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2 /* Simple program: Move N sprites around on the screen as fast as possible */
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3
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4 #include <stdio.h>
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5 #include <stdlib.h>
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6 #include <string.h>
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7 #include <ctype.h>
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8 #include <time.h>
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9
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10 #include "SDL.h"
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11
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12 #define NUM_SPRITES 100
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13 #define MAX_SPEED 1
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14
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15 SDL_Surface *sprite;
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16 int numsprites;
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17 SDL_Rect *sprite_rects;
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18 SDL_Rect *positions;
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19 SDL_Rect *velocities;
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20 int sprites_visible;
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21
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22 int LoadSprite(SDL_Surface *screen, char *file)
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23 {
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24 SDL_Surface *temp;
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25
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26 /* Load the sprite image */
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27 sprite = SDL_LoadBMP(file);
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28 if ( sprite == NULL ) {
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29 fprintf(stderr, "Couldn't load %s: %s", file, SDL_GetError());
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30 return(-1);
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31 }
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32
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33 /* Set transparent pixel as the pixel at (0,0) */
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34 if ( sprite->format->palette ) {
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35 SDL_SetColorKey(sprite, (SDL_SRCCOLORKEY|SDL_RLEACCEL),
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36 *(Uint8 *)sprite->pixels);
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37 }
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38
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39 /* Convert sprite to video format */
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40 temp = SDL_DisplayFormat(sprite);
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41 SDL_FreeSurface(sprite);
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42 if ( temp == NULL ) {
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43 fprintf(stderr, "Couldn't convert background: %s\n",
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44 SDL_GetError());
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45 return(-1);
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46 }
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47 sprite = temp;
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48
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49 /* We're ready to roll. :) */
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50 return(0);
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51 }
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52
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53 void MoveSprites(SDL_Surface *screen, Uint32 background)
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54 {
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55 int i, nupdates;
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56 SDL_Rect area, *position, *velocity;
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57
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58 nupdates = 0;
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59 /* Erase all the sprites if necessary */
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60 if ( sprites_visible ) {
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61 SDL_FillRect(screen, NULL, background);
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62 }
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63
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64 /* Move the sprite, bounce at the wall, and draw */
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65 for ( i=0; i<numsprites; ++i ) {
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66 position = &positions[i];
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67 velocity = &velocities[i];
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68 position->x += velocity->x;
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69 if ( (position->x < 0) || (position->x >= screen->w) ) {
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70 velocity->x = -velocity->x;
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71 position->x += velocity->x;
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72 }
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73 position->y += velocity->y;
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74 if ( (position->y < 0) || (position->y >= screen->h) ) {
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75 velocity->y = -velocity->y;
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76 position->y += velocity->y;
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77 }
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78
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79 /* Blit the sprite onto the screen */
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80 area = *position;
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81 SDL_BlitSurface(sprite, NULL, screen, &area);
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82 sprite_rects[nupdates++] = area;
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83 }
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84
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85 /* Update the screen! */
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86 if ( (screen->flags & SDL_DOUBLEBUF) == SDL_DOUBLEBUF ) {
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87 SDL_Flip(screen);
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88 } else {
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89 SDL_UpdateRects(screen, nupdates, sprite_rects);
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90 }
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91 sprites_visible = 1;
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92 }
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93
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94 /* This is a way of telling whether or not to use hardware surfaces */
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95 Uint32 FastestFlags(Uint32 flags)
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96 {
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97 const SDL_VideoInfo *info;
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98
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99 /* Hardware acceleration is only used in fullscreen mode */
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100 flags |= SDL_FULLSCREEN;
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101
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102 /* Check for various video capabilities */
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103 info = SDL_GetVideoInfo();
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104 if ( info->blit_hw_CC && info->blit_fill ) {
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105 /* We use accelerated colorkeying and color filling */
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106 flags |= SDL_HWSURFACE;
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107 }
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108 /* If we have enough video memory, and will use accelerated
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109 blits directly to it, then use page flipping.
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110 */
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111 if ( (flags & SDL_HWSURFACE) == SDL_HWSURFACE ) {
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112 /* Direct hardware blitting without double-buffering
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113 causes really bad flickering.
