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/* $Id: light.c,v 1.13 1997/06/20 04:15:43 brianp Exp $ */
/*
* Mesa 3-D graphics library
* Version: 2.3
* Copyright (C) 1995-1997 Brian Paul
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the Free
* Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
/*
* $Log: light.c,v $
* Revision 1.13 1997/06/20 04:15:43 brianp
* optimized changing of SHININESS (Henk Kok)
*
* Revision 1.12 1997/05/28 03:25:26 brianp
* added precompiled header (PCH) support
*
* Revision 1.11 1997/05/01 01:38:57 brianp
* now use NORMALIZE_3FV() macro from mmath.h
*
* Revision 1.10 1997/04/20 20:28:49 brianp
* replaced abort() with gl_problem()
*
* Revision 1.9 1997/04/07 02:59:17 brianp
* small optimization to setting of shininess and spot exponent
*
* Revision 1.8 1997/04/01 04:09:31 brianp
* misc code clean-ups. moved shading code to shade.c
*
* Revision 1.7 1997/03/11 00:37:39 brianp
* spotlight factor now effects ambient lighting
*
* Revision 1.6 1996/12/18 20:02:07 brianp
* glColorMaterial() and glMaterial() should finally work right!
*
* Revision 1.5 1996/12/07 10:22:41 brianp
* gl_Materialfv() now calls gl_set_material() if GL_COLOR_MATERIAL disabled
* implemented gl_GetLightiv()
*
* Revision 1.4 1996/11/08 04:39:23 brianp
* new gl_compute_spot_exp_table() contributed by Randy Frank
*
* Revision 1.3 1996/09/27 01:27:55 brianp
* removed unused variables
*
* Revision 1.2 1996/09/15 14:18:10 brianp
* now use GLframebuffer and GLvisual
*
* Revision 1.1 1996/09/13 01:38:16 brianp
* Initial revision
*
*/
#ifdef PCH
#include "all.h"
#else
#include <assert.h>
#include <float.h>
#include <math.h>
#include <stdlib.h>
#include "context.h"
#include "light.h"
#include "dlist.h"
#include "macros.h"
#include "matrix.h"
#include "mmath.h"
#include "types.h"
#include "vb.h"
#include "xform.h"
#endif
void gl_ShadeModel( GLcontext *ctx, GLenum mode )
{
if (INSIDE_BEGIN_END(ctx)) {
gl_error( ctx, GL_INVALID_OPERATION, "glShadeModel" );
return;
}
switch (mode) {
case GL_FLAT:
case GL_SMOOTH:
if (ctx->Light.ShadeModel!=mode) {
ctx->Light.ShadeModel = mode;
ctx->NewState |= NEW_RASTER_OPS;
}
break;
default:
gl_error( ctx, GL_INVALID_ENUM, "glShadeModel" );
}
}
void gl_Lightfv( GLcontext *ctx,
GLenum light, GLenum pname, const GLfloat *params,
GLint nparams )
{
GLint l;
if (INSIDE_BEGIN_END(ctx)) {
gl_error( ctx, GL_INVALID_OPERATION, "glShadeModel" );
return;
}
l = (GLint) (light - GL_LIGHT0);
if (l<0 || l>=MAX_LIGHTS) {
gl_error( ctx, GL_INVALID_ENUM, "glLight" );
return;
}
switch (pname) {
case GL_AMBIENT:
COPY_4V( ctx->Light.Light[l].Ambient, params );
break;
case GL_DIFFUSE:
COPY_4V( ctx->Light.Light[l].Diffuse, params );
break;
case GL_SPECULAR:
COPY_4V( ctx->Light.Light[l].Specular, params );
break;
case GL_POSITION:
/* transform position by ModelView matrix */
TRANSFORM_POINT( ctx->Light.Light[l].Position, ctx->ModelViewMatrix,
params );
break;
case GL_SPOT_DIRECTION:
/* transform direction by inverse modelview */
{
GLfloat direction[4];
direction[0] = params[0];
direction[1] = params[1];
direction[2] = params[2];
direction[3] = 0.0;
if (ctx->NewModelViewMatrix) {
