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Comparing ray/src/common/bsdf.h (file contents):
Revision 2.2 by greg, Mon Jun 14 22:02:22 2010 UTC vs.
Revision 2.10 by greg, Mon Apr 11 03:47:46 2011 UTC

# Line 1 | Line 1
1   /* RCSid $Id$ */
2   /*
3 + *  bsdf.h
4 + *  
5 + *  Declarations for bidirectional scattering distribution functions.
6 + *  Assumes <stdio.h> already included.
7 + *
8 + *  A material is oriented in right-hand coordinate system with X-axis
9 + *      in the surface plane pointed to the right as seen from the front.
10 + *      This means the Y-axis is "up" and the Z-axis is the surface normal.
11 + *
12 + *  Note that we reverse the identification of "front" and "back" from
13 + *      the conventions used in WINDOW 6.  "Front" in our library points
14 + *      in the +Z direction, towards the interior of the space rather
15 + *      than the exterior.
16 + *
17 + *  BSDF vectors always oriented away from surface, even when "incident."
18 + *
19 + *  Created by Greg Ward on 1/10/11.
20 + *
21 + */
22 +
23 + #ifndef _BSDF_H_
24 + #define _BSDF_H_
25 +
26 + #include "fvect.h"
27 + #include "ccolor.h"
28 +
29 + #ifdef __cplusplus
30 + extern "C" {
31 + #endif
32 +
33 + #define SDnameLn        128             /* maximum BSDF name length */
34 + #define SDmaxCh         3               /* maximum # spectral channels */
35 +
36 + /* Component flags for SDsampBSDF() and SDdirectHemi() */
37 + #define SDsampR         0x1             /* include reflection */
38 + #define SDsampT         0x2             /* include transmission */
39 + #define SDsampS         0x3             /* include scattering (R+T) */
40 + #define SDsampSp        0x4             /* include non-diffuse portion */
41 + #define SDsampDf        0x8             /* include diffuse portion */
42 + #define SDsampSpR       0x5             /* include non-diffuse reflection */
43 + #define SDsampSpT       0x6             /* include non-diffuse transmission */
44 + #define SDsampSpS       0x7             /* include non-diffuse scattering */
45 + #define SDsampAll       0xF             /* include everything */
46 +
47 + /* Projected solid angle query flags for SDsizeBSDF() */
48 + #define SDqueryVal      0x0             /* query single value */
49 + #define SDqueryMin      0x1             /* query minimum proj. solid angle */
50 + #define SDqueryMax      0x2             /* query maximum proj. solid angle */
51 +
52 + /* Error codes: normal return, out of memory, file i/o, file format, bad argument,
53 +                 bad data, unsupported feature, internal error, unknown error */
54 + typedef enum {SDEnone=0, SDEmemory, SDEfile, SDEformat, SDEargument,
55 +                SDEdata, SDEsupport, SDEinternal, SDEunknown} SDError;
56 +
57 + /* English ASCII strings corresponding to ennumerated errors */
58 + extern const char       *SDerrorEnglish[];
59 +
60 + /* Additional information on last error (ASCII English) */
61 + extern char             SDerrorDetail[];
62 +
63 + /* Holder for BSDF value and spectral color */
64 + typedef struct {
65 +        double          cieY;           /* photopic BSDF (Y) value */
66 +        C_COLOR         spec;           /* spectral and (x,y) color */
67 + } SDValue;
68 +
69 + /* Cached, encoded, cumulative distribution for one incident (solid) angle */
70 + #define SD_CDIST_BASE   double          cTotal; \
71 +                        struct SDCDst_s *next
72 + typedef struct SDCDst_s {
73 +        SD_CDIST_BASE;                  /* base fields first */
74 +        /* ...encoded distribution extends struct */
75 + } SDCDst;
76 +
77 + /* Forward declaration of BSDF component */
78 + typedef struct SDComp_s SDComponent;
79 +
80 + /* Methods needed to handle BSDF components (nothing is optional) */
81 + typedef const struct {
82 +                                        /* return non-diffuse BSDF */
83 +        int             (*getBSDFs)(float coef[SDmaxCh], const FVECT outVec,
84 +                                    const FVECT inVec, const void *dist);
85 +                                        /* query non-diffuse PSA for vector */
86 +        SDError         (*queryProjSA)(double *psa, const FVECT vec,
87 +                                                int qflags, const void *dist);
88 +                                        /* get cumulative distribution */
89 +        const SDCDst    *(*getCDist)(const FVECT inVec, SDComponent *sdc);
90 +                                        /* sample cumulative distribution */
91 +        SDError         (*sampCDist)(FVECT outVec, double randX,
92 +                                                const SDCDst *cdp);
93 +                                        /* free a spectral BSDF component */
