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1.1 root 1: /*** Mandel.c - compute and display Mandelbrot set
2: * R. A. Garmoe 86/12/10
3: */
4:
5:
6:
7: /** Mandel compute the elements of the Mandelbrot set
8: *
9: * z = z**2 + c
10: *
11: * where z and c are in the complex plane and z = 0 + 0i for the first
12: * iteration. The elements of the set along with the description of the
13: * computation are written to the .cnt file.
14: */
15:
16:
17:
18:
19: /** Call
20: *
21: * mandel -v {-u a+bi} {-l c+di} {-r num} {-c num} {-i itr} {-a f} {-f name}
22: * {-d display}
23: *
24: * where
25: *
26: * a compute each point with an aspect ratio of f where
27: * f is :
28: * f.ffff floating point number describing the
29: * ratio of width vs height of each pixel
30: *
31: * c number of points across the real coordinate. This
32: * value cannot exceed 2000 and is defaulted to 640.
33: *
34: * d set display to device. The default display is EGA.
35: * CGA Color Graphics Adapter
36: * columns = 350
37: * rows = 200
38: * aspect = 2.4
39: *
40: * EGA Extended Graphics Adapter
41: * columns = 640
42: * rows = 350
43: * aspect = 2.4
44: *
45: * PGA Professional Graphics Adapter
46: * columns = 640
47: * rows = 480
48: * aspect = 1.0
49: *
50: * f name for the .cnt file
51: * If name is not specified, "mandel" is used.
52: *
53: * i iteration limit. This value cannot exceed 1000 and
54: * the default is 256
55: *
56: * l lower right corner as c+di
57: *
58: *
59: * r number of points down the imaginary coordinate. This
60: * value is defaulted to 350.
61: *
62: * u upper left corner as a+bi
63: *
64: * v display information about each scan line as processed
65: *
66: * The .cnt file has the format
67: * int number of points along the real axis
68: * int number of points along the imaginary axis
69: * int maximum iteration point for each point
70: * double real coordinate of upper left
71: * double imaginary coordinate of upper left
72: * double real coordinate of lower right
73: * double imaginary coordinate lower rightft
74: * long (loop + 1) counters for histogram values
75: */
76:
77:
78:
79:
80: #include <stdio.h>
81: #include <doscalls.h>
82:
83: int mandinter ();
84:
85: #define FALSE 0
86: #define TRUE ~FALSE
87:
88: #define MAXREAL 2000 /* maximum number of points in line */
89: #define MAXLOOP 1000 /* maximum number of iterations */
90:
91: #define CGA_DEV 0 /* Color Graphics Adapter */
92: #define CGA_COL 350 /* number of display columns for CGA */
93: #define CGA_ROW 200 /* number of display rows for CGA */
94: #define CGA_ASP 12/5 /* aspect ratio (width/height) for CGA */
95:
96: #define EGA_DEV 1 /* Extended Graphics Adapter */
97: #define EGA_COL 640 /* number of display columns for EGA */
98: #define EGA_ROW 350 /* number of display rows for EGA */
99: #define EGA_ASP 1.33 /* aspect ratio (width/height) for EGA */
100:
101: #define PGA_DEV 2 /* Professional Graphics Adapter */
102: #define PGA_COL 640 /* number of display columns for PGA */
103: #define PGA_ROW 480 /* number of display rows for PGA */
104: #define PGA_ASP 1.0 /* aspect ratio (width/height) for PGA */
105:
106:
107: struct cmplx {
108: double realp; /* real part of number */
109: double imagp; /* imaginary part of number */
110: };
111:
112:
113:
114: char fp287; /* 287 processor status from DOSDEVCONFIG */
115: char pmand[60] = "mandel.cnt"; /* file name for loop counts */
116: FILE *fmand;
117:
118: double rinc; /* increment in real coordinate */
119: double iinc; /* increment in imaginary coordinate */
120:
121: int device = EGA_DEV; /* default device type */
122: int arg_device = -1; /* device type from arguments */
