Mapcreator for the simple sidescroller(SDL) - mapcreator.cpp

//This example program is created by thecplusplusuy for demonstration purposes (no video about this, I think, it's too simple, and not show nothing new, but I put the source up, to make a complete program with the simple sidescroller (there is video about that)). It's a map-creator for the simple sidescroller game.
//http://www.youtube.com/user/thecplusplusguy
//Free source, modify if you want, LGPL licence (I guess), I would be happy, if you would not delete the link
//so other people can see the tutorial
//this file is mapcreator.cpp
#include "mapcreator.h" //we include the header, which we have created

mapcreator::mapcreator()
{
    SDL_Init(SDL_INIT_EVERYTHING);  //don't forget to initialize the SDL, it's allocate the needed memory. We initialize everything
    screen=SDL_SetVideoMode(640,480,32,SDL_SWSURFACE);  //open our window
    background=load_image("endless.bmp");   //open our 3 image
    blocks=load_image("blocks.bmp");
    enemy=load_image("enemy.bmp");
    enemy_rect.x=enemy_rect.y=0;    //we set the coordinate of the enemy (it's not animated when you make the map, only in the game)
    enemy_rect.w=enemy_rect.h=40;
    for(int i=0;i<NUMRECT;i++)  //we set the coordinate of the blocks (tiles)
    {
        blocks_rect[i].x=i*50;  //only the x coordinate is change
        blocks_rect[i].y=0;         //we have just 1 row of tiles
        blocks_rect[i].w=50;        //width=50
        blocks_rect[i].h=50;        //hight=50

    }
    current=0;  //we use the current block 0 (green grass for me :D)
    for(int i=0;i<10;i++)   //we make the default map (10*50=500 which is just a little bigger then the 480 height of the window)
    {
        std::vector<int> vec;   //the map is represented by a vector in a vector (a multidimensional dynamically allocated array)
        for(int j=0;j<13;j++)   //13*50=650 which is just a little bigger then the with of the window (640)
            vec.push_back(0);       //default we put nothing in everywhere
        map.push_back(vec);     //and than add it
    }
    coord.x=0;  //we set the default coordinates, nothing to explain here
    coord.y=0;
    coord.w=640;
    coord.h=480;
    camera.x=0;
    camera.y=0;
    camera.w=640;
    camera.h=480;
    timeshift=0;
}

mapcreator::~mapcreator()
{
    SDL_FreeSurface(background);    //free the surfaces and escape from SDL
    SDL_FreeSurface(blocks);
    SDL_FreeSurface(enemy);
    SDL_Quit();
}

void mapcreator::start()    //the main loop is in here
{
    Uint32 start;   //to regulate the FPS
    const int FPS=30;   //we use 30 FPS (if you want you can use SDL_WaitEvent, so you don't need to specify the FPS)
    bool running=true;  //is the program running?
    SDL_Event event;
    int x,y;    //the x,y coordinate of the mouse cursor relative to the window
    while(running)
    {
        start=SDL_GetTicks();   //we fill start with the current time
        while(SDL_PollEvent(&event))    //while there are events
        {
            switch(event.type)  //which event is it?
            {
                case SDL_QUIT:
                    running=0;  //if we exited, exit from the program
                    break;
                case SDL_MOUSEBUTTONDOWN:   //if a mouse button is down then
                    if(event.button.button==SDL_BUTTON_RIGHT)   //if this button is the right mouse button
                    {
                        x=event.button.x;   //get the coordinate
                        y=event.button.y;
                        x=x-(x%50); //Little trickey, but basically we round down to the nearest 50 for example
                        y=y-(y%50); //if we are at 143 x coordinate then we set x to 100 if we are at 49 coordinate we set x to 0
                        //if we are at 50 coordinate we leave it as 50, we ded the same to y too.
                        current++;  //we increase the current (show the next block)
                        if(current>=NUMRECT)    //if we go too far, set it back to -2 (-2 enemy, -1 nothing)
                            current=-2;
                    }else if(event.button.button==SDL_BUTTON_LEFT)  //if the left button is pressed
                    {
                        x=event.button.x;   //get the current coordinates
                        y=event.button.y;
                        x=x-(x%50);//and do the same thing again with the x and y coordinates (round down to the nearest number dividable by 50)
                        y=y-(y%50);
                        map[((int)(y/50)+coord.y/50)][((int)(x/50)+coord.x/50)]=current+1;
                        //that's a little trickey again, but all we do in here is get the index for the tile, and then add our absolute coordinate to it
//for example, if we are at 0,0 coordinate, and we click at 150,200 coordinate, than change the map[3][4] coordinate to the current tile
//you may noticed, it's current+1, that's because originally the 0 is the nothing, and the first tile (according to C rules the 0th) is the 1st
//a little problem, nothing more. So another example, if we are at 1000,0 coordinate and we click at 150,200, than map[3][24]=current+1
                    }
                    break;
                case SDL_MOUSEMOTION:   //if we moved the mouse
                    x=event.motion.x;   //we get the coordinates again
                    y=event.motion.y;
                    x=x-(x%50); //and we round to the nearest 50 again
                    y=y-(y%50);
                    break;
                    case SDL_KEYDOWN:
                        if(event.key.keysym.sym==SDLK_s)    //if the s key is down
                            save(); //save the map
                        break;
            }
        }
//      std::cout << x << std::endl;
                    if(x>550)   //if we are at the right edge of the screen
                    {
                        if(timeshift==0)    //and the timeshift is 0
                        {
                            timeshift=20;   //change it to 20 (it's mean, that we move the camera 20 frame later)
                            coord.x+=50;    //move the camera
                            camera.x+=50; //move the camera
                            if(camera.x>=2000-640)  //if the background have to be reapeted
                                camera.x=0; //repeat it
                            for(int i=0;i<map.size();i++)   //we add on coloumn of nothing to the end of the map
                            {
                                map[i].push_back(0);
                            }
                        }else
                            timeshift--;    //just decrease the timeshift every time, it's not equal to 0
                    }
                    if(x<50 && coord.x>=50) //we do the same thing in the other direction too
                    {
                        if(timeshift==0)
                        {
                            timeshift=20;
                            coord.x-=50;
                            camera.x-=50;
                            if(camera.x<=0)
                                camera.x=2000-640;
                        }else
                            timeshift--;
                    }

