1
2 /* Simple program: Fill a colormap with gray and stripe it down the screen */
3
4 #include <stdio.h>
5 #include <stdlib.h>
6 #include <string.h>
7 #include <time.h>
8
9 #include "SDL.h"
10
11 #ifdef TEST_VGA16 /* Define this if you want to test VGA 16-color video modes */
12 #define NUM_COLORS 16
13 #else
14 #define NUM_COLORS 256
15 #endif
16
17 /* Draw a randomly sized and colored box centered about (X,Y) */
DrawBox(SDL_Surface * screen,int X,int Y,int width,int height)18 void DrawBox(SDL_Surface *screen, int X, int Y, int width, int height)
19 {
20 static unsigned int seeded = 0;
21 SDL_Rect area;
22 Uint32 color;
23 Uint32 randc;
24
25 /* Seed the random number generator */
26 if ( seeded == 0 ) {
27 srand((unsigned int) time(NULL));
28 seeded = 1;
29 }
30
31 /* Get the bounds of the rectangle */
32 area.w = (rand()%width);
33 area.h = (rand()%height);
34 area.x = X-(area.w/2);
35 area.y = Y-(area.h/2);
36 randc = (rand()%NUM_COLORS);
37
38 if (screen->format->BytesPerPixel==1)
39 {
40 color = randc;
41 }
42 else
43 {
44 color = SDL_MapRGB(screen->format, randc, randc, randc);
45 }
46
47 /* Do it! */
48 SDL_FillRect(screen, &area, color);
49 if ( screen->flags & SDL_DOUBLEBUF ) {
50 SDL_Flip(screen);
51 } else {
52 SDL_UpdateRects(screen, 1, &area);
53 }
54 }
55
DrawBackground(SDL_Surface * screen)56 void DrawBackground(SDL_Surface *screen)
57 {
58 int i, j, k;
59 Uint8 *buffer;
60 Uint16 *buffer16;
61 Uint16 color;
62 Uint8 gradient;
63
64 /* Set the surface pixels and refresh! */
65 /* Use two loops in case the surface is double-buffered (both sides) */
66
67 for ( j=0; j<2; ++j ) {
68 if ( SDL_LockSurface(screen) < 0 ) {
69 fprintf(stderr, "Couldn't lock display surface: %s\n",
70 SDL_GetError());
71 return;
72 }
73 buffer = (Uint8 *)screen->pixels;
74
75 if (screen->format->BytesPerPixel!=2) {
76 for ( i=0; i<screen->h; ++i ) {
77 memset(buffer,(i*(NUM_COLORS-1))/screen->h, screen->w * screen->format->BytesPerPixel);
78 buffer += screen->pitch;
79 }
80 }
81 else
82 {
83 for ( i=0; i<screen->h; ++i ) {
84 gradient=((i*(NUM_COLORS-1))/screen->h);
85 color = SDL_MapRGB(screen->format, gradient, gradient, gradient);
86 buffer16=(Uint16*)buffer;
87 for (k=0; k<screen->w; k++)
88 {
89 *(buffer16+k)=color;
90 }
91 buffer += screen->pitch;
92 }
93 }
94
95 SDL_UnlockSurface(screen);
96 if ( screen->flags & SDL_DOUBLEBUF ) {
97 SDL_Flip(screen);
98 } else {
99 SDL_UpdateRect(screen, 0, 0, 0, 0);
100 break;
101 }
102 }
103 }
104
CreateScreen(Uint16 w,Uint16 h,Uint8 bpp,Uint32 flags)105 SDL_Surface *CreateScreen(Uint16 w, Uint16 h, Uint8 bpp, Uint32 flags)
106 {
107 SDL_Surface *screen;
108 int i;
109 SDL_Color palette[NUM_COLORS];
110
111 /* Set the video mode */
112 screen = SDL_SetVideoMode(w, h, bpp, flags);
113 if ( screen == NULL ) {
114 fprintf(stderr, "Couldn't set display mode: %s\n",
115 SDL_GetError());
116 return(NULL);
117 }
118 fprintf(stderr, "Screen is in %s mode\n",
119 (screen->flags & SDL_FULLSCREEN) ? "fullscreen" : "windowed");
120
121 if (bpp==8) {
122 /* Set a gray colormap, reverse order from white to black */
123 for ( i=0; i<NUM_COLORS; ++i ) {
124 palette[i].r = (NUM_COLORS-1)-i * (256 / NUM_COLORS);
125 palette[i].g = (NUM_COLORS-1)-i * (256 / NUM_COLORS);
126 palette[i].b = (NUM_COLORS-1)-i * (256 / NUM_COLORS);
127 }
128 SDL_SetColors(screen, palette, 0, NUM_COLORS);
