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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 2.16 by greg, Sun Aug 21 22:38:12 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 incident & exiting vectors are always oriented away from surface.
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 + #ifdef _WIN32
34 + #define strcasecmp      stricmp
35 + #endif
36 +
37 + #define SDnameLn        128             /* maximum BSDF name length */
38 + #define SDmaxCh         3               /* maximum # spectral channels */
39 +
40 + /* Component flags for SDsampBSDF() and SDdirectHemi() */
41 + #define SDsampR         0x1             /* include reflection */
42 + #define SDsampT         0x2             /* include transmission */
43 + #define SDsampS         0x3             /* include scattering (R+T) */
44 + #define SDsampSp        0x4             /* include non-diffuse portion */
45 + #define SDsampDf        0x8             /* include diffuse portion */
46 + #define SDsampSpR       0x5             /* include non-diffuse reflection */
47 + #define SDsampSpT       0x6             /* include non-diffuse transmission */
48 + #define SDsampSpS       0x7             /* include non-diffuse scattering */
49 + #define SDsampAll       0xF             /* include everything */
50 +
51 + /* Projected solid angle query flags for SDsizeBSDF() */
52 + #define SDqueryVal      0x0             /* query single value */
53 + #define SDqueryMin      0x1             /* query minimum proj. solid angle */
54 + #define SDqueryMax      0x2             /* query maximum proj. solid angle */
55 +
56 + /* Error codes: normal return, out of memory, file i/o, file format, bad argument,
57 +                 bad data, unsupported feature, internal error, unknown error */
58 + typedef enum {SDEnone=0, SDEmemory, SDEfile, SDEformat, SDEargument,
59 +                SDEdata, SDEsupport, SDEinternal, SDEunknown} SDError;
60 +
61 + /* English ASCII strings corresponding to ennumerated errors */
62 + extern const char       *SDerrorEnglish[];
63 +
64 + /* Additional information on last error (ASCII English) */
65 + extern char             SDerrorDetail[];
66 +
67 + /* Holder for BSDF value and spectral color */
68 + typedef struct {
69 +        double          cieY;           /* photopic BSDF (Y) value */
70 +        C_COLOR         spec;           /* spectral and (x,y) color */
71 + } SDValue;
72 +
73 + /* Cached, encoded, cumulative distribution for one incident (solid) angle */
74 + #define SD_CDIST_BASE(styp)     double          cTotal; \
75 +                                struct styp     *next
76 + typedef struct SDCDst_s {
77 +        SD_CDIST_BASE(SDCDst_s);        /* base fields first */
78 +        /* ...encoded distribution extends struct */
79 + } SDCDst;
80 +
81 + /* Forward declaration of BSDF component */
82 + typedef struct SDComp_s SDComponent;
83 +
84 + /* Methods needed to handle BSDF components (nothing is optional) */
85 + typedef const struct {
86 +                                        /* return non-diffuse BSDF */
87 +        int             (*getBSDFs)(float coef[SDmaxCh], const FVECT outVec,
88 +                                    const FVECT inVec, SDComponent *sdc);
89 +                                        /* query non-diffuse PSA for vector */
90 +        SDError         (*queryProjSA)(double *psa, const FVECT v1,
91 +                                                const RREAL *v2, int qflags,
92 +                                                SDComponent *sdc);
93 +                                        /* get cumulative distribution */
94 +        const SDCDst    *(*getCDist)(const FVECT inVec, SDComponent *sdc);
95 +                                        /* sample cumulative distribution */
96 +        SDError         (*sampCDist)(FVECT ioVec, double randX,
97 +                                                const SDCDst *cdp);
98 +                                        /* free a spectral BSDF component */
99 +        void            (*freeSC)(void *dist);
100 + } SDFunc;
101 +
102 + /* Structure to hold a spectral BSDF component (typedef SDComponent above) */
103 + struct SDComp_s {
104 +        C_COLOR         cspec[SDmaxCh]; /* component spectral bases */
105 +        SDFunc          *func;          /* methods for this component */
106 +        void            *dist;          /* loaded distribution data */
107 +        SDCDst          *cdList;        /* cumulative distribution cache */
108 + };
109 +
110 + /* Container for non-diffuse BSDF components */
111 + typedef struct {
112 +        double          minProjSA;      /* minimum projected solid angle */
113 +        double          maxHemi;        /* maximum directional hemispherical */
114 +        int             ncomp;          /* number of separate components */
115 +        SDComponent     comp[1];        /* BSDF components (extends struct) */
116 + } SDSpectralDF;
117 +
118 + /* Loaded BSDF data */
119 + typedef struct {
120 +        char            name[SDnameLn]; /* BSDF name (usu. derived from file) */
