#include <stdio.h>
#include <stdlib.h>
#include <SDL/SDL.h>
SDL_Surface *back;
SDL_Surface *image;
SDL_Surface *screen;
int xpos=0,ypos=0;
int InitImages()
{
back = SDL_LoadBMP("bg.bmp");
image = SDL_LoadBMP("image.bmp");
return 0;
}
void DrawIMG(SDL_Surface *img, int x, int y)
{
SDL_Rect dest;
dest.x = x;
dest.y = y;
SDL_BlitSurface(img, NULL, screen, &dest);
}
void DrawIMG(SDL_Surface *img, int x, int y, int w, int h, int x2, int y2)
{
SDL_Rect dest;
dest.x = x;
dest.y = y;
SDL_Rect dest2;
dest2.x = x2;
dest2.y = y2;
dest2.w = w;
dest2.h = h;
SDL_BlitSurface(img, &dest2, screen, &dest);
}
void DrawBG()
{
DrawIMG(back, 0, 0);
}
void DrawScene()
{
DrawIMG(back, xpos-2, ypos-2, 132, 132, xpos-2, ypos-2);
DrawIMG(image, xpos, ypos);
SDL_Flip(screen);
}
int main(int argc, char *argv[])
{
Uint8* keys;
if ( SDL_Init(SDL_INIT_AUDIO|SDL_INIT_VIDEO) < 0 )
{
printf("Unable to init SDL: %s\n", SDL_GetError());
exit(1);
}
atexit(SDL_Quit);
screen=SDL_SetVideoMode(640,480,32,SDL_HWSURFACE|SDL_DOUBLEBUF);
if ( screen == NULL )
{
printf("Unable to set 640x480 video: %s\n", SDL_GetError());
exit(1);
}
InitImages();
DrawBG();
int done=0;
while(done == 0)
{
SDL_Event event;
if ( event.type == SDL_QUIT ) { done = 1; }
if ( event.type == SDL_KEYDOWN )
{
if (event.key.keysym.sym == SDLK_ESCAPE ) { done = 1; }
}
}
keys = SDL_GetKeyState(NULL);
if ( keys[SDLK_UP] ) { ypos -= 1; }
if ( keys[SDLK_DOWN] ) { ypos += 1;}
if ( keys[SDLK_LEFT]) { xpos -= 1; }
if ( keys[SDLK_RIGHT] ) { xpos += 1; }
DrawScene();
return 0;
}What's wrong with this SDL?
Author
Hi guys, I'm new here and a novice in Game programming.
But I have this code from Cone3D that just won't work. I compiles allright but when I run it, it crashes. I think the problem is that my images isn't being fetched allright.
The images are in the same folder as the source and binary
Not sure but maybe this part:
There is no width and height given to the dest rectangle?
Edit: I maybe wrong though, as I remember reading something about passing parametr 2 as NULL to blit the entire surface... dunno if that applies to the dest rectangle as well.
void DrawIMG(SDL_Surface *img, int x, int y){ SDL_Rect dest; dest.x = x; dest.y = y; SDL_BlitSurface(img, NULL, screen, &dest);}There is no width and height given to the dest rectangle?
Edit: I maybe wrong though, as I remember reading something about passing parametr 2 as NULL to blit the entire surface... dunno if that applies to the dest rectangle as well.
Author
Well it's the exact same code as Code3d made. It says that it should work and comments agree. But why oh why doesn't it work for me? :P
Just checking, you do have bg.bmp and image.bmp in the same folder as your .exe (or if you're running from your IDE, the same folder as your project file)?
Edit: Why oh why don't I read? However, if you are running it from your IDE, the parentheses apply, still.
Edit: Why oh why don't I read? However, if you are running it from your IDE, the parentheses apply, still.
Your code didn't work for me - your event loop is bork bork bork. You need to call either SDL_PollEvent or ... SDL_PeekEvent (I think that's the one) to fill the SDL_Event structure with data before you use it.
There were a couple other changes I made, can't remember them all; but this worked for me -
There were a couple other changes I made, can't remember them all; but this worked for me -
#include <stdio.h>#include <stdlib.h>#include <SDL/SDL.h>#pragma comment ( lib, "sdl.lib" )#pragma comment ( lib, "sdlmain.lib" )SDL_Surface *back;SDL_Surface *image;SDL_Surface *screen;int xpos=0,ypos=0;int InitImages(){ back = SDL_LoadBMP("forest.bmp"); image = SDL_LoadBMP("forest.bmp"); return 0;}void DrawIMG(SDL_Surface *img, int x, int y){ SDL_Rect dest; dest.x = x; dest.y = y; dest.w = img->w; dest.h = img->h; SDL_BlitSurface(img, NULL, screen, &dest);}void DrawIMG(SDL_Surface *img, int x, int y, int w, int h, int x2, int y2){ SDL_Rect dest; dest.x = x; dest.y = y; SDL_Rect dest2; dest2.x = x2; dest2.y = y2; dest2.w = w; dest2.h = h; SDL_BlitSurface(img, &dest2, screen, &dest);}void DrawBG(){ DrawIMG(back, 0, 0);}void DrawScene(){ DrawIMG(back, xpos-2, ypos-2, 132, 132, xpos-2, ypos-2); DrawIMG(image, xpos, ypos); SDL_UpdateRect( screen, 0, 0, 0 ,0 ); SDL_Flip(screen);}int main(int argc, char *argv[]){ Uint8* keys; if ( SDL_Init(SDL_INIT_AUDIO|SDL_INIT_VIDEO) < 0 ) { printf("Unable to init SDL: %s\n", SDL_GetError()); exit(1); } atexit(SDL_Quit); screen=SDL_SetVideoMode(640,480,32,SDL_HWSURFACE|SDL_DOUBLEBUF); if ( screen == NULL ) { printf("Unable to set 640x480 video: %s\n", SDL_GetError()); exit(1); } InitImages(); DrawBG(); int done=0; while(done == 0) { SDL_Event event; while ( SDL_PollEvent( &event ) ) { if ( event.type == SDL_QUIT ) done = 1; if ( event.type == SDL_KEYDOWN ) if (event.key.keysym.sym == SDLK_ESCAPE ) done = 1; } keys = SDL_GetKeyState(NULL); if ( keys[SDLK_UP] ) { ypos -= 1; } if ( keys[SDLK_DOWN] ) { ypos += 1;} if ( keys[SDLK_LEFT]) { xpos -= 1; } if ( keys[SDLK_RIGHT] ) { xpos += 1; } DrawScene(); } return 0;}
Author
I'm sorry to say that it didn't work either.
In debugging I get: "An access violation (Segmentation Fault) raised in your program"
I don't understand where I get my buffer overflow.
EDIT: Nevermind, I got it to work :D thanks guys!
In debugging I get: "An access violation (Segmentation Fault) raised in your program"
I don't understand where I get my buffer overflow.
EDIT: Nevermind, I got it to work :D thanks guys!
This topic is closed to new replies.
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