Example08_SpriteCollision.cpp

/*--------------------------------------------
   Examples - CRM32Pro SDK - Roberto Prieto
   Copyright (C) 2001-2011 MegaStorm Systems
  --------------------------------------------

  Example 8: Sprites collision
  ----------------------------
  - Initialize SDL and CRM32Pro.
  - Printing help on a window.
  - Use of log system.
  - Initialize graphics: window icon, video mode and cursor.
  - Load resources from DPF: images(IPF), fonts and sprite
  - Image following the mouse cursor.
  - Using Fixed Logic Rate.
  - With F1 key, you can enable/disable collision system.
  - Information panel with FPS(real time) and number of collisions.
  - Exiting using the right way ;)

  This example is totally free and can be used without 
any restriction but there is not any warranty for its usage.
Please, do not forget to include a copy of all the library licenses
located at /licenses directory if you distribute or share it.

Roberto Prieto
contact@megastormsystems.com
http://www.megastormsystems.com
*/

// ---Includes---
#include "CRM32Pro.h"

// ---Defines---
#define EXAMPLE_VERSION "Example 8: Sprites Collision"
#define GFX_RESOURCE "data/gfx.dpf"     // DPF with graphic resources

// ---Prototypes---
void RenderGraphics(int);
void RenderGraphicsGL(int);
void PrintHelp();

// ---Global vars---
SDL_Surface *bg, *info, *backinfo, *surfCursor;
CRM32Pro_CFont *fInfo;
CRM32Pro_CSprite *sprRabbit;
SDL_Rect inf, rCursor;
Uint32 last = 0, lastinfo = 0;
Uint8 bFlagCollision = 1;

// -------------MAIN FUNCTION----------------
int main(int argc,char *argv[])
{
    Uint8       done = 0;
    int         DirX = 1, DirY = 1, SprX = 100, SprY = 100;
    SDL_Event   event;

    // -Print help on a window-
    PrintHelp();

    // -Log system initialize-    
    ILogSystem.Init("SpriteCollision.log",LOG_FILE,LOG_NORMAL,EXAMPLE_VERSION);

    // -CRM32Pro and SDL initialize-   
    if(CRM32Pro.Init(SDL_INIT_VIDEO | SDL_INIT_AUDIO | SDL_INIT_TIMER) < 0)
    {
        ILogSystem.Msg(LOG_NORMAL," · [LOG] - Couldn´t initialize CRM32Pro: %s\n",SDL_GetError()); 
        return 1;
    }      

    // -Desired config-
    CRM32Pro.Config.Title = EXAMPLE_VERSION;
    CRM32Pro.Config.Icon = IImage->Load(GFX_RESOURCE,"icono");
    CRM32Pro.Config.bMTFriendly = 1;
    //CRM32Pro.Config.VideoRenderer = RENDER_OPENGL;
    //CRM32Pro.Config.VideoAccel = ACCEL_HARDSMOOTH ;

    // -Graphics system initialize-  
    if(!CRM32Pro.SetVideoMode())
    {
        CRM32Pro.Quit();
        return 1;
    }

    // -Time system initialize-
    ITimeSystem->Init();
    ITimeSystem->SetRate(0,20);  // Optional: desired Rendering and Logic Frame Rate

    // -Set our render graphics function to fullfil desired Rendering Frame Rate-
    if(!CRM32Pro.IsGL()) CRM32Pro.SetRenderCallback(RenderGraphics);
    else CRM32Pro.SetRenderCallback(RenderGraphicsGL);

