basic-sprite-collision

Basic Sprite Collision

This source code explores the understanding of Sprite Collision detection. Obviously one of the more important parts of developing a game is allowing a reaction based on two sprites touching. In this example, we'll have a center object (wall) that will prevent the sprite from entering it's boundries.

This is also the first example using the bottom screen!

Understanding the Code

The most important part of this example is the collision function. If the collision occurs, the function returns true.

bool collision() {
	int mainWidth = 8;
	int mainHeight = 8;
	int wallWidth = 40;
	int wallHeight = 40;

	int mainLeft = mainSprite.x;
	int wallLeft = wallSprite.x;
	int mainRight = mainSprite.x + mainWidth;
	int wallRight = wallSprite.x + wallWidth;
	int mainTop = mainSprite.y;
	int wallTop = wallSprite.y;
	int mainBottom = mainSprite.y + mainHeight;
	int wallBottom = wallSprite.y + wallHeight;

	if (mainLeft < wallRight && // left main will detect right wall
		mainRight > wallLeft && // right main will detect left wall
		mainTop < wallBottom && // top main will detect wall bottom
		mainBottom > wallTop) { // bottom main will detect wall top
    	return true;
	}
	return false;
}

What next?

Read up on more advance topics of collision such as hitbox detection (like above) or bitmap detection

Checkout these resources for more details:

• http://www.gamedev.net/page/resources/_/technical/game-programming/collision-detection-r735
• http://buildnewgames.com/gamephysics/