Yeah, I had to experiment with how key checking was done because it was not directly working correctly with the format where it checked to see if a key was up or down. I ended up having to put in variables press_u, press_d, press_l, and press_r to hold Boolean values and that ended up working differently. I don't really know fully why you can go faster by tapping the keys, it may just be how it processes. As for the source, it is just:
//The headers
#include "SDL/SDL.h"
#include "SDL/SDL_image.h"
#include <string>
//The screen attributes
const int SCREEN_WIDTH = 160;
const int SCREEN_HEIGHT = 144;
const int SCREEN_BPP = 32;
//The frame rate
const int FRAMES_PER_SECOND = 30;
//The dimensions of the dot
const int DOT_WIDTH = 16;
const int DOT_HEIGHT = 16;
//The surfaces
SDL_Surface *dot = NULL;
SDL_Surface *screen = NULL;
SDL_Rect clipsUp[ 4 ];
SDL_Rect clipsDown[ 4 ];
SDL_Rect clipsLeft[ 4 ];
SDL_Rect clipsRight[ 4 ];
//The event structure
SDL_Event event;
//The dot that will move around on the screen
class Dot
{
private:
//The X and Y offsets of the dot
int x, y, xprev, yprev;
//Psuedo-Keys
bool press_u, press_d, press_l, press_r;
//Direction Temp
int d;
//Animation Rate
int anima;
//Image Index
int index;
public:
//Initializes the variables
Dot();
//Moves the dot
void move();
//Shows the dot on the screen
void show();
};
//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, 255, 0, 255 ) );
}
}
//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 );
}
void set_clips()
{
//Up Sprites
clipsUp[ 0 ].x = 0;
clipsUp[ 0 ].y = 0;
clipsUp[ 0 ].w = DOT_WIDTH;
clipsUp[ 0 ].h = DOT_HEIGHT;
clipsUp[ 1 ].x = DOT_WIDTH;
clipsUp[ 1 ].y = 0;
clipsUp[ 1 ].w = DOT_WIDTH;
clipsUp[ 1 ].h = DOT_HEIGHT;
clipsUp[ 2 ].x = DOT_WIDTH * 2;
clipsUp[ 2 ].y = 0;
clipsUp[ 2 ].w = DOT_WIDTH;
clipsUp[ 2 ].h = DOT_HEIGHT;
clipsUp[ 3 ].x = DOT_WIDTH * 3;
clipsUp[ 3 ].y = 0;
clipsUp[ 3 ].w = DOT_WIDTH;
clipsUp[ 3 ].h = DOT_HEIGHT;
//Down Sprites
clipsDown[ 0 ].x = 0;
clipsDown[ 0 ].y = DOT_HEIGHT;
clipsDown[ 0 ].w = DOT_WIDTH;
clipsDown[ 0 ].h = DOT_HEIGHT;
clipsDown[ 1 ].x = DOT_WIDTH;
clipsDown[ 1 ].y = DOT_HEIGHT;
clipsDown[ 1 ].w = DOT_WIDTH;
clipsDown[ 1 ].h = DOT_HEIGHT;
clipsDown[ 2 ].x = DOT_WIDTH * 2;
clipsDown[ 2 ].y = DOT_HEIGHT;
clipsDown[ 2 ].w = DOT_WIDTH;
clipsDown[ 2 ].h = DOT_HEIGHT;
clipsDown[ 3 ].x = DOT_WIDTH * 3;
clipsDown[ 3 ].y = DOT_HEIGHT;
clipsDown[ 3 ].w = DOT_WIDTH;
clipsDown[ 3 ].h = DOT_HEIGHT;
//Left Sprites
clipsLeft[ 0 ].x = 0;
clipsLeft[ 0 ].y = DOT_HEIGHT * 2;
clipsLeft[ 0 ].w = DOT_WIDTH;
clipsLeft[ 0 ].h = DOT_HEIGHT;
clipsLeft[ 1 ].x = DOT_WIDTH;
clipsLeft[ 1 ].y = DOT_HEIGHT * 2;
clipsLeft[ 1 ].w = DOT_WIDTH;
clipsLeft[ 1 ].h = DOT_HEIGHT;
clipsLeft[ 2 ].x = DOT_WIDTH * 2;
clipsLeft[ 2 ].y = DOT_HEIGHT * 2;
clipsLeft[ 2 ].w = DOT_WIDTH;
clipsLeft[ 2 ].h = DOT_HEIGHT;
clipsLeft[ 3 ].x = DOT_WIDTH * 3;
clipsLeft[ 3 ].y = DOT_HEIGHT * 2;
clipsLeft[ 3 ].w = DOT_WIDTH;
clipsLeft[ 3 ].h = DOT_HEIGHT;
//Right Sprites
clipsRight[ 0 ].x = 0;
clipsRight[ 0 ].y = DOT_HEIGHT * 3;
clipsRight[ 0 ].w = DOT_WIDTH;
clipsRight[ 0 ].h = DOT_HEIGHT;
clipsRight[ 1 ].x = DOT_WIDTH;
clipsRight[ 1 ].y = DOT_HEIGHT * 3;
clipsRight[ 1 ].w = DOT_WIDTH;
clipsRight[ 1 ].h = DOT_HEIGHT;
clipsRight[ 2 ].x = DOT_WIDTH * 2;
clipsRight[ 2 ].y = DOT_HEIGHT * 3;
clipsRight[ 2 ].w = DOT_WIDTH;
clipsRight[ 2 ].h = DOT_HEIGHT;
clipsRight[ 3 ].x = DOT_WIDTH * 3;
clipsRight[ 3 ].y = DOT_HEIGHT * 3;
clipsRight[ 3 ].w = DOT_WIDTH;
clipsRight[ 3 ].h = DOT_HEIGHT;