gl_analyze_modelview_matrix( ctx );
}
gl_transform_vector( ctx->Light.Light[l].Direction,
direction, ctx->ModelViewInv);
}
break;
case GL_SPOT_EXPONENT:
if (params[0]<0.0 || params[0]>128.0) {
gl_error( ctx, GL_INVALID_VALUE, "glLight" );
return;
}
if (ctx->Light.Light[l].SpotExponent != params[0]) {
ctx->Light.Light[l].SpotExponent = params[0];
gl_compute_spot_exp_table( &ctx->Light.Light[l] );
}
break;
case GL_SPOT_CUTOFF:
if ((params[0]<0.0 || params[0]>90.0) && params[0]!=180.0) {
gl_error( ctx, GL_INVALID_VALUE, "glLight" );
return;
}
ctx->Light.Light[l].SpotCutoff = params[0];
ctx->Light.Light[l].CosCutoff = cos(params[0]*DEG2RAD);
break;
case GL_CONSTANT_ATTENUATION:
if (params[0]<0.0) {
gl_error( ctx, GL_INVALID_VALUE, "glLight" );
return;
}
ctx->Light.Light[l].ConstantAttenuation = params[0];
break;
case GL_LINEAR_ATTENUATION:
if (params[0]<0.0) {
gl_error( ctx, GL_INVALID_VALUE, "glLight" );
return;
}
ctx->Light.Light[l].LinearAttenuation = params[0];
break;
case GL_QUADRATIC_ATTENUATION:
if (params[0]<0.0) {
gl_error( ctx, GL_INVALID_VALUE, "glLight" );
return;
}
ctx->Light.Light[l].QuadraticAttenuation = params[0];
break;
default:
gl_error( ctx, GL_INVALID_ENUM, "glLight" );
break;
}
ctx->NewState |= NEW_LIGHTING;
}
void gl_GetLightfv( GLcontext *ctx,
GLenum light, GLenum pname, GLfloat *params )
{
GLint l = (GLint) (light - GL_LIGHT0);
if (l<0 || l>=MAX_LIGHTS) {
gl_error( ctx, GL_INVALID_ENUM, "glGetLightfv" );
return;
}
switch (pname) {
case GL_AMBIENT:
COPY_4V( params, ctx->Light.Light[l].Ambient );
break;
case GL_DIFFUSE:
COPY_4V( params, ctx->Light.Light[l].Diffuse );
break;
case GL_SPECULAR:
COPY_4V( params, ctx->Light.Light[l].Specular );
break;
case GL_POSITION:
COPY_4V( params, ctx->Light.Light[l].Position );
break;
case GL_SPOT_DIRECTION:
COPY_3V( params, ctx->Light.Light[l].Direction );
break;
case GL_SPOT_EXPONENT:
params[0] = ctx->Light.Light[l].SpotExponent;
break;
case GL_SPOT_CUTOFF:
params[0] = ctx->Light.Light[l].SpotCutoff;
break;
case GL_CONSTANT_ATTENUATION:
params[0] = ctx->Light.Light[l].ConstantAttenuation;
break;
case GL_LINEAR_ATTENUATION:
params[0] = ctx->Light.Light[l].LinearAttenuation;
break;
case GL_QUADRATIC_ATTENUATION:
params[0] = ctx->Light.Light[l].QuadraticAttenuation;
break;
default:
gl_error( ctx, GL_INVALID_ENUM, "glGetLightfv" );
break;
}
}
void gl_GetLightiv( GLcontext *ctx, GLenum light, GLenum pname, GLint *params )
{
GLint l = (GLint) (light - GL_LIGHT0);
if (l<0 || l>=MAX_LIGHTS) {
gl_error( ctx, GL_INVALID_ENUM, "glGetLightiv" );
return;
}
switch (pname) {
case GL_AMBIENT:
params[0] = FLOAT_TO_INT(ctx->Light.Light[l].Ambient[0]);
params[1] = FLOAT_TO_INT(ctx->Light.Light[l].Ambient[1]);
params[2] = FLOAT_TO_INT(ctx->Light.Light[l].Ambient[2]);
params[3] = FLOAT_TO_INT(ctx->Light.Light[l].Ambient[3]);
break;
case GL_DIFFUSE:
params[0] = FLOAT_TO_INT(ctx->Light.Light[l].Diffuse[0]);
params[1] = FLOAT_TO_INT(ctx->Light.Light[l].Diffuse[1]);
params[2] = FLOAT_TO_INT(ctx->Light.Light[l].Diffuse[2]);
params[3] = FLOAT_TO_INT(ctx->Light.Light[l].Diffuse[3]);
break;
case GL_SPECULAR:
params[0] = FLOAT_TO_INT(ctx->Light.Light[l].Specular[0]);
params[1] = FLOAT_TO_INT(ctx->Light.Light[l].Specular[1]);
params[2] = FLOAT_TO_INT(ctx->Light.Light[l].Specular[2]);
params[3] = FLOAT_TO_INT(ctx->Light.Light[l].Specular[3]);
break;
case GL_POSITION:
params[0] = ctx->Light.Light[l].Position[0];
params[1] = ctx->Light.Light[l].Position[1];
params[2] = ctx->Light.Light[l].Position[2];
params[3] = ctx->Light.Light[l].Position[3];
break;
case GL_SPOT_DIRECTION:
params[0] = ctx->Light.Light[l].Direction[0];
params[1] = ctx->Light.Light[l].Direction[1];
params[2] = ctx->Light.Light[l].Direction[2];
break;
case GL_SPOT_EXPONENT:
params[0] = ctx->Light.Light[l].SpotExponent;
break;
case GL_SPOT_CUTOFF:
params[0] = ctx->Light.Light[l].SpotCutoff;
break;
case GL_CONSTANT_ATTENUATION:
params[0] = ctx->Light.Light[l].ConstantAttenuation;
break;
case GL_LINEAR_ATTENUATION:
params[0] = ctx->Light.Light[l].LinearAttenuation;
break;
case GL_QUADRATIC_ATTENUATION:
params[0] = ctx->Light.Light[l].QuadraticAttenuation;
break;
default:
gl_error( ctx, GL_INVALID_ENUM, "glGetLightiv" );
break;
}
}
/**********************************************************************/
/*** Light Model ***/
/**********************************************************************/
void gl_LightModelfv( GLcontext *ctx, GLenum pname, const GLfloat *params )
{
switch (pname) {
case GL_LIGHT_MODEL_AMBIENT:
COPY_4V( ctx->Light.Model.Ambient, params );
break;
case GL_LIGHT_MODEL_LOCAL_VIEWER:
if (params[0]==0.0)
ctx->Light.Model.LocalViewer = GL_FALSE;
else
ctx->Light.Model.LocalViewer = GL_TRUE;
break;
case GL_LIGHT_MODEL_TWO_SIDE:
if (params[0]==0.0)
ctx->Light.Model.TwoSide = GL_FALSE;
else
ctx->Light.Model.TwoSide = GL_TRUE;
break;
default:
gl_error( ctx, GL_INVALID_ENUM, "glLightModel" );
break;
}
ctx->NewState |= NEW_LIGHTING;
}
/********** MATERIAL **********/
/*
* Given a face and pname value (ala glColorMaterial), compute a bitmask
* of the targeted material values.
*/
GLuint gl_material_bitmask( GLenum face, GLenum pname )
{
GLuint bitmask = 0;
/* Make a bitmask indicating what material attribute(s) we're updating */
switch (pname) {
case GL_EMISSION:
bitmask |= FRONT_EMISSION_BIT | BACK_EMISSION_BIT;
break;
case GL_AMBIENT:
bitmask |= FRONT_AMBIENT_BIT | BACK_AMBIENT_BIT;
break;
case GL_DIFFUSE:
bitmask |= FRONT_DIFFUSE_BIT | BACK_DIFFUSE_BIT;
break;
case GL_SPECULAR:
bitmask |= FRONT_SPECULAR_BIT | BACK_SPECULAR_BIT;
break;
case GL_SHININESS:
bitmask |= FRONT_SHININESS_BIT | BACK_SHININESS_BIT;
break;
case GL_AMBIENT_AND_DIFFUSE:
bitmask |= FRONT_AMBIENT_BIT | BACK_AMBIENT_BIT;
bitmask |= FRONT_DIFFUSE_BIT | BACK_DIFFUSE_BIT;
break;
case GL_COLOR_INDEXES:
bitmask |= FRONT_INDEXES_BIT | BACK_INDEXES_BIT;
break;
default:
gl_problem(NULL, "Bad param in gl_material_bitmask");
return 0;
}
ASSERT( face==GL_FRONT || face==GL_BACK || face==GL_FRONT_AND_BACK );
if (face==GL_FRONT) {
bitmask &= FRONT_MATERIAL_BITS;
}
else if (face==GL_BACK) {
bitmask &= BACK_MATERIAL_BITS;
}
return bitmask;
}
/*
* This is called by glColor() when GL_COLOR_MATERIAL is enabled and
* called by glMaterial() when GL_COLOR_MATERIAL is disabled.
