/*
* Copyright 1993, 1994, 1995, Silicon Graphics, Inc.
* ALL RIGHTS RESERVED
*
* UNPUBLISHED -- Rights reserved under the copyright laws of the United
* States. Use of a copyright notice is precautionary only and does not
* imply publication or disclosure.
*
* U.S. GOVERNMENT RESTRICTED RIGHTS LEGEND:
* Use, duplication or disclosure by the Government is subject to restrictions
* as set forth in FAR 52.227.19(c)(2) or subparagraph (c)(1)(ii) of the Rights
* in Technical Data and Computer Software clause at DFARS 252.227-7013 and/or
* in similar or successor clauses in the FAR, or the DOD or NASA FAR
* Supplement. Contractor/manufacturer is Silicon Graphics, Inc.,
* 2011 N. Shoreline Blvd. Mountain View, CA 94039-7311.
*
* THE CONTENT OF THIS WORK CONTAINS CONFIDENTIAL AND PROPRIETARY
* INFORMATION OF SILICON GRAPHICS, INC. ANY DUPLICATION, MODIFICATION,
* DISTRIBUTION, OR DISCLOSURE IN ANY FORM, IN WHOLE, OR IN PART, IS STRICTLY
* PROHIBITED WITHOUT THE PRIOR EXPRESS WRITTEN PERMISSION OF SILICON
* GRAPHICS, INC.
*/
/*
* lpoint.c
* --------------
* $Revision: 1.1 $
* $Date: 2000/11/21 21:39:36 $
*/
#include <string.h>
#include <values.h>
#include <math.h>
#include <Performer/pf.h>
#include <Performer/pfutil.h>
/*------------------------------------------------------*/
/* Make reflection map which describes the lightpoint envelope */
void
pfuMakeLPStateShapeTex(pfLPointState *lps, pfTexture *tex, int size)
{
int i, j, shapeMode;
char *img, *image;
pfMatrix rollMat;
pfVec3 norm;
float alpha;
float henv, venv, roll, falloff, ambient;
float horizParam, vertParam, ambientScale;
static pfVec3 eye = {0.0f, 1.0f, 0.0f};
static float eta = 1.0e-15f;
image = img = (char*)pfCalloc(1, sizeof(char) * size * size * 2,
pfGetArena(tex));
pfGetLPStateShape(lps, &henv, &venv, &roll, &falloff, &ambient);
shapeMode = pfGetLPStateMode(lps, PFLPS_SHAPE_MODE);
ambientScale = 1.0f - ambient;
pfMakeRotMat(rollMat, roll, 0.0f, 1.0f, 0.0f);
if (henv > 180.0f - eta && henv < 180.0f + eta)
horizParam = 0.0f;
else
{
horizParam = tanf(PF_DEG2RAD(henv / 2.0f));
horizParam = 1.0f / (horizParam * horizParam);
}
if (venv > 180.0f - eta && venv < 180.0f + eta)
vertParam = 0.0f;
else
{
vertParam = tanf(PF_DEG2RAD(venv / 2.0f));
vertParam = 1.0f / (vertParam * vertParam);
}
/* 'i' ranges over 't' texture coordinate which maps to Z */
for (i=0; i<size; i++)
{
norm[PF_Z] = ((float)i / (size - 1.0f) - 0.5f) * 2.0f;
/* 'j' ranges over 's' texture coordinate which maps to X */
for (j=0; j<size; j++)
{
float sqlen;
pfMatrix dirMat;
pfVec3 viewVec;
static pfVec3 zaxis = {0.0f, 0.0f, 1.0f};
/* Compute normal of unit sphere */
norm[PF_X] = ((float)j / (size - 1.0f) - 0.5f) * 2.0f;
norm[PF_Y] = 1.0f - (norm[PF_X] * norm[PF_X] +
norm[PF_Z] * norm[PF_Z]);
if (norm[PF_Y] < 0.0f)
{
*img++ = 0xff; /* Intensity is ON */
*img++ = ambient * 255.0f;
continue;
}
norm[PF_Y] = pfSqrt(norm[PF_Y]);
/* Construct coordinate system of lightpoint with normal
* becoming the +Y axis and "up" being aligned with the
* +Z axis in object coordinates.
*/
pfCopyVec3(dirMat[PF_Y], norm);
/* Compute new X axis */
pfCrossVec3(dirMat[PF_X], norm, zaxis);
/* Check for norm collinear with +Z axis */
if ((sqlen = pfDotVec3(dirMat[PF_X], dirMat[PF_X])) < 1e-15)
{
if (pfDotVec3(dirMat[PF_Y], zaxis) > 0.0f)
{
pfSetVec3(dirMat[PF_X], 1.0f, 0.0f, 0.0f);
pfSetVec3(dirMat[PF_Z], 0.0f, -1.0f, 0.0f);
}
else
{
pfSetVec3(dirMat[PF_X], 1.0f, 0.0f, 0.0f);
pfSetVec3(dirMat[PF_Z], 0.0f, 1.0f, 0.0f);
}
}
else
{
/* Normalize new X axis */
sqlen = 1.0f / sqlen;
PFSCALE_VEC3(dirMat[PF_X], sqlen, dirMat[PF_X]);
/* Compute new Z axis */
pfCrossVec3(dirMat[PF_Z], dirMat[PF_X], dirMat[PF_Y]);
}
/* Pre-roll new coordinate system */
if (roll)
pfPreMultMat(dirMat, rollMat);
/* Find image of eye in new coordinate system */
viewVec[PF_X] = PFDOT_VEC3(eye, dirMat[PF_X]);
viewVec[PF_Y] = PFDOT_VEC3(eye, dirMat[PF_Y]);
viewVec[PF_Z] = PFDOT_VEC3(eye, dirMat[PF_Z]);
if (shapeMode == PFLPS_SHAPE_MODE_UNI && viewVec[PF_Y] < 0.0f)
alpha = ambient;
else
{
float x, z, intens;
if (PF_ABSLT(viewVec[PF_Y], eta))
x = z = PF_HUGEVAL;
else
{
float iy;
iy = 1.0f / viewVec[PF_Y];
x = viewVec[PF_X] * iy;
z = viewVec[PF_Z] * iy;
}
intens = 1.0f - ((x * x) * horizParam + (z * z) * vertParam);
if (intens <= 0.0f)
alpha = ambient;
else if (intens >= 1.0f)
alpha = 1.0f;
else
alpha = powf(intens, falloff) * ambientScale + ambient;
}
*img++ = 0xff; /* Intensity is ON */
*img++ = alpha * 255.0f;
}
}
pfTexImage(tex, (uint*)image, 2, size, size, 1);
}
#define NOMINAL_NEAR_PIX_DIST 1236.075f
/*
* Make texture map which descibes light point fade ramp and/or
* fog ramp.
