src/common/rglsrc.c

/* Copyright (c) 1998 Silicon Graphics, Inc. */

#ifndef lint
static char SCCSid[] = "$SunId$ SGI";
#endif

/*
 * Routines for handling OpenGL light sources
 */

#include "radogl.h"

double  expval = 0.;                    /* global exposure value */

COLOR   ambval = {0.2, 0.2, 0.2};       /* global ambient value */

int     dolights = MAXLIGHTS;           /* do how many more light sources? */

static int      lightid[MAXLIGHTS] = {GL_LIGHT0, GL_LIGHT1, GL_LIGHT2,
                        GL_LIGHT3, GL_LIGHT4, GL_LIGHT5, GL_LIGHT6, GL_LIGHT7};

static int      lightlist;              /* light list id */

                                /* source types */
#define L_NONE          0
#define L_SOURCE        1
#define L_FLAT          2
#define L_SPHERE        3

static struct {
        int     type;           /* light type (0 if none) */
        MATREC  *m;             /* light material */
        FVECT   pos;            /* light position (or direction) */
        FVECT   norm;           /* flat source normal */
        double  area;           /* source area (or solid angle) */
} lightrec[MAXLIGHTS];  /* light source list */

static int      nlights;                /* number of defined lights */

static int      l_flatsrc(), l_spheresrc(), l_source();


lightinit()                     /* initialize lighting */
{
        GLfloat ambv[4];
        register int    i;

        if (!dolights)
                return;
        glPushAttrib(GL_LIGHTING_BIT);
        if (expval <= FTINY && bright(ambval) > FTINY)
                expval = 0.2/bright(ambval);
        ambv[0] = expval*colval(ambval,RED);
        ambv[1] = expval*colval(ambval,GRN);
        ambv[2] = expval*colval(ambval,BLU);
        ambv[3] = 1.;
        glLightModelfv(GL_LIGHT_MODEL_AMBIENT, ambv);
        glCallList(lightlist = newglist());
        rgl_checkerr("in lightinit");
        nlights = 0;
}


lightclean()                    /* clean up light source commands */
{
        if ((dolights += nlights) <= 0)
                return;
        glPopAttrib();
}


lightdefs()                     /* define light source list */
{
        register int    i;

        if (!nlights)
                return;
        glNewList(lightlist, GL_COMPILE);
        while (nlights--) {
                switch (lightrec[nlights].type) {
                case L_FLAT:
                        l_flatsrc(nlights);
                        break;
                case L_SPHERE:
                        l_sphsrc(nlights);
                        break;
                case L_SOURCE:
                        l_source(nlights);
                        break;
                default:
                        error(CONSISTENCY, "botched light type in lightdefs");
                }
                freemtl(lightrec[nlights].m);
                lightrec[nlights].type = L_NONE;
        }
        glEndList();
        rgl_checkerr("defining lights");
}


o_source(o)                     /* record a distant source */
register OBJREC *o;
{
        if (!dolights || !issrcmat((MATREC *)o->os))
                return(0);
        if (o->oargs.nfargs != 4)
                objerror(o, USER, "bad # real arguments");
                                                /* record type & material */
        lightrec[nlights].type = L_SOURCE;
        (lightrec[nlights].m = (MATREC *)o->os)->nlinks++;
                                                /* assign direction */
        VCOPY(lightrec[nlights].pos, o->oargs.farg);
                                                /* compute solid angle */
        if (o->oargs.farg[3] <= FTINY)
                objerror(o, USER, "zero size");
        lightrec[nlights].area = 2.*PI*(1. - cos(PI/180./2.*o->oargs.farg[3]));
        nlights++; dolights--;
        return(1);
}


