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Copy pathNV20VolRen3D-old.cpp
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NV20VolRen3D-old.cpp
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// ________ ____ ___
// | \ / | / /
// +---+ \/ |/ /
// +--+| |\ /| <
// | || | \ / | |\ \
// | | \/ | | \ \
// \_____| |__| \__\
// Copyright 2001
// Joe Michael Kniss
// << [email protected] >>
// "All Your Base are Belong to Us"
//-------------------------------------------------------------------------
// NV20VolRen3D.cpp: implementation of the NV20VolRen3D class.
//
//////////////////////////////////////////////////////////////////////
#ifdef WIN32
#include <windows.h>
#endif
#include "NV20VolRen3D.h"
#include <iostream.h>
#include "VectorMath.h"
#include "glUE.h"
//////////////////////////////////////////////////////////////////////
// Construction/Destruction
//////////////////////////////////////////////////////////////////////
NV20VolRen3D::NV20VolRen3D()
{
go = 0;
}
NV20VolRen3D::~NV20VolRen3D()
{
}
//================================================================= INIT
//======================================================================
void NV20VolRen3D::init()
{
if(gluvv.mv){
go = 1;
createVolumes();
}
create2DDepTex();
}
//================================================================= DRAW
//======================================================================
void NV20VolRen3D::draw()
{
if(!go) return;
renderVolume();
//renderSlice();
}
//======================================================== Render Volume
//======================================================================
//========== NOTES ===========================================
// Standard brick vertex ordering:
//
// (011) (111)
// 6 +---------+ 7 Where 1's are the size of the brick
// /| /| allong that axis
// / | / |
// (001)/ |(101) / |
// 4 +---------+ 5 |
// | | | |(110) z axis
// | 2 +-----+---+ 3 ^
// | /(010) | / | y axis
// | / | / | /
// |/ |/ |/
// 0 +---------+ 1 +-------> x axis
// (000) (100)
//
void NV20VolRen3D::renderVolume()
{
//-------------- Re-Scale Alpha values ---------------------------------
if(gluvv.volren.scaleAlphas){
if((lastSamp != gluvv.volren.sampleRate)||(gluvv.volren.loadTLUT)){ //see if the sample rate changed
if((lastGoodSamp != gluvv.volren.goodSamp) || gluvv.volren.loadTLUT){ //good sample rate changed
copyScale(gluvv.volren.goodSamp * 1/gluvv.volren.gamma, gDeptex);
lastGoodSamp = gluvv.volren.goodSamp;
}
if((lastInteSamp != gluvv.volren.interactSamp) || gluvv.volren.loadTLUT){ //interact samp rate changed
copyScale(gluvv.volren.interactSamp * 1/gluvv.volren.gamma, iDeptex);
lastInteSamp = gluvv.volren.interactSamp;
}
if(gluvv.volren.sampleRate == gluvv.volren.goodSamp){ //which one do we load (good)
loadDepTex(gDeptex);
lastSamp = gluvv.volren.goodSamp;
}
else if(gluvv.volren.sampleRate == gluvv.volren.interactSamp){ //(interactive)
loadDepTex(iDeptex);
lastSamp = gluvv.volren.interactSamp;
}
if(gluvv.volren.loadTLUT){ //now load the transfer function
loadDepTex(gluvv.volren.deptex2, deptex2Name);
}
gluvv.volren.loadTLUT = 0;
}
} else { //just do gamma scale, don't update for the sample rate (for testing purposes)
if(gluvv.volren.loadTLUT){
copyScale(1/gluvv.volren.gamma, gDeptex);
loadDepTex(gDeptex);
loadDepTex(gluvv.volren.deptex2, deptex2Name);
