HGE tutorial 03 学习笔记及摘录

Tutorial 03 - Using helper classes

In this tutorial we will learn how to use some of HGE helper classes. First, we include all the needed headers and declare the global pointer to the HGEinterface that is required by most of the helper classes to work:

#include <hge.h>#include <hgesprite.h>#include <hgefont.h>#include <hgeparticle.h>HGE *hge=0;

Now we declare the pointers to the HGE objects we will use.

hgeSprite*          spr;hgeSprite*          spt;hgeFont*            fnt;hgeParticleSystem*  par;HTEXTURE            tex;

In the FrameFunc (frame function) we update the particle system object: we adjust it's emission rate based on the current sprite speed and move it to the current sprite location.

 
 par->info.nEmission=(int)(dx*dx+dy*dy)*2; par->MoveTo(x,y); par->Update(dt);

In the RenderFunc we render all our objects, calling their render methods:

 
  hge->Gfx_BeginScene();  hge->Gfx_Clear(0);  par->Render();  spr->Render(x, y);  fnt->printf(5, 5, HGETEXT_LEFT, "dt:%.3f\nFPS:%d",              hge->Timer_GetDelta(), hge->Timer_GetFPS());  hge->Gfx_EndScene();

In the WinMain function after HGE is initiated we create the HGE objects, that we will use. First, we create and set up a sprite:

    
spr=new hgeSprite(tex, 96, 64, 32, 32);spr->SetColor(0xFFFFA000);spr->SetHotSpot(16, 16);

Then we load a font. The font is represented with two disk files: font1.fntand font1.png.

  
  fnt=new hgeFont("font1.fnt");

We create a particle system and a sprite for it:

    
spt=new hgeSprite(tex, 32, 32, 32, 32);spt->SetBlendMode(          BLEND_COLORMUL | BLEND_ALPHAADD | BLEND_NOZWRITE);spt->SetHotSpot(16, 16);par=new hgeParticleSystem("trail.psi", spt);par->Fire();

Now all our objects have been created and we start the game loop:

 
   hge->System_Start();

When the game loop is finished, we delete all created HGE objects:

  
  delete par;  delete fnt;  delete spt;  delete spr;

The rest of shutdown process is identical to the one demonstrated in previous tutorials. 

The complete source code with detailed comments for this tutorial you may find in the folder tutorials\tutorial03. The required media files you'll find in the folder tutorials\precompiled.

源码及简单注释

/*** Haaf's Game Engine 1.8** Copyright (C) 2003-2007, Relish Games** hge.relishgames.com**** hge_tut03 - Using helper classes*/// Copy the files "particles.png", "menu.wav",// "font1.fnt", "font1.png" and "trail.psi" from// the folder "precompiled" to the folder with// executable file. Also copy hge.dll and bass.dll// to the same folder.#include "..\..\include\hge.h"#include "..\..\include\hgesprite.h"#include "..\..\include\hgefont.h"#include "..\..\include\hgeparticle.h"// Pointer to the HGE interface.// Helper classes require this to work.HGE *hge=0;// Pointers to the HGE objects we will usehgeSprite*spr;hgeSprite*spt;hgeFont*fnt;hgeParticleSystem*par;// Handles for HGE resourccesHTEXTUREtex;HEFFECTsnd;// Some "gameplay" variablesfloat x=100.0f, y=100.0f;float dx=0.0f, dy=0.0f;const float speed=90;const float friction=0.98f;// Play sound effectvoid boom() {int pan=int((x-400)/4);float pitch=(dx*dx+dy*dy)*0.0005f+0.2f;hge->Effect_PlayEx(snd,100,pan,pitch);}bool FrameFunc(){float dt=hge->Timer_GetDelta();// Process keysif (hge->Input_GetKeyState(HGEK_ESCAPE)) return true;if (hge->Input_GetKeyState(HGEK_LEFT)) dx-=speed*dt;if (hge->Input_GetKeyState(HGEK_RIGHT)) dx+=speed*dt;if (hge->Input_GetKeyState(HGEK_UP)) dy-=speed*dt;if (hge->Input_GetKeyState(HGEK_DOWN)) dy+=speed*dt;// Do some movement calculations and collision detectiondx*=friction; dy*=friction; x+=dx; y+=dy;if(x>784) {x=784-(x-784);dx=-dx;boom();}if(x<16) {x=16+16-x;dx=-dx;boom();}if(y>584) {y=584-(y-584);dy=-dy;boom();}if(y<16) {y=16+16-y;dy=-dy;boom();}// Update particle systempar->info.nEmission=(int)(dx*dx+dy*dy)*2;par->MoveTo(x,y);par->Update(dt);return false;}bool RenderFunc(){// Render graphicshge->Gfx_BeginScene();hge->Gfx_Clear(0);par->Render();spr->Render(x, y);//打印间隔时间和FPS 注意：要将字体文件 .fnt文件和同名.png文件都要放到该工程下，不然不会显示字体fnt->printf(5, 5, HGETEXT_LEFT, "dt:%.3f\nFPS:%d (constant)", hge->Timer_GetDelta(), hge->Timer_GetFPS());hge->Gfx_EndScene();return false;}int WINAPI WinMain(HINSTANCE, HINSTANCE, LPSTR, int){hge = hgeCreate(HGE_VERSION);hge->System_SetState(HGE_LOGFILE, "hge_tut03.log");hge->System_SetState(HGE_FRAMEFUNC, FrameFunc);hge->System_SetState(HGE_RENDERFUNC, RenderFunc);hge->System_SetState(HGE_TITLE, "HGE Tutorial 03 - Using helper classes");hge->System_SetState(HGE_FPS, 100);hge->System_SetState(HGE_WINDOWED, true);hge->System_SetState(HGE_SCREENWIDTH, 800);hge->System_SetState(HGE_SCREENHEIGHT, 600);hge->System_SetState(HGE_SCREENBPP, 32);if(hge->System_Initiate()) {// Load sound and texturesnd=hge->Effect_Load("menu.wav");tex=hge->Texture_Load("particles.png");if(!snd || !tex){// If one of the data files is not found, display// an error message and shutdown.MessageBox(NULL, "Can't load one of the following files:\nMENU.WAV, PARTICLES.PNG, FONT1.FNT, FONT1.PNG, TRAIL.PSI", "Error", MB_OK | MB_ICONERROR | MB_APPLMODAL);hge->System_Shutdown();hge->Release();return 0;}// Create and set up a spritespr=new hgeSprite(tex, 96, 64, 32, 32);spr->SetColor(0xFFFFA000);spr->SetHotSpot(16,16);// Load a fontfnt=new hgeFont("font1.fnt");// Create and set up a particle systemspt=new hgeSprite(tex, 32, 32, 32, 32);spt->SetBlendMode(BLEND_COLORMUL | BLEND_ALPHAADD | BLEND_NOZWRITE);spt->SetHotSpot(16,16);par=new hgeParticleSystem("trail.psi",spt); //加载粒子系统par->Fire();// Let's rock now!hge->System_Start();// Delete created objects and free loaded resourcesdelete par;delete fnt;delete spt;delete spr;hge->Texture_Free(tex);hge->Effect_Free(snd);}// Clean up and shutdownhge->System_Shutdown();hge->Release();return 0;}