int
doflatsrc(m, pos, norm, area)   /* record a flat source */
MATREC  *m;
FVECT   pos, norm;
double  area;
{
        if (!dolights || !issrcmat(m) || area <= FTINY)
                return(0);
                                                /* record type & material */
        lightrec[nlights].type = L_FLAT;
        (lightrec[nlights].m = m)->nlinks++;
                                                /* assign geometry */
        VCOPY(lightrec[nlights].pos, pos);
        VCOPY(lightrec[nlights].norm, norm);
        lightrec[nlights].area = area;
        nlights++; dolights--;
        return(1);
}


int
dosphsrc(m, pos, area)          /* record a spherical source */
register MATREC *m;
FVECT   pos;
double  area;
{
        if (!dolights || !issrcmat(m) || area <= FTINY)
                return(0);
                                                /* record type & material */
        lightrec[nlights].type = L_SPHERE;
        (lightrec[nlights].m = m)->nlinks++;
                                                /* assign geometry */
        VCOPY(lightrec[nlights].pos, pos);
        lightrec[nlights].area = area;
        nlights++; dolights--;
        return(1);
}


static
l_source(n)                     /* convert a distant source */
register int    n;
{
        register MATREC *m = lightrec[n].m;
        int     thislight = lightid[n];
        GLfloat vec[4];
                                                /* assign direction */
        VCOPY(vec, lightrec[n].pos);
        vec[3] = 0.;
        glLightfv(thislight, GL_POSITION, vec);
                                                /* assign color */
        vec[0] = expval*lightrec[n].area*colval(m->u.l.emission,RED);
        vec[1] = expval*lightrec[n].area*colval(m->u.l.emission,GRN);
        vec[2] = expval*lightrec[n].area*colval(m->u.l.emission,BLU);
        vec[3] = 1.;
        glLightfv(thislight, GL_SPECULAR, vec);
        glLightfv(thislight, GL_DIFFUSE, vec);
        vec[0] = vec[1] = vec[2] = 0.; vec[3] = 1.;
        glLightfv(thislight, GL_AMBIENT, vec);
        glEnable(thislight);
}


static
l_flatsrc(n)                    /* convert a flat source */
register int    n;
{
        GLfloat vec[4];
        register MATREC *m = lightrec[n].m;
        int     thislight = lightid[n];
                                                /* assign position */
        VCOPY(vec, lightrec[n].pos); vec[3] = 1.;
        glLightfv(thislight, GL_POSITION, vec);
                                                /* assign color */
        vec[0] = expval*lightrec[n].area*colval(m->u.l.emission,RED);
        vec[1] = expval*lightrec[n].area*colval(m->u.l.emission,GRN);
        vec[2] = expval*lightrec[n].area*colval(m->u.l.emission,BLU);
        vec[3] = 1.;
        glLightfv(thislight, GL_SPECULAR, vec);
        glLightfv(thislight, GL_DIFFUSE, vec);
        vec[0] = vec[1] = vec[2] = 0.; vec[3] = 1.;
        glLightfv(thislight, GL_AMBIENT, vec);
        glLightf(thislight, GL_SPOT_EXPONENT, 1.);
        glLightf(thislight, GL_CONSTANT_ATTENUATION, 0.);
        glLightf(thislight, GL_LINEAR_ATTENUATION, 0.);
        glLightf(thislight, GL_QUADRATIC_ATTENUATION, 1.);
        if (m->type == MAT_SPOT && m->u.l.spotang < 90.) {
                glLightf(thislight, GL_SPOT_CUTOFF, m->u.l.spotang);
                glLightfv(thislight, GL_SPOT_DIRECTION, m->u.l.spotdir);
        } else {
                glLightf(thislight, GL_SPOT_CUTOFF, 90.);
                VCOPY(vec, lightrec[n].norm);
                glLightfv(thislight, GL_SPOT_DIRECTION, vec);
        }
        glEnable(thislight);
}


