87 lines
2.3 KiB
C
87 lines
2.3 KiB
C
/*
|
|
* Copyright (c) 1993-1995 Argonaut Technologies Limited. All rights reserved.
|
|
*
|
|
* $Id: lightmac.h 1.1 1997/07/11 16:15:30 jon Exp JON $
|
|
* $Locker: JON $
|
|
*
|
|
* Macros for building the lighting functions
|
|
*/
|
|
|
|
/*
|
|
* Clamp a component to (0,1], scale and offset
|
|
*/
|
|
#define CLAMP_SCALE(c) do { \
|
|
if ((c) >= BR_SCALAR(1.0)) \
|
|
(c) = BR_SCALAR(256.0) - BR_SCALAR_EPSILON; \
|
|
else if ((c) <= BR_SCALAR(0.0)) \
|
|
(c) = BR_SCALAR(0.0); \
|
|
else \
|
|
(c) = BR_MUL(BR_SCALAR(256.0), (c)); \
|
|
} while(0);
|
|
|
|
|
|
/*
|
|
* Find dot product of reflected vector and eye
|
|
*
|
|
* uses dirn_norm, n, and rend.eye_l
|
|
*
|
|
* produces dot
|
|
*/
|
|
#define SPECULAR_DOT() do { \
|
|
br_vector3 r; \
|
|
br_scalar rd; \
|
|
\
|
|
rd = BR_CONST_MUL(BrVector3Dot(&dirn_norm,n),2); \
|
|
BrVector3Scale(&r,n,rd); \
|
|
BrVector3Sub(&r,&r,&dirn_norm); \
|
|
\
|
|
dot = BrVector3Dot(&rend.eye_l,&r); \
|
|
} while(0)
|
|
|
|
/*
|
|
* Given the dot-product of eye & reflected vector, returns specular component of lighting eqn.
|
|
*/
|
|
#define SPECULAR_POWER(l) BR_MULDIV(dot,l,self->state.surface.power-BR_MUL(self->state.surface.power,dot)+dot)
|
|
|
|
/*
|
|
* Given dist, calculates dirn_norm & dist
|
|
*/
|
|
#define CALCULATE_DIRN_NORM() do { \
|
|
br_scalar s; \
|
|
dist = BrVector3Length(&dirn); \
|
|
if(dist <= 2 * BR_SCALAR_EPSILON) \
|
|
return; \
|
|
s = BR_RCP(dist); \
|
|
BrVector3Scale(&dirn_norm,&dirn,s); \
|
|
} while(0)
|
|
|
|
/*
|
|
* Given dist, calculates attn
|
|
*/
|
|
#define CALCULATE_ATTENUATION() do { \
|
|
br_scalar dist2; \
|
|
if(dist >= BR_SCALAR(180.0)) \
|
|
dist2 = BR_SCALAR(32767.0); \
|
|
else \
|
|
dist2 = BR_MUL(dist,dist); \
|
|
\
|
|
attn = BR_RCP(alp->s->attenuation_c \
|
|
+ BR_MUL(dist,alp->s->attenuation_l) \
|
|
+ BR_MUL(dist2,alp->s->attenuation_q)); \
|
|
} while(0)
|
|
|
|
#define DIFFUSE_DOT() do { \
|
|
dot = BrVector3Dot(n,&dirn_norm); \
|
|
if(dot <= BR_SCALAR(0.0)) \
|
|
return; \
|
|
} while(0)
|
|
|
|
|
|
#define SPOT_DOT() do { \
|
|
dot_spot = BrVector3Dot(&dirn_norm,&alp->direction); \
|
|
if(dot_spot < alp->s->spot_outer) \
|
|
return; \
|
|
} while(0)
|
|
|
|
#define SPOT_FALLOFF(v) ((dot_spot < alp->s->spot_inner)?\
|
|
BR_MULDIV((v),alp->s->spot_outer - dot_spot, alp->s->spot_outer - alp->s->spot_inner) : (v))
|