/
envtoirr.c
512 lines (416 loc) · 15.7 KB
/
envtoirr.c
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
/* Copyright (c) 2010-2013 Robert Kooima */
/* */
/* Permission is hereby granted, free of charge, to any person obtaining a */
/* copy of this software and associated documentation files (the "Software"), */
/* to deal in the Software without restriction, including without limitation */
/* the rights to use, copy, modify, merge, publish, distribute, sublicense, */
/* and/or sell copies of the Software, and to permit persons to whom the */
/* Software is furnished to do so, subject to the following conditions: */
/* */
/* The above copyright notice and this permission notice shall be included in */
/* all copies or substantial portions of the Software. */
/* */
/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR */
/* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, */
/* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL */
/* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER */
/* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING */
/* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER */
/* DEALINGS IN THE SOFTWARE. */
#include <tiffio.h>
#include <stdlib.h>
#include <string.h>
#include <getopt.h>
#include <stdio.h>
#include <math.h>
#include "gray.h"
#include "sRGB.h"
#define PI 3.1415927f
/* See "An Efficient Representation for Irradiance Environment Maps" by */
/* Ramamorrthi & Handrahan, SIGGRAPH 2001 */
/*----------------------------------------------------------------------------*/
/* This array defines the X, Y, and Z axes of each of the six cube map faces, */
/* which determine the orientation of each face and the mapping between 2D */
/* image space and 3D cube map space. */
static const double nx[3] = { -1.0, 0.0, 0.0 };
static const double px[3] = { 1.0, 0.0, 0.0 };
static const double ny[3] = { 0.0, -1.0, 0.0 };
static const double py[3] = { 0.0, 1.0, 0.0 };
static const double nz[3] = { 0.0, 0.0, -1.0 };
static const double pz[3] = { 0.0, 0.0, 1.0 };
const double *cubemap_axis[6][3] = {
{ pz, py, nx },
{ nz, py, px },
{ nx, nz, ny },
{ nx, pz, py },
{ nx, py, nz },
{ px, py, pz },
};
static void normalize(double *a, const double *b)
{
const double k = 1.0 / sqrt(b[0] * b[0] + b[1] * b[1] + b[2] * b[2]);
a[0] = b[0] * k;
a[1] = b[1] * k;
a[2] = b[2] * k;
}
void transform(double *a, const double *M, const double *b)
{
a[0] = M[ 0] * b[0] + M[ 4] * b[1] + M[ 8] * b[2] + M[12] * b[3];
a[1] = M[ 1] * b[0] + M[ 5] * b[1] + M[ 9] * b[2] + M[13] * b[3];
a[2] = M[ 2] * b[0] + M[ 6] * b[1] + M[10] * b[2] + M[14] * b[3];
a[3] = M[ 3] * b[0] + M[ 7] * b[1] + M[11] * b[2] + M[15] * b[3];
}
static void vector(double *v, int f, double x, double y, double z)
{
const double *X = cubemap_axis[f][0];
const double *Y = cubemap_axis[f][1];
const double *Z = cubemap_axis[f][2];
double w[3];
w[0] = X[0] * x + Y[0] * y + Z[0] * z;
w[1] = X[1] * x + Y[1] * y + Z[1] * z;