static
l_sphsrc(n)                     /* convert a spherical source */
register int    n;
{
        GLfloat vec[4];
        register MATREC *m = lightrec[n].m;
        int     thislight = lightid[n];
                                                /* assign position */
        VCOPY(vec, lightrec[n].pos); vec[3] = 1.;
        glLightfv(thislight, GL_POSITION, vec);
                                                /* assign color */
        vec[0] = expval*lightrec[n].area*colval(m->u.l.emission,RED);
        vec[1] = expval*lightrec[n].area*colval(m->u.l.emission,GRN);
        vec[2] = expval*lightrec[n].area*colval(m->u.l.emission,BLU);
        vec[3] = 1.;
        glLightfv(thislight, GL_SPECULAR, vec);
        glLightfv(thislight, GL_DIFFUSE, vec);
        vec[0] = vec[1] = vec[2] = 0.; vec[3] = 1.;
        glLightfv(thislight, GL_AMBIENT, vec);
        glLightf(thislight, GL_SPOT_EXPONENT, 0.);
        glLightf(thislight, GL_CONSTANT_ATTENUATION, 0.);
        glLightf(thislight, GL_LINEAR_ATTENUATION, 0.);
        glLightf(thislight, GL_QUADRATIC_ATTENUATION, 1.);
        if (m->type == MAT_SPOT && m->u.l.spotang <= 90.) {
                glLightf(thislight, GL_SPOT_CUTOFF, m->u.l.spotang);
                glLightfv(thislight, GL_SPOT_DIRECTION, m->u.l.spotdir);
        } else
                glLightf(thislight, GL_SPOT_CUTOFF, 180.);
        glEnable(thislight);
}
Revision:	3.1
Committed:	Tue Jun 9 11:18:36 1998 UTC (25 years, 10 months ago) by gwlarson
Content type:	text/plain
Branch:	MAIN
Log Message:	Initial revision
#	User	Rev	Content
1	gwlarson	3.1	/* Copyright (c) 1998 Silicon Graphics, Inc. */
2
3			#ifndef lint
4			static char SCCSid[] = "$SunId$ SGI";
5			#endif
6
7			/*
8			* Routines for handling OpenGL light sources
9			*/
10
11			#include "radogl.h"
12
13			double expval = 0.; /* global exposure value */
14
15			COLOR ambval = {0.2, 0.2, 0.2}; /* global ambient value */
16
17			int dolights = MAXLIGHTS; /* do how many more light sources? */
18
19			static int lightid[MAXLIGHTS] = {GL_LIGHT0, GL_LIGHT1, GL_LIGHT2,
20			GL_LIGHT3, GL_LIGHT4, GL_LIGHT5, GL_LIGHT6, GL_LIGHT7};
21
22			static int lightlist; /* light list id */
23
24			/* source types */
25			#define L_NONE 0
26			#define L_SOURCE 1
27			#define L_FLAT 2
28			#define L_SPHERE 3
29
30			static struct {
31			int type; /* light type (0 if none) */
32			MATREC m; / light material */
33			FVECT pos; /* light position (or direction) */
34			FVECT norm; /* flat source normal */
35			double area; /* source area (or solid angle) */
36			} lightrec[MAXLIGHTS]; /* light source list */
37
38			static int nlights; /* number of defined lights */
39
40			static int l_flatsrc(), l_spheresrc(), l_source();
41
42
43			lightinit() /* initialize lighting */
44			{
45			GLfloat ambv[4];
46			register int i;
47
48			if (!dolights)
49			return;
50			glPushAttrib(GL_LIGHTING_BIT);
51			if (expval <= FTINY && bright(ambval) > FTINY)
52			expval = 0.2/bright(ambval);
53			ambv[0] = expval*colval(ambval,RED);
54			ambv[1] = expval*colval(ambval,GRN);
