PSP程序开发例子解析(十一)HGEParticles

HGEParticles这个例子很BT 模仿WindowsMediaPlayer的效果 跟随mp3的播放的波形来显示一些特效
暂时没怎么看明白 慢慢解析
GameApp.h
#ifndef _GAMEAPP_H_
#define _GAMEAPP_H_

#include <JApp.h>

class hgeParticleSystem;
class JTexture;
class JQuad;
class hgeFont;
class JMusic;

class GameApp: public JApp
{

public:
GameApp();
virtual ~GameApp();
virtual void Create();
virtual void Destroy();
virtual void Update();
virtual void Render();
virtual void Pause();
virtual void Resume();

void LoadNewParticleSys();

private:
float mAngle;
float mTimer;

hgeFont* mFont;//屏幕文字显示利用hge的字体类库 具体和TTF的类有什么区别不清楚

hgeParticleSystem* mMovingParticleSys;
hgeParticleSystem* mParticleSys;
JTexture *mTexture;
JQuad *mCircle;

JQuad *mParticles[16];

int mCurrParticleSys;
int mCurrParticle;

float x;
float y;
float dx;
float dy;

float mSpeed;
float mFriction;


JMusic* mMusic;
};

#endif

GameApp.cpp
#include <stdio.h>

#include <JAssert.h>
#include <JGE.h>
#include <JRenderer.h>
#include <JSoundSystem.h>
#include <JLBFont.h>

#include <hge\hgeparticle.h>
#include <hge\hgefont.h>

#include "GameApp.h"



//-------------------------------------------------------------------------------------
// Constructor. Variables can be initialized here.
//
//-------------------------------------------------------------------------------------
GameApp::GameApp()
{
mAngle = 0.0f;
mTimer = 0.0f;

for (int i=0;i<16;i++)
   mParticles[i] = NULL;

mMovingParticleSys = NULL;
mParticleSys = NULL;
mTexture = NULL;
mCircle = NULL;

x = 100.0f;
y = 100.0f;
dx = 0.0f;
dy = 0.0f;

mSpeed = 90;
mFriction = 0.98f;
}


//-------------------------------------------------------------------------------------
// Destructor.
//
//-------------------------------------------------------------------------------------
GameApp::~GameApp()
{

}


//-------------------------------------------------------------------------------------
// This is the init callback function. You should load and create your in-game 
// resources here.
// 
//-------------------------------------------------------------------------------------
void GameApp::Create()
{

mTexture = JRenderer::GetInstance()->LoadTexture("particles.png", TEX_TYPE_USE_VRAM);

// load all the particle images
int n = 0;
for (int i=0;i<4;i++)
{
   for (int j=0;j<4;j++)
   {
    mParticles[n] = new JQuad(mTexture, j*32, i*32, 32, 32);
    mParticles[n]->SetHotSpot(16,16);
    n++;
   }
}

mCircle =new JQuad(mTexture, 96, 64, 32, 32);
mCircle->SetColor(ARGB(0xFF,0xFF,0xA0,0x00));
mCircle->SetHotSpot(16,16);

// the particle system that move with the circle
mMovingParticleSys = new hgeParticleSystem("trail.psi", mParticles[5]);
mMovingParticleSys->Fire();

mCurrParticleSys = 0;
mCurrParticle = 0;

// Load a font
mFont = new hgeFont("font2.fnt");

LoadNewParticleSys();

JSoundSystem* sound = JSoundSystem::GetInstance();

if (sound)
    mMusic = sound->LoadMusic("12thWarrior.mp3"); // Load a background music.

   if (mMusic)
    JSoundSystem::GetInstance()->PlayMusic(mMusic, true);
}


void GameApp::LoadNewParticleSys()
{
if (mParticleSys)
{
   delete mParticleSys;
   mParticleSys = NULL;
}

char s[80];
sprintf(s, "particle%d.psi", (mCurrParticleSys+1));
mParticleSys = new hgeParticleSystem(s, mParticles[mCurrParticle]);
mParticleSys->MoveTo(SCREEN_WIDTH_F/2, SCREEN_HEIGHT_F/2);
mParticleSys->Fire();
}


//-------------------------------------------------------------------------------------
// This is the clean up callback function. You should delete all your in-game 
// resources, for example texture and quads, here.
// 
//-------------------------------------------------------------------------------------
void GameApp::Destroy()
{

SAFE_DELETE(mMovingParticleSys);

SAFE_DELETE(mCircle);

for (int i=0;i<16;i++)
   SAFE_DELETE(mParticles[i]);

SAFE_DELETE(mParticleSys);

SAFE_DELETE(mTexture);

SAFE_DELETE(mFont);

SAFE_DELETE(mMusic);
}


//-------------------------------------------------------------------------------------
// This is the update callback function and is called at each update frame
// before rendering. You should update the game logic here.
//
//-------------------------------------------------------------------------------------
void GameApp::Update()
{

JGE* engine = JGE::GetInstance();

// do a screen shot when the TRIANGLE button is pressed
if (engine->GetButtonClick(PSP_CTRL_TRIANGLE))  
{
   char s[80];

