So im using the source code off a tutorial to learn and add a feature to drop a block.
Ive learned so much so fra but now ive come to a dead end!
You move with the arrow keys- works
You press space to show the block- doesnt work

heres my code:

/*This source code copyrighted by Lazy Foo' Productions (2004-2012)
and may not be redestributed without written permission.*/

//The headers
#include "SDL.h"
#include "SDL_image.h"
#include <string>

//Class files
#include "player.cpp"
#include "drop.cpp"

//Screen attributes
const int SCREEN_WIDTH = 640;
const int SCREEN_HEIGHT = 480;
const int SCREEN_BPP = 32;

//The frame rate
const int FRAMES_PER_SECOND = 32;

//The attributes of the square
const int SQUARE_WIDTH = 20;
const int SQUARE_HEIGHT = 20;

//The attributes of the block
const int BLOCK_WIDTH = 30;
const int BLOCK_HEIGHT = 30;

//The surfaces
SDL_Surface *square = NULL;
SDL_Surface *block = NULL;
SDL_Surface *screen = NULL;

//The event structure
SDL_Event event;

//The wall
SDL_Rect wall;

//Other wall
SDL_Rect wall2;

//The timer
class Timer
{
    private:
    //The clock time when the timer started
    int startTicks;

    //The ticks stored when the timer was paused
    int pausedTicks;

    //The timer status
    bool paused;
    bool started;

    public:
    //Initializes variables
    Timer();

    //The various clock actions
    void start();
    void stop();
    void pause();
    void unpause();

    //Gets the timer's time
    int get_ticks();

    //Checks the status of the timer
    bool is_started();
    bool is_paused();
};

SDL_Surface *load_image( std::string filename )
{
    //The image that's loaded
    SDL_Surface* loadedImage = NULL;

    //The optimized surface that will be used
    SDL_Surface* optimizedImage = NULL;

    //Load the image
    loadedImage = IMG_Load( filename.c_str() );

    //If the image loaded
    if( loadedImage != NULL )
    {
        //Create an optimized surface
        optimizedImage = SDL_DisplayFormat( loadedImage );

        //Free the old surface
        SDL_FreeSurface( loadedImage );

        //If the surface was optimized
        if( optimizedImage != NULL )
        {
            //Color key surface
            SDL_SetColorKey( optimizedImage, SDL_SRCCOLORKEY, SDL_MapRGB( optimizedImage->format, 0, 0xFF, 0xFF ) );
        }
    }

    //Return the optimized surface
    return optimizedImage;
}

void apply_surface( int x, int y, SDL_Surface* source, SDL_Surface* destination, SDL_Rect* clip = NULL )
{
    //Holds offsets
    SDL_Rect offset;

    //Get offsets
    offset.x = x;
    offset.y = y;

    //Blit
    SDL_BlitSurface( source, clip, destination, &offset );
}

bool check_collision( SDL_Rect A, SDL_Rect B )
{
    //The sides of the rectangles
    int leftA, leftB;
    int rightA, rightB;
    int topA, topB;
    int bottomA, bottomB;

    //Calculate the sides of rect A
    leftA = A.x;
    rightA = A.x + A.w;
    topA = A.y;
    bottomA = A.y + A.h;

    //Calculate the sides of rect B
    leftB = B.x;
    rightB = B.x + B.w;
    topB = B.y;
    bottomB = B.y + B.h;

    //If any of the sides from A are outside of B
    if( bottomA <= topB )
    {
        return false;
    }

    if( topA >= bottomB )
    {
        return false;
    }

    if( rightA <= leftB )
    {
        return false;
    }

    if( leftA >= rightB )
    {
        return false;
    }

    //If none of the sides from A are outside B
    return true;
}

bool init()
{
    //Initialize all SDL subsystems
    if( SDL_Init( SDL_INIT_EVERYTHING ) == -1 )
    {
        return false;
    }

    //Set up the screen
    screen = SDL_SetVideoMode( SCREEN_WIDTH, SCREEN_HEIGHT, SCREEN_BPP, SDL_SWSURFACE );

    //If there was an error in setting up the screen
    if( screen == NULL )
    {
        return false;
    }