        SDL_BlitSurface(background,&camera,screen,NULL);    //we draw the background at the correct position
                                                                                                            //(watch the scrollable background tutorial, if it's not clear
        showmap();  //and we show the map
        SDL_Rect tmp={x,y};
        if(current>=0)  //if the current is not 0 (or less then except the enemy)
            SDL_BlitSurface(blocks,&blocks_rect[current],screen,&tmp);  //draw the block, which we are holding to the position of the mouse cursor
        else if(current==-2)    //if it's an enemy
            SDL_BlitSurface(enemy,&enemy_rect,screen,&tmp); //draw it
        SDL_Flip(screen);   //show the screen
        if(1000/FPS>(SDL_GetTicks()-start)) //regulate the FPS (watch regulate FPS tutorial, if it's not clear)
            SDL_Delay(1000/FPS-(SDL_GetTicks()-start));
    }
}

SDL_Surface* mapcreator::load_image(const char* c)  //load the image
{
    SDL_Surface* tmp=SDL_LoadBMP(c);    //load the BMP file
    SDL_Surface* tmp2=SDL_DisplayFormat(tmp);   //then convert it to the format of the screen
    SDL_FreeSurface(tmp);   //free it, we don't need it anymore
    SDL_SetColorKey(tmp2,SDL_SRCCOLORKEY,SDL_MapRGB(screen->format,0x00,0xff,0xff)); //set a color key, so 00ffff is transparent
    return tmp2;    //return a pointer to the surface
}

void mapcreator::showmap()
{
    //it should be familiar to you, because basically it's the same as in the sidescroller game
    int start=(coord.x-(coord.x%50))/50;    //calculate the first number which is dividable by 50 and it's in the screen
    int end=(coord.x+coord.w+(50-(coord.x+coord.w)%50))/50; //round last number, dividable by 50, which is in the screen
    if(end>map[0].size())   //if the end is too big
        end=map[0].size();  //set it to the size of the map
    if(start<0) //if start is too small
        start=0;    //set it to the first element
    for(int i=0;i<map.size();i++)
        for(int j=0;j<map[0].size();j++)    //go through the visible map
            if(map[i][j]!=0)    //if it's not "nothing"
            {
                if(map[i][j]==-1)   //if it's an enemy
                {
                    //draw it
                    SDL_Rect blockrect = {0,0,40,40};
                    SDL_Rect destrect= {j*50-coord.x,i*50};
                    SDL_BlitSurface(enemy,&blockrect,screen,&destrect);
                        continue;   //and don't draw anything else
                }
                //else draw the block which is needed
                SDL_Rect blockrect = {(map[i][j]-1)*50,0,50,50};
                SDL_Rect destrect= {j*50-coord.x,i*50};
                SDL_BlitSurface(blocks,&blockrect,screen,&destrect);
            }
}


void mapcreator::save()
{
    char c[30]; //filename
    sprintf(c,"%d",time(0));    //we use the current time in seconds from 1970.01.01 (it's always changing, so every time it will get a uniqe filename)
    //pretty basic, but easy and fairly effective
    strcat(c,".map");   //we cat the map extension to the end of the number
    std::ofstream out(c);   //open the filestream for output with the current name
//  std::cout << "Saved" << std::endl;
    out << map[0].size() << " " << map.size() << std::endl; //first we write out the size of the map
    for(int i=0;i<map.size();i++)   //go through the array
    {
        for(int j=0;j<map[0].size();j++)
        {
            out << map[i][j] << " ";    //and write the tile number separated by space
        }
        out << std::endl;
    }
}