*/
void gl_set_material( GLcontext *ctx, GLuint bitmask, const GLfloat *params )
{
struct gl_material *mat;
if (INSIDE_BEGIN_END(ctx)) {
struct vertex_buffer *VB = ctx->VB;
/* Save per-vertex material changes in the Vertex Buffer.
* The update_material function will eventually update the global
* ctx->Light.Material values.
*/
mat = VB->Material[VB->Count];
VB->MaterialMask[VB->Count] |= bitmask;
VB->MonoMaterial = GL_FALSE;
}
else {
/* just update the global material property */
mat = ctx->Light.Material;
ctx->NewState |= NEW_LIGHTING;
}
if (bitmask & FRONT_AMBIENT_BIT) {
COPY_4V( mat[0].Ambient, params );
}
if (bitmask & BACK_AMBIENT_BIT) {
COPY_4V( mat[1].Ambient, params );
}
if (bitmask & FRONT_DIFFUSE_BIT) {
COPY_4V( mat[0].Diffuse, params );
}
if (bitmask & BACK_DIFFUSE_BIT) {
COPY_4V( mat[1].Diffuse, params );
}
if (bitmask & FRONT_SPECULAR_BIT) {
COPY_4V( mat[0].Specular, params );
}
if (bitmask & BACK_SPECULAR_BIT) {
COPY_4V( mat[1].Specular, params );
}
if (bitmask & FRONT_EMISSION_BIT) {
COPY_4V( mat[0].Emission, params );
}
if (bitmask & BACK_EMISSION_BIT) {
COPY_4V( mat[1].Emission, params );
}
if (bitmask & FRONT_SHININESS_BIT) {
GLfloat shininess = CLAMP( params[0], 0.0F, 128.0F );
if (mat[0].Shininess != shininess) {
mat[0].Shininess = shininess;
gl_compute_material_shine_table( &mat[0] );
}
}
if (bitmask & BACK_SHININESS_BIT) {
GLfloat shininess = CLAMP( params[0], 0.0F, 128.0F );
if (mat[1].Shininess != shininess) {
mat[1].Shininess = shininess;
gl_compute_material_shine_table( &mat[1] );
}
}
if (bitmask & FRONT_INDEXES_BIT) {
mat[0].AmbientIndex = params[0];
mat[0].DiffuseIndex = params[1];
mat[0].SpecularIndex = params[2];
}
if (bitmask & BACK_INDEXES_BIT) {
mat[1].AmbientIndex = params[0];
mat[1].DiffuseIndex = params[1];
mat[1].SpecularIndex = params[2];
}
}
void gl_ColorMaterial( GLcontext *ctx, GLenum face, GLenum mode )
{
if (INSIDE_BEGIN_END(ctx)) {
gl_error( ctx, GL_INVALID_OPERATION, "glColorMaterial" );
return;
}
switch (face) {
case GL_FRONT:
case GL_BACK:
case GL_FRONT_AND_BACK:
ctx->Light.ColorMaterialFace = face;
break;
default:
gl_error( ctx, GL_INVALID_ENUM, "glColorMaterial(face)" );
return;
}
switch (mode) {
case GL_EMISSION:
case GL_AMBIENT:
case GL_DIFFUSE:
case GL_SPECULAR:
case GL_AMBIENT_AND_DIFFUSE:
ctx->Light.ColorMaterialMode = mode;
break;
default:
gl_error( ctx, GL_INVALID_ENUM, "glColorMaterial(mode)" );
return;
}
ctx->Light.ColorMaterialBitmask = gl_material_bitmask( face, mode );
}
/*
* This is only called via the api_function_table struct or by the
* display list executor.