55			ambv[2] = expval*colval(ambval,BLU);
56			ambv[3] = 1.;
57			glLightModelfv(GL_LIGHT_MODEL_AMBIENT, ambv);
58			glCallList(lightlist = newglist());
59			rgl_checkerr("in lightinit");
60			nlights = 0;
61			}
62
63
64			lightclean() /* clean up light source commands */
65			{
66			if ((dolights += nlights) <= 0)
67			return;
68			glPopAttrib();
69			}
70
71
72			lightdefs() /* define light source list */
73			{
74			register int i;
75
76			if (!nlights)
77			return;
78			glNewList(lightlist, GL_COMPILE);
79			while (nlights--) {
80			switch (lightrec[nlights].type) {
81			case L_FLAT:
82			l_flatsrc(nlights);
83			break;
84			case L_SPHERE:
85			l_sphsrc(nlights);
86			break;
87			case L_SOURCE:
88			l_source(nlights);
89			break;
90			default:
91			error(CONSISTENCY, "botched light type in lightdefs");
92			}
93			freemtl(lightrec[nlights].m);
94			lightrec[nlights].type = L_NONE;
95			}
96			glEndList();
97			rgl_checkerr("defining lights");
98			}
99
100
101			o_source(o) /* record a distant source */
102			register OBJREC *o;
103			{
104			if (!dolights \|\| !issrcmat((MATREC *)o->os))
105			return(0);
106			if (o->oargs.nfargs != 4)
107			objerror(o, USER, "bad # real arguments");
108			/* record type & material */
109			lightrec[nlights].type = L_SOURCE;
110			(lightrec[nlights].m = (MATREC *)o->os)->nlinks++;
111			/* assign direction */
112			VCOPY(lightrec[nlights].pos, o->oargs.farg);
113			/* compute solid angle */
114			if (o->oargs.farg[3] <= FTINY)
115			objerror(o, USER, "zero size");
116			lightrec[nlights].area = 2.PI(1. - cos(PI/180./2.*o->oargs.farg[3]));
117			nlights++; dolights--;
118			return(1);
119			}
120
121
122			int
123			doflatsrc(m, pos, norm, area) /* record a flat source */
124			MATREC *m;
125			FVECT pos, norm;
126			double area;
127			{
128			if (!dolights \|\| !issrcmat(m) \|\| area <= FTINY)
129			return(0);
130			/* record type & material */
131			lightrec[nlights].type = L_FLAT;
132			(lightrec[nlights].m = m)->nlinks++;
133			/* assign geometry */
134			VCOPY(lightrec[nlights].pos, pos);
135			VCOPY(lightrec[nlights].norm, norm);
136			lightrec[nlights].area = area;
137			nlights++; dolights--;
138			return(1);
139			}
140
141
142			int
143			dosphsrc(m, pos, area) /* record a spherical source */
144			register MATREC *m;
145			FVECT pos;
146			double area;
147			{
148			if (!dolights \|\| !issrcmat(m) \|\| area <= FTINY)
149			return(0);
150			/* record type & material */
151			lightrec[nlights].type = L_SPHERE;
152			(lightrec[nlights].m = m)->nlinks++;
153			/* assign geometry */
154			VCOPY(lightrec[nlights].pos, pos);
155			lightrec[nlights].area = area;
156			nlights++; dolights--;
157			return(1);
158			}
159
160
161			static
162			l_source(n) /* convert a distant source */
163			register int n;
164			{
165			register MATREC *m = lightrec[n].m;
166			int thislight = lightid[n];
167			GLfloat vec[4];
168			/* assign direction */
169			VCOPY(vec, lightrec[n].pos);
170			vec[3] = 0.;
171			glLightfv(thislight, GL_POSITION, vec);