w[2] = X[2] * x + Y[2] * y + Z[2] * z;
normalize(v, w);
v[3] = 1.0;
}
double solid_angle(const double *a,
const double *b,
const double *c)
{
double n = fabs(a[0] * (b[1] * c[2] - b[2] * c[1]) +
a[1] * (b[2] * c[0] - b[0] * c[2]) +
a[2] * (b[0] * c[1] - b[1] * c[0]));
double d = 1.0 + a[0] * b[0] + a[1] * b[1] + a[2] * b[2]
+ a[0] * c[0] + a[1] * c[1] + a[2] * c[2]
+ b[0] * c[0] + b[1] * c[1] + b[2] * c[2];
return 2.0 * atan2(n, d);
}
/*----------------------------------------------------------------------------*/
double *sph_grace_cathedral(uint16 *C)
{
double *L = 0;
if ((L = (double *) malloc(9 * 3 * sizeof (double))))
{
L[ 0] = 0.79; L[ 1] = 0.44; L[ 2] = 0.54;
L[ 3] = 0.39; L[ 4] = 0.35; L[ 5] = 0.60;
L[ 6] = -0.34; L[ 7] = -0.18; L[ 8] = -0.27;
L[ 9] = -0.29; L[10] = -0.06; L[11] = 0.01;
L[12] = -0.11; L[13] = -0.05; L[14] = -0.12;
L[15] = -0.26; L[16] = -0.22; L[17] = -0.47;
L[18] = -0.16; L[19] = -0.09; L[20] = -0.15;
L[21] = 0.56; L[22] = 0.21; L[23] = 0.14;
L[24] = 0.21; L[25] = -0.05; L[26] = -0.30;
*C = 3;
}
return L;
}
double *sph_eucalyptus_grove(uint16 *C)
{
double *L = 0;
if ((L = (double *) malloc(9 * 3 * sizeof (double))))
{
L[ 0] = 0.38; L[ 1] = 0.43; L[ 2] = 0.45;
L[ 3] = 0.29; L[ 4] = 0.36; L[ 5] = 0.41;
L[ 6] = 0.04; L[ 7] = 0.03; L[ 8] = 0.01;
L[ 9] = -0.10; L[10] = -0.10; L[11] = -0.09;
L[12] = -0.06; L[13] = -0.06; L[14] = -0.04;
L[15] = 0.01; L[16] = -0.01; L[17] = -0.05;
L[18] = -0.09; L[19] = -0.13; L[20] = -0.15;
L[21] = -0.06; L[22] = -0.05; L[23] = -0.04;
L[24] = 0.02; L[25] = -0.00; L[26] = -0.05;
*C = 3;
}
return L;
}
double *sph_st_peters_basilica(uint16 *C)
{
double *L = 0;
if ((L = (double *) malloc(9 * 3 * sizeof (double))))
{
L[ 0] = 0.36; L[ 1] = 0.26; L[ 2] = 0.23;
L[ 3] = 0.18; L[ 4] = 0.14; L[ 5] = 0.13;
L[ 6] = -0.02; L[ 7] = -0.01; L[ 8] = -0.00;
L[ 9] = 0.03; L[10] = 0.02; L[11] = 0.01;
L[12] = 0.02; L[13] = 0.01; L[14] = 0.00;
L[15] = -0.05; L[16] = -0.03; L[17] = -0.01;
L[18] = -0.09; L[19] = -0.08; L[20] = -0.07;
L[21] = 0.01; L[22] = 0.00; L[23] = 0.00;
L[24] = -0.08; L[25] = -0.06; L[26] = 0.00;
*C = 3;
}
return L;
}
/*----------------------------------------------------------------------------*/
double calc_domega(const double *v00,
const double *v01,
const double *v10,
const double *v11)
{
return (solid_angle(v00, v11, v01) +
solid_angle(v11, v00, v10)) / (4 * PI);
}
void calc_Y(double *Y, double x, double y, double z)
{
Y[0] = 0.282095;
Y[1] = 0.488603 * y;
Y[2] = 0.488603 * z;
Y[3] = 0.488603 * x;
Y[4] = 1.092548 * x * y;
Y[5] = 1.092548 * y * z;
Y[6] = 0.315392 * (3 * z * z - 1);
Y[7] = 1.092548 * x * z;
Y[8] = 0.546274 * (x * x - y * y);
}
void env_to_sph_face(double *L, TIFF *I, int F, uint32 N, uint16 C, uint16 B)
{
/* Confirm the parameters of the current face. */
if (TIFFSetDirectory(I, F))
{
uint32 w, h;
uint16 b, c;
float *s;
TIFFGetField(I, TIFFTAG_IMAGEWIDTH, &w);
TIFFGetField(I, TIFFTAG_IMAGELENGTH, &h);
