[SDL] SDL fullscreen problem

[Torsten Giebl]

Hello !


>> When I run a program  in X system on F7 ,the X crashed ,just like I
>> press
>> CTRL+ALT+BACKSPACE.
>> It is sure that the code has no problem,I get it from linux game
>> programming.
>> What's the problem?
>>
>>
>> the code is below,
>>
>> #include <SDL/SDL.h>
>> #include <stdio.h>
>> #include <stdlib.h>

Use #include "SDL.h" and use it after stdio.h and stdlib.h

>> Uint16 CreateHicolorPixel(SDL_PixelFormat * fmt, Uint8 red,
>>                           Uint8 green, Uint8 blue)
>> {
>>     Uint16 value;

You use Uint16 but you are running with SDL_SetVideoMode (..,24,..)
so better use a Uint32 for pixel values.

>>     value = ((red >> fmt->Rloss) << fmt->Rshift) +
>>             ((green >> fmt->Gloss) << fmt->Gshift) +
>>             ((blue >> fmt->Bloss) << fmt->Bshift);
>>     return value;
>> }

Better use the SetPixel function from the SDL website.

>> int main()

To be portable do int main(int argc, char *argv [])

>> {
>>     SDL_Surface *screen;
>>     Uint16 *raw_pixels;
>>     int x, y;
>>    if (SDL_Init(SDL_INIT_VIDEO) != 0) {
>>        printf("Unable to initialize SDL: %s\n", SDL_GetError());
>>        return 1;
>>    }
>>    atexit(SDL_Quit);
>>    screen = SDL_SetVideoMode(256, 256, 24,
>> SDL_FULLSCREEN|SDL_SWSURFACE);
>>    if (screen == NULL) {
>>        printf("Unable to set video mode: %s\n", SDL_GetError());
>>        return 1;
>>    }

Do an if SDL_MUSTLOCK (screen) true then only lock the surface.

>>    SDL_LockSurface(screen);
>>    raw_pixels = (Uint16 *) screen->pixels;
>>    for (x = 0; x < 256; x++) {
>>        for (y = 0; y < 256; y++) {
>>            Uint16 pixel_color;
>>            int offset;
>>            pixel_color = CreateHicolorPixel(screen->format,
>>                                           x, 0, y);
>>            offset = (screen->pitch / 2 * y + x);
>>            raw_pixels[offset] = pixel_color;
>>         }
>>     }
>>     SDL_UnlockSurface(screen);

The same with SDL_MUSTLOCK as above

>>     SDL_UpdateRect(screen, 10, 10, 200, 120);
>>     SDL_Delay(3000);
>>     return 0;
>>  }


CU