hello i have a problem to set more than 3 image SDL surfaces into the screen.i make 4 objects in this :
SDL_Surface *foo = NULL;//as main player
SDL_Surface *dot = NULL;//as enemy artificial intelligence
SDL_Surface *background = NULL;//as game background
SDL_Surface *screen = NULL;//white screen
this is the code :
#include "SDL.h"
#include "SDL_image.h"
#include <string>
//Screen attributes
const int SCREEN_WIDTH = 640;
const int SCREEN_HEIGHT = 480;
const int SCREEN_BPP = 32;
//The frames per second
const int FRAMES_PER_SECOND = 5;
//The dimenstions of the stick figure
const int FOO_WIDTH = 80;
const int FOO_HEIGHT = 160;
const int DOT_WIDTH = 20;
const int DOT_HEIGHT = 20;
const int LEVEL_WIDTH = 1900;
const int LEVEL_HEIGHT = 960;
//The direction status of the stick figure
const int FOO_RIGHT = 0;
const int FOO_LEFT = 1;
const int FOO_FRONT = 2;
const int FOO_BACK = 3;
//The surfaces
SDL_Surface *foo = NULL;
SDL_Surface *dot = NULL;
SDL_Surface *background = NULL;
SDL_Surface *screen = NULL;
//The event structure
SDL_Event event;
//The areas of the sprite sheet
SDL_Rect clipsRight[ 2 ];
SDL_Rect clipsLeft[ 2 ];
SDL_Rect clipsFront[ 2 ];
SDL_Rect clipsBack[ 2 ];
SDL_Rect camera = { 0, 0, SCREEN_WIDTH, SCREEN_HEIGHT};
SDL_Rect wall;
SDL_Rect tree;
SDL_Rect treef;
SDL_Rect treeb;
//The stick figure
class Foo
{
private:
//The offset
SDL_Rect box;
//Its rate of movement
int xVel, yVel;
//Its current frame
int frame;
//Its animation status
int status;
public:
//Initializes the variables
Foo();
//Handles input
void handle_events();
//Moves the stick figure
void move();
//Shows the stick figure
void show();
void set_camera();
};
//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 )
{
Uint32 colorkey = SDL_MapRGB( optimizedImage->format, 0, 0xFF, 0xFF );
//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 );
}
void set_clips()
{
//Clip the sprites
clipsRight[ 0 ].x = 0;
clipsRight[ 0 ].y = 480;
clipsRight[ 0 ].w = FOO_WIDTH;
clipsRight[ 0 ].h = FOO_HEIGHT;
clipsRight[ 1 ].x = FOO_WIDTH;
clipsRight[ 1 ].y = 480;
clipsRight[ 1 ].w = FOO_WIDTH;
clipsRight[ 1 ].h = FOO_HEIGHT;
clipsLeft[ 0 ].x = 0;
clipsLeft[ 0 ].y = 320;
clipsLeft[ 0 ].w = FOO_WIDTH;
clipsLeft[ 0 ].h = FOO_HEIGHT;
clipsLeft[ 1 ].x = FOO_WIDTH;
clipsLeft[ 1 ].y = 320;
clipsLeft[ 1 ].w = FOO_WIDTH;
clipsLeft[ 1 ].h = FOO_HEIGHT;
clipsBack[ 0 ].x = 0;
clipsBack[ 0 ].y = 160;
clipsBack[ 0 ].w = FOO_WIDTH;
clipsBack[ 0 ].h = FOO_HEIGHT;
clipsBack[ 1 ].x = FOO_WIDTH;
clipsBack[ 1 ].y = 160;
clipsBack[ 1 ].w = FOO_WIDTH;
clipsBack[ 1 ].h = FOO_HEIGHT;
clipsFront[ 0 ].x = 0;
clipsFront[ 0 ].y = 0;
clipsFront[ 0 ].w = FOO_WIDTH;
clipsFront[ 0 ].h = FOO_HEIGHT;
clipsFront[ 1 ].x = FOO_WIDTH;
clipsFront[ 1 ].y = 0;
clipsFront[ 1 ].w = FOO_WIDTH;
clipsFront[ 1 ].h = FOO_HEIGHT;
}
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( "Animation Test", NULL );
//If everything initialized fine
return true;
}
bool load_files()
{
//Load the sprite sheet
foo = load_image( "player.png" );
//If there was a problem in loading the sprite
if( foo == NULL )
{
return false;
}
dot = load_image( "garden.bmp" );
if( dot = NULL )
{
return false;
}
background = load_image( "ground.png" );
if( background == NULL )
{
return false;
}
//If everything loaded fine
return true;
}
void clean_up()
{
//Free the surface
SDL_FreeSurface( background );
SDL_FreeSurface( dot );
SDL_FreeSurface( foo );
//Quit SDL
SDL_Quit();
}
Foo::Foo()
{
//Initialize movement variables
box.x = 0;
box.y = 250;
box.w = FOO_WIDTH;
box.h = FOO_HEIGHT;
xVel = 0;
yVel = 0;
//Initialize animation variables
frame = 0;
status = FOO_RIGHT;
}
void Foo::handle_events()
{
//If a key was pressed
if( event.type == SDL_KEYDOWN )
{
//Set the velocity
switch( event.key.keysym.sym )
{
case SDLK_RIGHT: xVel += FOO_WIDTH / 2; break;
case SDLK_LEFT: xVel -= FOO_WIDTH / 2; break;