94 +        void            (*freeSC)(void *dist);
95 + } SDFunc;
96 +
97 + /* Structure to hold a spectral BSDF component (typedef SDComponent above) */
98 + struct SDComp_s {
99 +        C_COLOR         cspec[SDmaxCh]; /* component spectral bases */
100 +        SDFunc          *func;          /* methods for this component */
101 +        void            *dist;          /* loaded distribution data */
102 +        SDCDst          *cdList;        /* cumulative distribution cache */
103 + };
104 +
105 + /* Container for non-diffuse BSDF components */
106 + typedef struct {
107 +        double          minProjSA;      /* minimum projected solid angle */
108 +        double          maxHemi;        /* maximum directional hemispherical */
109 +        int             ncomp;          /* number of separate components */
110 +        SDComponent     comp[1];        /* BSDF components (extends struct) */
111 + } SDSpectralDF;
112 +
113 + /* Loaded BSDF data */
114 + typedef struct {
115 +        char            name[SDnameLn]; /* BSDF name (derived from file) */
116 +        char            *mgf;           /* geometric description (if any) */
117 +        float           dim[3];         /* width, height, thickness (meters) */
118 +        SDValue         rLambFront;     /* diffuse front reflectance */
119 +        SDValue         rLambBack;      /* diffuse rear reflectance */
120 +        SDValue         tLamb;          /* diffuse transmission */
121 +        SDSpectralDF    *rf, *rb, *tf;  /* non-diffuse BSDF components */
122 + } SDData;
123 +
124 + /* List of loaded BSDFs */
125 + extern struct SDCache_s {
126 +        SDData          bsdf;           /* BSDF data */
127 +        unsigned        refcnt;         /* how many callers are using us? */
128 +        struct SDCache_s                /* next in cache list */
129 +                        *next;
130 + } *SDcacheList;         /* Global BSDF cache */
131 +
132 + /* BSDF cache retention preference */
133 + #define SDretainNone    0               /* free unreferenced data (default) */
134 + #define SDretainBSDFs   1               /* keep loaded BSDFs in cache */
135 + #define SDretainAll     2               /* also keep cumulative cache data */
136 +
137 + extern int              SDretainSet;    /* set to SDretainNone by default */
138 +
139 + /*****************************************************************
140 + * The following routines are less commonly used by applications.
141 + */
142 +
143 + #define SDisLoaded(sd)  ((sd)->rLambFront.spec.flags != 0)
144 +
145 + /* Report an error to the indicated stream (in English) */
146 + extern SDError          SDreportEnglish(SDError ec, FILE *fp);
147 +
148 + /* Shorten file path to useable BSDF name, removing suffix */
149 + extern void             SDclipName(char res[SDnameLn], const char *fname);
150 +
151 + /* Allocate new spectral distribution function */
152 + extern SDSpectralDF     *SDnewSpectralDF(int nc);
153 +
154 + /* Free a spectral distribution function */
155 + extern void             SDfreeSpectralDF(SDSpectralDF *df);
156 +
157 + /* Initialize an unused BSDF struct and assign name (calls SDclipName) */
158 + extern void             SDclearBSDF(SDData *sd, const char *fname);
159 +
160 + /* Load a BSDF struct from the given file (keeps name unchanged) */
161 + extern SDError          SDloadFile(SDData *sd, const char *fname);
162 +
163 + /* Free data associated with BSDF struct */
164 + extern void             SDfreeBSDF(SDData *sd);
165 +
166 + /* Find writeable BSDF by name, or allocate new cache entry if absent */
167 + extern SDData           *SDgetCache(const char *bname);
168 +
169 + /* Free cached cumulative distributions for BSDF component */
170 + extern void             SDfreeCumulativeCache(SDSpectralDF *df);
171 +
172 + /* Sample an individual BSDF component */
173 + extern SDError          SDsampComponent(SDValue *sv, FVECT outVec,
174 +                                        const FVECT inVec, double randX,
175 +                                        SDComponent *sdc);
176 +
177 + /* Convert 1-dimensional random variable to N-dimensional */
178 + extern void             SDmultiSamp(double t[], int n, double randX);
179 +
180 + /* Map a [0,1]^2 square to a unit radius disk */
181 + void                    SDsquare2disk(double ds[2], double seedx, double seedy);
182 +
183 + /* Map point on unit disk to a unit square in [0,1]^2 range */
184 + void                    SDdisk2square(double sq[2], double diskx, double disky);
185 +
186 + /*****************************************************************
187 + * The calls below are the ones most applications require.
188 + * All directions are assumed to be unit vectors.