}
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( "Pokemon Blue SDL", NULL );
//If everything initialized fine
return true;
}
bool load_files()
{
//Load the dot image
dot = load_image( "character.bmp" );
//If there was a problem in loading the dot
if( dot == NULL )
{
return false;
}
//If everything loaded fine
return true;
}
void clean_up()
{
//Free the surface
SDL_FreeSurface( dot );
//Quit SDL
SDL_Quit();
}
Dot::Dot()
{
//Initialize the offsets
x = 0;
y = 0;
xprev = 0;
yprev = 0;
d = 1;
anima = 0;
index = 0;
press_u = false;
press_d = false;
press_l = false;
press_r = false;
}
void Dot::move()
{
//If a key was pressed
if( event.type == SDL_KEYDOWN )
{
switch( event.key.keysym.sym )
{
case SDLK_UP: press_u = true;; break;
case SDLK_DOWN: press_d = true; break;
case SDLK_LEFT: press_l = true; break;
case SDLK_RIGHT: press_r = true; break;
}
}
else if( event.type == SDL_KEYUP )
{
switch( event.key.keysym.sym )
{
case SDLK_UP: press_u = false; break;
case SDLK_DOWN: press_d = false; break;
case SDLK_LEFT: press_l = false; break;
case SDLK_RIGHT: press_r = false; break;
}
}
if (x % 16 == 0 && y % 16 == 0)
{
//if (xprev != x || yprev != y)
//{
xprev = x;
yprev = y;
//return;
//}
if (press_u)
{
y -= 2;
d = 0;
if (index % 2 != 0 && index < 4)
{
index++;
}
anima = 1;
return;
}
else if (press_d)
{
y += 2;
d = 1;
if (index % 2 != 0 && index < 4)
{
index++;
}
anima = 1;
return;
}
else if (press_l)
{
x -= 2;
d = 2;
if (index % 2 != 0 && index < 4)
{
index++;
}
anima = 1;
return;
}
else if (press_r)
{
x += 2;
d = 3;
if (index % 2 != 0 && index < 4)
{
index++;
}
anima = 1;
return;
}
else if (!press_u && !press_d && !press_l && !press_r)
{
if (index % 2 != 0 && index < 4)
{
index++;
return;
}
if (index % 2 == 0)
{
anima = 0;
return;
}
}
}
else
{
switch (d)
{
case 0: y -= 2; anima++; return; break;
case 1: y += 2; anima++; return; break;
case 2: x -= 2; anima++; return; break;
case 3: x += 2; anima++; return; break;
}
}
}
void Dot::show()
{
if (index == 4)
{
index = 0;
}
switch (d)
{
case 0: apply_surface( x, y - 4, dot, screen, &clipsUp[ index ] ); break;
case 1: apply_surface( x, y - 4, dot, screen, &clipsDown[ index ] ); break;
case 2: apply_surface( x, y - 4, dot, screen, &clipsLeft[ index ] ); break;
case 3: apply_surface( x, y - 4, dot, screen, &clipsRight[ index ] ); break;
}
if (anima == 3)
{
if (index <= 3)
{
index++;
}
if (index == 4)
{
index = 0;
}
return;
}
else if (anima == 4)
{
anima = 0;
return;
}
}
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 dot that will be used
Dot myDot;
set_clips();
//The frame rate regulator
Timer fps;
//Initialize
if( init() == false )
{
return 1;
}
//Load the files
if( load_files() == false )
{
return 1;
}
//While the user hasn't quit
while( quit == false )
{
//Start the frame timer
fps.start();
//While there's events to handle
while( SDL_PollEvent( &event ) )
{
//Handle events for the dot
myDot.move();
//If the user has Xed out the window
if( event.type == SDL_QUIT )
{
//Quit the program
quit = true;
}
}
//Fill the screen white
SDL_FillRect( screen, &screen->clip_rect, SDL_MapRGB( screen->format, 248, 248, 248 ) );
//Move the dot
myDot.move();
//Show the dot on the screen
myDot.show();
//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;
}
Yeah, I just modified the dot movement Lazy Foo tutorial from that project page so that it moved in a grid and would animate. It isn't that great and probably has redundancies in it due to that I was just seeing if I could get it to work.
