Pausing My Program
Author
I use Visual Studio C++ Express and SDL. I am making a simple program that makes a sprite walk when the user presses the left or right keys, but when I run the .exe it just flashes up and doesn't wait for me to quit before closing. I have a loop that is not supposed to close the program until the user presses the backspace key, but it isn't working. Also I tried system("pause"); and cin.get(); and neither are working.
Post your code.
system("pause") will probably fail because the process has no standard input stream, as will std::cin.get().
system("pause") will probably fail because the process has no standard input stream, as will std::cin.get().
Author
Here is the main file of my program. The timer and squirrel headers don't really matter they are just the class definitions for the sprite and the timer.
[Edited by - 13moonsago on March 7, 2008 9:22:46 AM]
#include "SDL/SDL.h"#include "SDL/SDL_image.h"#include "Timer.h"#include "Squirrel.h"#include <string>using namespace std;//The surfacesSDL_Surface *squirrel = NULL;SDL_Surface *screen = NULL;//The event structureSDL_Event event;//The areas of the sprite sheetSDL_Rect clipsNoKnifeRight[CLIPS];SDL_Rect clipsNoKnifeLeft[CLIPS];SDL_Rect clipsKnifeRight[CLIPS];SDL_Rect clipsKnifeLeft[CLIPS];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, 0)); } } //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 for(int count = 0; count < 4; count++) { clipsNoKnifeRight[count].x = (SQUIRREL_WIDTH * count); clipsNoKnifeRight[count].y = 0; clipsNoKnifeRight[count].w = SQUIRREL_WIDTH; clipsNoKnifeRight[count].h = SQUIRREL_HEIGHT; } for(int count = 4; count < 8; count++) { clipsNoKnifeLeft[(count - 4)].x = (SQUIRREL_WIDTH * count); clipsNoKnifeLeft[(count - 4)].y = 0; clipsNoKnifeLeft[(count - 4)].w = SQUIRREL_WIDTH; clipsNoKnifeLeft[(count - 4)].h = SQUIRREL_HEIGHT; } for(int count = 0; count < 4; count++) { clipsKnifeRight[count].x = (SQUIRREL_WIDTH * count); clipsKnifeRight[count].y = SQUIRREL_HEIGHT; clipsKnifeRight[count].w = SQUIRREL_WIDTH; clipsKnifeRight[count].h = SQUIRREL_HEIGHT; } for(int count = 4; count < 8; count++) { clipsKnifeLeft[(count - 4)].x = (SQUIRREL_WIDTH * count); clipsKnifeLeft[(count - 4)].y = SQUIRREL_HEIGHT; clipsKnifeLeft[(count - 4)].w = SQUIRREL_WIDTH; clipsKnifeLeft[(count - 4)].h = SQUIRREL_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( "Make The Squirrel Walk", NULL ); //If everything initialized fine return true;}bool load_files(){ //Load the sprite sheet squirrel = load_image( "squirrelSpriteSheet.png" ); //If there was a problem in loading the sprite if( squirrel == NULL ) { return false; } //If everything loaded fine return true;}void clean_up(){ //Free the surface SDL_FreeSurface( squirrel ); //Quit SDL SDL_Quit();}int main( int argc, char* args[] ){ bool quit = false; //Initialize if( init() == false ) { return 1; } //Load the files if( load_files() == false ) { return 1; } //Clip the sprite sheet set_clips(); //The frame rate regulator Timer fps; //The squirrel Squirrel walk; //Start the frame timer fps.start(); while(!quit) { if( event.type == SDL_KEYDOWN ) { //Set quit to true if backspace is pressed switch( event.key.keysym.sym ) { case SDLK_BACKSPACE: quit = true; break; } } //While there's events to handle while( SDL_PollEvent(&event)) { //Handle events for the squirrel walk.handle_events(); } //Move the squirrel walk.move(); //Fill the screen white SDL_FillRect( screen, &screen->clip_rect, SDL_MapRGB(screen->format, 0xFF, 0xFF, 0xFF)); //Show the squirrel on the screen walk.show(clipsNoKnifeRight, clipsNoKnifeLeft, clipsKnifeRight, clipsKnifeLeft); //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; }[Edited by - 13moonsago on March 7, 2008 9:22:46 AM]
Also, can you post Squirrel::handle_events()?
You probably should have code like this:
Otherwise, how does the squirrel know which event to handle?
You probably should have code like this:
class Squirrel {public: void handle_event( const SDL_Event &event ) { // do whatever }};int main(){ Squirrel squirrel; SDL_Event event; while(running) { while(SDL_PollEvent(&event)) { if(event.type == SDL_KEYDOWN && event.key.keysym.sym == SDLK_BACKSPACE ) { running = false; } else { squirrel.handle_event(event); } } // ... }}Otherwise, how does the squirrel know which event to handle?