172			/* assign color */
173			vec[0] = expvallightrec[n].areacolval(m->u.l.emission,RED);
174			vec[1] = expvallightrec[n].areacolval(m->u.l.emission,GRN);
175			vec[2] = expvallightrec[n].areacolval(m->u.l.emission,BLU);
176			vec[3] = 1.;
177			glLightfv(thislight, GL_SPECULAR, vec);
178			glLightfv(thislight, GL_DIFFUSE, vec);
179			vec[0] = vec[1] = vec[2] = 0.; vec[3] = 1.;
180			glLightfv(thislight, GL_AMBIENT, vec);
181			glEnable(thislight);
182			}
183
184
185			static
186			l_flatsrc(n) /* convert a flat source */
187			register int n;
188			{
189			GLfloat vec[4];
190			register MATREC *m = lightrec[n].m;
191			int thislight = lightid[n];
192			/* assign position */
193			VCOPY(vec, lightrec[n].pos); vec[3] = 1.;
194			glLightfv(thislight, GL_POSITION, vec);
195			/* assign color */
196			vec[0] = expvallightrec[n].areacolval(m->u.l.emission,RED);
197			vec[1] = expvallightrec[n].areacolval(m->u.l.emission,GRN);
198			vec[2] = expvallightrec[n].areacolval(m->u.l.emission,BLU);
199			vec[3] = 1.;
200			glLightfv(thislight, GL_SPECULAR, vec);
201			glLightfv(thislight, GL_DIFFUSE, vec);
202			vec[0] = vec[1] = vec[2] = 0.; vec[3] = 1.;
203			glLightfv(thislight, GL_AMBIENT, vec);
204			glLightf(thislight, GL_SPOT_EXPONENT, 1.);
205			glLightf(thislight, GL_CONSTANT_ATTENUATION, 0.);
206			glLightf(thislight, GL_LINEAR_ATTENUATION, 0.);
207			glLightf(thislight, GL_QUADRATIC_ATTENUATION, 1.);
208			if (m->type == MAT_SPOT && m->u.l.spotang < 90.) {
209			glLightf(thislight, GL_SPOT_CUTOFF, m->u.l.spotang);
210			glLightfv(thislight, GL_SPOT_DIRECTION, m->u.l.spotdir);
211			} else {
212			glLightf(thislight, GL_SPOT_CUTOFF, 90.);
213			VCOPY(vec, lightrec[n].norm);
214			glLightfv(thislight, GL_SPOT_DIRECTION, vec);
215			}
216			glEnable(thislight);
217			}
218
219
220			static
221			l_sphsrc(n) /* convert a spherical source */
222			register int n;
223			{
224			GLfloat vec[4];
225			register MATREC *m = lightrec[n].m;
226			int thislight = lightid[n];
227			/* assign position */
228			VCOPY(vec, lightrec[n].pos); vec[3] = 1.;
229			glLightfv(thislight, GL_POSITION, vec);
230			/* assign color */
231			vec[0] = expvallightrec[n].areacolval(m->u.l.emission,RED);
232			vec[1] = expvallightrec[n].areacolval(m->u.l.emission,GRN);
233			vec[2] = expvallightrec[n].areacolval(m->u.l.emission,BLU);
234			vec[3] = 1.;
235			glLightfv(thislight, GL_SPECULAR, vec);
236			glLightfv(thislight, GL_DIFFUSE, vec);
237			vec[0] = vec[1] = vec[2] = 0.; vec[3] = 1.;
238			glLightfv(thislight, GL_AMBIENT, vec);
239			glLightf(thislight, GL_SPOT_EXPONENT, 0.);
240			glLightf(thislight, GL_CONSTANT_ATTENUATION, 0.);
241			glLightf(thislight, GL_LINEAR_ATTENUATION, 0.);
242			glLightf(thislight, GL_QUADRATIC_ATTENUATION, 1.);
243			if (m->type == MAT_SPOT && m->u.l.spotang <= 90.) {
244			glLightf(thislight, GL_SPOT_CUTOFF, m->u.l.spotang);
245			glLightfv(thislight, GL_SPOT_DIRECTION, m->u.l.spotdir);
246			} else
247			glLightf(thislight, GL_SPOT_CUTOFF, 180.);
248			glEnable(thislight);
249			}