*/
void gl_Materialfv( GLcontext *ctx,
GLenum face, GLenum pname, const GLfloat *params )
{
GLuint bitmask;
/* error checking */
if (face!=GL_FRONT && face!=GL_BACK && face!=GL_FRONT_AND_BACK) {
gl_error( ctx, GL_INVALID_ENUM, "glMaterial(face)" );
return;
}
switch (pname) {
case GL_EMISSION:
case GL_AMBIENT:
case GL_DIFFUSE:
case GL_SPECULAR:
case GL_SHININESS:
case GL_AMBIENT_AND_DIFFUSE:
case GL_COLOR_INDEXES:
/* OK */
break;
default:
gl_error( ctx, GL_INVALID_ENUM, "glMaterial(pname)" );
return;
}
/* convert face and pname to a bitmask */
bitmask = gl_material_bitmask( face, pname );
if (ctx->Light.ColorMaterialEnabled) {
/* The material values specified by glColorMaterial() can't be */
/* updated by glMaterial() while GL_COLOR_MATERIAL is enabled! */
bitmask &= ~ctx->Light.ColorMaterialBitmask;
}
gl_set_material( ctx, bitmask, params );
}
void gl_GetMaterialfv( GLcontext *ctx,
GLenum face, GLenum pname, GLfloat *params )
{
GLuint f;
if (INSIDE_BEGIN_END(ctx)) {
gl_error( ctx, GL_INVALID_OPERATION, "glGetMaterialfv" );
return;
}
if (face==GL_FRONT) {
f = 0;
}
else if (face==GL_BACK) {
f = 1;
}
else {
gl_error( ctx, GL_INVALID_ENUM, "glGetMaterialfv(face)" );
return;
}
switch (pname) {
case GL_AMBIENT:
COPY_4V( params, ctx->Light.Material[f].Ambient );
break;
case GL_DIFFUSE:
COPY_4V( params, ctx->Light.Material[f].Diffuse );
break;
case GL_SPECULAR:
COPY_4V( params, ctx->Light.Material[f].Specular );
break;
case GL_EMISSION:
COPY_4V( params, ctx->Light.Material[f].Emission );
break;
case GL_SHININESS:
*params = ctx->Light.Material[f].Shininess;
break;
case GL_COLOR_INDEXES:
params[0] = ctx->Light.Material[f].AmbientIndex;
params[1] = ctx->Light.Material[f].DiffuseIndex;
params[2] = ctx->Light.Material[f].SpecularIndex;
break;
default:
gl_error( ctx, GL_INVALID_ENUM, "glGetMaterialfv(pname)" );
}
}
void gl_GetMaterialiv( GLcontext *ctx,
GLenum face, GLenum pname, GLint *params )
{
GLuint f;
if (INSIDE_BEGIN_END(ctx)) {
gl_error( ctx, GL_INVALID_OPERATION, "glGetMaterialiv" );
return;
}
if (face==GL_FRONT) {
f = 0;
}
else if (face==GL_BACK) {
f = 1;
}
else {
gl_error( ctx, GL_INVALID_ENUM, "glGetMaterialiv(face)" );
return;
}
switch (pname) {
case GL_AMBIENT:
params[0] = FLOAT_TO_INT( ctx->Light.Material[f].Ambient[0] );
params[1] = FLOAT_TO_INT( ctx->Light.Material[f].Ambient[1] );
params[2] = FLOAT_TO_INT( ctx->Light.Material[f].Ambient[2] );
params[3] = FLOAT_TO_INT( ctx->Light.Material[f].Ambient[3] );
break;
case GL_DIFFUSE:
params[0] = FLOAT_TO_INT( ctx->Light.Material[f].Diffuse[0] );
params[1] = FLOAT_TO_INT( ctx->Light.Material[f].Diffuse[1] );
params[2] = FLOAT_TO_INT( ctx->Light.Material[f].Diffuse[2] );
params[3] = FLOAT_TO_INT( ctx->Light.Material[f].Diffuse[3] );
break;
case GL_SPECULAR:
params[0] = FLOAT_TO_INT( ctx->Light.Material[f].Specular[0] );
params[1] = FLOAT_TO_INT( ctx->Light.Material[f].Specular[1] );
params[2] = FLOAT_TO_INT( ctx->Light.Material[f].Specular[2] );
params[3] = FLOAT_TO_INT( ctx->Light.Material[f].Specular[3] );
break;
case GL_EMISSION:
params[0] = FLOAT_TO_INT( ctx->Light.Material[f].Emission[0] );
params[1] = FLOAT_TO_INT( ctx->Light.Material[f].Emission[1] );
params[2] = FLOAT_TO_INT( ctx->Light.Material[f].Emission[2] );
params[3] = FLOAT_TO_INT( ctx->Light.Material[f].Emission[3] );
break;
case GL_SHININESS:
*params = ROUNDF( ctx->Light.Material[f].Shininess );
break;
case GL_COLOR_INDEXES:
params[0] = ROUNDF( ctx->Light.Material[f].AmbientIndex );
params[1] = ROUNDF( ctx->Light.Material[f].DiffuseIndex );
params[2] = ROUNDF( ctx->Light.Material[f].SpecularIndex );
break;
default:
gl_error( ctx, GL_INVALID_ENUM, "glGetMaterialfv(pname)" );
}
}
/**********************************************************************/
/***** Lighting computation *****/
/**********************************************************************/
/*
* Notes:
* When two-sided lighting is enabled we compute the color (or index)
* for both the front and back side of the primitive. Then, when the
* orientation of the facet is later learned, we can determine which
* color (or index) to use for rendering.