gluvv.volren.loadTLUT = 0;
}
}
//-------------- end Re-Scale Alpha values ------------------------------
//-------------- do dot product with clip and view dir
float vdir[3];
subV3(vdir, gluvv.env.eye, gluvv.clip.pos);
normalizeV3(vdir);
normalizeV3(gluvv.clip.dir);
float dv = dotV3(vdir,gluvv.clip.dir);
float globalModV[16]; //save original tranform
glGetFloatv(GL_MODELVIEW_MATRIX, globalModV); //save the world model view
//-------------- end do dot product with clip and view dir
glPushMatrix();{ //move to the volume location
glTranslatef(gluvv.rinfo.trans[0], //translate
gluvv.rinfo.trans[1],
gluvv.rinfo.trans[2]);
glMultMatrixf(gluvv.rinfo.xform); //rotate
glTranslatef(-gluvv.mv->xfSize/2, //center
-gluvv.mv->yfSize/2,
-gluvv.mv->zfSize/2);
//-------------- draw clip slices --------------------------------------
for(int i=0; i<gluvv.mv->numSubVols; ++i){
drawClip(i, dv, globalModV);
}
//-------------- end draw clip slices ----------------------------------
//----------------------------------------------------------------------
//-------------- render the volume -------------------------------------
setupShaders();
setupRegComb();
GLdouble mv[16];
glGetDoublev(GL_MODELVIEW_MATRIX, mv); //save modelview matrix
renderBricks(mv); //RENDER!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
resetShaders();
resetRegComb();
//-------------- end render the volume ---------------------------------
//----------------------------------------------------------------------
//-------------- draw clip slices --------------------------------------
for(i=0; i<gluvv.mv->numSubVols; ++i){
drawClip(i, -dv, globalModV);
}
//-------------- end draw clip slices ----------------------------------
} glPopMatrix();
resetShaders();
resetRegComb();
resetClips();
}
//======================================================== Render Bricks
//======================================================================
void NV20VolRen3D::renderBricks(GLdouble mv[16])
{
if(gluvv.mv->numSubVols > 1){ //render multiple bricked volumes
int *order = new int[gluvv.mv->numSubVols]; //the correct draw order
float *zval = new float[gluvv.mv->numSubVols];//zvalue of each subvolume
for(int i=0; i< gluvv.mv->numSubVols; ++i){ //compute zvalues
Volume *v = &gluvv.mv->volumes[i];
order[i] = i;
float c[3] = {v->xfPos + v->xfSize/2.0, v->yfPos + v->yfSize/2.0, v->zfPos + v->zfSize/2.0};
float center[3];
translateV3W(center, mv, c);
zval[i] = (float)(center[0]*center[0] + center[1]*center[1] + center[2]*center[2]);
}
for(i=0; i< gluvv.mv->numSubVols-1; ++i){ //now sort
for(int j=i+1; j<gluvv.mv->numSubVols; ++j){
if(zval[order[i]] < zval[order[j]]){//test for swap
int tmp = order[i];
order[i] = order[j];
order[j] = tmp;
}
}
}
for(i=0 ; i< gluvv.mv->numSubVols; ++i){ //finaly render
Volume *v = &gluvv.mv->volumes[order[i]];
float sxf = v->xfSize;
float syf = v->yfSize;
float szf = v->zfSize;
float vo[8][3] = {{0,0,0},{sxf,0,0},{0,syf,0},{sxf,syf,0},{0,0,szf},{sxf,0,szf},{0,syf,szf},{sxf,syf,szf}};
float tx[8][3] = {{0,0,0},{1 ,0,0},{0,1 ,0},{1 ,1 ,0},{0,0,1 },{1 ,0,1 },{0,1 ,1 },{1 ,1 ,1 }};
float axis[3] = {0,0,1};
glPushMatrix(); {
setupClips(order[i],vo,tx);
glTranslatef(v->xfPos, v->yfPos, v->zfPos);
render3DVA(gluvv.volren.sampleRate,mv,order[i],vo,tx,axis);
} glPopMatrix();
}
} else { //just render one volume!