121 +        char            *mgf;           /* geometric description (if any) */
122 +        float           dim[3];         /* width, height, thickness (meters) */
123 +        SDValue         rLambFront;     /* diffuse front reflectance */
124 +        SDValue         rLambBack;      /* diffuse rear reflectance */
125 +        SDValue         tLamb;          /* diffuse transmission */
126 +        SDSpectralDF    *rf, *rb, *tf;  /* non-diffuse BSDF components */
127 + } SDData;
128 +
129 + /* List of loaded BSDFs */
130 + extern struct SDCache_s {
131 +        SDData          bsdf;           /* BSDF data */
132 +        unsigned        refcnt;         /* how many callers are using us? */
133 +        struct SDCache_s                /* next in cache list */
134 +                        *next;
135 + } *SDcacheList;         /* Global BSDF cache */
136 +
137 + /* BSDF cache retention policies */
138 + #define SDretainNone    0               /* free unreferenced BSDF data */
139 + #define SDretainBSDFs   1               /* keep loaded BSDFs in memory */
140 + #define SDretainAll     2               /* also keep cumulative cache data */
141 +
142 + extern int              SDretainSet;    /* =SDretainNone by default */
143 +
144 + /*****************************************************************
145 + * The following routines are less commonly used by applications.
146 + */
147 +
148 + #define SDisLoaded(sd)  ((sd)->rLambFront.spec.flags != 0)
149 +
150 + /* Report an error to the indicated stream (in English) */
151 + extern SDError          SDreportEnglish(SDError ec, FILE *fp);
152 +
153 + /* Shorten file path to useable BSDF name, removing suffix */
154 + extern void             SDclipName(char res[SDnameLn], const char *fname);
155 +
156 + /* Allocate new spectral distribution function */
157 + extern SDSpectralDF     *SDnewSpectralDF(int nc);
158 +
159 + /* Free a spectral distribution function */
160 + extern void             SDfreeSpectralDF(SDSpectralDF *df);
161 +
162 + /* Initialize an unused BSDF struct and assign name (calls SDclipName) */
163 + extern void             SDclearBSDF(SDData *sd, const char *fname);
164 +
165 + /* Load a BSDF struct from the given file (keeps name unchanged) */
166 + extern SDError          SDloadFile(SDData *sd, const char *fname);
167 +
168 + /* Free data associated with BSDF struct */
169 + extern void             SDfreeBSDF(SDData *sd);
170 +
171 + /* Find writeable BSDF by name, or allocate new cache entry if absent */
172 + extern SDData           *SDgetCache(const char *bname);
173 +
174 + /* Free cached cumulative distributions for BSDF component */
175 + extern void             SDfreeCumulativeCache(SDSpectralDF *df);
176 +
177 + /* Sample an individual BSDF component */
178 + extern SDError          SDsampComponent(SDValue *sv, FVECT ioVec,
179 +                                        double randX, SDComponent *sdc);
180 +
181 + /* Convert 1-dimensional random variable to N-dimensional */
182 + extern void             SDmultiSamp(double t[], int n, double randX);
183 +
184 + /* Map a [0,1]^2 square to a unit radius disk */
185 + void                    SDsquare2disk(double ds[2], double seedx, double seedy);
186 +
187 + /* Map point on unit disk to a unit square in [0,1]^2 range */
188 + void                    SDdisk2square(double sq[2], double diskx, double disky);
189 +
190 + /*****************************************************************
191 + * The calls below are the ones most applications require.
192 + * All directions are assumed to be unit vectors.
193 + */
194 +
195 + /* Get BSDF from cache (or load and cache it on first call) */
196 + /* Report any problems to stderr (in English), return NULL on failure */
197 + extern const SDData     *SDcacheFile(const char *fname);
198 +
199 + /* Free a BSDF from our cache (clear all if sd==NULL) */
200 + extern void             SDfreeCache(const SDData *sd);
201 +
202 + /* Query projected solid angle resolution for non-diffuse BSDF direction(s) */
203 + extern SDError          SDsizeBSDF(double *projSA, const FVECT v1,
204 +                                        const RREAL *v2, int qflags,
205 +                                        const SDData *sd);
206 +
207 + /* Return BSDF for the given incident and scattered ray vectors */
208 + extern SDError          SDevalBSDF(SDValue *sv, const FVECT outVec,
209 +                                        const FVECT inVec, const SDData *sd);
210 +
211 + /* Compute directional hemispherical scattering at given incident angle */
212 + extern double           SDdirectHemi(const FVECT inVec,
213 +                                        int sflags, const SDData *sd);
214 +
215 + /* Sample BSDF direction based on the given random variable */
216 + extern SDError          SDsampBSDF(SDValue *sv, FVECT ioVec, double randX,
217 +                                        int sflags, const SDData *sd);
218 +
219 + /*****************************************************************
220 + * Vector math for getting between world and local BSDF coordinates.