123: int mcount[MAXREAL]; /* array holding interation counters */
124: int rlcount[MAXREAL + 2]; /* run length encoded interation counters */
125: int nreal = EGA_COL; /* number of points on real coordinate */
126: int arg_nreal = 0; /* number real coordinate from arguments */
127: int nimag = EGA_ROW; /* number of points on imaginary coordinate */
128: int arg_nimag = 0; /* number imaginary coordinate from arguments */
129: int loop = 256; /* maximum loop count for each point */
130: int verbose = FALSE; /* display scan line information if true */
131: double aspect = EGA_ASP; /* default screen aspect ratio */
132: double arg_aspect = 0.0; /* aspect from arguments */
133:
134: long hist[MAXLOOP + 1] = {0}; /* histogram counters */
135:
136: struct cmplx c; /* value of mandelbrot seed */
137: struct cmplx ul; /* coordinates of upper left corner */
138: struct cmplx lr; /* coordinates of lower right corner */
139:
140:
141: main (argc, argv)
142: int argc;
143: char **argv;
144: {
145: int nr;
146: int ni;
147: int i;
148: int temp;
149: int *rl;
150: long position;
151:
152: if (DOSDEVCONFIG ((char far *)&fp287, 3, 0) != 0) {
153: printf ("Unable to get fp processor presence flag\n");
154: exit (1);
155: }
156: if (fp287 != 1) {
157: printf ("There is not a 287 fp processor present\n");
158: exit (1);
159: }
160: nextarg (argc, argv);
161: if ((fmand = fopen (pmand, "wb")) == NULL) {
162: printf ("Unable to open count file %s\n", pmand);
163: exit (3);
164: }
165: if (ul.realp == lr.realp && ul.imagp == lr.imagp) {
166: printf ("%15.13lf+%15.13lfi, %15.13lf+%15.13lfi\n",ul.realp,ul.imagp,lr.realp,lr.imagp);
167: printf ("Upper left real = lower right real\n");
168: exit (3);
169: }
170:
171: /* reset nreal, nimag, aspect from command line device type */
172:
173: switch (arg_device) {
174: case CGA_DEV:
175: nreal = CGA_COL;
176: nimag = CGA_ROW;
177: aspect = CGA_ASP;
178: break;
179:
180: case EGA_DEV:
181: nreal = EGA_COL;
182: nimag = EGA_ROW;
183: aspect = EGA_ASP;
184: break;
185:
186: case PGA_DEV:
187: nreal = PGA_COL;
188: nimag = PGA_ROW;
189: aspect = PGA_ASP;
190: break;
191: }
192:
193: /* reset individual parameters */
194:
195: if (arg_nreal != 0)
196: nreal = arg_nreal;
197: if (arg_nimag != 0)
198: nimag = arg_nimag;
199: if (arg_aspect != 0)
200: aspect = arg_aspect;
201:
202: /* compute the step increments for the specifed aspect */
203:
204: rinc = (lr.realp - ul.realp) / (double)nreal;
205: iinc = rinc * aspect;
206:
207: lr.imagp = ul.imagp - iinc * nimag;
208:
209: fwrite ((char *)&nreal, sizeof (int), 1, fmand);
210: fwrite ((char *)&nimag, sizeof (int), 1, fmand);
211: fwrite ((char *)&loop, sizeof (int), 1, fmand);
212: fwrite ((char *)&ul, sizeof (ul), 1, fmand);
213: fwrite ((char *)&lr, sizeof (lr), 1, fmand);
214: fwrite ((char *)&rinc, sizeof (rinc), 1, fmand);
215: fwrite ((char *)&iinc, sizeof (iinc), 1, fmand);
216: fwrite ((char *)&aspect, sizeof (aspect), 1, fmand);
217: position = ftell (fmand);
218: fwrite ((char *)hist, sizeof (long), loop + 1, fmand);
219:
220: c.imagp = ul.imagp;
221: for (ni = 0; ni < nimag; ni++) {
222: c.realp = ul.realp;
223: if (verbose)
224: printf ("%4d, %15.13lf + %15.13lfi", ni, c.realp, c.imagp);
225: manditer (c.realp, c.imagp, loop, nreal, mcount, rinc);
226: for (nr = 0; nr < nreal; nr++) {
227: i = mcount[nr];
228: hist[i]++;
229: }
230:
231: /* run length encode counts for this scan line */
232:
233: temp = *mcount;
234: nr = 1;
235: rl = rlcount + 1;
236: i = -1;
237: for (; nr < nreal; nr++) {
238: i++;
239: if (mcount[nr] != temp) {
240: /* process change in value */
241: if (i != 0)