float sxf = gluvv.mv->xfSize;
float syf = gluvv.mv->yfSize;
float szf = gluvv.mv->zfSize;
float vo[8][3] = {{0,0,0},{sxf,0,0},{0,syf,0},{sxf,syf,0},{0,0,szf},{sxf,0,szf},{0,syf,szf},{sxf,syf,szf}};
float tx[8][3] = {{0,0,0},{1 ,0,0},{0,1 ,0},{1 ,1 ,0},{0,0,1 },{1 ,0,1 },{0,1 ,1 },{1 ,1 ,1 }};
float axis[3] = {0,0,1};
setupClips(0,vo,tx);
render3DVA(gluvv.volren.sampleRate,mv,0,vo,tx,axis);
}
}
//========================================================== Setup Clips
//======================================================================
void NV20VolRen3D::setupClips(int vol, float vo[8][3], float tx[8][3])
{
Volume *v = &gluvv.mv->volumes[vol];
if(gluvv.clip.on && gluvv.clip.ortho){
float cp[3];
cp[0] = gluvv.clip.vpos[0] > v->xfPos ?
(gluvv.clip.vpos[0] < v->xfSize + v->xfPos ? gluvv.clip.vpos[0] - v->xfPos : v->xfSize) : 0;
cp[1] = gluvv.clip.vpos[1] > v->yfPos ?
(gluvv.clip.vpos[1] < v->yfSize + v->yfPos ? gluvv.clip.vpos[1] - v->yfPos : v->yfSize) : 0;
cp[2] = gluvv.clip.vpos[2] > v->zfPos ?
(gluvv.clip.vpos[2] < v->zfSize + v->zfPos ? gluvv.clip.vpos[2] - v->zfPos : v->zfSize) : 0;
switch(gluvv.clip.oaxis){
case VolRenAxisXPos:
tx[1][0] = cp[0]/v->xfSize;
tx[3][0] = cp[0]/v->xfSize;
tx[5][0] = cp[0]/v->xfSize;
tx[7][0] = cp[0]/v->xfSize;
vo[1][0] = cp[0];
vo[3][0] = cp[0];
vo[5][0] = cp[0];
vo[7][0] = cp[0];
break;
case VolRenAxisXNeg:
tx[0][0] = cp[0]/v->xfSize;
tx[2][0] = cp[0]/v->xfSize;
tx[4][0] = cp[0]/v->xfSize;
tx[6][0] = cp[0]/v->xfSize;
vo[0][0] = cp[0];
vo[2][0] = cp[0];
vo[4][0] = cp[0];
vo[6][0] = cp[0];
break;
case VolRenAxisYPos:
tx[2][1] = cp[1]/v->yfSize;
tx[3][1] = cp[1]/v->yfSize;
tx[6][1] = cp[1]/v->yfSize;
tx[7][1] = cp[1]/v->yfSize;
vo[2][1] = cp[1];
vo[3][1] = cp[1];
vo[6][1] = cp[1];
vo[7][1] = cp[1];
break;
case VolRenAxisYNeg:
tx[0][1] = cp[1]/v->yfSize;
tx[1][1] = cp[1]/v->yfSize;
tx[4][1] = cp[1]/v->yfSize;
tx[5][1] = cp[1]/v->yfSize;
vo[0][1] = cp[1];
vo[1][1] = cp[1];
vo[4][1] = cp[1];
vo[5][1] = cp[1];
break;
case VolRenAxisZPos:
tx[4][2] = cp[2]/v->zfSize;
tx[5][2] = cp[2]/v->zfSize;
tx[6][2] = cp[2]/v->zfSize;
tx[7][2] = cp[2]/v->zfSize;
vo[4][2] = cp[2];
vo[5][2] = cp[2];
vo[6][2] = cp[2];
vo[7][2] = cp[2];
break;
case VolRenAxisZNeg:
tx[0][2] = cp[2]/v->zfSize;
tx[1][2] = cp[2]/v->zfSize;
tx[2][2] = cp[2]/v->zfSize;
tx[3][2] = cp[2]/v->zfSize;
vo[0][2] = cp[2];
vo[1][2] = cp[2];
vo[2][2] = cp[2];
vo[3][2] = cp[2];
break;
}
}
}
//============================================================ drawClips
//======================================================================
