Creation of a Flash Stabilize! clone using Box2D – part 3

Read all posts about "" game

Here we are with the 3rd step.

Read steps 1 and 2, then continue with this post.

One thing I missed in Stabilize! was the “next” feature, something showing the block we are going do drop after the current one.

The first time I saw this feature was in Tetris… now try to imagine yourself playing Tetris without the “next” piece displayed somewhere on the screen. What a lack of strategy!!

So we are going to introduce the “next” feature in this game.

In order to do this, we must have different crates. So now each crate has a random color (from 1 to 5) and a random weight (from 1 to 9).

The principle of this feature is to randomly generate both the current and the next crate when we start the game, and give the player the current one.

When the player drops the current crate, give him the previously generated “next” one and randomly generate the next “next” one, that will be given to the player once he drops the old “next” one, and so on.

So here it is the commented script:

package {
	import flash.display.Sprite;
	import flash.events.Event;
	import flash.events.MouseEvent;
	import Box2D.Dynamics.*;
	import Box2D.Collision.*;
	import Box2D.Collision.Shapes.*;
	import Box2D.Common.Math.*;
	public class stabilize extends Sprite {
		public var m_sprite: Sprite = new Sprite();
		public var m_world:b2World;
		// the_crate is the crate sprite
		public var the_crate:crate=new crate();
		// next_crate
		public var next_crate:crate=new crate();
		// droppable_area is the sprite representing the area your mouse
		// must overlap to drop a crate
		public var droppable_area:drop_area = new drop_area();
		// this is the weight of the current crate I am dropping
		public var cur_drop:int=Math.ceil(Math.random()*9);
		// this is the color of the current crate I am dropping
		public var cur_color:int=Math.ceil(Math.random()*5);
		// weight and color of "next" crate
		public var next_drop:int=Math.ceil(Math.random()*9);
		public var next_color:int=Math.ceil(Math.random()*5);
		public function stabilize() {
			var gravity:b2Vec2=new b2Vec2(0,9.8);
			var worldAABB:b2AABB = new b2AABB();
			worldAABB.lowerBound.Set(-1000,-1000);
			worldAABB.upperBound.Set(1000,1000);
			m_world=new b2World(worldAABB,gravity,true);
			m_sprite = new Sprite();
			addChild(m_sprite);
			addChild(droppable_area);
			addChild(the_crate);
			// assigning the crate current weight and color
			the_crate.weight.text=cur_drop.toString();
			the_crate.gotoAndStop(cur_color);
			addChild(next_crate);
			// assigning "next" crate weight and color
			next_crate.weight.text=next_drop.toString();
			next_crate.gotoAndStop(next_color);
			next_crate.x=250;
			next_crate.y=385;
			debug_draw();
			AddBox(250/30,350/30,10/30,10/30,0,false);
			AddBox(250/30,350/30,200/30,10/30,20,false);
			addEventListener(Event.ENTER_FRAME,Update);
			stage.addEventListener(MouseEvent.MOUSE_DOWN,mousePressed);
			stage.addEventListener(MouseEvent.MOUSE_MOVE,mouseMoved);
		}
		public function mousePressed(e:MouseEvent) {
			// look at hitTestPoint... the final true value says it's going to to check against the actual pixels
			// instead of the bounding box
			if (droppable_area.hitTestPoint(mouseX,mouseY,true)) {
				// notice the cur_drop parameter, I am passing the weight of the current crate to the AddBox function
				AddBox(mouseX/30,mouseY/30,0.5,0.5,cur_drop,true);
			}
		}
		public function mouseMoved(e:MouseEvent) {
			the_crate.x=mouseX;
			the_crate.y=mouseY;
			if (droppable_area.hitTestPoint(mouseX,mouseY,true)) {
				the_crate.alpha=1;
			} else {
				the_crate.alpha=0.5;
			}
		}
		// function AddBox
		// px: x position
		// py: y position
		// _halfwidth: half of the box width
		// _halfheight: half of the box height
		// density: density of the box (0: static)
		// is_crate: if true, it's a crate (and you should render the proper movieclip
		public function AddBox(px:Number,py:Number,_halfwidth:Number,_halfheight:Number,density:Number,is_crate:Boolean) {
			var bodyDef:b2BodyDef = new b2BodyDef();
			bodyDef.position.Set(px,py);
			var boxDef:b2PolygonDef = new b2PolygonDef();
			boxDef.SetAsBox(_halfwidth,_halfheight);
			boxDef.density=density;
			boxDef.friction=0.3;
			boxDef.restitution=0.2;
			if (is_crate) {
				bodyDef.userData = new crate();
			}
			var body:b2Body=m_world.CreateBody(bodyDef);
			body.CreateShape(boxDef);
			body.SetMassFromShapes();
			if (is_crate) {
				addChild(bodyDef.userData);
				// assigning current weight and color to the Box2D sprite bound to the box I created
				bodyDef.userData.weight.text=cur_drop.toString();
				bodyDef.userData.gotoAndStop(cur_color);
				// updating current weight and color with the next ones
				cur_drop=next_drop;
				cur_color=next_color;
				// changing current crate movieclip according to its weight and color
				the_crate.weight.text=cur_drop.toString();
				the_crate.gotoAndStop(cur_color);
				// calculating next crate weight and color
				next_drop=Math.ceil(Math.random()*9);
				next_color=Math.ceil(Math.random()*5);
				// updating next crate movieclip according to its weight and color
				next_crate.weight.text=next_drop.toString();
				next_crate.gotoAndStop(next_color);
			}
		}
		public function Update(e:Event) {
			m_world.Step(1/30,10);
			for (var bb:b2Body = m_world.m_bodyList; bb; bb = bb.m_next) {
				if (bb.m_userData is Sprite) {
					bb.m_userData.x=bb.GetPosition().x*30;
					bb.m_userData.y=bb.GetPosition().y*30;
					bb.m_userData.rotation = bb.GetAngle() * (180/Math.PI);
				}
			}
		}
		public function debug_draw() {
			var dbgDraw:b2DebugDraw = new b2DebugDraw();
			var dbgSprite:Sprite = new Sprite();
			m_sprite.addChild(dbgSprite);
			dbgDraw.m_sprite=m_sprite;
			dbgDraw.m_drawScale=30;
			dbgDraw.m_alpha=1;
			dbgDraw.m_fillAlpha=0.5;
			dbgDraw.m_lineThickness=1;
			dbgDraw.m_drawFlags=b2DebugDraw.e_shapeBit;
			m_world.SetDebugDraw(dbgDraw);

