1 /* -*- Mode: C; tab-width: 4 -*- */
2 /* triangle --- create a triangle-mountain */
5 static const char sccsid[] = "@(#)triangle.c 4.04 97/07/28 xlockmore";
9 * Copyright (c) 1995 by Tobias Gloth
11 * Permission to use, copy, modify, and distribute this software and its
12 * documentation for any purpose and without fee is hereby granted,
13 * provided that the above copyright notice appear in all copies and that
14 * both that copyright notice and this permission notice appear in
15 * supporting documentation.
17 * This file is provided AS IS with no warranties of any kind. The author
18 * shall have no liability with respect to the infringement of copyrights,
19 * trade secrets or any patents by this file or any part thereof. In no
20 * event will the author be liable for any lost revenue or profits or
21 * other special, indirect and consequential damages.
24 * 10-May-97: Compatible with xscreensaver
25 * 10-Mar-96: re-arranged and re-formatted the code for appearance and
26 * to make common subroutines. Simplified.
27 * Ron Hitchens <ron@idiom.com>
28 * 07-Mar-96: Removed internal delay code, set MI_PAUSE(mi) for inter-scene
29 * delays. No other delays are needed here.
30 * Made pause time sensitive to value of cycles (in 10ths of a
31 * second). Removed (hopefully) all references to globals.
32 * Ron Hitchens <ron@idiom.com>
33 * 27-Feb-96: Undid the changes listed below. Added ModeInfo argument.
34 * Implemented delay between scenes using the MI_PAUSE(mi)
35 * scheme. Ron Hitchens <ron@idiom.com>
36 * 27-Dec-95: Ron Hitchens <ron@idiom.com>
37 * Modified logic of draw_triangle() to provide a delay
38 * (sensitive to the value of cycles) between each iteration.
39 * Because this mode is so compute intensive, when the new
40 * event loop adjusted the delay to compensate, this mode had
41 * almost no delay time left. This change pauses between each
42 * new landscape, but could still be done better (it is not
43 * sensitive to input events while drawing, for example).
44 * 03-Nov-95: Many changes (hopefully some good ones) by David Bagley
45 * 01-Oct-95: Written by Tobias Gloth
49 # define DEFAULTS "*delay: 10000 \n" \
51 "*fpsSolid: true \n" \
53 # define SMOOTH_COLORS
54 # define reshape_triangle 0
55 # define triangle_handle_event 0
56 # include "xlockmore.h" /* in xscreensaver distribution */
57 #else /* STANDALONE */
58 # include "xlock.h" /* in xlockmore distribution */
59 #endif /* STANDALONE */
61 ENTRYPOINT ModeSpecOpt triangle_opts =
62 {0, NULL, 0, NULL, NULL};
65 #define MAX_SIZE (1<<MAX_STEPS)
66 #define MAX_LEVELS 1000
68 #undef TOP /* FTSO AIX */
75 #define BLUE 45 /* Just the right shade of blue */
77 #define BACKFACE_REMOVAL
79 #define DISPLACE(h,d) ((h)/2+LRAND()/(MAXRAND/(2*(d)+1))-d)
92 short level[MAX_LEVELS];
93 int xpos[2 * MAX_SIZE + 1];