*
* Variables:
* n = normal vector
* V = vertex position
* P = light source position
* Pe = (0,0,0,1)
*
* Precomputed:
* IF P[3]==0 THEN
* // light at infinity
* IF local_viewer THEN
* VP_inf_norm = unit vector from V to P // Precompute
* ELSE
* // eye at infinity
* h_inf_norm = Normalize( VP + <0,0,1> ) // Precompute
* ENDIF
* ENDIF
*
* Functions:
* Normalize( v ) = normalized vector v
* Magnitude( v ) = length of vector v
*/
/*
* Whenever the spotlight exponent for a light changes we must call
* this function to recompute the exponent lookup table.
*/
void gl_compute_spot_exp_table( struct gl_light *l )
{
int i;
double exponent = l->SpotExponent;
double tmp;
int clamp = 0;
l->SpotExpTable[0][0] = 0.0;
for (i=EXP_TABLE_SIZE-1;i>0;i--) {
if (clamp == 0) {
tmp = pow(i/(double)(EXP_TABLE_SIZE-1), exponent);
if (tmp < FLT_MIN*100.0) {
tmp = 0.0;
clamp = 1;
}
}
l->SpotExpTable[i][0] = tmp;
}
for (i=0;i<EXP_TABLE_SIZE-1;i++) {
l->SpotExpTable[i][1] = l->SpotExpTable[i+1][0] - l->SpotExpTable[i][0];
}
l->SpotExpTable[EXP_TABLE_SIZE-1][1] = 0.0;
}
/*
* Whenever the shininess of a material changes we must call this
* function to recompute the exponential lookup table.
*/
void gl_compute_material_shine_table( struct gl_material *m )
{
int i;
double exponent = m->Shininess;
m->ShineTable[0] = 0.0F;
for (i=1;i<SHINE_TABLE_SIZE;i++) {
#if 0
double x = pow( i/(double)(SHINE_TABLE_SIZE-1), exponent );
if (x<1.0e-10) {
m->ShineTable[i] = 0.0F;
}
else {
m->ShineTable[i] = x;
}
#else
/* just invalidate the table */
m->ShineTable[i] = -1.0;
#endif
}
}
/*
* Examine current lighting parameters to determine if the optimized lighting
* function can be used.
* Also, precompute some lighting values such as the products of light
* source and material ambient, diffuse and specular coefficients.
*/
void gl_update_lighting( GLcontext *ctx )
{
GLint i, side;
struct gl_light *prev_enabled, *light;
if (!ctx->Light.Enabled) {
/* If lighting is not enabled, we can skip all this. */
return;
}
/* Setup linked list of enabled light sources */
prev_enabled = NULL;
ctx->Light.FirstEnabled = NULL;
for (i=0;i<MAX_LIGHTS;i++) {
ctx->Light.Light[i].NextEnabled = NULL;
if (ctx->Light.Light[i].Enabled) {
if (prev_enabled) {
prev_enabled->NextEnabled = &ctx->Light.Light[i];
}
else {
ctx->Light.FirstEnabled = &ctx->Light.Light[i];
}
prev_enabled = &ctx->Light.Light[i];
}
}
/* base color = material_emission + global_ambient * material_ambient */
for (side=0; side<2; side++) {
ctx->Light.BaseColor[side][0] = ctx->Light.Material[side].Emission[0]
+ ctx->Light.Model.Ambient[0] * ctx->Light.Material[side].Ambient[0];
ctx->Light.BaseColor[side][1] = ctx->Light.Material[side].Emission[1]
+ ctx->Light.Model.Ambient[1] * ctx->Light.Material[side].Ambient[1];
ctx->Light.BaseColor[side][2] = ctx->Light.Material[side].Emission[2]
+ ctx->Light.Model.Ambient[2] * ctx->Light.Material[side].Ambient[2];
ctx->Light.BaseColor[side][3]
= MIN2( ctx->Light.Material[side].Diffuse[3], 1.0F );
}
/* Precompute some lighting stuff */
for (light = ctx->Light.FirstEnabled; light; light = light->NextEnabled) {
