Root/solidify/povray.c

1/*
2 * povray.c - Generate POV-Ray output
3 *
4 * Written 2010 by Werner Almesberger
5 * Copyright 2010 by Werner Almesberger
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 */
12
13
14#include <stdint.h>
15#include <stdlib.h>
16#include <stdio.h>
17#include <string.h>
18#include <math.h>
19
20#include "face.h"
21#include "solid.h"
22
23
24static void height_field(const char *name, const struct face *f)
25{
26    FILE *file;
27    int x, y;
28    int z;
29    uint16_t g;
30    uint8_t v[2];
31
32    file = fopen(name, "w");
33    if (!file) {
34        perror(name);
35        exit(1);
36    }
37    if (fprintf(file, "P5\n%d %d\n65535\n", f->sx, f->sy) < 0) {
38        perror(name);
39        exit(1);
40    }
41    for (y = 0; y != f->sy; y++)
42        for (x = 0; x != f->sx; x++) {
43            z = get(f->a, x+f->a->min_x, y+f->a->min_y);
44            g = z == UNDEF ? 0 :
45                65535*(z-f->a->min_z)/(f->a->max_z-f->a->min_z);
46            v[0] = g >> 8;
47            v[1] = g;
48            if (fwrite(v, 2, 1, file) != 1) {
49                perror(name);
50                exit(1);
51            }
52        }
53    if (fclose(file) < 0) {
54        perror(name);
55        exit(1);
56    }
57}
58
59
60static void sanitize(const char *s, char *res)
61{
62    while (*s) {
63        if ((*s >= 'A' && *s <= 'Z') ||
64            (*s >= 'a' && *s <= 'z') ||
65            (*s >= '0' && *s <= '9') || *s == '_')
66            *res = *s;
67        else
68            *res = '_';
69        res++;
70        s++;
71    }
72    *res = 0;
73}
74
75
76/*
77 * For now, we put the part such that its x/y/z center is at the origin.
78 * Later, we will also have to consider the changes the user made and the
79 * relation with the opposing face.
80 */
81
82static void povray_face(FILE *file, const struct face *f, const char *side,
83    const char *prefix, int flip, double dist)
84{
85    double a;
86
87    /*
88     * 1/65535 = 0.000015..., so we set the water level a bit lower, e.g.,
89     * to 0.0001
90     */
91    a = asin(-f->m.a[0][1])/M_PI*180;
92        if (f->m.a[0][0] < 0)
93                a = 180-a;
94    fprintf(file,
95"\theight_field {\n"
96"\t pgm \"%s-%s.pgm\"\n"
97"\t water_level 0.00001\n"
98"\t smooth\n"
99"\t scale <%g, %g, %g> /* scale from unit cube to real size */\n"
100"\t rotate <90, 0, 0> /* swap Y/Z axis */\n"
101"\t translate <%g, %g, 0> /* move to X/Y center */\n"
102"\t rotate <%g, %g, 0> /* z0 plane tilt */\n"
103"\t translate <0, 0, %g> /* min_z offset */\n"
104"\t translate <0, 0, %g> /* z0 plane offset */\n"
105"\t rotate <0, 0, %g> /* overlay - rotation */\n"
106"\t translate <%g, %g, 0> /* overlay - shift */\n"
107"%s" /* flip bottom face */
108"\t translate <0, 0, %g> /* half the distance between faces */\n"
109"\t}\n", prefix, side,
110    f->sx*f->x_step, (f->sz-1)*f->z_step, f->sy*f->y_step,
111    -f->sx*f->x_step/2, f->sy*f->y_step/2,
112    -fy_to_angle(f), fx_to_angle(f),
113    f->a->min_z*f->z_step,
114    -f->z_ref*f->z_step,
115    a,
116    f->m.b[0]*f->x_step, f->m.b[1]*f->y_step,
117    flip ? "\t rotate <0, 180, 0>\t/* flip bottom face */\n" : "",
118    dist*f->z_step);
119}
120
121
122void povray(const char *file_name, const char *name, const struct solid *s)
123{
124    FILE *file;
125    char tmp[1000]; /* @@@ enough */
126
127    file = strcmp(file_name, "-") ? fopen(file_name, "w") : stdout;
128    if (!file) {
129        perror(file_name);
130        exit(1);
131    }
132
133    sprintf(tmp, "%s-top.pgm", name);
134    height_field(tmp, s->a);
135    sprintf(tmp, "%s-bot.pgm", name);
136    height_field(tmp, s->b);
137
138    sanitize(name, tmp);
139    fprintf(file, "#declare Part_%s =\n intersection {\n", tmp);
140    povray_face(file, s->a, "top", name, 0, s->dist/2);
141    povray_face(file, s->b, "bot", name, 1, -s->dist/2);
142    fprintf(file, " }\n");
143
144    /* @@@ not reliable */
145    if (ferror(file)) {
146        perror(file_name);
147        exit(1);
148    }
149    if (fflush(file) == EOF) {
150        perror(file_name);
151        exit(1);
152    }
153    if (file != stdout)
154        if (fclose(file) < 0) {
155            perror(file_name);
156            exit(1);
157        }
158}
159

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