94 int ypos[MAX_SIZE + 1];
95 short H[(MAX_SIZE + 1) * (MAX_SIZE + 2) / 2];
96 short *h[MAX_SIZE + 1];
97 short delta[MAX_STEPS];
100 static trianglestruct *triangles = NULL;
104 draw_atriangle(ModeInfo * mi, XPoint * p, int y_0, int y_1, int y_2, double dinv)
106 Display *display = MI_DISPLAY(mi);
107 Window window = MI_WINDOW(mi);
110 if (MI_NPIXELS(mi) > 2) { /* color */
114 dmin = MIN(y_0, y_1);
115 dmin = MIN(dmin, y_2);
116 dmax = MAX(y_0, y_1);
117 dmax = MAX(dmax, y_2);
122 color = MI_NPIXELS(mi) -
123 (int) ((double) MI_NPIXELS(mi) / M_PI_2 * atan(dinv * (dmax - dmin)));
126 XSetForeground(display, gc, MI_PIXEL(mi, color % MI_NPIXELS(mi)));
127 XFillPolygon(display, window, gc, p, 3, Convex, CoordModeOrigin);
130 #ifdef BACKFACE_REMOVAL
131 XSetForeground(display, gc, MI_WIN_BLACK_PIXEL(mi));
132 XFillPolygon(display, window, gc, p, 3, Convex, CoordModeOrigin);
134 XSetForeground(display, gc, MI_WIN_WHITE_PIXEL(mi));
135 XDrawLine(display, window, gc, p[0].x, p[0].y, p[1].x, p[1].y);
136 XDrawLine(display, window, gc, p[1].x, p[1].y, p[2].x, p[2].y);
137 XDrawLine(display, window, gc, p[2].x, p[2].y, p[0].x, p[0].y);
143 calc_points1(trianglestruct * tp, int d, int *y0_p, int *y1_p, int *y2_p, XPoint * p)
145 *y0_p = tp->level[MAX(tp->h[tp->i][tp->j], 0)];
146 *y1_p = tp->level[MAX(tp->h[tp->i + d][tp->j], 0)];
147 *y2_p = tp->level[MAX(tp->h[tp->i][tp->j + d], 0)];
149 p[0].x = tp->xpos[2 * tp->i + tp->j];
150 p[1].x = tp->xpos[2 * (tp->i + d) + tp->j];
151 p[2].x = tp->xpos[2 * tp->i + (tp->j + d)];
153 p[0].y = tp->ypos[tp->j] - *y0_p;
154 p[1].y = tp->ypos[tp->j] - *y1_p;
155 p[2].y = tp->ypos[tp->j + d] - *y2_p;
160 calc_points2(trianglestruct * tp, int d, int *y0_p, int *y1_p, int *y2_p, XPoint * p)
162 *y0_p = tp->level[MAX(tp->h[tp->i + d][tp->j], 0)];
163 *y1_p = tp->level[MAX(tp->h[tp->i + d][tp->j + d], 0)];
164 *y2_p = tp->level[MAX(tp->h[tp->i][tp->j + d], 0)];
166 p[0].x = tp->xpos[2 * (tp->i + d) + tp->j];
167 p[1].x = tp->xpos[2 * (tp->i + d) + (tp->j + d)];
168 p[2].x = tp->xpos[2 * tp->i + (tp->j + d)];
170 p[0].y = tp->ypos[tp->j] - *y0_p;
171 p[1].y = tp->ypos[tp->j + d] - *y1_p;
172 p[2].y = tp->ypos[tp->j + d] - *y2_p;
178 draw_mesh(ModeInfo * mi, trianglestruct * tp, int d, int count)
183 double dinv = 0.2 / d;
185 if ((tp->j == 0) && (tp->i == 0)) {
187 XClearWindow(MI_DISPLAY(mi), MI_WINDOW(mi));
192 int x2 = MI_WIN_WIDTH(mi);
193 int y2 = tp->ypos[0];
194 XSetForeground(MI_DISPLAY(mi), MI_GC(mi), MI_WIN_BLACK_PIXEL(mi));
195 XFillRectangle(MI_DISPLAY(mi), MI_WINDOW(mi), MI_GC(mi),
200 for (; (tp->j < tp->size) && (count > 0); tp->j += ((count) ? d : 0)) {
201 for (tp->i = (first) ? tp->i : 0, first = 0;
202 (tp->i < MAX_SIZE - tp->j) && (count > 0);
203 tp->i += d, count--) {
204 if (tp->i + tp->j < tp->size) {
205 calc_points1(tp, d, &y_0, &y_1, &y_2, p);