case SDLK_UP: yVel -= FOO_HEIGHT / 2; break;
case SDLK_DOWN: yVel += FOO_HEIGHT / 2; break;
}
}
//If a key was released
else if( event.type == SDL_KEYUP )
{
//Set the velocity
switch( event.key.keysym.sym )
{
case SDLK_RIGHT: xVel -= FOO_WIDTH / 2; break;
case SDLK_LEFT: xVel += FOO_WIDTH / 2; break;
case SDLK_UP: yVel += FOO_HEIGHT / 2; break;
case SDLK_DOWN: yVel -= FOO_HEIGHT / 2; break;
}
}
}
void Foo::move()
{
//Move
box.x += xVel;
//Keep the stick figure in bounds
if( ( box.x < 0 ) || ( box.x + FOO_WIDTH > LEVEL_WIDTH ) || ( check_collision( box, wall ) ) || ( check_collision( box, tree ) ) || ( check_collision( box, treef ) ) || ( check_collision( box, treeb ) ) )
{
box.x -= xVel;
}
box.y += yVel;
if( ( box.y < 0 ) || ( box.y + FOO_HEIGHT > LEVEL_HEIGHT ) || ( check_collision( box, wall ) ) || ( check_collision( box, tree ) ) || ( check_collision( box, treef ) ) || ( check_collision( box, treeb ) ) )
{
box.y -= yVel;
}
}
void Foo::show()
{
//If Foo is moving left
if( xVel < 0 )
{
//Set the animation to left
status = FOO_LEFT;
//Move to the next frame in the animation
frame++;
}
//If Foo is moving right
else if( xVel > 0 )
{
//Set the animation to right
status = FOO_RIGHT;
//Move to the next frame in the animation
frame++;
}
else if(yVel > 0)
{
status = FOO_FRONT;
frame++;
}
else if(yVel < 0)
{
status = FOO_BACK;
frame++;
}
//If Foo standing
else
{
//Restart the animation
frame = 0;
}
//Loop the animation
if( frame >= 2 )
{
frame = 0;
}
//Show the stick figure
if( status == FOO_RIGHT )
{
apply_surface( box.x - camera.x, box.y - camera.y, foo, screen, &clipsRight[ frame ] );
}
else if( status == FOO_LEFT )
{
apply_surface( box.x - camera.x, box.y - camera.y, foo, screen, &clipsLeft[ frame ] );
}
else if( status == FOO_FRONT )
{
apply_surface( box.x - camera.x, box.y - camera.y, foo, screen, &clipsFront[ frame ] );
}
else if( status == FOO_BACK )
{
apply_surface( box.x - camera.x, box.y - camera.y, foo, screen, &clipsBack[ frame ] );
}
}
void Foo::set_camera()
{
camera.x = (box.x + FOO_WIDTH/2) - SCREEN_WIDTH/2;
camera.y = (box.y + FOO_HEIGHT/2) - SCREEN_HEIGHT/2;
//Keep the camera in bounds.
if( camera.x < 0 )
{
camera.x = 0;
}
if( camera.y < 0 )
{
camera.y = 0;
}
if( camera.x > LEVEL_WIDTH - camera.w )
{
camera.x = LEVEL_WIDTH - camera.w;
}
if( camera.y > LEVEL_HEIGHT - camera.h )
{
camera.y = LEVEL_HEIGHT - camera.h;
}
}
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;
//Initialize
if( init() == false )
{
return 1;
}
//Load the files
if( load_files() == false )
{
return 1;
}
wall.x = 800;
wall.y = 30;
wall.w = 60;
wall.h = 200;
tree.x = 400;
tree.y = 50;
tree.w = 60;
tree.h = 200;
treef.x = 1400;
treef.y = 200;
treef.w = 120;
treef.h = 500;
treeb.x = 1500;
treeb.y = 500;
treeb.w = 400;
treeb.h = 150;
//Clip the sprite sheet
set_clips();
//The frame rate regulator
Timer fps;
//The stick figure
Foo walk;
//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 stick figure
walk.handle_events();
//If the user has Xed out the window
if( event.type == SDL_QUIT )
{
//Quit the program
quit = true;
}
}
//Move the stick figure
walk.move();
walk.set_camera();
//Fill the screen white
SDL_FillRect( screen, &screen->clip_rect, SDL_MapRGB( screen->format, 0xFF, 0xFF, 0xFF ) );
//Show the stick figure on the screen
apply_surface( 0, 0, background, screen, &camera );
walk.show();
apply_surface( 0, 0, dot, screen );//HERE I CAN'T APPLY DOT SURFACE
//Update the screen
if( SDL_Flip( screen ) == -1 )
{
return 1;
}
//Cap the frame rate
if( fps.get_ticks() < 500 / FRAMES_PER_SECOND )
{
SDL_Delay( ( 700 / FRAMES_PER_SECOND ) - fps.get_ticks() );
}
}
//Clean up
clean_up();
return 0;
}
look on the main entry : i can’t apply dot surface on my background.the output didn’t display dot object as my third sprite.why i can’t apply more than 3 images/sprites in SDL?