#include <stdio.h> #include <stdlib.h> #include <SDL/SDL.h> // SDL Surface Variables, Back-> Background, Image->Sprint Image // Global so all functions can use them // Probably Set up a Surface Class?? SDL_Surface *back; SDL_Surface *image; SDL_Surface *screen; // Used for the location of the image box int xpos=0,ypos=0; // Called fromt he DrawIMG functions to Blit our Sprite to the screen // src is the SCreen Surface to Blit the Sprite to int SDL_BlitSurface(SDL_Surface *src, SDL_Rect *srcrect, SDL_Surface *dst, SDL_Rect *dstrect); // *** Inline Functions... // Loads the BMP Files into the variables names // SDL_LoadBMP allows us to do that // The SDL_LoadBMP argumet is path of the picture int InitImages() { back = SDL_LoadBMP( "pics/pinstripe.bmp" ); image = SDL_LoadBMP( "pics/triangles.bmp" ); return 0; } // First of 2 DrawIMG functions // This is going to be where the img is going to be drawn on the surface void DrawIMG(SDL_Surface *img, int x, int y) { SDL_Rect dest; dest.x = x; dest.y = y; SDL_BlitSurface(img, NULL, screen, &dest); } // Second of 2 DrawIMG functions // I think this has to do with blitting an image on a part of the screen surface, notthe whole thing?? 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); } // Draws the background to the screen surface starting at x,y ( 0, 0 ) // No Screen Locking ( only with pixel manipulation ) void DrawBG() { DrawIMG(back, 0, 0); } // Actually draws our image on the background provided // DrawIMG is determined by the parameters // The two functions work together to make an image that // draws the img but deletes the trail void DrawScene() { DrawIMG(back, xpos-2, ypos-2, 132, 132, xpos-2, ypos-2); DrawIMG(image, xpos, ypos); SDL_Flip(screen); // Screen Update } int main(int argc, char *argv[]) { Uint8* keys; // Standard Init Stuff *** 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(640,480,16,SDL_HWSURFACE|SDL_DOUBLEBUF); if ( screen == NULL ) { printf("Unable to set 640x480 video: %s\n", SDL_GetError()); exit(1); } // *** End of standard stuff InitImages(); // Init Images, BG and IMG DrawBG(); // Draws the background to screen // Game Loop 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; } } } // Key POsitions and Manipultaions 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(); // Hopefully that will draw the sceene } return 0; }