Author
Here is Squirrel.h
and here is Squirrel.cpp
#ifndef SQUIRREL_H#define SQUIRREL_H#include "SDL/SDL.h"#include "SDL/SDL_image.h"//Screen attributesconst int SCREEN_WIDTH = 640;const int SCREEN_HEIGHT = 480;const int SCREEN_BPP = 32;//The frames per secondconst int FRAMES_PER_SECOND = 10;//The dimenstions of the squirrelconst int SQUIRREL_WIDTH = 50;const int SQUIRREL_HEIGHT = 50;//The direction status of the squirrelconst int SQUIRREL_RIGHT = 0;const int SQUIRREL_LEFT = 1;//The number of squirrel framesconst int CLIPS = 4;//The squirrelclass Squirrel{ private: //The offset int offSet; //Its rate of movement int velocity; //Its current frame int frame; //Its animation status int status; public: //Construstor Squirrel(); //Handles input void handle_events(); //Moves the squirrel void move(); //Shows the squirrel void show(SDL_Rect [CLIPS], SDL_Rect [CLIPS], SDL_Rect [CLIPS], SDL_Rect [CLIPS]); };#endifand here is Squirrel.cpp
#include "Squirrel.h"#include "SDL/SDL.h"#include "SDL/SDL_image.h"#include <string>using namespace std;Squirrel::Squirrel(){ //Initialize movement variables offSet = 0; velocity = 0; //Initialize animation variables frame = 0; status = SQUIRREL_RIGHT;}void Squirrel::move(){ //Move offSet += velocity; //Keep the squirrel in bounds if( ( offSet < 0 ) || ( offSet + SQUIRREL_WIDTH > SCREEN_WIDTH ) ) { offSet -= velocity; }}void Squirrel::show(SDL_Rect (clipsNoKnifeRight)[CLIPS], SDL_Rect (clipsNoKnifeLeft)[CLIPS], SDL_Rect (clipsKnifeRight)[CLIPS], SDL_Rect (clipsKnifeLeft)[CLIPS]){ //If Squirrel is moving left if( velocity < 0 ) { //Set the animation to left status = SQUIRREL_LEFT; //Move to the next frame in the animation frame++; } //If Squirrel is moving right else if( velocity > 0 ) { //Set the animation to right status = SQUIRREL_RIGHT; //Move to the next frame in the animation frame++; } //If Squirrel standing else { //Restart the animation frame = 0; } //Loop the animation if( frame >= CLIPS ) { frame = 0; } //Show the squirrel if( status == SQUIRREL_RIGHT ) { apply_surface( offSet, SCREEN_HEIGHT - SQUIRREL_HEIGHT, squirrel, screen, &clipsNoKnifeRight[frame] ); } else if( status == SQUIRREL_LEFT ) { apply_surface( offSet, SCREEN_HEIGHT - SQUIRREL_HEIGHT, squirrel, screen, &clipsNoKnifeLeft[frame] ); }}void Squirrel::handle_events(){ //If a key was pressed if( event.type == SDL_KEYDOWN ) { //Set the velocity switch( event.key.keysym.sym ) { case SDLK_RIGHT: velocity += SQUIRREL_WIDTH / 4; break; case SDLK_LEFT: velocity -= SQUIRREL_WIDTH / 4; break; } } //If a key was released else if( event.type == SDL_KEYUP ) { //Set the velocity switch( event.key.keysym.sym ) { case SDLK_RIGHT: velocity -= SQUIRREL_WIDTH / 4; break; case SDLK_LEFT: velocity += SQUIRREL_WIDTH / 4; break; } }}
I can't see how that compiles. There appears to be no declaration of the "event" variable in Squirrel::handle_events.
My advice would be to pass the event as an argument to the handle_event, like I showed in the above post.
My advice would be to pass the event as an argument to the handle_event, like I showed in the above post.
Author
I used the old version of the source code before I moved the definition of Squirrel::handle_events() and Squirrel::show() into main.cpp.
