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testsprite.c
328 lines (296 loc) · 9.37 KB
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/* Simple program: Move N sprites around on the screen as fast as possible */
#include <stdlib.h>
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#include <stdio.h>
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#include <string.h>
#include <ctype.h>
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#include <time.h>
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#include <math.h>
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#include "SDL.h"
#define NUM_SPRITES 100
#define MAX_SPEED 1
SDL_Surface *sprite;
int numsprites;
SDL_Rect *sprite_rects;
SDL_Rect *positions;
SDL_Rect *velocities;
int sprites_visible;
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int debug_flip;
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Uint16 sprite_w, sprite_h;
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/* Call this instead of exit(), so we can clean up SDL: atexit() is evil. */
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static void
quit(int rc)
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{
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SDL_Quit();
exit(rc);
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}
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int
LoadSprite(char *file)
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{
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SDL_Surface *temp;
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/* Load the sprite image */
sprite = SDL_LoadBMP(file);
if (sprite == NULL) {
fprintf(stderr, "Couldn't load %s: %s", file, SDL_GetError());
return (-1);
}
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/* Set transparent pixel as the pixel at (0,0) */
if (sprite->format->palette) {
SDL_SetColorKey(sprite, (SDL_SRCCOLORKEY | SDL_RLEACCEL),
*(Uint8 *) sprite->pixels);
}
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/* Convert sprite to video format */
temp = SDL_DisplayFormat(sprite);
SDL_FreeSurface(sprite);
if (temp == NULL) {
fprintf(stderr, "Couldn't convert background: %s\n", SDL_GetError());
return (-1);
}
sprite = temp;
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/* We're ready to roll. :) */
return (0);
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}
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void
MoveSprites(SDL_Surface * screen, Uint32 background)
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{
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int i, nupdates;
SDL_Rect area, *position, *velocity;
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nupdates = 0;
/* Erase all the sprites if necessary */
if (sprites_visible) {
SDL_FillRect(screen, NULL, background);
}
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/* Move the sprite, bounce at the wall, and draw */
for (i = 0; i < numsprites; ++i) {
position = &positions[i];
velocity = &velocities[i];
position->x += velocity->x;
if ((position->x < 0) || (position->x >= (screen->w - sprite_w))) {
velocity->x = -velocity->x;
position->x += velocity->x;
}
position->y += velocity->y;
if ((position->y < 0) || (position->y >= (screen->h - sprite_w))) {
velocity->y = -velocity->y;
position->y += velocity->y;
}
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/* Blit the sprite onto the screen */
area = *position;
SDL_BlitSurface(sprite, NULL, screen, &area);
sprite_rects[nupdates++] = area;
}
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if (debug_flip) {
if ((screen->flags & SDL_DOUBLEBUF) == SDL_DOUBLEBUF) {
static int t = 0;
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Uint32 color = SDL_MapRGB(screen->format, 255, 0, 0);
SDL_Rect r;
r.x =
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(int)((sin((float) t * 2 * 3.1459) + 1.0) / 2.0 * (screen->w - 20));
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r.y = 0;
r.w = 20;
r.h = screen->h;
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SDL_FillRect(screen, &r, color);
t += 2;
}
}
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/* Update the screen! */
if ((screen->flags & SDL_DOUBLEBUF) == SDL_DOUBLEBUF) {
SDL_Flip(screen);
} else {
SDL_UpdateRects(screen, nupdates, sprite_rects);
}
sprites_visible = 1;
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}
/* This is a way of telling whether or not to use hardware surfaces */
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Uint32
FastestFlags(Uint32 flags, int width, int height, int bpp)
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{
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const SDL_VideoInfo *info;
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/* Hardware acceleration is only used in fullscreen mode */
flags |= SDL_FULLSCREEN;
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/* Check for various video capabilities */
info = SDL_GetVideoInfo();
if (info->blit_hw_CC && info->blit_fill) {
/* We use accelerated colorkeying and color filling */
flags |= SDL_HWSURFACE;
}
/* If we have enough video memory, and will use accelerated
blits directly to it, then use page flipping.
*/
if ((flags & SDL_HWSURFACE) == SDL_HWSURFACE) {
/* Direct hardware blitting without double-buffering
causes really bad flickering.