129 }
130
131 return(screen);
132 }
133
main(int argc,char * argv[])134 int main(int argc, char *argv[])
135 {
136 SDL_Surface *screen;
137 Uint32 videoflags;
138 int done;
139 SDL_Event event;
140 int width, height, bpp;
141
142 /* Initialize SDL */
143 if ( SDL_Init(SDL_INIT_VIDEO) < 0 ) {
144 fprintf(stderr, "Couldn't initialize SDL: %s\n",SDL_GetError());
145 exit(1);
146 }
147
148 /* See if we try to get a hardware colormap */
149 width = 640;
150 height = 480;
151 bpp = 8;
152 videoflags = SDL_SWSURFACE;
153 while ( argc > 1 ) {
154 --argc;
155 if ( argv[argc-1] && (strcmp(argv[argc-1], "-width") == 0) ) {
156 width = atoi(argv[argc]);
157 --argc;
158 } else
159 if ( argv[argc-1] && (strcmp(argv[argc-1], "-height") == 0) ) {
160 height = atoi(argv[argc]);
161 --argc;
162 } else
163 if ( argv[argc-1] && (strcmp(argv[argc-1], "-bpp") == 0) ) {
164 bpp = atoi(argv[argc]);
165 --argc;
166 } else
167 if ( argv[argc] && (strcmp(argv[argc], "-hw") == 0) ) {
168 videoflags |= SDL_HWSURFACE;
169 } else
170 if ( argv[argc] && (strcmp(argv[argc], "-hwpalette") == 0) ) {
171 videoflags |= SDL_HWPALETTE;
172 } else
173 if ( argv[argc] && (strcmp(argv[argc], "-flip") == 0) ) {
174 videoflags |= SDL_DOUBLEBUF;
175 } else
176 if ( argv[argc] && (strcmp(argv[argc], "-noframe") == 0) ) {
177 videoflags |= SDL_NOFRAME;
178 } else
179 if ( argv[argc] && (strcmp(argv[argc], "-resize") == 0) ) {
180 videoflags |= SDL_RESIZABLE;
181 } else
182 if ( argv[argc] && (strcmp(argv[argc], "-fullscreen") == 0) ) {
183 videoflags |= SDL_FULLSCREEN;
184 } else {
185 fprintf(stderr, "Usage: %s [-width] [-height] [-bpp] [-hw] [-hwpalette] [-flip] [-noframe] [-fullscreen] [-resize]\n",
186 argv[0]);
187 exit(1);
188 }
189 }
190
191 /* Set a video mode */
192 screen = CreateScreen(width, height, bpp, videoflags);
193 if ( screen == NULL ) {
194 exit(2);
195 }
196
197 DrawBackground(screen);
198
199 /* Wait for a keystroke */
200 done = 0;
201 while ( !done && SDL_WaitEvent(&event) ) {
202 switch (event.type) {
203 case SDL_MOUSEBUTTONDOWN:
204 DrawBox(screen, event.button.x, event.button.y, width, height);
205 break;
206 case SDL_KEYDOWN:
207 /* Ignore ALT-TAB for windows */
208 if ( (event.key.keysym.sym == SDLK_LALT) ||
209 (event.key.keysym.sym == SDLK_TAB) ) {
210 break;
211 }
212 /* Center the mouse on <SPACE> */
213 if ( event.key.keysym.sym == SDLK_SPACE ) {
214 SDL_WarpMouse(width/2, height/2);
215 break;
216 }
217 /* Toggle fullscreen mode on <RETURN> */
218 if ( event.key.keysym.sym == SDLK_RETURN ) {
219 videoflags ^= SDL_FULLSCREEN;
220 screen = CreateScreen(
221 screen->w, screen->h,
222 screen->format->BitsPerPixel,
223 videoflags);
224 if ( screen == NULL ) {
225 fprintf(stderr,
226 "Couldn't toggle fullscreen mode\n");
227 done = 1;
228 }
229 DrawBackground(screen);
230 break;
231 }
232 /* Any other key quits the application... */
233 case SDL_QUIT:
234 done = 1;
235 break;
236 case SDL_VIDEOEXPOSE:
237 DrawBackground(screen);
238 break;
239 case SDL_VIDEORESIZE:
240 screen = CreateScreen(
241 event.resize.w, event.resize.h,
242 screen->format->BitsPerPixel,
243 videoflags);
244 if ( screen == NULL ) {
245 fprintf(stderr,
246 "Couldn't resize video mode\n");
247 done = 1;
248 }
249 DrawBackground(screen);
250 break;
251 default:
252 break;
253 }
254 }
255 SDL_Quit();
256 return(0);
257 }
258