for (side=0; side<2; side++) {
struct gl_material *mat = &ctx->Light.Material[side];
/* Add each light's ambient component to base color */
ctx->Light.BaseColor[side][0] += light->Ambient[0] * mat->Ambient[0];
ctx->Light.BaseColor[side][1] += light->Ambient[1] * mat->Ambient[1];
ctx->Light.BaseColor[side][2] += light->Ambient[2] * mat->Ambient[2];
/* compute product of light's ambient with front material ambient */
light->MatAmbient[side][0] = light->Ambient[0] * mat->Ambient[0];
light->MatAmbient[side][1] = light->Ambient[1] * mat->Ambient[1];
light->MatAmbient[side][2] = light->Ambient[2] * mat->Ambient[2];
/* compute product of light's diffuse with front material diffuse */
light->MatDiffuse[side][0] = light->Diffuse[0] * mat->Diffuse[0];
light->MatDiffuse[side][1] = light->Diffuse[1] * mat->Diffuse[1];
light->MatDiffuse[side][2] = light->Diffuse[2] * mat->Diffuse[2];
/* compute product of light's specular with front material specular */
light->MatSpecular[side][0] = light->Specular[0] * mat->Specular[0];
light->MatSpecular[side][1] = light->Specular[1] * mat->Specular[1];
light->MatSpecular[side][2] = light->Specular[2] * mat->Specular[2];
/* VP (VP) = Normalize( Position ) */
COPY_3V( light->VP_inf_norm, light->Position );
NORMALIZE_3FV( light->VP_inf_norm );
/* h_inf_norm = Normalize( V_to_P + <0,0,1> ) */
COPY_3V( light->h_inf_norm, light->VP_inf_norm );
light->h_inf_norm[2] += 1.0F;
NORMALIZE_3FV( light->h_inf_norm );
COPY_3V( light->NormDirection, light->Direction );
NORMALIZE_3FV( light->NormDirection );
/* Compute color index diffuse and specular light intensities */
light->dli = 0.30F * light->Diffuse[0]
+ 0.59F * light->Diffuse[1]
+ 0.11F * light->Diffuse[2];
light->sli = 0.30F * light->Specular[0]
+ 0.59F * light->Specular[1]
+ 0.11F * light->Specular[2];
} /* loop over materials */
} /* loop over lights */
/* Determine if the fast lighting function can be used */
ctx->Light.Fast = GL_TRUE;
if ( ctx->Light.BaseColor[0][0]<0.0F
|| ctx->Light.BaseColor[0][1]<0.0F
|| ctx->Light.BaseColor[0][2]<0.0F
|| ctx->Light.BaseColor[0][3]<0.0F
|| ctx->Light.BaseColor[1][0]<0.0F
|| ctx->Light.BaseColor[1][1]<0.0F
|| ctx->Light.BaseColor[1][2]<0.0F
|| ctx->Light.BaseColor[1][3]<0.0F
|| ctx->Light.Model.LocalViewer
|| ctx->Light.ColorMaterialEnabled) {
ctx->Light.Fast = GL_FALSE;
}
else {
for (light=ctx->Light.FirstEnabled; light; light=light->NextEnabled) {
if ( light->Position[3]!=0.0F
|| light->SpotCutoff!=180.0F
|| light->MatDiffuse[0][0]<0.0F
|| light->MatDiffuse[0][1]<0.0F
|| light->MatDiffuse[0][2]<0.0F
|| light->MatSpecular[0][0]<0.0F
|| light->MatSpecular[0][1]<0.0F
|| light->MatSpecular[0][2]<0.0F
|| light->MatDiffuse[1][0]<0.0F
|| light->MatDiffuse[1][1]<0.0F
|| light->MatDiffuse[1][2]<0.0F
|| light->MatSpecular[1][0]<0.0F
|| light->MatSpecular[1][1]<0.0F
|| light->MatSpecular[1][2]<0.0F) {
ctx->Light.Fast = GL_FALSE;
break;
}
}
}
}
These are the contents of the former NiCE NeXT User Group NeXTSTEP/OpenStep software archive, currently hosted by Netfuture.ch.