    // -Load resources: background, info panel, info font, sprite and image to follow the cursor-    
    bg = IImage->Load(GFX_RESOURCE,"background2");
    info = IImage->Load(GFX_RESOURCE,"info");
    inf.x = 6;inf.y = 6;inf.w = info->w;inf.h = info->h;
    backinfo = IImage->Load(GFX_RESOURCE,"info");      
    fInfo = new CRM32Pro_CFont();
    fInfo->Load(GFX_RESOURCE,"InfoFont");
    sprRabbit = new CRM32Pro_CSprite();
    sprRabbit->Load(GFX_RESOURCE,"rabbit");
    sprRabbit->AutoRestore(0);
    surfCursor = IImage->Load(GFX_RESOURCE,"Smiley");
    if(surfCursor == NULL) exit(1);
    rCursor.x = 100;rCursor.y = 110;rCursor.w = surfCursor->w;rCursor.h = surfCursor->h;

    // -Main loop-
    bFlagCollision = 1;
    done = 0;         
    while(!done)
    {                                       
        // 1.Logic frame stuff
        // Each logic frame (20 per seconds) we move the sprite. We assume that sprRabbit size is 64x64                  
        SprX = SprX + (2 * DirX);
        SprY = SprY + (2 * DirY);
        if((SprX + 64) > CRM32Pro.screen->w) DirX = DirX * (-1);
        if((SprY + 64) > CRM32Pro.screen->h) DirY = DirY * (-1);
        if(SprX < 2) DirX = DirX * (-1);
        if(SprY < 2) DirY = DirY * (-1);
        sprRabbit->SetPosition(SprX,SprY);

        // 2.Event loop: update all systems: graphics,events,timing...
        // surfCursor follow the position of mouse. With F1 activate/desactivate collision system. ESC exit.
        while(CRM32Pro.Update(&event))      
        {
            switch(event.type)
            {
            case SDL_KEYDOWN:
                if(event.key.keysym.sym == SDLK_ESCAPE) done = 1;
                if(event.key.keysym.sym == SDLK_F1) bFlagCollision = bFlagCollision * (-1);
                break;
            case SDL_MOUSEMOTION:
                rCursor.x = event.motion.x - rCursor.w / 2;
                rCursor.y = event.motion.y - rCursor.h / 2;
                // As we have moved the sprite that follows the cursor, we order a render update
                CRM32Pro.RenderNeeded();
                break;

            case SDL_QUIT:
                done = 1;
                break;
            case EVENT_LOGICWAIT:
                // While CRM32Pro.Update() wait for fulfill the logic rate this event is raised    
                // You could do some stuff here.
                // Is possible to call here to your Rendering Graphics after checking the user.code returned instead of using the CRM32Pro callback,
                // but it will have some extra overdraw.
                break;
            default:
                break;
            }
        }
    }

    // -Free resources, show information and exit-
    delete fInfo;   
    sprRabbit->Info();
    delete sprRabbit;
    CRM32Pro.FreeSurface(bg);
    CRM32Pro.FreeSurface(info);
    CRM32Pro.FreeSurface(backinfo);
    CRM32Pro.FreeSurface(surfCursor);
    ITimeSystem->Info();
    CRM32Pro.VideoInfo();
    CRM32Pro.Quit();
    return 0;
}

// ---Our render graphics function---
// We render our graphics if a logic frame occurred(bLogicUpdate = 1) or if CRM32Pro.IsRenderNeeded() return 1
void RenderGraphics(int bLogicUpdate)
{
    char  sTmp[16];
    int   isCollision = 0, nCollisions = 0;

    // Check if we need to render everything
    if(!CRM32Pro.IsRenderNeeded() && (!bLogicUpdate)) return;

    // Blit background
    SDL_BlitSurface(bg, NULL, CRM32Pro.screen, NULL);

    // Sprite blitting
    sprRabbit->Draw();

    // Detecting collisions
    nCollisions = 0;
    if(bFlagCollision == 1)
    {
        isCollision = sprRabbit->Collision(surfCursor,&rCursor,-1,-1,1);
        if(isCollision) nCollisions++;
    }
    // Image following the cursor blitting
    SDL_BlitSurface(surfCursor, NULL, CRM32Pro.screen, &rCursor);                                                                   