this is main.cpp
and here the the new Squirrel.cpp
this is main.cpp
#include "SDL/SDL.h"#include "SDL/SDL_image.h"#include "Timer.h"#include "Squirrel.h"#include <string>using namespace std;//The surfacesSDL_Surface *squirrel = NULL;SDL_Surface *screen = NULL;//The event structureSDL_Event event;//The areas of the sprite sheetSDL_Rect clipsNoKnifeRight[CLIPS];SDL_Rect clipsNoKnifeLeft[CLIPS];SDL_Rect clipsKnifeRight[CLIPS];SDL_Rect clipsKnifeLeft[CLIPS];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, 0)); } } //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 for(int count = 0; count < 4; count++) { clipsNoKnifeRight[count].x = (SQUIRREL_WIDTH * count); clipsNoKnifeRight[count].y = 0; clipsNoKnifeRight[count].w = SQUIRREL_WIDTH; clipsNoKnifeRight[count].h = SQUIRREL_HEIGHT; } for(int count = 4; count < 8; count++) { clipsNoKnifeLeft[(count - 4)].x = (SQUIRREL_WIDTH * count); clipsNoKnifeLeft[(count - 4)].y = 0; clipsNoKnifeLeft[(count - 4)].w = SQUIRREL_WIDTH; clipsNoKnifeLeft[(count - 4)].h = SQUIRREL_HEIGHT; } for(int count = 0; count < 4; count++) { clipsKnifeRight[count].x = (SQUIRREL_WIDTH * count); clipsKnifeRight[count].y = SQUIRREL_HEIGHT; clipsKnifeRight[count].w = SQUIRREL_WIDTH; clipsKnifeRight[count].h = SQUIRREL_HEIGHT; } for(int count = 4; count < 8; count++) { clipsKnifeLeft[(count - 4)].x = (SQUIRREL_WIDTH * count); clipsKnifeLeft[(count - 4)].y = SQUIRREL_HEIGHT; clipsKnifeLeft[(count - 4)].w = SQUIRREL_WIDTH; clipsKnifeLeft[(count - 4)].h = SQUIRREL_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( "Make The Squirrel Walk", NULL ); //If everything initialized fine return true;}bool load_files(){ //Load the sprite sheet squirrel = load_image( "squirrelSpriteSheet.png" ); //If there was a problem in loading the sprite if( squirrel == NULL ) { return false; } //If everything loaded fine return true;}void clean_up(){ //Free the surface SDL_FreeSurface( squirrel ); //Quit SDL SDL_Quit();}int main( int argc, char* args[] ){ bool quit = false; //Initialize if( init() == false ) { return 1; } //Load the files if( load_files() == false ) { return 1; } //Clip the sprite sheet set_clips(); //The frame rate regulator Timer fps; //The squirrel Squirrel walk; //Start the frame timer fps.start(); while(!quit) { if( event.type == SDL_KEYDOWN ) { //Set the velocity switch( event.key.keysym.sym ) { case SDLK_BACKSPACE: quit = true; break; } } //While there's events to handle while( SDL_PollEvent(&event)) { //Handle events for the squirrel walk.handle_events(); } //Move the squirrel walk.move(); //Fill the screen white SDL_FillRect( screen, &screen->clip_rect, SDL_MapRGB(screen->format, 0xFF, 0xFF, 0xFF)); //Show the squirrel on the screen walk.show(clipsNoKnifeRight, clipsNoKnifeLeft, clipsKnifeRight, clipsKnifeLeft); //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; }void Squirrel::show(SDL_Rect (clipsNoKnifeRight)[CLIPS], SDL_Rect (clipsNoKnifeLeft)[CLIPS], SDL_Rect (clipsKnifeRight)[CLIPS], SDL_Rect (clipsKnifeLeft)[CLIPS]){ //If Squirrel is moving left if( velocity < 0 ) { //Set the animation to left status = SQUIRREL_LEFT; //Move to the next frame in the animation frame++; } //If Squirrel is moving right else if( velocity > 0 ) { //Set the animation to right status = SQUIRREL_RIGHT; //Move to the next frame in the animation frame++; } //If Squirrel standing else { //Restart the animation frame = 0; } //Loop the animation if( frame >= CLIPS ) { frame = 0; } //Show the squirrel if( status == SQUIRREL_RIGHT ) { apply_surface( offSet, SCREEN_HEIGHT - SQUIRREL_HEIGHT, squirrel, screen, &clipsNoKnifeRight[frame] ); } else if( status == SQUIRREL_LEFT ) { apply_surface( offSet, SCREEN_HEIGHT - SQUIRREL_HEIGHT, squirrel, screen, &clipsNoKnifeLeft[frame] ); }}void Squirrel::handle_events(){ //If a key was pressed if( event.type == SDL_KEYDOWN ) { //Set the velocity switch( event.key.keysym.sym ) { case SDLK_RIGHT: velocity += SQUIRREL_WIDTH / 4; break; case SDLK_LEFT: velocity -= SQUIRREL_WIDTH / 4; break; } } //If a key was released else if( event.type == SDL_KEYUP ) { //Set the velocity switch( event.key.keysym.sym ) { case SDLK_RIGHT: velocity -= SQUIRREL_WIDTH / 4; break; case SDLK_LEFT: velocity += SQUIRREL_WIDTH / 4; break; } }}and here the the new Squirrel.cpp
#include "Squirrel.h"#include "SDL/SDL.h"#include "SDL/SDL_image.h"#include <string>using namespace std;Squirrel::Squirrel(){ //Initialize movement variables offSet = 0; velocity = 0; //Initialize animation variables frame = 0; status = SQUIRREL_RIGHT;}void Squirrel::move(){ //Move offSet += velocity; //Keep the squirrel in bounds if( ( offSet < 0 ) || ( offSet + SQUIRREL_WIDTH > SCREEN_WIDTH ) ) { offSet -= velocity; }}This topic is closed to new replies.
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