[nacltoons] Add initial frontend and physics game scenes.

nacltoons/src/PhysicsLayer.cc

+// Copyright (c) 2013 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+#include "PhysicsLayer.h"
+#include "physics_nodes/CCPhysicsSprite.h"
+
+// Pixels-to-meters ratio for converting screen coordinates
+// to Box2D "meters".
+#define PTM_RATIO 32
+#define SCREEN_TO_WORLD(n) ((n) / PTM_RATIO)
+#define WORLD_TO_SCREEN(n) ((n) * PTM_RATIO)
+#define VELOCITY_ITERATIONS 8
+#define POS_ITERATIONS 1
+
+#define SPRITE_BATCH_NODE_TAG 99
+#define MAX_SPRITES 100
+
+USING_NS_CC_EXT;
+
+bool PhysicsLayer::init() {
+  if (!CCLayerColor::initWithColor(ccc4(0,0x8F,0xD8,0xD8)))
+    return false;
+
+  setTouchEnabled(true);
+  InitPhysics();
+
+  CCSpriteBatchNode* batch;
+  batch = CCSpriteBatchNode::create("blocks.png", MAX_SPRITES);
+  addChild(batch, 0, SPRITE_BATCH_NODE_TAG);
+
+  // cache texture pointer for creating sprites
+  sprite_texture_ = batch->getTexture();
+
+  // script physics updates each frame
+  schedule(schedule_selector(PhysicsLayer::UpdateWorld));
+  return true;
+}
+
+PhysicsLayer::~PhysicsLayer() {
+  delete world_;
+}
+
+bool PhysicsLayer::InitPhysics() {
+  b2Vec2 gravity(0.0f, -9.8f);
+  world_ = new b2World(gravity);
+  world_->SetAllowSleeping(true);
+  world_->SetContinuousPhysics(true);
+
+  // create the ground
+  b2BodyDef groundBodyDef;
+  groundBodyDef.position.Set(0, 0);
+  b2Body* groundBody = world_->CreateBody(&groundBodyDef);
+
+  CCSize win_size = CCDirector::sharedDirector()->getWinSize();
+  int world_width = SCREEN_TO_WORLD(win_size.width);
+  int world_height = SCREEN_TO_WORLD(win_size.height);
+
+  // Define the ground box shape.
+  b2EdgeShape groundBox;
+  // bottom
+  groundBox.Set(b2Vec2(0, 0), b2Vec2(world_width, 0));
+  groundBody->CreateFixture(&groundBox, 0);
+  // top
+  groundBox.Set(b2Vec2(0, world_height), b2Vec2(world_width, world_height));
+  groundBody->CreateFixture(&groundBox, 0);
+  // left
+  groundBox.Set(b2Vec2(0, world_height), b2Vec2(0,0));
+  groundBody->CreateFixture(&groundBox, 0);
+  // right
+  groundBox.Set(b2Vec2(world_width, world_height), b2Vec2(world_width, 0));
+  groundBody->CreateFixture(&groundBox, 0);
+}
+
+void PhysicsLayer::UpdateWorld(float dt) {
+   world_->Step(dt, VELOCITY_ITERATIONS, POS_ITERATIONS);
+}
+
+void PhysicsLayer::ccTouchesEnded(CCSet* touches, CCEvent* event) {
+  for (CCSetIterator it = touches->begin(); it != touches->end(); it++) {
+    CCTouch* touch = (CCTouch*)(*it);
+    if (!touch)
+      break;
+
+    CCPoint location = touch->getLocation();
+    //CCLOG("PhysicsLayer touch x:%.f, y:%.f", location.x, location.y);
+    AddNewSpriteAtPosition(location);
+  }
+}
+
+void PhysicsLayer::AddNewSpriteAtPosition(CCPoint p) {
+  CCLOG("Add sprite %0.fx%.f", p.x, p.y);
+
+  // Create a new physics body at the given position.
+  b2BodyDef body_def;
+  body_def.type = b2_dynamicBody;
+  body_def.position.Set(SCREEN_TO_WORLD(p.x), SCREEN_TO_WORLD(p.y));
+  b2Body* body = world_->CreateBody(&body_def);
+
+  b2PolygonShape dynamicBox;
+  dynamicBox.SetAsBox(.5f, .5f);
+
+  b2FixtureDef fixtureDef;
+  fixtureDef.shape = &dynamicBox;
+  fixtureDef.density = 1.0f;
+  fixtureDef.friction = 0.3f;
+  body->CreateFixture(&fixtureDef);
+
+  // Create new sprite an link it to the physics body.
+  CCPhysicsSprite* sprite;
+  sprite = CCPhysicsSprite::createWithTexture(sprite_texture_,
+                                              CCRectMake(0, 0, 32, 32));
+
+  // Find the sprite batch node and attach new sprite to it.
+  CCNode* parent = getChildByTag(SPRITE_BATCH_NODE_TAG);
+  parent->addChild(sprite);
+  sprite->setB2Body(body);
+  sprite->setPTMRatio(PTM_RATIO);
+  sprite->setPosition(ccp(p.x, p.y));
+}