		}
	}
}

And this is the result:

The “next” crate is the one under the bar. Download the source code

Next time, we’ll see how to remove crates when three or more of them have the same color and collide

Get the most popular Phaser 3 book

Through 202 pages, 32 source code examples and an Android Studio project you will learn how to build cross platform HTML5 games and create a complete game along the way.

Get the book

214 GAME PROTOTYPES EXPLAINED WITH SOURCE CODE
// 1+2=3
// 100 rounds
// 10000000
// 2 Cars
// 2048
// A Blocky Christmas
// A Jumping Block
// A Life of Logic
// Angry Birds
// Angry Birds Space
// Artillery
// Astro-PANIC!
// Avoider
// Back to Square One
// Ball Game
// Ball vs Ball
// Ball: Revamped
// Balloon Invasion
// BallPusher
// Ballz
// Bar Balance
// Bejeweled
// Biggification
// Block it
// Blockage
// Bloons
// Boids
// Bombuzal
// Boom Dots
// Bouncing Ball
// Bouncing Ball 2
// Bouncy Light
// BoxHead
// Breakout
// Bricks
// Bubble Chaos
// Bubbles 2
// Card Game
// Castle Ramble
// Chronotron
// Circle Chain
// Circle Path
// Circle Race
// Circular endless runner
// Cirplosion
// CLOCKS - The Game
// Color Hit
// Color Jump
// ColorFill
// Columns
// Concentration
// Crossy Road
// Crush the Castle
// Cube Jump
// CubesOut
// Dash N Blast
// Dashy Panda
// Deflection
// Diamond Digger Saga
// Don't touch the spikes
// Dots
// Down The Mountain
// Drag and Match
// Draw Game
// Drop Wizard
// DROP'd
// Dudeski
// Dungeon Raid
// Educational Game
// Elasticity
// Endless Runner
// Erase Box
// Eskiv
// Farm Heroes Saga
// Filler
// Flappy Bird
// Fling
// Flipping Legend
// Floaty Light
// Fuse Ballz
// GearTaker
// Gem Sweeper
// Globe
// Goat Rider
// Gold Miner
// Grindstone
// GuessNext
// Helicopter
// Hero Emblems
// Hero Slide
// Hexagonal Tiles
// HookPod
// Hop Hop Hop Underwater
// Horizontal Endless Runner
// Hundreds
// Hungry Hero
// Hurry it's Christmas
// InkTd
// Iromeku
// Jet Set Willy
// Jigsaw Game
// Knife Hit
// Knightfall
// Legends of Runeterra
// Lep's World
// Line Rider
// Lumines
// Magick
// MagOrMin
// Mass Attack
// Math Game
// Maze
// Meeblings
// Memdot
// Metro Siberia Underground
// Mike Dangers
// Mikey Hooks
// Nano War
// Nodes
// o:anquan
// One Button Game
// One Tap RPG
// Ononmin
// Pacco
// Perfect Square!
// Perfectionism
// Phyballs
// Pixel Purge
// PixelField
// Planet Revenge
// Plants Vs Zombies
// Platform
// Platform game
// Plus+Plus
// Pocket Snap
// Poker
// Pool
// Pop the Lock
// Pop to Save
// Poux
// Pudi
// Pumpkin Story
// Puppet Bird
// Pyramids of Ra
// qomp
// Quick Switch
// Racing
// Radical
// Rebuild Chile
// Renju
// Rise Above
// Risky Road
// Roguelike
// Roly Poly
// Run Around
// Rush Hour
// SameGame
// SamePhysics
// Save the Totem
// Security
// Serious Scramblers
// Shrink it
// Sling
// Slingy
// Snowflakes
// Sokoban
// Space Checkers
// Space is Key
// Spellfall
// Spinny Gun
// Splitter
// Spring Ninja
// Sproing
// Stabilize!
// Stack
// Stick Hero
// String Avoider
// Stringy
// Sudoku
// Super Mario Bros
// Surfingers
// Survival Horror
// Talesworth Adventure
// Tetris
// The Impossible Line
// The Moops - Combos of Joy
// The Next Arrow
// Threes
// Tic Tac Toe
// Timberman
// Tiny Wings
// Tipsy Tower
// Toony
// Totem Destroyer
// Tower Defense
// Trick Shot
// Tunnelball
// Turn
// Turnellio
// TwinSpin
// vvvvvv
// Warp Shift
// Way of an Idea
// Whack a Creep
// Wheel of Fortune
// Where's my Water
// Wish Upon a Star
// Word Game
// Wordle
// Worms
// Yanga
// Yeah Bunny
// Zhed
// zNumbers