    //Set the window caption
    SDL_WM_SetCaption( "Move the Square", NULL );

    //If everything initialized fine
    return true;
}

bool load_files()
{
    //Load the square image
    square = load_image( "square.bmp" );
    block = load_image( "block.bmp" );
    //If there was a problem in loading the square
    if( square == NULL )
    {
        return false;
    }

    //If everything loaded fine
    return true;// makes the bool true meaning load_files() is true(completed succesfully)
}

void clean_up()
{
    //Free the surface
    SDL_FreeSurface( square );
    SDL_FreeSurface( block );

    //Quit SDL
    SDL_Quit();
}

Square::Square()
{
    //Initialize the offsets
    box.x = 0;
    box.y = 0;

    //Set the square's dimentions
    box.w = SQUARE_WIDTH;
    box.h = SQUARE_HEIGHT;

    //Initialize the velocity
    xVel = 0;
    yVel = 0;
}

void Square::handle_input()
{
    //If a key was pressed
    if( event.type == SDL_KEYDOWN )
    {
        //Adjust the velocity
        switch( event.key.keysym.sym )
        {
            case SDLK_UP: yVel -= SQUARE_HEIGHT / 2; break;
            case SDLK_DOWN: yVel += SQUARE_HEIGHT / 2; break;
            case SDLK_LEFT: xVel -= SQUARE_WIDTH / 2; break;
            case SDLK_RIGHT: xVel += SQUARE_WIDTH / 2; break;
        }
    }
    //If a key was released
    else if( event.type == SDL_KEYUP )
    {
        //Adjust the velocity
        switch( event.key.keysym.sym )
        {
            case SDLK_UP: yVel += SQUARE_HEIGHT / 2; break;
            case SDLK_DOWN: yVel -= SQUARE_HEIGHT / 2; break;
            case SDLK_LEFT: xVel += SQUARE_WIDTH / 2; break;
            case SDLK_RIGHT: xVel -= SQUARE_WIDTH / 2; break;
        }
    }
}

void Square::move()
{
    //Move the square left or right
    box.x += xVel;

    //If the square went too far to the left or right or has collided with the wall
    if( ( box.x < 0 ) || ( box.x + SQUARE_WIDTH > SCREEN_WIDTH ) ||
       ( check_collision( box, wall ) ) ||
       ( check_collision( box, wall2 ) ) )
    {
        //Move back
        box.x -= xVel;
    }

    //Move the square up or down
    box.y += yVel;

    //If the square went too far up or down or has collided with the wall
    if( ( box.y < 0 ) || ( box.y + SQUARE_HEIGHT > SCREEN_HEIGHT ) ||
       ( check_collision( box, wall ) )  ||
       ( check_collision( box, wall2 ) ) )
    {
        //Move back
        box.y -= yVel;
    }
}

void Square::show()
{
    //Show the square
    apply_surface( box.x, box.y, square, screen );
}


Block::Block()
{
    //Initialize the offsets
    blockBox.x = 200;
    blockBox.y = 300;

    //Set the blocks dimentions
    blockBox.w = BLOCK_WIDTH;
    blockBox.h = BLOCK_HEIGHT;

    bool drop = false;
}

void Block::input_drop()
{
    //If a key was pressed
    if( event.type == SDL_KEYDOWN )
    {
        //Adjust the velocity
        switch( event.key.keysym.sym )
        {
            case SDLK_SPACE: drop == true; break;
        }
    }
    //If a key was released
    else if( event.type == SDL_KEYUP )
    {
        //Adjust the velocity
        switch( event.key.keysym.sym )
        {
            case SDLK_SPACE: drop == false; break;
        }
    }
}

void Block::doDrop(){
    oldx == 100;
    oldy == 130;
    bool dropped = true;
}

void Block::showBlock(){
    if (drop == true){
    apply_surface( blockBox.x, blockBox.y, block, screen );
    }
}

//End class functions
Timer::Timer()
{
    //Initialize the variables
    startTicks = 0;
    pausedTicks = 0;
    paused = false;
    started = false;
}

void Timer::start()
{
    //Start the timer
    started = true;