void NV20VolRen3D::drawClip(int vol, float dv, float wmv[16])
{
if((!gluvv.clip.ortho)){
switch(gluvv.dmode){
case GDM_V1:
case GDM_V1G:
case GDM_V2:
case GDM_VGH_VG:
case GDM_VGH_V:
cerr << "clipping" << endl;
glActiveTexture(GL_TEXTURE2_ARB); { //3rd & 4th axis, or clipping
glEnable(GL_TEXTURE_2D);
glDisable(GL_TEXTURE_3D);
glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_NONE);
glTexEnvi(GL_TEXTURE_SHADER_NV, GL_SHADER_OPERATION_NV, GL_CULL_FRAGMENT_NV);
}
glPushMatrix();{ //this sets the clipping plane
glLoadIdentity(); //clips are set in world space
glMultMatrixf(wmv); //origional world space coords
glTranslatef(gluvv.clip.pos[0], //location of clipping plane
gluvv.clip.pos[1],
gluvv.clip.pos[2]);
glMultMatrixf(gluvv.clip.xform); //rotation of clip plane
GLdouble zup[4] = {0, 0, -1, 0}; // always in z direction
glEnable(GL_CLIP_PLANE5); //enable the gl clip plane
glClipPlane(GL_CLIP_PLANE5, zup);
} glPopMatrix();
break;
}
}
if((!gluvv.clip.on)||(!gluvv.clip.ortho)) return;
Volume *v = &gluvv.mv->volumes[vol];
float c[4][3];
copyV3(c[0],gluvv.clip.corners[0]);
copyV3(c[1],gluvv.clip.corners[1]);
copyV3(c[2],gluvv.clip.corners[2]);
copyV3(c[3],gluvv.clip.corners[3]);
//this moves the clip plane to sub-volume space
c[0][0] = CLAMP_ARB(0,c[0][0]-v->xfPos,v->xfSize);
c[1][0] = CLAMP_ARB(0,c[1][0]-v->xfPos,v->xfSize);
c[2][0] = CLAMP_ARB(0,c[2][0]-v->xfPos,v->xfSize);
c[3][0] = CLAMP_ARB(0,c[3][0]-v->xfPos,v->xfSize);
c[0][1] = CLAMP_ARB(0,c[0][1]-v->yfPos,v->yfSize);
c[1][1] = CLAMP_ARB(0,c[1][1]-v->yfPos,v->yfSize);
c[2][1] = CLAMP_ARB(0,c[2][1]-v->yfPos,v->yfSize);
c[3][1] = CLAMP_ARB(0,c[3][1]-v->yfPos,v->yfSize);
c[0][2] = CLAMP_ARB(0,c[0][2]-v->zfPos,v->zfSize);
c[1][2] = CLAMP_ARB(0,c[1][2]-v->zfPos,v->zfSize);
c[2][2] = CLAMP_ARB(0,c[2][2]-v->zfPos,v->zfSize);
c[3][2] = CLAMP_ARB(0,c[3][2]-v->zfPos,v->zfSize);
glEnable(GL_REGISTER_COMBINERS_NV);
glCombinerParameteriNV(GL_NUM_GENERAL_COMBINERS_NV, 2);
// I am just using these to replace the texture's alpha with a different one
float alpha[4] = {1,0,0,gluvv.clip.alpha};
glCombinerParameterfvNV(GL_CONSTANT_COLOR0_NV, alpha); //set W
float greenish[4] = {0,1,0,1};
glCombinerParameterfvNV(GL_CONSTANT_COLOR1_NV, greenish); //set W
//blue is the primary color
glColor4f(0,0,1,1);
//now for some painfull swizling
//extract the red, extract the green
glCombinerInputNV(GL_COMBINER0_NV, GL_RGB, GL_VARIABLE_A_NV, GL_TEXTURE0_ARB, GL_UNSIGNED_IDENTITY_NV, GL_RGB);
