Color Collision

Check if a pixel on the screen matches a specific color.

ColorCollision Function

p8.ColorCollision(x, y, colorIndex) bool

Returns true if the pixel at (x, y) is the specified color.

Parameters

Example

func (g *game) Update() {
    newX := g.playerX + g.dx
    
    // Check if player would hit a wall (color 3)
    if p8.ColorCollision(newX, g.playerY, 3) {
        // Don't move
        return
    }
    
    g.playerX = newX
}

How It Works

1. All objects are drawn to the screen
2. ColorCollision reads the pixel color using Pget
3. Returns true if it matches the target color

Use Cases

• Simple platformer collision (walls are a specific color)
• Trigger zones (invisible areas using specific colors)
• Art-based collision shapes

Limitations

• Must draw before checking collision
• Only works with screen pixels (affected by camera)
• Single-pixel checks need multiple calls for bounding boxes

Full Bounding Box Check

func hitWall(x, y, w, h float64, wallColor int) bool {
    // Check corners and edges
    return p8.ColorCollision(x, y, wallColor) ||
           p8.ColorCollision(x+w, y, wallColor) ||
           p8.ColorCollision(x, y+h, wallColor) ||
           p8.ColorCollision(x+w, y+h, wallColor)
}