    //Unpause the timer
    paused = false;

    //Get the current clock time
    startTicks = SDL_GetTicks();
}

void Timer::stop()
{
    //Stop the timer
    started = false;

    //Unpause the timer
    paused = false;
}

void Timer::pause()
{
    //If the timer is running and isn't already paused
    if( ( started == true ) && ( paused == false ) )
    {
        //Pause the timer
        paused = true;

        //Calculate the paused ticks
        pausedTicks = SDL_GetTicks() - startTicks;
    }
}

void Timer::unpause()
{
    //If the timer is paused
    if( paused == true )
    {
        //Unpause the timer
        paused = false;

        //Reset the starting ticks
        startTicks = SDL_GetTicks() - pausedTicks;

        //Reset the paused ticks
        pausedTicks = 0;
    }
}

int Timer::get_ticks()
{
    //If the timer is running
    if( started == true )
    {
        //If the timer is paused
        if( paused == true )
        {
            //Return the number of ticks when the timer was paused
            return pausedTicks;
        }
        else
        {
            //Return the current time minus the start time
            return SDL_GetTicks() - startTicks;
        }
    }

    //If the timer isn't running
    return 0;
}

bool Timer::is_started()
{
    return started;
}

bool Timer::is_paused()
{
    return paused;
}

int main( int argc, char* args[] )
{
    //Quit flag
    bool quit = false;

    //The square
    Square mySquare;

    //The block
    Block myBlock;

    //The frame rate regulator
    Timer fps;

    //Initialize
    if( init() == false )
    {
        return 1;
    }

    //Load the files
    if( load_files() == false )
    {
        return 1;
    }

    //Set the right wall
    wall.x = 300;
    wall.y = 40;
    wall.w = 40;
    wall.h = 400;

    //Set the top wall
    wall2.x = 100;
    wall2.y = 40;
    wall2.w = 200;
    wall2.h = 40;

    //While the user hasn't quit
    while( quit == false )
    {
        //Start the frame timer//COUNTS EACH FRAME?? SO THIS CODE RUNS ONCE PER FRAME?
        fps.start();

        //While there's events to handle
        while( SDL_PollEvent( &event ) )
        {
            //Handle events for the square
            mySquare.handle_input();
            myBlock.input_drop();

            //If the user has Xed out the window
            if( event.type == SDL_QUIT )
            {
                //Quit the program
                quit = true;
            }
        }

        //Move the square
        mySquare.move();
        //Do the drop stuff
        myBlock.doDrop();

        //Fill the screen white
        SDL_FillRect( screen, &screen->clip_rect, SDL_MapRGB( screen->format, 0xFF, 0xFF, 0xFF ) );

        //Show the wall
        SDL_FillRect( screen, &wall, SDL_MapRGB( screen->format, 0x77, 0x77, 0x77 ) );

        //Show the other wall
        SDL_FillRect( screen, &wall2, SDL_MapRGB( screen->format, 0x77, 0x77, 0x77 ) );

        //Show the square on the screen
        mySquare.show();
        //Show the dropped block on the screen
        myBlock.showBlock();

        //Update the screen
        if( SDL_Flip( screen ) == -1 )
        {
            return 1;
        }

        //Cap the frame rate
        if( fps.get_ticks() < 1000 / FRAMES_PER_SECOND )
        {
            SDL_Delay( ( 1000 / FRAMES_PER_SECOND ) - fps.get_ticks() );
        }
    }

    //Clean up
    clean_up();

    return 0;
}

I know not to copy and paste code and say "someone fix it" so all im asking is what looks wrong? its something to do Block::showBlock();

i know that the dropped block is in the same place everytime but thats only because im doing 1 step at a time, 1. input 2. do the drop 3. show the drop 4. save the drop position from the players coordinates.
All help appreciated :) btw im only 16 but ive learned so so much from this code!

Too long? yes!

Step 1, describe what the game does.
Step 2, tell us what is not working right.
Step 3, post only the relevant code (class structures help as well). In your case, you are including a lot of timing and other cruft that is probably totally unnecessary to deal with your problem.

This article has been dead for over six months. Start a new discussion instead.