TIFFGetField(I, TIFFTAG_SAMPLESPERPIXEL, &c);
TIFFGetField(I, TIFFTAG_BITSPERSAMPLE, &b);
if (w == N && h == N && b == B && c == C)
{
/* Allocate a scanline buffer. */
if ((s = (float *) malloc(TIFFScanlineSize(I))))
{
uint32 i;
uint32 j;
uint16 k;
/* Iterate over all pixels of the current cube face. */
for (i = 0; i < N; ++i)
{
if (TIFFReadScanline(I, s, i, 0) == 1)
{
for (j = 0; j < N; ++j)
{
float *p = s + j * c;
/* Compute the direction vector to this pixel. */
double y0 = (2.0 * (i ) - N) / N;
double y = (2.0 * (i + 0.5) - N) / N;
double y1 = (2.0 * (i + 1.0) - N) / N;
double x0 = (2.0 * (j ) - N) / N;
double x = (2.0 * (j + 0.5) - N) / N;
double x1 = (2.0 * (j + 1.0) - N) / N;
double v00[4];
double v01[4];
double v10[4];
double v11[4];
double v[4];
double Y[9];
double dd;
vector(v00, F, x0, y0, 1.f);
vector(v01, F, x0, y1, 1.f);
vector(v10, F, x1, y0, 1.f);
vector(v11, F, x1, y1, 1.f);
vector(v, F, x, y, 1.f);
dd = calc_domega(v00, v01, v10, v11);
calc_Y(Y, v[0], v[1], v[2]);
for (k = 0; k < c; ++k)
{
L[0 * c + k] += Y[0] * (double) p[k] * dd;
L[1 * c + k] += Y[1] * (double) p[k] * dd;
L[2 * c + k] += Y[2] * (double) p[k] * dd;
L[3 * c + k] += Y[3] * (double) p[k] * dd;
L[4 * c + k] += Y[4] * (double) p[k] * dd;
L[5 * c + k] += Y[5] * (double) p[k] * dd;
L[6 * c + k] += Y[6] * (double) p[k] * dd;
L[7 * c + k] += Y[7] * (double) p[k] * dd;
L[8 * c + k] += Y[8] * (double) p[k] * dd;
}
}
}
}
free(s);
}
}
}
}
double *env_to_sph(TIFF *I, uint32 N, uint16 C, uint16 B)
{
double *L = 0;
int F;
/* Allocate storage for spherical harmonic coefficients. */
if ((L = (double *) calloc(9 * C, sizeof (double))))
{
/* Iterate over all faces, accumulating coefficients for all. */
for (F = 0; F < 6; ++F)
env_to_sph_face(L, I, F, N, C, B);
}
return L;
}
/*----------------------------------------------------------------------------*/
void irrmatrix(double *M, double Lzz, double Lpn, double Lpz,
double Lpp, double Lqm, double Lqn,
double Lqz, double Lqp, double Lqq)
{
const double c1 = 0.429043;
const double c2 = 0.511664;
const double c3 = 0.743125;
const double c4 = 0.886227;
const double c5 = 0.247708;
M[ 0] = c1 * Lqq;
M[ 1] = c1 * Lqm;
M[ 2] = c1 * Lqp;
M[ 3] = c2 * Lpp;
M[ 4] = c1 * Lqm;
M[ 5] = -c1 * Lqq;
M[ 6] = c1 * Lqn;
M[ 7] = c2 * Lpn;
M[ 8] = c1 * Lqp;
M[ 9] = c1 * Lqn;
M[10] = c3 * Lqz;
M[11] = c2 * Lpz;
M[12] = c2 * Lpp;
M[13] = c2 * Lpn;
M[14] = c2 * Lpz;
M[15] = c4 * Lzz - c5 * Lqz;
}
void sph_to_irr_face(float *d, const double *M, int F, uint32 N, uint16 C, uint16 k)
{
uint32 i;
uint32 j;
/* Iterate over all pixels of the current cube face. */
for (i = 0; i < N; ++i)
for (j = 0; j < N; ++j)
{
/* Compute the direction vector of the current pixel. */
double y = (double) (2.0 * (i + 0.5) - N) / N;
double x = (double) (2.0 * (j + 0.5) - N) / N;
double v[4];
double w[4];
vector(v, F, x, y, 1.0);
/* Compute the irradiance. */
transform(w, M, v);
(d + i * N * C + j * C)[k] = (float) (v[0] * w[0] +
v[1] * w[1] +