189 + */
190 +
191 + /* Get BSDF from cache (or load and cache it on first call) */
192 + /* Report any problems to stderr and return NULL on failure */
193 + extern const SDData     *SDcacheFile(const char *fname);
194 +
195 + /* Free a BSDF from our cache (clear all if NULL) */
196 + extern void             SDfreeCache(const SDData *sd);
197 +
198 + /* Query projected solid angle resolution for non-diffuse BSDF direction */
199 + extern SDError          SDsizeBSDF(double *projSA, const FVECT vec,
200 +                                        int qflags, const SDData *sd);
201 +
202 + /* Return BSDF for the given incident and scattered ray vectors */
203 + extern SDError          SDevalBSDF(SDValue *sv, const FVECT outVec,
204 +                                        const FVECT inVec, const SDData *sd);
205 +
206 + /* Compute directional hemispherical scattering at given incident angle */
207 + extern double           SDdirectHemi(const FVECT inVec,
208 +                                        int sflags, const SDData *sd);
209 +
210 + /* Sample BSDF direction based on the given random variable */
211 + extern SDError          SDsampBSDF(SDValue *sv, FVECT outVec,
212 +                                        const FVECT inVec, double randX,
213 +                                        int sflags, const SDData *sd);
214 +
215 + /*****************************************************************
216 + * Vector math for getting between world and local BSDF coordinates.
217 + * Directions may be passed unnormalized to these routines.
218 + */
219 +
220 + /* Compute World->BSDF transform from surface normal and up (Y) vector */
221 + extern SDError          SDcompXform(RREAL vMtx[3][3], const FVECT sNrm,
222 +                                        const FVECT uVec);
223 +
224 + /* Compute inverse transform */
225 + extern SDError          SDinvXform(RREAL iMtx[3][3], RREAL vMtx[3][3]);
226 +
227 + /* Transform and normalize direction (column) vector */
228 + extern SDError          SDmapDir(FVECT resVec, RREAL vMtx[3][3],
229 +                                        const FVECT inpVec);
230 +
231 + /* System-specific BSDF loading routine (not part of our library) */
232 + extern SDData           *loadBSDF(char *name);
233 +
234 + /* System-specific BSDF error translator (not part of our library) */
235 + extern char             *transSDError(SDError ec);
236 +
237 + /*################################################################*/
238 + /*######### DEPRECATED DEFINITIONS AWAITING PERMANENT REMOVAL #######*/
239 + /*
240   * Header for BSDF i/o and access routines
241   */
242  
243 < #ifndef _RAD_BSDF_H_
7 < #define _RAD_BSDF_H_
243 > #include "mat4.h"
244                                  /* up directions */
245   typedef enum {
246          UDzneg=-3,
# Line 17 | Line 253 | typedef enum {
253   } UpDir;
254                                  /* BSDF coordinate calculation routines */
255                                  /* vectors always point away from surface */
20 typedef int     b_vecf(FVECT, int, void *);
21 typedef int     b_ndxf(FVECT, void *);
22 typedef double  b_radf(int, void *);
256  
257 + typedef int     b_vecf2(FVECT v, int n, void *cd);
258 + typedef int     b_ndxf2(FVECT v, void *cd);
259 + typedef double  b_radf2(int n, void *cd);
260 +
261   /* Bidirectional Scattering Distribution Function */
262   struct BSDF_data {
263          int     ninc;                   /* number of incoming directions */
264          int     nout;                   /* number of outgoing directions */
265 +        float   dim[3];                 /* width, height, thickness (meters) */
266 +        char    *mgf;                   /* geometric description (if any) */
267          void    *ib_priv;               /* input basis private data */
268 <        b_vecf  *ib_vec;                /* get input vector from index */
269 <        b_ndxf  *ib_ndx;                /* get input index from vector */
270 <        b_radf  *ib_ohm;                /* get input radius for index */
268 >        b_vecf2 *ib_vec;                /* get input vector from index */
269 >        b_ndxf2 *ib_ndx;                /* get input index from vector */
270 >        b_radf2 *ib_ohm;                /* get input radius for index */
271          void    *ob_priv;               /* output basis private data */
272 <        b_vecf  *ob_vec;                /* get output vector from index */
273 <        b_ndxf  *ob_ndx;                /* get output index from vector */
274 <        b_radf  *ob_ohm;                /* get output radius for index */
272 >        b_vecf2 *ob_vec;                /* get output vector from index */
273 >        b_ndxf2 *ob_ndx;                /* get output index from vector */
274 >        b_radf2 *ob_ohm;                /* get output radius for index */
275          float   *bsdf;                  /* scattering distribution data */
276   };                              /* bidirectional scattering distrib. func. */
277  
# Line 50 | Line 289 | extern int r_BSDF_incvec(FVECT v, struct BSDF_data *b,
289                                  double rv, MAT4 xm);
290   extern int r_BSDF_outvec(FVECT v, struct BSDF_data *b, int o,
291                                  double rv, MAT4 xm);
292 < extern int getBSDF_xfm(MAT4 xm, FVECT nrm, UpDir ud);
292 > extern int getBSDF_xfm(MAT4 xm, FVECT nrm, UpDir ud, char *xfbuf);
293  
294 < #endif  /* ! _RAD_BSDF_H_ */
294 > /*######### END DEPRECATED DEFINITIONS #######*/
295 > /*################################################################*/
296 >
297 > #ifdef __cplusplus
298 > }
299 > #endif
300 > #endif  /* ! _BSDF_H_ */

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