242: /* output count of duplicate values */
243: *rl++ = -(i + 1);
244: /* output value */
245: *rl++ = temp;
246: /* reset compression values */
247: temp = mcount[nr];
248: i = -1;
249: }
250: }
251: if (i != -1) {
252: if (i != 0)
253: /* output count of duplicate values */
254: *rl++ = -(i + 2);
255: /* output value */
256: *rl++ = temp;
257: }
258: *rlcount = rl - rlcount -1;
259: if (verbose)
260: printf ("%4d\n", *rlcount);
261: if (fwrite ((char *)rlcount, sizeof (int), *rlcount + 1, fmand) !=
262: *rlcount + 1) {
263: printf ("error writing count file %s\n", pmand);
264: exit (4);
265: }
266: c.imagp -= iinc;
267: }
268: fseek (fmand, position, 0);
269: if (fwrite ((char *)hist, sizeof (long), loop + 1, fmand) != loop + 1) {
270: printf ("error writing histogram to file %s\n", pmand);
271: exit (4);
272: }
273: }
274:
275:
276:
277: /** nextarg - process arguments
278: *
279: */
280:
281:
282: nextarg (argc, argv)
283: int argc;
284: char **argv;
285: {
286:
287: argv++;
288: while ((argc-- > 0) && (**argv == '-')) {
289: switch (*(*argv+1)) {
290: case 'a':
291: /* specify aspect ratio */
292: argv++;
293: if ((argc < 1) ||
294: (sscanf (*argv++, "%lf", &arg_aspect) != 1)) {
295: printf ("Error specifing aspect\n");
296: exit (1);
297: }
298: argc--;
299: break;
300:
301: case 'c':
302: /* specify number of columns and limit to maximum value */
303: argv++;
304: if ((argc < 1) ||
305: (sscanf (*argv++, " %d", &arg_nreal) != 1)) {
306: printf ("Error specifying number of real points\n");
307: exit (1);
308: }
309: argc--;
310: if (arg_nreal > MAXREAL) {
311: arg_nreal = MAXREAL;
312: printf ("Number of columns limited to %d\n", MAXREAL);
313: }
314: break;
315:
316: case 'd':
317: /* specify default device paramters */
318: argv++;
319: if (strcmp (*argv, "CGA") == 0)
320: arg_device = CGA_DEV;
321: else if (strcmp (*argv, "EGA") == 0)
322: arg_device = EGA_DEV;
323: else if (strcmp (*argv, "PGA") == 0)
324: arg_device = PGA_DEV;
325: else {
326: printf ("Error specifing device\n");
327: exit (1);
328: }
329: argv++;
330: argc--;
331: break;
332:
333: case 'f':
334: /* specify output file name */
335: argv++;
336: /* set file name */
337: strcpy (pmand, *argv);
338: strcat (pmand, ".cnt");
339: break;
340:
341: case 'i':
342: /* specify iteration count and limit to maximum */
343: argv++;
344: if ((argc < 1) ||
345: (sscanf (*argv++, " %d", &loop) != 1)) {
346: printf ("Error specifying iteration limit\n");
347: exit (1);
348: }
349: argc--;
350: if (loop > MAXLOOP) {
351: loop = MAXREAL;
352: printf ("Iteration count limited to %d\n", MAXLOOP);
353: }
354: break;
355:
356: case 'l':
357: /* specify lower right corner as c+di */
358: argv++;
359: if ((argc < 1) || (sscanf (*argv++, "%lf%lfi",
360: &lr.realp, &lr.imagp) != 2)) {
361: printf ("Error specifying lower right\n");
362: exit (1);
363: }
364: argc--;
365: break;
366:
367:
368: case 'r':
369: /* specify number of rows */
370: argv++;
371: if ((argc < 1) ||
372: (sscanf (*argv++, " %d", &arg_nimag) != 1)) {
373: printf ("Error specifying number of imaginary points\n");
374: exit (1);
375: }
376: argc--;
377: break;
378:
379: case 'u':
380: /* specify upper right corner as a+bi */
381: argv++;
382: if ((argc < 1) || (sscanf (*argv++, "%lf%lfi",
383: &ul.realp, &ul.imagp) != 2)) {
384: printf ("Error specifying upper left\n");
385: exit (1);
386: }
387: argc--;
388: break;
389:
390: case 'v':
391: /* specify verbose output */
392: argv++;
393: verbose = TRUE;
394: break;
395:
396: default:
397: printf ("Unknown argument %s\n", *argv);
398: exit (1);
399:
400: }
401: }
402: }
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