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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 2.7 by greg, Sat Feb 19 23:42:09 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 + *  BSDF vectors always oriented away from surface, even when "incident."
13 + *
14 + *  Created by Greg Ward on 1/10/11.
15 + *
16 + */
17 +
18 + #ifndef _BSDF_H_
19 + #define _BSDF_H_
20 +
21 + #include "fvect.h"
22 + #include "ccolor.h"
23 +
24 + #ifdef __cplusplus
25 + extern "C" {
26 + #endif
27 +
28 + #define SDnameLn        128             /* maximum BSDF name length */
29 + #define SDmaxCh         3               /* maximum # spectral channels */
30 +
31 + /* Component flags for SDsampBSDF() and SDhemiScatter() */
32 + #define SDsampR         0x1             /* include reflection */
33 + #define SDsampT         0x2             /* include transmission */
34 + #define SDsampS         0x3             /* include scattering (R+T) */
35 + #define SDsampSp        0x4             /* include non-diffuse portion */
36 + #define SDsampDf        0x8             /* include diffuse portion */
37 + #define SDsampSpR       0x5             /* include non-diffuse reflection */
38 + #define SDsampSpT       0x6             /* include non-diffuse transmission */
39 + #define SDsampSpS       0x7             /* include non-diffuse scattering */
40 + #define SDsampAll       0xF             /* include everything */
41 +
42 + /* Projected solid angle query flags fos SDsizeBSDF() */
43 + #define SDqueryVal      0x0             /* query single value */
44 + #define SDqueryMin      0x1             /* query minimum proj. solid angle */
45 + #define SDqueryMax      0x2             /* query maximum proj. solid angle */
46 +
47 + /* Error codes: normal return, out of memory, file i/o, file format, bad argument,
48 +                 bad data, unsupported feature, internal error, unknown error */
49 + typedef enum {SDEnone=0, SDEmemory, SDEfile, SDEformat, SDEargument,
50 +                SDEdata, SDEsupport, SDEinternal, SDEunknown} SDError;
51 +
52 + /* English ASCII strings corresponding to ennumerated errors */
53 + extern const char       *SDerrorEnglish[];
54 +
55 + /* Additional information on last error (ASCII English) */
56 + extern char             SDerrorDetail[];
57 +
58 + /* Holder for BSDF value and spectral color */
59 + typedef struct {
60 +        double          cieY;           /* photopic BSDF (Y) value */
61 +        C_COLOR         spec;           /* spectral and (x,y) color */
62 + } SDValue;
63 +
64 + /* Cached, encoded, cumulative distribution for one incident (solid) angle */
65 + #define SD_CDIST_BASE   double          cTotal; \
66 +                        struct SDCDst_s *next
67 + typedef struct SDCDst_s {
68 +        SD_CDIST_BASE;                  /* base fields first */
69 +        /* ...encoded distribution extends struct */
70 + } SDCDst;
71 +
72 + /* Forward declaration of BSDF component */
73 + typedef struct SDComp_s SDComponent;
74 +
75 + /* Methods needed to handle BSDF components (nothing is optional) */
76 + typedef const struct {
77 +                                        /* return non-diffuse BSDF */
78 +        int             (*getBSDFs)(float coef[SDmaxCh], const FVECT outVec,
79 +                                    const FVECT inVec, const void *dist);
80 +                                        /* query non-diffuse PSA for vector */
81 +        SDError         (*queryProjSA)(double *psa, const FVECT vec,
82 +                                                int qflags, const void *dist);
83 +                                        /* get cumulative distribution */
84 +        const SDCDst    *(*getCDist)(const FVECT inVec, SDComponent *sdc);
85 +                                        /* sample cumulative distribution */
86 +        SDError         (*sampCDist)(FVECT outVec, double randX,
87 +                                                const SDCDst *cdp);
88 +                                        /* free a spectral BSDF component */
89 +        void            (*freeSC)(void *dist);
90 + } SDFunc;
91 +
92 + /* Structure to hold a spectral BSDF component (typedef SDComponent above) */
93 + struct SDComp_s {
94 +        C_COLOR         cspec[SDmaxCh]; /* component spectral bases */
95 +        SDFunc          *func;          /* methods for this component */
96 +        void            *dist;          /* loaded distribution data */
97 +        SDCDst          *cdList;        /* cumulative distribution cache */
98 + };
99 +
100 + /* Container for non-diffuse BSDF components */
101 + typedef struct {
102 +        double          minProjSA;      /* minimum projected solid angle */
103 +        double          maxHemi;        /* maximum directional hemispherical */
104 +        int             ncomp;          /* number of separate components */
105 +        SDComponent     comp[1];        /* BSDF components (extends struct) */
106 + } SDSpectralDF;
107 +
108 + /* Loaded BSDF data */
109 + typedef struct {
110 +        char            name[SDnameLn]; /* BSDF name (derived from file) */
