1 // $Id: screen.cpp 2334 2005-04-04 16:26:14Z grumbel $
3 // SuperTux - A Jump'n Run
4 // Copyright (C) 2000 Bill Kendrick <bill@newbreedsoftware.com>
6 // This program is free software; you can redistribute it and/or
7 // modify it under the terms of the GNU General Public License
8 // as published by the Free Software Foundation; either version 2
9 // of the License, or (at your option) any later version.
11 // This program is distributed in the hope that it will be useful,
12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 // GNU General Public License for more details.
16 // You should have received a copy of the GNU General Public License
17 // along with this program; if not, write to the Free Software
18 // Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
31 #include <SDL_image.h>
34 #include <sys/types.h>
38 #include "gameconfig.h"
41 #include "video/drawing_context.h"
42 #include "math/vector.h"
44 static const float LOOP_DELAY = 20.0;
45 extern SDL_Surface* screen;
47 /* 'Stolen' from the SDL documentation.
48 * Return the pixel value at (x, y)
49 * NOTE: The surface must be locked before calling this!
51 Uint32 getpixel(SDL_Surface *surface, int x, int y)
53 int bpp = surface->format->BytesPerPixel;
54 /* Here p is the address to the pixel we want to retrieve */
55 Uint8 *p = (Uint8 *)surface->pixels + y * surface->pitch + x * bpp;
65 if(SDL_BYTEORDER == SDL_BIG_ENDIAN)
66 return p[0] << 16 | p[1] << 8 | p[2];
68 return p[0] | p[1] << 8 | p[2] << 16;
74 return 0; /* shouldn't happen, but avoids warnings */
78 /* 'Stolen' from the SDL documentation.
79 * Set the pixel at (x, y) to the given value
80 * NOTE: The surface must be locked before calling this!
82 void putpixel(SDL_Surface *surface, int x, int y, Uint32 pixel)
84 int bpp = surface->format->BytesPerPixel;
85 /* Here p is the address to the pixel we want to set */
86 Uint8 *p = (Uint8 *)surface->pixels + y * surface->pitch + x * bpp;
98 if(SDL_BYTEORDER == SDL_BIG_ENDIAN)
100 p[0] = (pixel >> 16) & 0xff;
101 p[1] = (pixel >> 8) & 0xff;
107 p[1] = (pixel >> 8) & 0xff;
108 p[2] = (pixel >> 16) & 0xff;
113 *(Uint32 *)p = pixel;
121 /* Draw a single pixel on the screen. */
122 void drawpixel(int x, int y, Uint32 pixel)
124 /* Lock the screen for direct access to the pixels */
125 if ( SDL_MUSTLOCK(screen) )
127 if ( SDL_LockSurface(screen) < 0 )
129 fprintf(stderr, "Can't lock screen: %s\n", SDL_GetError());
134 if(!(x < 0 || y < 0 || x > SCREEN_WIDTH || y > SCREEN_HEIGHT))
135 putpixel(screen, x, y, pixel);
137 if ( SDL_MUSTLOCK(screen) )
139 SDL_UnlockSurface(screen);
141 /* Update just the part of the display that we've changed */
142 SDL_UpdateRect(screen, x, y, 1, 1);
145 /* --- FILL A RECT --- */
147 void fillrect(float x, float y, float w, float h, int r, int g, int b, int a)
160 glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
161 glColor4ub(r, g, b,a);
166 glVertex2f(x+w, y+h);
172 SDL_Surface *temp = NULL;
180 temp = SDL_CreateRGBSurface(screen->flags, rect.w, rect.h, screen->format->BitsPerPixel,
181 screen->format->Rmask,
182 screen->format->Gmask,
183 screen->format->Bmask,
184 screen->format->Amask);
192 SDL_FillRect(temp, &src, SDL_MapRGB(screen->format, r, g, b));
193 SDL_SetAlpha(temp, SDL_SRCALPHA, a);
194 SDL_BlitSurface(temp,0,screen,&rect);
195 SDL_FreeSurface(temp);
197 SDL_FillRect(screen, &rect, SDL_MapRGB(screen->format, r, g, b));
202 /* Needed for line calculations */
203 #define SGN(x) ((x)>0 ? 1 : ((x)==0 ? 0:(-1)))
204 #define ABS(x) ((x)>0 ? (x) : (-x))
206 void draw_line(float x1, float y1, float x2, float y2,
207 int r, int g, int b, int a)
211 glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
212 glColor4ub(r, g, b,a);
220 /* Basic unantialiased Bresenham line algorithm */
221 int lg_delta, sh_delta, cycle, lg_step, sh_step;
222 Uint32 color = SDL_MapRGBA(screen->format, r, g, b, a);
224 lg_delta = (int)(x2 - x1);
225 sh_delta = (int)(y2 - y1);
226 lg_step = SGN(lg_delta);
227 lg_delta = ABS(lg_delta);
228 sh_step = SGN(sh_delta);
229 sh_delta = ABS(sh_delta);
230 if (sh_delta < lg_delta) {
231 cycle = lg_delta >> 1;
233 drawpixel((int)x1, (int)y1, color);
235 if (cycle > lg_delta) {
241 drawpixel((int)x1, (int)y1, color);
243 cycle = sh_delta >> 1;
245 drawpixel((int)x1, (int)y1, color);
247 if (cycle > sh_delta) {
253 drawpixel((int)x1, (int)y1, color);
258 void fadeout(int fade_time)
260 float alpha_inc = 256 / (fade_time / LOOP_DELAY);
265 fillrect(0, 0, SCREEN_WIDTH, SCREEN_HEIGHT, 0,0,0, (int)alpha_inc); // left side
267 DrawingContext context; // ugly...
268 context.do_drawing();
270 SDL_Delay(int(LOOP_DELAY));
273 fillrect(0, 0, SCREEN_WIDTH, SCREEN_HEIGHT, 0, 0, 0, 255);
276 void shrink_fade(const Vector& point, int fade_time)
278 float left_inc = point.x / ((float)fade_time / LOOP_DELAY);
279 float right_inc = (SCREEN_WIDTH - point.x) / ((float)fade_time / LOOP_DELAY);
280 float up_inc = point.y / ((float)fade_time / LOOP_DELAY);
281 float down_inc = (SCREEN_HEIGHT - point.y) / ((float)fade_time / LOOP_DELAY);
283 float left_cor = 0, right_cor = 0, up_cor = 0, down_cor = 0;
285 while(left_cor < point.x && right_cor < SCREEN_WIDTH - point.x &&
286 up_cor < point.y && down_cor < SCREEN_HEIGHT - point.y) {
287 left_cor += left_inc;
288 right_cor += right_inc;
290 down_cor += down_inc;
292 fillrect(0, 0, left_cor, SCREEN_HEIGHT, 0,0,0); // left side
293 fillrect(SCREEN_WIDTH - right_cor, 0, right_cor, SCREEN_HEIGHT, 0,0,0); // right side
294 fillrect(0, 0, SCREEN_WIDTH, up_cor, 0,0,0); // up side
295 fillrect(0, SCREEN_HEIGHT - down_cor, SCREEN_WIDTH, down_cor+1, 0,0,0); // down side
296 DrawingContext context; // ugly...
297 context.do_drawing();
299 SDL_Delay(int(LOOP_DELAY));