49 Pyxel Commands Cheatsheet (Lessons 15a-15f)

49.1 Initialization and Core Functions

Command	Description	Example
`pyxel.init(width, height, title="Title")`	Initialize Pyxel with specified screen dimensions	`pyxel.init(160, 120, title="My Game")`
`pyxel.run(update, draw)`	Start the Pyxel application with update and draw functions	`pyxel.run(self.update, self.draw)`
`pyxel.quit()`	Exit the Pyxel application	`if pyxel.btnp(pyxel.KEY_Q): pyxel.quit()`
`pyxel.cls(col)`	Clear the screen with specified color	`pyxel.cls(0) # Clear with black`
`pyxel.frame_count`	Get the number of frames since the application started	`animation_frame = pyxel.frame_count % 30`

49.2 Input Handling

Command	Description	Example
`pyxel.btn(key)`	Check if a button is being held down	`if pyxel.btn(pyxel.KEY_RIGHT): player_x += 2`
`pyxel.btnp(key)`	Check if a button was just pressed	`if pyxel.btnp(pyxel.KEY_SPACE): fire_weapon()`
`pyxel.mouse_x`	Get current mouse X position	`cursor_x = pyxel.mouse_x`
`pyxel.mouse_y`	Get current mouse Y position	`cursor_y = pyxel.mouse_y`
`pyxel.mouse(visible)`	Show or hide the mouse cursor	`pyxel.mouse(True) # Show mouse cursor`

49.3 Constants for Keys

Constant	Description
`pyxel.KEY_UP`	Up arrow key
`pyxel.KEY_DOWN`	Down arrow key
`pyxel.KEY_LEFT`	Left arrow key
`pyxel.KEY_RIGHT`	Right arrow key
`pyxel.KEY_SPACE`	Space key
`pyxel.KEY_RETURN`	Enter/Return key
`pyxel.KEY_Q`	Q key (commonly used to quit)
`pyxel.MOUSE_BUTTON_LEFT`	Left mouse button
`pyxel.MOUSE_BUTTON_RIGHT`	Right mouse button

49.4 Drawing Primitives

Command	Description	Example
`pyxel.pset(x, y, col)`	Draw a single pixel	`pyxel.pset(10, 10, 7) # White pixel`
`pyxel.line(x1, y1, x2, y2, col)`	Draw a line	`pyxel.line(10, 10, 50, 50, 8) # Red line`
`pyxel.rect(x, y, w, h, col)`	Draw a filled rectangle	`pyxel.rect(10, 10, 40, 30, 3) # Dark green rect`
`pyxel.rectb(x, y, w, h, col)`	Draw a rectangle outline	`pyxel.rectb(10, 10, 40, 30, 7) # White outline`
`pyxel.circ(x, y, r, col)`	Draw a filled circle	`pyxel.circ(40, 40, 10, 12) # Light blue circle`
`pyxel.circb(x, y, r, col)`	Draw a circle outline	`pyxel.circb(40, 40, 10, 7) # White circle outline`
`pyxel.tri(x1, y1, x2, y2, x3, y3, col)`	Draw a filled triangle	`pyxel.tri(30, 10, 50, 50, 10, 50, 11) # Green triangle`
`pyxel.trib(x1, y1, x2, y2, x3, y3, col)`	Draw a triangle outline	`pyxel.trib(30, 10, 50, 50, 10, 50, 7) # White outline`
`pyxel.text(x, y, text, col)`	Draw text	`pyxel.text(10, 10, "Hello Pyxel!", 7) # White text`

49.5 Sprite and Image Handling

Command	Description	Example
`pyxel.blt(x, y, img, u, v, w, h, [colkey])`	Draw a sprite from the image bank	`pyxel.blt(10, 10, 0, 0, 0, 16, 16, 0) # 16x16 sprite with black transparent`
`pyxel.load(filename)`	Load resources from a .pyxres file	`pyxel.load("game_resources.pyxres")`
`pyxel.images[bank].load(x, y, filename)`	Load an image into the image bank	`pyxel.images[0].load(0, 0, "character.png")`
`pyxel.images[bank].pset(x, y, col)`	Set a pixel color in the image bank	`pyxel.images[0].pset(5, 5, 8) # Red pixel in bank 0`

49.6 Image Bank Structure

pyxel.images[0]  # First image bank page (0)
pyxel.images[1]  # Second image bank page (1)
pyxel.images[2]  # Third image bank page (2)

Each image bank is a 256x256 pixel area where you can store sprites and other graphical assets.

49.7 Colors

Pyxel has a fixed 16-color palette (0-15):

Color Number	Color Name
0	Black
1	Dark Blue
2	Purple
3	Dark Green
4	Brown
5	Dark Gray
6	Light Gray
7	White
8	Red
9	Orange
10	Yellow
11	Light Green
12	Light Blue
13	Gray
14	Pink
15	Peach

49.8 Game Development Patterns

49.8.1 Basic Game Structure

import pyxel

class Game:
    def __init__(self):
        pyxel.init(160, 120, title="My Pyxel Game")
        self.player_x = 80
        self.player_y = 60
        pyxel.run(self.update, self.draw)
    
    def update(self):
        # Handle quitting
        if pyxel.btnp(pyxel.KEY_Q):
            pyxel.quit()
            
        # Update game state here
        if pyxel.btn(pyxel.KEY_RIGHT):
            self.player_x += 2
        
    def draw(self):
        # Clear screen
        pyxel.cls(0)
        
        # Draw game elements
        pyxel.circ(self.player_x, self.player_y, 8, 11)

# Start the game
Game()

49.8.2 Boundary Management

def keep_in_bounds(x, y, width, height, screen_width, screen_height):
    """Keep an object within screen boundaries."""
    x = max(0, min(x, screen_width - width))
    y = max(0, min(y, screen_height - height))
    return x, y

49.8.3 Sprite Atlas Pattern

# Sprite atlas dictionary
atlas = {
    "player": (0, 0, 0, 16, 16, 0),  # bank, x, y, width, height, colorkey
    "enemy": (0, 16, 0, 16, 16, 0),
    "item": (0, 0, 16, 8, 8, 0)
}

def draw_sprite(name, x, y):
    if name in atlas:
        bank, u, v, w, h, colorkey = atlas[name]
        pyxel.blt(x, y, bank, u, v, w, h, colorkey)

49.9 Tips and Best Practices

Organization: Group related sprites together in the image bank
Transparency: Use color 0 (black) as the transparent color for sprites
Coordinate System: (0,0) is at the top-left corner; x increases right, y increases down
Performance: Minimize drawing operations for better performance
Input: Use btn() for continuous actions (movement) and btnp() for one-time actions (shooting)