206 draw_atriangle(mi, p, y_0, y_1, y_2, dinv);
208 if (tp->i + tp->j + d < tp->size) {
209 calc_points2(tp, d, &y_0, &y_1, &y_2, p);
210 draw_atriangle(mi, p, y_0, y_1, y_2, dinv);
215 if (tp->j == tp->size) {
221 init_triangle (ModeInfo * mi)
227 if (triangles == NULL) {
228 if ((triangles = (trianglestruct *) calloc(MI_NUM_SCREENS(mi),
229 sizeof (trianglestruct))) == NULL)
232 tp = &triangles[MI_SCREEN(mi)];
234 tp->width = MI_WIN_WIDTH(mi);
235 tp->height = MI_WIN_HEIGHT(mi);
239 XClearWindow(MI_DISPLAY(mi), MI_WINDOW(mi));
243 tp->steps = MAX_STEPS;
245 tp->size = 1 << --tp->steps;
246 } while (tp->size * 5 > tp->width);
248 for (i = 0; i < tp->size + 1; i++) {
250 tmp += (tp->size) + 1 - i;
254 dim = MIN(tp->width, tp->height);
256 for (i = 0; i < 2 * tp->size + 1; i++) {
257 tp->xpos[i] = (short) ((((double) i)
258 / ((double) (2 * tp->size)) * (RIGHT - LEFT) + LEFT)
259 * dim) + (tp->width - dim) / 2;
262 for (i = 0; i < (tp->size + 1); i++) {
263 tp->ypos[i] = (short) ((((double) i)
264 / ((double) tp->size) * (BOTTOM - TOP) + TOP) * dim)
265 + (tp->height - dim) / 2;
268 for (i = 0; i < tp->steps; i++) {
269 tp->delta[i] = ((short) (DELTA * dim)) >> i;
275 for (i = 0; i < MAX_LEVELS; i++) {
276 tp->level[i] = (i * i) / one;
281 draw_triangle (ModeInfo * mi)
283 trianglestruct *tp = &triangles[MI_SCREEN(mi)];
284 int d, d2, i, j, delta;
287 draw_mesh(mi, tp, tp->d / 2, MAX_SIZE / tp->d);
289 /* The init_now flag will pop up when the scene is complete.
290 * Cycles specifies how long to wait, in 1/10 secs.
291 TODO: This is wrong for multi-screens ***
295 MI_PAUSE(mi) = 2000000;
299 XClearWindow(MI_DISPLAY(mi), MI_WINDOW(mi));
302 free_colors(mi->dpy, mi->xgwa.colormap, mi->colors,
304 make_smooth_colormap (mi->dpy,
305 mi->xgwa.visual, mi->xgwa.colormap,
306 mi->colors, &mi->npixels,
307 True, &mi->writable_p, True);
314 if (tp->delta[0] > 0) {
315 if (!(++tp->stage)) {
316 tp->h[0][0] = (short int) MAX(0, DISPLACE(0, tp->delta[0]));
317 tp->h[tp->size][0] = (short int) MAX(0, DISPLACE(0, tp->delta[0]));
318 tp->h[0][tp->size] = (short int) MAX(0, DISPLACE(0, tp->delta[0]));
320 d = 2 << (tp->steps - tp->stage);
322 delta = tp->delta[tp->stage - 1];
324 for (i = 0; i < tp->size; i += d) {
325 for (j = 0; j < (tp->size - i); j += d) {
326 tp->h[i + d2][j] = (short int) DISPLACE(tp->h[i][j] +
327 tp->h[i + d][j], delta);
328 tp->h[i][j + d2] = (short int) DISPLACE(tp->h[i][j] +
329 tp->h[i][j + d], delta);
330 tp->h[i + d2][j + d2] = (short int) DISPLACE(tp->h[i + d][j] +
331 tp->h[i][j + d], delta);
341 if (tp->stage == tp->steps) {
347 release_triangle(ModeInfo * mi)
349 if (triangles != NULL) {
350 (void) free((void *) triangles);
356 refresh_triangle (ModeInfo * mi)
358 /* Do nothing, it will refresh by itself */
361 XSCREENSAVER_MODULE ("Triangle", triangle)