• github.com/Koubae/java-libGDX

• krita

  • How to make 2D game art! Simple assets, even if you are bad at drawing

• kenney.nl

• opengameart

1. Check the license for each asset
   Always verify that the license allows commercial use and note any obligations
   (e.g., attribution or share-alike).

2. Record attribution details
   Save the following for every asset you use:

   • Name of the asset
   • Author/creator
   • License type
   • Link to the original source
     This makes it easier to include proper credits in your game.

3. Prefer safe licenses
   Use assets under CC0, OGA-BY, or CC-BY (with attribution)
   for the simplest usage in both commercial and closed-source projects.

4. Be cautious with GPL / CC-BY-SA

   • ShareAlike (SA): requires derivatives to use the same license.
   • GPL: often conflicts with closed-source or proprietary games.
     Use only if you fully understand the implications.

5. Bundle license info with your game
   Include a file or folder in your game distribution listing:

   • All used assets
   • Their licenses
   • Full license texts (if required)
     This keeps everything transparent and legally safe.

• License matters per asset
  Just because the site is “free assets” doesn’t mean every piece is CC0.
  Each upload has its own license.

• CC-BY / CC-BY-SA / OGA-BY require attribution

  • CC-BY: You must credit the original creator.
  • CC-BY-SA: In addition to attribution, derivatives must carry the same license.
  • OGA-BY: Similar to CC-BY but removes certain technical restrictions.

• GPL-licensed assets are tricky
  GPL is designed for software, not art.
  Using GPL assets in a non-GPL (closed-source) game can create licensing conflicts.

• Technical restriction clauses
  Some licenses (like CC-BY) include clauses against DRM or technical limitations.
  OGA-BY was created to avoid these issues.

• Safe choices for commercial games
  Stick with CC0, OGA-BY, or CC-BY (with proper attribution)
  to avoid complications.

A direction AND magnitude - tells you both how far AND which way.

Use it when you need to know:

• "Which direction should I face?"
• "Where should I move?"
• "What angle is the target at?"

Vector2 position = Vector2(x=10, y=20);
Vector2 target = Vector2(x=25, y=30);
Vector2 displacement = Vector2(x=target.x - position.x, y=target.y - position.y);

Vector2 displacement = new Vector2(100, 50); # 100 units right, 50 units up
float angle = Math.atan2(displacement.y, displacement.x); #  Calculate direction
#  Now I know which way to rotate/aim

A single number - the straight-line distance between two points. Use it when you need to know:

• "How far away is something?"
• "Is the target within range?"
• "Am I close enough to stop moving?"

float distance = 150.5f; // 150.5 units away
if (distance < 200f) {
    // Target is within shooting range
}

Vector2 position = Vector2(x=10, y=20);
Vector2 target = Vector2(x=25, y=30);
Vector2 displacement = Vector2(x=target.x - position.x, y=target.y - position.y);
float eucledianDistance = (float)Math.sqrt((displacement.x * displacement.x) + (displacement.y * displacement.y));
// Also
float distance = (float) Math.hypot(displacement.x, displacement.y);

Practical Example - Chasing a target:

// Where is the target relative to me?
Vector2 displacement = new Vector2(
    target.x - self.x,  // +100 means target is 100 units to the right
    target.y - self.y   // -50 means target is 50 units down
);

// How far away is it?
float distance = displacement.len(); // e.g., 111.8 units eucledian

// Decision making:
if (distance > 200) {
    // Use DISPLACEMENT to know which direction to move
    float angle = Math.atan2(displacement.y, displacement.x);
    rotateTowards(angle);
    moveForward();
} else {
    // Use DISTANCE to know we're close enough
    stop();
}