    // Blit information panel: state of collision system and FPS (four times per second)
    SDL_BlitSurface(info,NULL,CRM32Pro.screen,&inf);   
    if((lastinfo + 250) < ITimeSystem->GetTime())
    {
        lastinfo = ITimeSystem->GetTime();
        // Restore original info panel
        SDL_BlitSurface(backinfo,NULL,info,NULL);

        // Are we detecting collisions?                
        if(bFlagCollision == 1) fInfo->PutString(info,62,7,"ON");
        else
            fInfo->PutString(info,62,7,"OFF");

        // Frames per second (real time)
        sprintf(sTmp,"%d",(Uint32)ITimeSystem->GetCurrentRFR());
        fInfo->PutString(info,43,23,sTmp);

        // Print number of collisions
        sprintf(sTmp,"%d",nCollisions);
        fInfo->PutString(info,70,42,sTmp);
    }
}

// ---Our render graphics function for OpenGL mode---
// In OpenGL modes, blitting from a surface to another surface requires some conversions
// so the best workaround is just blit everything to CRM32Pro.screen surface.
// CRM32Pro.IsRenderNeeded() knows we are on an OpenGL mode so it will force to render everything
void RenderGraphicsGL(int bLogicUpdate)
{
    char  sTmp[16];
    int   isCollision = 0, nCollisions = 0;

    // Check if we need to render everything
    if(!CRM32Pro.IsRenderNeeded() && (!bLogicUpdate)) return;

    // Blit background
    SDL_BlitSurface(bg, NULL, CRM32Pro.screen, NULL);

    // Sprite blitting
    sprRabbit->Draw();

    // Detecting collisions
    nCollisions = 0;
    if(bFlagCollision == 1)
    {
        isCollision = sprRabbit->Collision(surfCursor,&rCursor,-1,-1,1);
        if(isCollision) nCollisions++;
    }

    // Image following the cursor blitting
    SDL_BlitSurface(surfCursor, NULL, CRM32Pro.screen, &rCursor);                                                                   

    // Blit information panel: state of collision system and FPS (four times per second)
    lastinfo = ITimeSystem->GetTime();
    // Restore original info panel
    SDL_BlitSurface(backinfo,NULL,CRM32Pro.screen,&inf);

    // Are we detecting collisions?                    
    if(bFlagCollision == 1) fInfo->PutString(CRM32Pro.screen,68,13,"ON");
    else   fInfo->PutString(CRM32Pro.screen,68,13,"OFF");

    // Frames per second (real time)
    sprintf(sTmp,"%d",(Uint32)ITimeSystem->GetCurrentRFR());
    fInfo->PutString(CRM32Pro.screen,49,29,sTmp);

    // Print number of collisions
    sprintf(sTmp,"%d",nCollisions);
    fInfo->PutString(CRM32Pro.screen,79,48,sTmp); 
}

// --------------------Help STUFF------------------------
// -Print help-
void PrintHelp()
{
    char *sMsg;

    // Create the message
    sMsg = new char[1024];
    strcpy(sMsg,"-----------------------------------------------------------\n");
    strcat(sMsg,"                     ");
    strcat(sMsg,EXAMPLE_VERSION);
    strcat(sMsg,"\n-----------------------------------------------------------\n\n");
    strcat(sMsg," Press [ESCAPE] key to exit.\n");
    strcat(sMsg," Press [F1] key to enable/disable collision detection.\n");
    strcat(sMsg,"\n Runtime information is logged into 'SpriteCollision.log' file.\n");
    strcat(sMsg,"\n");

    // Display the message
#ifdef _WINDOWS
    MessageBox(NULL,sMsg,"CRM32Pro SDK - HelpScreen",MB_OK);
#endif
#ifdef _LINUX 
    printf("CRM32Pro SDK - HelpScreen\n%s",sMsg);
#endif

    // Free the message
    delete sMsg;
}