111 +        char            *mgf;           /* geometric description (if any) */
112 +        float           dim[3];         /* width, height, thickness (meters) */
113 +        SDValue         rLambFront;     /* diffuse front reflectance */
114 +        SDValue         rLambBack;      /* diffuse rear reflectance */
115 +        SDValue         tLamb;          /* diffuse transmission */
116 +        SDSpectralDF    *rf, *rb, *tf;  /* non-diffuse BSDF components */
117 + } SDData;
118 +
119 + /* List of loaded BSDFs */
120 + extern struct SDCache_s {
121 +        SDData          bsdf;           /* BSDF data */
122 +        unsigned        refcnt;         /* how many callers are using us? */
123 +        struct SDCache_s                /* next in cache list */
124 +                        *next;
125 + } *SDcacheList;         /* Global BSDF cache */
126 +
127 + /* BSDF cache retention preference */
128 + #define SDretainNone    0               /* free unreferenced data (default) */
129 + #define SDretainBSDFs   1               /* keep loaded BSDFs in cache */
130 + #define SDretainAll     2               /* also keep cumulative cache data */
131 +
132 + extern int              SDretainSet;    /* set to SDretainNone by default */
133 +
134 + /*****************************************************************
135 + * The following routines are less commonly used by applications.
136 + */
137 +
138 + #define SDisLoaded(sd)  ((sd)->rLambFront.spec.flags != 0)
139 +
140 + /* Report an error to the indicated stream (in English) */
141 + extern SDError          SDreportEnglish(SDError ec, FILE *fp);
142 +
143 + /* Shorten file path to useable BSDF name, removing suffix */
144 + extern void             SDclipName(char res[SDnameLn], const char *fname);
145 +
146 + /* Allocate new spectral distribution function */
147 + extern SDSpectralDF     *SDnewSpectralDF(int nc);
148 +
149 + /* Free a spectral distribution function */
150 + extern void             SDfreeSpectralDF(SDSpectralDF *df);
151 +
152 + /* Initialize an unused BSDF struct (clears to zeroes) */
153 + extern void             SDclearBSDF(SDData *sd);
154 +
155 + /* Load a BSDF struct from the given file (keeps name unchanged) */
156 + extern SDError          SDloadFile(SDData *sd, const char *fname);
157 +
158 + /* Free data associated with BSDF struct */
159 + extern void             SDfreeBSDF(SDData *sd);
160 +
161 + /* Find writeable BSDF by name, or allocate new cache entry if absent */
162 + extern SDData           *SDgetCache(const char *bname);
163 +
164 + /* Free cached cumulative distributions for BSDF component */
165 + extern void             SDfreeCumulativeCache(SDSpectralDF *df);
166 +
167 + /* Sample an individual BSDF component */
168 + extern SDError          SDsampComponent(SDValue *sv, FVECT outVec,
169 +                                        const FVECT inVec, double randX,
170 +                                        SDComponent *sdc);
171 +
172 + /* Convert 1-dimensional random variable to N-dimensional */
173 + extern void             SDmultiSamp(double t[], int n, double randX);
174 +
175 + /* Map a [0,1]^2 square to a unit radius disk */
176 + void                    SDsquare2disk(double ds[2], double seedx, double seedy);
177 +
178 + /* Map point on unit disk to a unit square in [0,1]^2 range */
179 + void                    SDdisk2square(double sq[2], double diskx, double disky);
180 +
181 + /*****************************************************************
182 + * The calls below are the ones most applications require.
183 + * All directions are assumed to be unit vectors.
184 + */
185 +
186 + /* Get BSDF from cache (or load and cache it on first call) */
187 + /* Report any problems to stderr and return NULL on failure */
188 + extern const SDData     *SDcacheFile(const char *fname);
189 +
190 + /* Free a BSDF from our cache (clear all if NULL) */
191 + extern void             SDfreeCache(const SDData *sd);
192 +
193 + /* Query projected solid angle resolution for non-diffuse BSDF direction */
194 + extern SDError          SDsizeBSDF(double *projSA, const FVECT vec,
195 +                                        int qflags, const SDData *sd);
196 +
197 + /* Return BSDF for the given incident and scattered ray vectors */
198 + extern SDError          SDevalBSDF(SDValue *sv, const FVECT outVec,
199 +                                        const FVECT inVec, const SDData *sd);
200 +
201 + /* Compute directional hemispherical scattering at given incident angle */
202 + extern double           SDdirectHemi(const FVECT inVec,
203 +                                        int sflags, const SDData *sd);
204 +
205 + /* Sample BSDF direction based on the given random variable */
206 + extern SDError          SDsampBSDF(SDValue *sv, FVECT outVec,
207 +                                        const FVECT inVec, double randX,
208 +                                        int sflags, const SDData *sd);
209 +
210 + /*****************************************************************
211 + * Vector math for getting between world and local BSDF coordinates.