*/
void
pfuMakeLPStateRangeTex(pfLPointState *lps, pfTexture *tex, int size, pfFog *fog)
{
float isize;
int i, j, dim, tsize;
char *img, *image;
int transpRangeMode, fogRangeMode;
float transpScale, actualSize, transpPixSize, transpClamp, transpExp;
float maxTranspRange, minTranspRange, deltaTranspRange;
float maxFogRange, minFogRange, deltaFogRange;
transpRangeMode = pfGetLPStateMode(lps, PFLPS_TRANSP_MODE);
fogRangeMode = pfGetLPStateMode(lps, PFLPS_FOG_MODE);
actualSize = pfGetLPStateVal(lps, PFLPS_SIZE_ACTUAL);
transpScale = pfGetLPStateVal(lps, PFLPS_TRANSP_SCALE);
transpPixSize = pfGetLPStateVal(lps, PFLPS_TRANSP_PIXEL_SIZE);
transpExp = pfGetLPStateVal(lps, PFLPS_TRANSP_EXPONENT);
transpClamp = pfGetLPStateVal(lps, PFLPS_TRANSP_CLAMP);
dim = (transpRangeMode == PFLPS_TRANSP_MODE_TEX) +
(fogRangeMode == PFLPS_FOG_MODE_TEX);
if (dim == 0)
{
pfNotify(PFNFY_WARN, PFNFY_USAGE, "pfuMakeLPStateRangeTex() 0x%x "
"is not configured to use texturing for fog or "
"transparency.\n", lps);
return;
}
if (dim == 1)
{
image = img = (char*)pfCalloc(1, sizeof(char) * size * 2,
pfGetArena(tex));
}
else
{
image = img = (char*)pfCalloc(1, sizeof(char) * size * size * 2,
pfGetArena(tex));
}
if (transpRangeMode == PFLPS_TRANSP_MODE_TEX)
{
minTranspRange =
transpScale * actualSize *
NOMINAL_NEAR_PIX_DIST /
(transpScale * transpPixSize);
maxTranspRange = transpScale * actualSize *
NOMINAL_NEAR_PIX_DIST /
(transpScale * transpPixSize -
powf(1.0f - transpClamp, 1.0f / transpExp));
deltaTranspRange = maxTranspRange - minTranspRange;
}
if (fogRangeMode == PFLPS_FOG_MODE_TEX)
{
float onset, opaque, a, b;
pfGetFogOffsets(fog, &onset, &opaque);
pfGetFogRange(fog, &a, &b);
minFogRange = onset + a;
maxFogRange = opaque + b;
deltaFogRange = maxFogRange - minFogRange;
}
tsize = (transpRangeMode == PFLPS_TRANSP_MODE_TEX) ? size : 1;
isize = 1.0f / ((float)size - 1.0f);
for (i=0; i<tsize; i++) /* transp loop */
{
float s, a, d, f;
if (transpRangeMode == PFLPS_TRANSP_MODE_TEX)
{
d = minTranspRange + (float)i * isize * deltaTranspRange;
s = actualSize * NOMINAL_NEAR_PIX_DIST / d;
if (transpPixSize > s)
{
if (transpExp == 1.0f)
a = 1.0f - transpScale * (transpPixSize - s);
else
a = 1.0f - transpScale *
powf((transpPixSize - s), transpExp);
if (a < transpClamp)
a = transpClamp;
}
else
a = 1.0f;
}
else
a = 1.0f;
if (fogRangeMode == PFLPS_FOG_MODE_TEX)
{
for (j=0; j<size; j++) /* fog loop */
{
d = minFogRange + (float)j * isize * deltaFogRange;
f = 1.0f - pfGetFogDensity(fog, d);
*img++ = 0xff; /* intensity */
*img++ = f * a * 0xff; /* alpha */
}
}
else
{
*img++ = 0xff; /* Intensity is ON */
*img++ = a * 0xff; /* alpha */
}
}
pfTexRepeat(tex, PFTEX_WRAP, PFTEX_CLAMP);
pfTexFilter(tex, PFTEX_MAGFILTER, PFTEX_BILINEAR);
pfTexFilter(tex, PFTEX_MINFILTER, PFTEX_MIPMAP_TRILINEAR);
pfTexFormat(tex, PFTEX_INTERNAL_FORMAT, PFTEX_IA_8);
if (dim == 1)
pfTexImage(tex, (uint*)image, 2, size, 1, 1);
else
pfTexImage(tex, (uint*)image, 2, size, size, 1);
return;
}
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