221 + * Directions may be passed unnormalized to these routines.
222 + */
223 +
224 + /* Compute World->BSDF transform from surface normal and BSDF up vector */
225 + extern SDError          SDcompXform(RREAL vMtx[3][3], const FVECT sNrm,
226 +                                        const FVECT uVec);
227 +
228 + /* Compute inverse transform */
229 + extern SDError          SDinvXform(RREAL iMtx[3][3], RREAL vMtx[3][3]);
230 +
231 + /* Transform and normalize direction (column) vector */
232 + extern SDError          SDmapDir(FVECT resVec, RREAL vMtx[3][3],
233 +                                        const FVECT inpVec);
234 +
235 + /* Application-specific BSDF loading routine (not part of our library) */
236 + extern SDData           *loadBSDF(char *name);
237 +
238 + /* Application-specific BSDF error translator (not part of our library) */
239 + extern char             *transSDError(SDError ec);
240 +
241 + /*################################################################*/
242 + /*######### DEPRECATED DEFINITIONS AWAITING PERMANENT REMOVAL #######*/
243 + /*
244   * Header for BSDF i/o and access routines
245   */
246  
247 < #ifndef _RAD_BSDF_H_
7 < #define _RAD_BSDF_H_
247 > #include "mat4.h"
248                                  /* up directions */
249   typedef enum {
250          UDzneg=-3,
# Line 17 | Line 257 | typedef enum {
257   } UpDir;
258                                  /* BSDF coordinate calculation routines */
259                                  /* 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 *);
260  
261 + typedef int     b_vecf2(FVECT v, int n, void *cd);
262 + typedef int     b_ndxf2(FVECT v, void *cd);
263 + typedef double  b_radf2(int n, void *cd);
264 +
265   /* Bidirectional Scattering Distribution Function */
266   struct BSDF_data {
267          int     ninc;                   /* number of incoming directions */
268          int     nout;                   /* number of outgoing directions */
269 +        float   dim[3];                 /* width, height, thickness (meters) */
270 +        char    *mgf;                   /* geometric description (if any) */
271          void    *ib_priv;               /* input basis private data */
272 <        b_vecf  *ib_vec;                /* get input vector from index */
273 <        b_ndxf  *ib_ndx;                /* get input index from vector */
274 <        b_radf  *ib_ohm;                /* get input radius for index */
272 >        b_vecf2 *ib_vec;                /* get input vector from index */
273 >        b_ndxf2 *ib_ndx;                /* get input index from vector */
274 >        b_radf2 *ib_ohm;                /* get input radius for index */
275          void    *ob_priv;               /* output basis private data */
276 <        b_vecf  *ob_vec;                /* get output vector from index */
277 <        b_ndxf  *ob_ndx;                /* get output index from vector */
278 <        b_radf  *ob_ohm;                /* get output radius for index */
276 >        b_vecf2 *ob_vec;                /* get output vector from index */
277 >        b_ndxf2 *ob_ndx;                /* get output index from vector */
278 >        b_radf2 *ob_ohm;                /* get output radius for index */
279          float   *bsdf;                  /* scattering distribution data */
280   };                              /* bidirectional scattering distrib. func. */
281  
# Line 50 | Line 293 | extern int r_BSDF_incvec(FVECT v, struct BSDF_data *b,
293                                  double rv, MAT4 xm);
294   extern int r_BSDF_outvec(FVECT v, struct BSDF_data *b, int o,
295                                  double rv, MAT4 xm);
296 < extern int getBSDF_xfm(MAT4 xm, FVECT nrm, UpDir ud);
296 > extern int getBSDF_xfm(MAT4 xm, FVECT nrm, UpDir ud, char *xfbuf);
297  
298 < #endif  /* ! _RAD_BSDF_H_ */
298 > /*######### END DEPRECATED DEFINITIONS #######*/
299 > /*################################################################*/
300 >
301 > #ifdef __cplusplus
302 > }
303 > #endif
304 > #endif  /* ! _BSDF_H_ */

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