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114 */
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115 SDL_Surface *screen = SDL_GetVideoSurface();
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116 if ( info->video_mem > (screen->h*screen->pitch) ) {
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117 flags |= SDL_DOUBLEBUF;
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118 } else {
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119 flags &= ~SDL_HWSURFACE;
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120 }
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121 }
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122
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123 /* Return the flags */
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124 return(flags);
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125 }
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126
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127 int main(int argc, char *argv[])
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128 {
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129 SDL_Surface *screen;
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130 Uint8 *mem;
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131 int width, height;
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132 Uint8 video_bpp;
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133 Uint32 videoflags;
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134 Uint32 background;
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135 int i, done;
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136 SDL_Event event;
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137 Uint32 then, now, frames;
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138
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139 /* Initialize SDL */
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140 if ( SDL_Init(SDL_INIT_VIDEO) < 0 ) {
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141 fprintf(stderr, "Couldn't initialize SDL: %s\n",SDL_GetError());
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142 exit(1);
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143 }
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144 atexit(SDL_Quit);
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145
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146 numsprites = NUM_SPRITES;
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147 videoflags = SDL_SWSURFACE|SDL_ANYFORMAT;
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148 width = 640;
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149 height = 480;
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150 video_bpp = 8;
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151 while ( argc > 1 ) {
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152 --argc;
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153 if ( strcmp(argv[argc-1], "-width") == 0 ) {
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154 width = atoi(argv[argc]);
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155 --argc;
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156 } else
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157 if ( strcmp(argv[argc-1], "-height") == 0 ) {
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158 height = atoi(argv[argc]);
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159 --argc;
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160 } else
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161 if ( strcmp(argv[argc-1], "-bpp") == 0 ) {
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162 video_bpp = atoi(argv[argc]);
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163 videoflags &= ~SDL_ANYFORMAT;
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164 --argc;
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165 } else
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166 if ( strcmp(argv[argc], "-fast") == 0 ) {
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167 videoflags = FastestFlags(videoflags);
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168 } else
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169 if ( strcmp(argv[argc], "-hw") == 0 ) {
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170 videoflags ^= SDL_HWSURFACE;
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171 } else
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172 if ( strcmp(argv[argc], "-flip") == 0 ) {
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173 videoflags ^= SDL_DOUBLEBUF;
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174 } else
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175 if ( strcmp(argv[argc], "-fullscreen") == 0 ) {
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176 videoflags ^= SDL_FULLSCREEN;
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177 } else
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178 if ( isdigit(argv[argc][0]) ) {
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179 numsprites = atoi(argv[argc]);
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180 } else {
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181 fprintf(stderr,
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182 "Usage: %s [-bpp N] [-hw] [-flip] [-fast] [-fullscreen] [numsprites]\n",
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183 argv[0]);
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184 exit(1);
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185 }
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186 }
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187
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188 /* Set video mode */
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189 screen = SDL_SetVideoMode(width, height, video_bpp, videoflags);
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190 if ( ! screen ) {
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191 fprintf(stderr, "Couldn't set %dx%d video mode: %s\n",
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192 width, height, SDL_GetError());
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193 exit(2);
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194 }
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195
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196 /* Load the sprite */
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197 if ( LoadSprite(screen, "icon.bmp") < 0 ) {
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198 exit(1);
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199 }
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200
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201 /* Allocate memory for the sprite info */
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202 mem = (Uint8 *)malloc(4*sizeof(SDL_Rect)*numsprites);
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203 if ( mem == NULL ) {
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204 SDL_FreeSurface(sprite);
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205 fprintf(stderr, "Out of memory!\n");
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206 exit(2);
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207 }
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208 sprite_rects = (SDL_Rect *)mem;
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209 positions = sprite_rects;
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210 sprite_rects += numsprites;
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211 velocities = sprite_rects;
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212 sprite_rects += numsprites;
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213 srand(time(NULL));
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214 for ( i=0; i<numsprites; ++i ) {
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215 positions[i].x = rand()%screen->w;
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216 positions[i].y = rand()%screen->h;
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217 positions[i].w = sprite->w;
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218 positions[i].h = sprite->h;
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219 velocities[i].x = 0;
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220 velocities[i].y = 0;
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221 while ( ! velocities[i].x && ! velocities[i].y ) {
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222 velocities[i].x = (rand()%(MAX_SPEED*2+1))-MAX_SPEED;
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223 velocities[i].y = (rand()%(MAX_SPEED*2+1))-MAX_SPEED;
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224 }
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225 }
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226 background = SDL_MapRGB(screen->format, 0x00, 0x00, 0x00);
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227
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228 /* Print out information about our surfaces */
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229 printf("Screen is at %d bits per pixel\n",screen->format->BitsPerPixel);
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230 if ( (screen->flags & SDL_HWSURFACE) == SDL_HWSURFACE ) {
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231 printf("Screen is in video memory\n");
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232 } else {
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233 printf("Screen is in system memory\n");
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234 }
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235 if ( (screen->flags & SDL_DOUBLEBUF) == SDL_DOUBLEBUF ) {
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236 printf("Screen has double-buffering enabled\n");
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237 }
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238 if ( (sprite->flags & SDL_HWSURFACE) == SDL_HWSURFACE ) {
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239 printf("Sprite is in video memory\n");
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240 } else {
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241 printf("Sprite is in system memory\n");
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242 }
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243 /* Run a sample blit to trigger blit acceleration */
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244 { SDL_Rect dst;
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245 dst.x = 0;
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246 dst.y = 0;
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247 dst.w = sprite->w;
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248 dst.h = sprite->h;
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249 SDL_BlitSurface(sprite, NULL, screen, &dst);
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250 SDL_FillRect(screen, &dst, background);
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251 }
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252 if ( (sprite->flags & SDL_HWACCEL) == SDL_HWACCEL ) {
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253 printf("Sprite blit uses hardware acceleration\n");
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254 }
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255 if ( (sprite->flags & SDL_RLEACCEL) == SDL_RLEACCEL ) {
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256 printf("Sprite blit uses RLE acceleration\n");
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257 }
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258
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259 /* Loop, blitting sprites and waiting for a keystroke */
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260 frames = 0;
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261 then = SDL_GetTicks();
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262 done = 0;
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263 sprites_visible = 0;
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264 while ( !done ) {
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265 /* Check for events */
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266 ++frames;
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267 while ( SDL_PollEvent(&event) ) {
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268 switch (event.type) {
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269 case SDL_KEYDOWN:
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270 /* Any keypress quits the app... */
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271 case SDL_QUIT:
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272 done = 1;
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273 break;
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274 default:
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275 break;
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276 }
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277 }
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278 MoveSprites(screen, background);
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279 }
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280 SDL_FreeSurface(sprite);
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281 free(mem);
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282
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283 /* Print out some timing information */
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284 now = SDL_GetTicks();
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285 if ( now > then ) {
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286 printf("%2.2f frames per second\n",
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287 ((double)frames*1000)/(now-then));
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288 }
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289 return(0);
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290 }
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