glCombinerInputNV(GL_COMBINER0_NV, GL_RGB, GL_VARIABLE_B_NV, GL_CONSTANT_COLOR0_NV, GL_UNSIGNED_IDENTITY_NV, GL_RGB);
glCombinerInputNV(GL_COMBINER0_NV, GL_RGB, GL_VARIABLE_C_NV, GL_TEXTURE0_ARB, GL_UNSIGNED_IDENTITY_NV, GL_RGB);
glCombinerInputNV(GL_COMBINER0_NV, GL_RGB, GL_VARIABLE_D_NV, GL_CONSTANT_COLOR1_NV, GL_UNSIGNED_IDENTITY_NV, GL_RGB);
glCombinerOutputNV(GL_COMBINER0_NV, GL_RGB,
GL_SPARE0_NV, GL_SPARE1_NV, GL_DISCARD_NV, GL_NONE, GL_NONE, GL_TRUE, GL_TRUE, GL_FALSE);
GlErr("nv20volren","gcom0.4");
//alpha goes to red + green
glCombinerInputNV(GL_COMBINER1_NV, GL_RGB, GL_VARIABLE_A_NV, GL_TEXTURE0_ARB, GL_UNSIGNED_IDENTITY_NV, GL_ALPHA);
glCombinerInputNV(GL_COMBINER1_NV, GL_RGB, GL_VARIABLE_B_NV, GL_CONSTANT_COLOR0_NV, GL_UNSIGNED_IDENTITY_NV, GL_RGB);
glCombinerInputNV(GL_COMBINER1_NV, GL_RGB, GL_VARIABLE_C_NV, GL_SPARE0_NV, GL_UNSIGNED_IDENTITY_NV, GL_RGB);
glCombinerInputNV(GL_COMBINER1_NV, GL_RGB, GL_VARIABLE_D_NV, GL_CONSTANT_COLOR1_NV, GL_UNSIGNED_INVERT_NV, GL_RGB);
glCombinerOutputNV(GL_COMBINER1_NV, GL_RGB,
GL_DISCARD_NV, GL_DISCARD_NV, GL_TEXTURE0_ARB, GL_NONE, GL_NONE, GL_FALSE, GL_FALSE, GL_FALSE);
GlErr("nv20volren","gcom1.4");
//add blue now, set the correct alpha
glFinalCombinerInputNV(GL_VARIABLE_A_NV, GL_SPARE1_NV, GL_UNSIGNED_IDENTITY_NV, GL_RGB);
GlErr("nv20volren","fcom1");
glFinalCombinerInputNV(GL_VARIABLE_B_NV, GL_PRIMARY_COLOR_NV, GL_UNSIGNED_IDENTITY_NV, GL_RGB);
GlErr("nv20volren","fcom2");
glFinalCombinerInputNV(GL_VARIABLE_C_NV, GL_ZERO, GL_UNSIGNED_IDENTITY_NV, GL_RGB);
GlErr("nv20volren","fcom3");
glFinalCombinerInputNV(GL_VARIABLE_D_NV, GL_TEXTURE0_ARB, GL_UNSIGNED_IDENTITY_NV, GL_RGB);
GlErr("nv20volren","fcom0");
glFinalCombinerInputNV(GL_VARIABLE_G_NV, GL_CONSTANT_COLOR0_NV, GL_UNSIGNED_IDENTITY_NV, GL_ALPHA);
glEnable(GL_BLEND);
float offset = .001; //this is used to avoid z-compete when the slice is on top
glPushMatrix();{
//make sure we draw this in sub-volume space
glTranslatef(v->xfPos, v->yfPos, v->zfPos);
switch(gluvv.clip.oaxis){
case VolRenAxisXPos:
if((dv < 0)&&(c[0][0] > 0)&&(c[0][0]<v->xfSize)){
float ov[3] = {offset, 0, 0}; //offset vector
for(int i=0; i<4; ++ i)
addV3(c[i],c[i],ov);
renderSlice(c,vol);
}
break;
case VolRenAxisXNeg:
if(dv > 0){
float ov[3] = {-offset, 0, 0}; //offset vector
for(int i=0; i<4; ++ i)
addV3(c[i],c[i],ov);
renderSlice(c,vol);
}
break;
case VolRenAxisYPos:
if((dv > 0)&&(c[0][1] > 0)&&(c[0][1]<v->yfSize)){
float ov[3] = {0, offset, 0}; //offset vector
for(int i=0; i<4; ++ i)
addV3(c[i],c[i],ov);
renderSlice(c,vol);
}
break;
case VolRenAxisYNeg:
if((dv < 0)&&(c[0][1] > 0)&&(c[0][1]<v->yfSize)){
float ov[3] = {0, -offset, 0}; //offset vector
for(int i=0; i<4; ++ i)
addV3(c[i],c[i],ov);
renderSlice(c,vol);
}
break;
case VolRenAxisZPos:
if((dv < 0)&&(c[0][2] > 0)&&(c[0][2]<v->zfSize)){
float ov[3] = {0, 0, offset}; //offset vector
for(int i=0; i<4; ++ i)
addV3(c[i],c[i],ov);
renderSlice(c,vol);
}
break;
case VolRenAxisZNeg:
if((dv > 0)&&(c[0][2] > 0)&&(c[0][2]<v->zfSize)){
float ov[3] = {0, 0, -offset}; //offset vector
for(int i=0; i<4; ++ i)
addV3(c[i],c[i],ov);
renderSlice(c,vol);
}
break;
}
} glPopMatrix();
glDisable(GL_REGISTER_COMBINERS_NV); //clean up opengl state
glActiveTexture(GL_TEXTURE0_ARB); {
glDisable(GL_TEXTURE_2D);
glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_NONE);
glTexEnvi(GL_TEXTURE_SHADER_NV, GL_SHADER_OPERATION_NV, GL_TEXTURE_2D);
}
glDisable(GL_BLEND);
}
//============================================== Render Slice w/ corners
//======================================================================
void NV20VolRen3D::renderSlice(float c[4][3], int vol)
{
glActiveTexture(GL_TEXTURE0_ARB); { //this is for the slice
glEnable(GL_TEXTURE_3D);
glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);
glTexEnvi(GL_TEXTURE_SHADER_NV, GL_SHADER_OPERATION_NV, GL_TEXTURE_3D);
glBindTexture(GL_TEXTURE_3D, texNames[vol]);
}
Volume *v = &gluvv.mv->volumes[vol];
glBegin(GL_QUADS);{
glMultiTexCoord3fARB(GL_TEXTURE0_ARB,c[0][0]/(v->xfSize),c[0][1]/(v->yfSize),c[0][2]/(v->zfSize));
glVertex3f(c[0][0], c[0][1], c[0][2]);
glMultiTexCoord3fARB(GL_TEXTURE0_ARB,c[1][0]/(v->xfSize),c[1][1]/(v->yfSize),c[1][2]/(v->zfSize));
glVertex3f(c[1][0], c[1][1], c[1][2]);
glMultiTexCoord3fARB(GL_TEXTURE0_ARB,c[2][0]/(v->xfSize),c[2][1]/(v->yfSize),c[2][2]/(v->zfSize));
glVertex3f(c[2][0], c[2][1], c[2][2]);
glMultiTexCoord3fARB(GL_TEXTURE0_ARB,c[3][0]/(v->xfSize),c[3][1]/(v->yfSize),c[3][2]/(v->zfSize));
glVertex3f(c[3][0], c[3][1], c[3][2]);
} glEnd();
}
//=========================================================== resetClips
//======================================================================
void NV20VolRen3D::resetClips()
{
glDisable(GL_CLIP_PLANE0);
}
//======================================================== Setup Shaders
//======================================================================
void NV20VolRen3D::setupShaders()
{
glEnable(GL_TEXTURE_SHADER_NV); {
GlErr("nv20volren", "enable shader");
glActiveTexture(GL_TEXTURE0_ARB); { //this is for the slice
glEnable(GL_TEXTURE_3D);
glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_NONE);
