Discussion :

[Halarp27]

Bonjour j'ai commencer à m'intéresser au scrolling avec la SDL. J'ai un code qui marche très bien tant que la vitesse du scrolling n'est pas trop élevé. Sinon je vois apparaître des bandes noire à droite et en bas.



Vous avez une solution ?

Sinon voici toujours mon code :

Code :

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#include "main.h"
 
void UpdateEvents(Input *in)
{
    SDL_Event event;
 
    in->mousebuttons[SDL_BUTTON_WHEELUP] = 0;
    in->mousebuttons[SDL_BUTTON_WHEELDOWN] = 0;
 
    while(SDL_PollEvent(&event))
    {
        switch(event.type)
        {
            case SDL_QUIT:
                in->quit = 1;
                break;
            case SDL_KEYDOWN:
                in->key[event.key.keysym.sym] = 1;
                break;
            case SDL_KEYUP:
                in->key[event.key.keysym.sym] = 0;
                break;
            case SDL_MOUSEMOTION:
                in->mousex = event.motion.x;
                in->mousey = event.motion.y;
                in->mousexrel = event.motion.xrel;
                in->mouseyrel = event.motion.yrel;
                break;
            case SDL_MOUSEBUTTONDOWN:
                in->mousebuttons[event.button.button] = 1;
                break;
            case SDL_MOUSEBUTTONUP:
                if(event.button.button != SDL_BUTTON_WHEELDOWN && event.button.button != SDL_BUTTON_WHEELUP)
                    in->mousebuttons[event.button.button] = 0;
                break;
            default:
                break;
        }
    }
}
 
SDL_Surface *LoadAdaptedIMG(const char IMG_Name[])
{
    SDL_Surface *IMG = NULL;
    SDL_Surface *IMG_Result = NULL;
 
    if((IMG = IMG_Load(IMG_Name)) == NULL)
    {
        fprintf(stderr, "%s", IMG_GetError());
        exit(-1);
    }
 
    IMG_Result = SDL_DisplayFormat(IMG);
    SDL_FreeSurface(IMG);
 
    return IMG_Result;
}
 
SDL_Surface *InitSDL(int width, int height, const char WindowsTitle[])
{
    SDL_Surface *screen = NULL;
 
    if(SDL_Init(SDL_INIT_VIDEO) == -1)
    {
        fprintf(stderr, "Erreur lors de l'initialisation de la SDL : %s", SDL_GetError());
        exit(-1);
    }
 
    if((screen = SDL_SetVideoMode(width, height, 32, SDL_HWSURFACE | SDL_DOUBLEBUF)) == NULL)
    {
        fprintf(stderr, "Erreur lors du chargement du mode video : %s", SDL_GetError());
        exit(-1);
    }
 
    SDL_WM_SetCaption(WindowsTitle, NULL);
 
    return screen;
}
 
int main(int argc, char* argv[])
{
    Input in;
 
    int width, height;
 
    width = 640;
    height = 480;
    SDL_Surface *screen = InitSDL(width, height, "Scrolling");
    SDL_Surface *picture = LoadAdaptedIMG("level.jpg");
 
    char scrollSpeed = 16;
 
    SDL_Rect camera;
 
    memset(&in, 0, sizeof(in));
 
    camera.x = 0;
    camera.y = 0;
    camera.w = width;
    camera.h = height;
 
    SDL_ShowCursor(SDL_DISABLE);
 
    while(!in.key[SDLK_ESCAPE] && !in.quit)
    {
        UpdateEvents(&in);
 
        if(in.key[SDLK_UP] && camera.y > 0)
        {
            camera.y -= scrollSpeed;
        }
        if(in.key[SDLK_DOWN] && camera.y < picture->h - camera.h)
        {
            camera.y += scrollSpeed;
        }
        if(in.key[SDLK_LEFT] && camera.x > 0)
        {
            camera.x -= scrollSpeed;
        }
        if(in.key[SDLK_RIGHT] && camera.x < picture->w - camera.w)
        {
            camera.x += scrollSpeed;
        }
 
        SDL_FillRect(screen, NULL, SDL_MapRGB(screen->format, 0, 0, 0));
        SDL_BlitSurface(picture, &camera, screen, NULL);
        SDL_Flip(screen);
        SDL_Delay(5);
    }
 
    SDL_FreeSurface(picture);
    SDL_Quit();
 
    return 0;
}