212 + * Directions may be passed unnormalized to these routines.
213 + */
214 +
215 + /* Compute World->BSDF transform from surface normal and up (Y) vector */
216 + extern SDError          SDcompXform(RREAL vMtx[3][3], const FVECT sNrm,
217 +                                        const FVECT uVec);
218 +
219 + /* Compute inverse transform */
220 + extern SDError          SDinvXform(RREAL iMtx[3][3], RREAL vMtx[3][3]);
221 +
222 + /* Transform and normalize direction (column) vector */
223 + extern SDError          SDmapDir(FVECT resVec, RREAL vMtx[3][3],
224 +                                        const FVECT inpVec);
225 +
226 + /* System-specific BSDF loading routine (not part of our library) */
227 + extern SDData           *loadBSDF(char *name);
228 +
229 + /* System-specific BSDF error translator (not part of our library) */
230 + extern char             *transSDError(SDError ec);
231 +
232 + /*################################################################*/
233 + /*######### DEPRECATED DEFINITIONS AWAITING PERMANENT REMOVAL #######*/
234 + /*
235   * Header for BSDF i/o and access routines
236   */
237  
238 < #ifndef _RAD_BSDF_H_
7 < #define _RAD_BSDF_H_
238 > #include "mat4.h"
239                                  /* up directions */
240   typedef enum {
241          UDzneg=-3,
# Line 17 | Line 248 | typedef enum {
248   } UpDir;
249                                  /* BSDF coordinate calculation routines */
250                                  /* 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 *);
251  
252 + typedef int     b_vecf2(FVECT v, int n, void *cd);
253 + typedef int     b_ndxf2(FVECT v, void *cd);
254 + typedef double  b_radf2(int n, void *cd);
255 +
256   /* Bidirectional Scattering Distribution Function */
257   struct BSDF_data {
258          int     ninc;                   /* number of incoming directions */
259          int     nout;                   /* number of outgoing directions */
260 +        float   dim[3];                 /* width, height, thickness (meters) */
261 +        char    *mgf;                   /* geometric description (if any) */
262          void    *ib_priv;               /* input basis private data */
263 <        b_vecf  *ib_vec;                /* get input vector from index */
264 <        b_ndxf  *ib_ndx;                /* get input index from vector */
265 <        b_radf  *ib_ohm;                /* get input radius for index */
263 >        b_vecf2 *ib_vec;                /* get input vector from index */
264 >        b_ndxf2 *ib_ndx;                /* get input index from vector */
265 >        b_radf2 *ib_ohm;                /* get input radius for index */
266          void    *ob_priv;               /* output basis private data */
267 <        b_vecf  *ob_vec;                /* get output vector from index */
268 <        b_ndxf  *ob_ndx;                /* get output index from vector */
269 <        b_radf  *ob_ohm;                /* get output radius for index */
267 >        b_vecf2 *ob_vec;                /* get output vector from index */
268 >        b_ndxf2 *ob_ndx;                /* get output index from vector */
269 >        b_radf2 *ob_ohm;                /* get output radius for index */
270          float   *bsdf;                  /* scattering distribution data */
271   };                              /* bidirectional scattering distrib. func. */
272  
# Line 50 | Line 284 | extern int r_BSDF_incvec(FVECT v, struct BSDF_data *b,
284                                  double rv, MAT4 xm);
285   extern int r_BSDF_outvec(FVECT v, struct BSDF_data *b, int o,
286                                  double rv, MAT4 xm);
287 < extern int getBSDF_xfm(MAT4 xm, FVECT nrm, UpDir ud);
287 > extern int getBSDF_xfm(MAT4 xm, FVECT nrm, UpDir ud, char *xfbuf);
288  
289 < #endif  /* ! _RAD_BSDF_H_ */
289 > /*######### END DEPRECATED DEFINITIONS #######*/
290 > /*################################################################*/
291 >
292 > #ifdef __cplusplus
293 > }
294 > #endif
295 > #endif  /* ! _BSDF_H_ */

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