   // save screen shot to root of Memory Stick 
   sprintf(s, "ms0:/screenshot.png");    
   JRenderer::GetInstance()->ScreenShot(s);
}

// exit when the CROSS button is pressed
if (engine->GetButtonClick(PSP_CTRL_CROSS)) 
{
   engine->End();
   return;
}

int quadIdx[] =
{
   7, 15, 0, 5, 7, 0, 1, 15, 4
};

// change particle image if PSP_CTRL_LEFT or PSP_CTRL_RIGHT is down
if (engine->GetButtonClick(PSP_CTRL_LEFT))
{
   mCurrParticle--;
   if (mCurrParticle < 0)
    mCurrParticle = 15;

   mParticleSys->info.sprite = mParticles[mCurrParticle];
   mMovingParticleSys->info.sprite = mParticles[15-mCurrParticle];
}
if (engine->GetButtonClick(PSP_CTRL_RIGHT))
{
   mCurrParticle++;
   if (mCurrParticle > 15)
    mCurrParticle = 0;

   mParticleSys->info.sprite = mParticles[mCurrParticle];
   mMovingParticleSys->info.sprite = mParticles[15-mCurrParticle];
}

// change particle system if PSP_CTRL_DOWN or PSP_CTRL_UP is down
if (engine->GetButtonClick(PSP_CTRL_DOWN))
{
   mCurrParticleSys--;
   if (mCurrParticleSys < 0)
    mCurrParticleSys = 8;

   mCurrParticle = quadIdx[mCurrParticleSys];
   LoadNewParticleSys();
}
if (engine->GetButtonClick(PSP_CTRL_UP))
{
   mCurrParticleSys++;
   if (mCurrParticleSys > 8)
    mCurrParticleSys = 0;

   mCurrParticle = quadIdx[mCurrParticleSys];
   LoadNewParticleSys();
}

float dt = engine->GetDelta();   // Get time elapsed since last update.

mTimer += dt;


mAngle += 2.0f*dt;
if (mAngle >= M_PI*2)
   mAngle = 0;

if (mTimer > 0.01f)   // update the moving circle and particle at about 100fps
{
   if (engine->GetAnalogX()<64) 
    dx-=mSpeed*mTimer;
   if (engine->GetAnalogX()>192) 
    dx+=mSpeed*mTimer;
   if (engine->GetAnalogY()<64) 
    dy-=mSpeed*mTimer;
   if (engine->GetAnalogY()>192) 
    dy+=mSpeed*mTimer;

   // Do some movement calculations and collision detection 
   dx *= mFriction;
   dy *= mFriction;
   x += dx; 
   y += dy;

   if (x>470) 
   {
    x=470-(x-470);
    dx=-dx;
   }
   if (x<16) 
   {
    x=16+16-x;
    dx=-dx;
   }
   if (y>260)
   {
    y=260-(y-260);
    dy=-dy;
   }
   if (y<16)
   {
    y=16+16-y;
    dy=-dy;
   }

   // Update particle system
   mMovingParticleSys->info.nEmission=(int) (dx*dx+dy*dy)*2;
   mMovingParticleSys->MoveTo(x,y);

   mTimer = 0.0f;

}

mMovingParticleSys->Update(dt);
mParticleSys->Update(dt);

}


//-------------------------------------------------------------------------------------
// All rendering operations should be done in Render() only.
// 
//-------------------------------------------------------------------------------------
void GameApp::Render()
{

// get JRenderer instance
JRenderer* renderer = JRenderer::GetInstance();  

// clear screen to black
renderer->ClearScreen(ARGB(0,0,0,0));

// render circle
renderer->RenderQuad(mCircle, x, y);

// set additive blending
renderer->SetTexBlend(BLEND_SRC_ALPHA, BLEND_ONE);

mParticleSys->Render();
mMovingParticleSys->Render();

// set normal blending
renderer->SetTexBlend(BLEND_SRC_ALPHA, BLEND_ONE_MINUS_SRC_ALPHA);

// draw the current image used for the particle system shown in the middle
renderer->FillRect(SCREEN_WIDTH_F-37, 3, 34, 34, ARGB(255,0,0,128));
mParticles[mCurrParticle]->SetColor(ARGB(255,255,255,255));
renderer->RenderQuad(mParticles[mCurrParticle], SCREEN_WIDTH_F-20, 20);

// turn off bilinear filtering to render sharp text
renderer->EnableTextureFilter(false);

mFont->printf(5, 5, HGETEXT_LEFT, "[Left/Right] Change Particle Image");
char s[80];
mFont->printf(5, 20, HGETEXT_LEFT, "[Up/Down] Change Effect -> particle%d.psi", (mCurrParticleSys+1));
mFont->printf(5, 35, HGETEXT_LEFT, "[Analog] Move Circle");

renderer->EnableTextureFilter(true);
}


//-------------------------------------------------------------------------------------
// This function is called when the system wants to pause the game. You can set a flag
// here to stop the update loop and audio playback.
//
//-------------------------------------------------------------------------------------
void GameApp::Pause()
{

}


//-------------------------------------------------------------------------------------
// This function is called when the game returns from the pause state.
//
//-------------------------------------------------------------------------------------
void GameApp::Resume()
{

}