Ryan C. Gordon <icculus clutteredmind.org> writes:
I’m having a problem with windowed SDL applications. Whenever I start
them, the frame appears, but the graphics do not; whatever was running
in the background
appears in the screen. Has anyone else had this problem, and what is the
easiest solution to this problem?
What platform are you using, and can you show us a simple program that
does it? (or just an existing SDL program that does it)?
I’m using Windows XP SP2 with Visual C++ 6 for a compiler. Here’s some of the
code that gives me this problem:
// Lock surface if needed
if (SDL_LockSurface(screen) < 0)
// Ask SDL for the time in milliseconds
int tick = SDL_GetTicks();
// Declare a couple of variables
int i, j, yofs, ofs;
// Draw to screen
yofs = 0;
for (i = 0; i < 480; i++)
for (j = 0, ofs = yofs; j < 640; j++, ofs++)
((unsigned int*)screen->pixels)[ofs] = i * i + j * j + tick;
yofs += screen->pitch / 4;
// Unlock if needed
// Tell SDL to update the whole screen
SDL_UpdateRect(screen, 0, 0, 640, 480);
// Entry point
int main(int argc, char *argv)
// Initialize SDL’s subsystems - in this case, only video.
if ( SDL_Init(SDL_INIT_VIDEO) < 0 )
fprintf(stderr, “Unable to init SDL: %s\n”, SDL_GetError());
// Register SDL_Quit to be called at exit; makes sure things are
// cleaned up when we quit.
// Attempt to create a 640x480 window with 32bit pixels.
screen = SDL_SetVideoMode(640, 480, 32, SDL_SWSURFACE);
// If we fail, return error.
if ( screen == NULL )
fprintf(stderr, “Unable to set 640x480 video: %s\n”, SDL_GetError());
// Main loop: loop forever.
// Render stuff
// Poll for events, and handle the ones we care about.
// If escape is pressed, return (and thus, quit)
if (event.key.keysym.sym == SDLK_ESCAPE)
I’m including all the necessary files(there’s a bunch of commented-out old code
inbetween the includes and this code, so I didn’t post them). This code is from
Sol’s SDL tutorial. If I change the video type from SDL_SWSURFACE to
SDL_FULLSCREEN, then it works fine. The problem is, the application I am
developing needs to be contained within a window.