*/
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if (info->video_mem * 1024 > (Uint32)(height * width * bpp / 8)) {
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flags |= SDL_DOUBLEBUF;
} else {
flags &= ~SDL_HWSURFACE;
}
}
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/* Return the flags */
return (flags);
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}
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int
main(int argc, char *argv[])
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{
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SDL_Surface *screen;
Uint8 *mem;
int width, height;
Uint8 video_bpp;
Uint32 videoflags;
Uint32 background;
int i, done;
SDL_Event event;
Uint32 then, now, frames;
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/* Initialize SDL */
if (SDL_Init(SDL_INIT_VIDEO) < 0) {
fprintf(stderr, "Couldn't initialize SDL: %s\n", SDL_GetError());
return (1);
}
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numsprites = NUM_SPRITES;
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videoflags = SDL_SWSURFACE | SDL_ANYFORMAT | SDL_RESIZABLE;
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width = 640;
height = 480;
video_bpp = 8;
debug_flip = 0;
while (argc > 1) {
--argc;
if (strcmp(argv[argc - 1], "-width") == 0) {
width = atoi(argv[argc]);
--argc;
} else if (strcmp(argv[argc - 1], "-height") == 0) {
height = atoi(argv[argc]);
--argc;
} else if (strcmp(argv[argc - 1], "-bpp") == 0) {
video_bpp = atoi(argv[argc]);
videoflags &= ~SDL_ANYFORMAT;
--argc;
} else if (strcmp(argv[argc], "-fast") == 0) {
videoflags = FastestFlags(videoflags, width, height, video_bpp);
} else if (strcmp(argv[argc], "-hw") == 0) {
videoflags ^= SDL_HWSURFACE;
} else if (strcmp(argv[argc], "-flip") == 0) {
videoflags ^= SDL_DOUBLEBUF;
} else if (strcmp(argv[argc], "-debugflip") == 0) {
debug_flip ^= 1;
} else if (strcmp(argv[argc], "-fullscreen") == 0) {
videoflags ^= SDL_FULLSCREEN;
} else if (isdigit(argv[argc][0])) {
numsprites = atoi(argv[argc]);
} else {
fprintf(stderr,
"Usage: %s [-bpp N] [-hw] [-flip] [-fast] [-fullscreen] [numsprites]\n",
argv[0]);
quit(1);
}
}
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/* Set video mode */
screen = SDL_SetVideoMode(width, height, video_bpp, videoflags);
if (!screen) {
fprintf(stderr, "Couldn't set %dx%d video mode: %s\n",
width, height, SDL_GetError());
quit(2);
}
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/* Load the sprite */
if (LoadSprite("icon.bmp") < 0) {
quit(1);
}
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/* Allocate memory for the sprite info */
mem = (Uint8 *) malloc(4 * sizeof(SDL_Rect) * numsprites);
if (mem == NULL) {
SDL_FreeSurface(sprite);
fprintf(stderr, "Out of memory!\n");
quit(2);
}
sprite_rects = (SDL_Rect *) mem;
positions = sprite_rects;
sprite_rects += numsprites;
velocities = sprite_rects;
sprite_rects += numsprites;
sprite_w = sprite->w;
sprite_h = sprite->h;
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srand((unsigned int)time(NULL));
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for (i = 0; i < numsprites; ++i) {
positions[i].x = rand() % (screen->w - sprite_w);
positions[i].y = rand() % (screen->h - sprite_h);
positions[i].w = sprite->w;
positions[i].h = sprite->h;
velocities[i].x = 0;
velocities[i].y = 0;
while (!velocities[i].x && !velocities[i].y) {
velocities[i].x = (rand() % (MAX_SPEED * 2 + 1)) - MAX_SPEED;
velocities[i].y = (rand() % (MAX_SPEED * 2 + 1)) - MAX_SPEED;
}
}
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/* Clear the background to grey */
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background = SDL_MapRGB(screen->format, 0xA0, 0xA0, 0xA0);
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SDL_FillRect(screen, NULL, background);
SDL_Flip(screen);
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/* Print out information about our surfaces */
printf("Screen is at %d bits per pixel\n", screen->format->BitsPerPixel);
if ((screen->flags & SDL_HWSURFACE) == SDL_HWSURFACE) {
printf("Screen is in video memory\n");
} else {
printf("Screen is in system memory\n");
}
if ((screen->flags & SDL_DOUBLEBUF) == SDL_DOUBLEBUF) {
printf("Screen has double-buffering enabled\n");
}
if ((sprite->flags & SDL_HWSURFACE) == SDL_HWSURFACE) {
printf("Sprite is in video memory\n");
} else {
printf("Sprite is in system memory\n");
}
/* Run a sample blit to trigger blit acceleration */
{
SDL_Rect dst;
dst.x = 0;
dst.y = 0;
dst.w = sprite->w;
dst.h = sprite->h;
SDL_BlitSurface(sprite, NULL, screen, &dst);
SDL_FillRect(screen, &dst, background);
}
if ((sprite->flags & SDL_HWACCEL) == SDL_HWACCEL) {
printf("Sprite blit uses hardware acceleration\n");
}
if ((sprite->flags & SDL_RLEACCEL) == SDL_RLEACCEL) {
printf("Sprite blit uses RLE acceleration\n");
}
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/* Loop, blitting sprites and waiting for a keystroke */
frames = 0;
then = SDL_GetTicks();
done = 0;
sprites_visible = 0;
while (!done) {
/* Check for events */
++frames;
while (SDL_PollEvent(&event)) {
switch (event.type) {
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case SDL_VIDEORESIZE:
screen = SDL_SetVideoMode(event.resize.w, event.resize.h, video_bpp, videoflags);
break;
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case SDL_MOUSEBUTTONDOWN:
SDL_WarpMouse(screen->w / 2, screen->h / 2);
break;
case SDL_KEYDOWN:
/* Any keypress quits the app... */
case SDL_QUIT:
done = 1;
break;
default:
break;
}
}
MoveSprites(screen, background);
}
SDL_FreeSurface(sprite);
free(mem);
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/* Print out some timing information */
now = SDL_GetTicks();
if (now > then) {
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double fps = ((double) frames * 1000) / (now - then);
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printf("%2.2f frames per second\n", fps);
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}
SDL_Quit();
return (0);
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}