v[2] * w[2] +
v[3] * w[3]);
}
}
void sph_to_irr(double *L, TIFF *O, uint32 N, uint16 C)
{
double M[16];
float *d;
uint16 k;
uint32 i;
size_t S;
int F;
/* Allocate a scratch buffer for one cube face. */
if ((d = (float *) malloc(N * N * C * sizeof (float))))
{
/* Iterate over all cube faces. */
for (F = 0; F < 6; ++F)
{
TIFFSetField(O, TIFFTAG_IMAGEWIDTH, N);
TIFFSetField(O, TIFFTAG_IMAGELENGTH, N);
TIFFSetField(O, TIFFTAG_SAMPLESPERPIXEL, C);
TIFFSetField(O, TIFFTAG_BITSPERSAMPLE, 32);
TIFFSetField(O, TIFFTAG_ORIENTATION, ORIENTATION_TOPLEFT);
TIFFSetField(O, TIFFTAG_PLANARCONFIG, PLANARCONFIG_CONTIG);
TIFFSetField(O, TIFFTAG_SAMPLEFORMAT, SAMPLEFORMAT_IEEEFP);
if (C == 1)
{
TIFFSetField(O, TIFFTAG_PHOTOMETRIC, PHOTOMETRIC_MINISBLACK);
TIFFSetField(O, TIFFTAG_ICCPROFILE, sizeof (grayicc), grayicc);
}
else
{
TIFFSetField(O, TIFFTAG_PHOTOMETRIC, PHOTOMETRIC_RGB);
TIFFSetField(O, TIFFTAG_ICCPROFILE, sizeof (sRGBicc), sRGBicc);
}
S = (size_t) TIFFScanlineSize(O);
/* Iterate over all channels. */
for (k = 0; k < C; ++k)
{
/* Generate the irradiance matrix for the current channel. */
irrmatrix(M, L[0 * C + k],
L[1 * C + k],
L[2 * C + k],
L[3 * C + k],
L[4 * C + k],
L[5 * C + k],
L[6 * C + k],
L[7 * C + k],
L[8 * C + k]);
/* Render the current cube face using the current irradiance. */
sph_to_irr_face(d, M, F, N, C, k);
}
/* Write the result to an image file. */
for (i = 0; i < N; ++i)
TIFFWriteScanline(O, (uint8 *) d + S * i, i, 0);
TIFFWriteDirectory(O);
}
free(d);
}
}
/*----------------------------------------------------------------------------*/
static void sph_dump(const double *L, int c)
{
int i;
int k;
printf("Spherical harmonic coefficients:\n");
for (i = 0; i < 9; ++i)
{
for (k = 0; k < c; ++k)
printf("% 12.5f ", L[i * c + k]);
printf("\n");
}
}
static double *sph_file(const char *name, uint16 *C)
{
double *L = 0;
TIFF *T;
if ((T = TIFFOpen(name, "r")))
{
uint32 W, H;
uint16 B;
TIFFGetField(T, TIFFTAG_IMAGEWIDTH, &W);
TIFFGetField(T, TIFFTAG_IMAGELENGTH, &H);
TIFFGetField(T, TIFFTAG_SAMPLESPERPIXEL, C);
TIFFGetField(T, TIFFTAG_BITSPERSAMPLE, &B);
if (W == H)
L = env_to_sph(T, W, *C, B);
TIFFClose(T);
}
return L;
}
/*----------------------------------------------------------------------------*/
static int usage(const char *exe)
{
fprintf(stderr, "Usage: %s [-n n] [-f in.tif] [-ges] out.tif n\n", exe);
return 1;
}
int main(int argc, char *argv[])
{
double *L = 0;
TIFF *T;
uint16 C;
int n = 256;
int c;
while ((c = getopt(argc, argv, "n:f:ges")) != -1)
switch (c)
{
case 'n': n = strtol(optarg, 0, 0); break;
case 'f': L = sph_file(optarg, &C); break;
case 'g': L = sph_grace_cathedral (&C); break;
case 'e': L = sph_eucalyptus_grove (&C); break;
case 's': L = sph_st_peters_basilica(&C); break;
default: return usage(argv[0]);
}
if (L && optind < argc)
{
if ((T = TIFFOpen(argv[optind], "w")))
{
sph_dump(L, C);
sph_to_irr(L, T, n, C);
TIFFClose(T);
}
free(L);
}
else return usage(argv[0]);
return 0;
}