parent) make class Child inherit from class Parent

    Pixelbox components

    Texture

    Texture is a canvas that can be drawn, and inside which things can be drawn. In Canvas2D mode, it is implemented with a HTML canvas. In WebGL mode, it is implemented with a GLTexture2D.

    The main screen (accessible by the global variable $screen) is an instance of Texture and most of its methods are accessible from the global scope.

    To create new texture, you need to require the Texture module:

    var Texture = require('pixelbox/Texture');
    var texture = new Texture(128, 128); // create a new texture of 128 by 128 pixels

    Texture settings

    texture.resize(width, height);
    texture.setPalette(palette);
    texture.pen(colorIndex); // set PEN color index from palette (pen is used for text and stroke)
    texture.paper(colorIndex); // set PAPER color index from palette (paper is used for fill)
    texture.setTilesheet(tilesheet); // set tilesheet used for this texture

    A tilesheet is an Image containing 256 sprites organized in a 16 x 16 grid (the size of the tilesheet depend of the sprite size you set for your game).

    Rendering

    texture.clear(); // clear texture (it becomes transparent)
    texture.cls(); // clear screen (the whole texture is filled with the PAPER color)
    texture.sprite(sprite, x, y, flipH, flipV, flipR); // draw a sprite from current tilesheet in the texture
    texture.draw((img, x, y, flipH, flipV, flipR); // draw an image (or Texture or Map) in the texture
    texture.rect(x, y, width, height); // stroke a rectangle
    texture.rectf(x, y, width, height); // fill a rectangle

    Printing text

    texture.locate(i, j); // set text cursor to specified location
    texture.print(text, x, y); // print some text
    texture.println(text); // print some text and feed a new line

    Tile Maps

    Pixelbox has a built-in TileMap component. A TileMap consist of:

    • A name
    • A tilesheet — when the tilesheet is changed, the whole map will be redrawn with the new tilesheet
    • A grid of sprites from the tilesheet plus few flags to flip or rotate sprites

    Once created, a tile map is rendered in one draw call only.

    TileMap can be used to render a level made of sprites, or just to store game data.

    You can create tile maps from your game code; But usually, you will be using Pixelbox's tools (see the Tools section below) to create and manage your maps as game assets. A map can then be retrieved by its name with Pixelbox's getMap function. The tile map can then be drawn on screen (or in another Texture), modified, copied, pasted, resized, etc.

    When stored in assets, the map is compressed to Pixelbox format to reduce file size.

    Get tile map

    var map = getMap('mapName'); // get a tile map by its name

    To create new maps, you need to require the Map module:

    var TileMap = require('pixelbox/TileMap');
    var map = new TileMap(16, 16); // create a new tile map of 16 by 16 tiles

    Draw map

    map.draw(x, y);  // draw map on screen at [x, y] position
    draw(map, x, y); // idem, using the global draw function
    texture.draw(map, x, y); // draw a map in another texture
    map.setTilesheet(tilesheet); // set tilesheet to use for this map
                                 // The whole map is redrawn when calling this function

    Access map content

    map.get(x, y); // returns the Tile at position [x, y]. null if empty
    map.set(x, y, tile, flipH, flipV, flipR, flagA, flagB); // add a tile
    map.remove(x, y); // remove tile at position [x, y]. (set it to null)
    map.find(tile, flagA, flagB); // find all tiles with specified properties

    Modifying maps programatically

    map.resize(width, height); // resize the map (size unit is tiles)
    map.clear(); // Reset the whole map content by setting all its tiles to null
    var mapCopy = map.copy(x, y, width, height); // copy this map to a new one
                   // x, y, width, height can be specified to copy only a rectangular part of the map
    map.paste(mapCopy, x, y, merge); // paste map data in the map at position offset [x, y]
                   // if 'merge' flag is set, then null tiles will not overwrite current map tile

    Gamepad

    The gamepad module allows for easy access to gamepads if the browser supports it. When the gamepad feature is enabled in the project settings, you get access to these objects on the global scope:

    gamepads[id]; // get gamepad state. id is a number in the range [0..4] (4 is computer keyboard)
    gamepad; // Merge states of all gamepads and return a global gamepad state.

    Gamepad state works like keyboard controls: You get the state of each button, button presses and button releases, plus the values of analog controls.

    var state = gamepads[0]; // get state of gamepad id 0
    
    // buttons:
    state.btn.A; // state of A button
    state.btn.B; // state of B button
    state.btn.X; // state of X button
    state.btn.Y; // state of Y button
    state.btn.start; // state of 'start' button
    state.btn.back;  // state of 'back' button
    state.btn.up;    // directionnal pad's up button
    state.btn.down;  // directionnal pad's down button
    state.btn.left;  // directionnal pad's left button
    state.btn.right; // directionnal pad's right button
    state.btn.lb; // left bumper button
    state.btn.rb; // right bumper button
    state.btn.lt; // left trigger button
    state.btn.rt; // right trigger button
    
    // button press and release.
    // the structure is the same as state.btn but the values are true only
    // on button press or release.
    state.btnp; // button press
    state.btnr; // button release
    
    // analog values
    state.x  // x axe value (first stick horizontal)
    state.y  // y axe value (first stick vertical)
    state.z  // z axe value (second stick horizontal)
    state.w  // w axe value (second stick vertical)
    state.lt // left trigger analog value
    state.rt // right trigger analog value

    PataTracker

    Pixelbox editor is bundled with a music tracker called PataTracker. The tracker player must be enabled in the project settings. Player allows to directly plays the songs in the json formatted tracker files.

    PataTracker player is exposed as a patatracker global variable.

    patatracker.playSong(songNumber);
    patatracker.stop();

    PataTracker automatically loads the project's album data (assets/patatracker.json). If you need to load a different album, you can do it with the following API:

    patatracker.loadData(data);

    Bleeper

    Bleeper is the sound effect editor of Pixelbox. Like for PataTracker, it must be enabled in the project settings. Note that Bleeper depends on the AudioManager component.

    There are several ways to play Bleeper sounds:

    Named sounds

    If the sound is named, it is accessible on the assets global, and automatically added to AudioManager.

    // from assets global
    assets.bleeper.mySound.play(volume, panoramic, pitch); // all parameters optional
    
    // using audioManager
    sfx('mySound', volume, panoramic, pitch); // using default channel
    audioManager.playSound('sfx', 'mySound', volume, panoramic, pitch);

    Using bleeper module

    The Bleeper module exposes an array of all sounds defined in the program.

    var bleeper = require('pixelbox/bleeper');
    bleeper.sounds[3].play(volume, panoramic, pitch);

    Install

    npm i pixelbox

    DownloadsWeekly Downloads

    125

    Version

    2.1.1

    License

    MIT

    Unpacked Size

    247 kB

    Total Files

    50

    Last publish

    Collaborators

    • cstoquer