glTexEnvi(GL_TEXTURE_SHADER_NV, GL_SHADER_OPERATION_NV, GL_TEXTURE_3D);
}
glActiveTexture(GL_TEXTURE1_ARB); { //this is for the transfer function
glEnable(GL_TEXTURE_2D);
glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);
glTexEnvi(GL_TEXTURE_SHADER_NV, GL_SHADER_OPERATION_NV, GL_DEPENDENT_AR_TEXTURE_2D_NV);
glTexEnvi(GL_TEXTURE_SHADER_NV, GL_PREVIOUS_TEXTURE_INPUT_NV, GL_TEXTURE0_ARB);
glBindTexture(GL_TEXTURE_2D, deptexName);
}
glActiveTexture(GL_TEXTURE2_ARB); { // for shading or clipping (not both)
if((gluvv.shade == gluvvShadeDiff) || (gluvv.shade == gluvvShadeDSpec)){
glEnable(GL_TEXTURE_3D);
glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);
glTexEnvi(GL_TEXTURE_SHADER_NV, GL_SHADER_OPERATION_NV, GL_TEXTURE_3D);
//glBindTexture(GL_TEXTURE_3D, shadeNames[0]);
} else {
glDisable(GL_TEXTURE_2D);
glDisable(GL_TEXTURE_3D);
glTexEnvi(GL_TEXTURE_SHADER_NV, GL_SHADER_OPERATION_NV, GL_NONE);
glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_NONE);
}
}
glActiveTexture(GL_TEXTURE3_ARB); { //3rd & 4th axis, or clipping
switch(gluvv.dmode){ //hey! we use this for 3rd & 4th axies
case GDM_VGH:
case GDM_V1GH:
case GDM_V2G:
case GDM_V2GH:
case GDM_V3:
case GDM_V3G:
case GDM_V4:
glEnable(GL_TEXTURE_2D);
glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);
glTexEnvi(GL_TEXTURE_SHADER_NV, GL_SHADER_OPERATION_NV, GL_DEPENDENT_GB_TEXTURE_2D_NV);
glTexEnvi(GL_TEXTURE_SHADER_NV, GL_PREVIOUS_TEXTURE_INPUT_NV, GL_TEXTURE0_ARB);
glBindTexture(GL_TEXTURE_2D, deptex2Name);
break;
case GDM_V1:
case GDM_V1G:
case GDM_V2:
case GDM_VGH_VG:
case GDM_VGH_V:
if(!gluvv.clip.ortho) break; //we want to take care of this elsewhere
default:
glDisable(GL_TEXTURE_2D);
glDisable(GL_TEXTURE_3D);
glTexEnvi(GL_TEXTURE_SHADER_NV, GL_SHADER_OPERATION_NV, GL_NONE);
glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_NONE);
}
}
GlErr("set up shader", "after texture3");
}
}
void NV20VolRen3D::resetShaders()
{
glActiveTexture(GL_TEXTURE3_ARB); { //not used
glDisable(GL_TEXTURE_2D);
glDisable(GL_TEXTURE_3D);
glTexEnvi(GL_TEXTURE_SHADER_NV, GL_SHADER_OPERATION_NV, GL_NONE);
glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_NONE);
}
glActiveTexture(GL_TEXTURE2_ARB); { //not used
glDisable(GL_TEXTURE_2D);
glDisable(GL_TEXTURE_3D);
glTexEnvi(GL_TEXTURE_SHADER_NV, GL_SHADER_OPERATION_NV, GL_NONE);
glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_NONE);
}
glActiveTexture(GL_TEXTURE1_ARB); { //not used
glDisable(GL_TEXTURE_2D);
glDisable(GL_TEXTURE_3D);
glTexEnvi(GL_TEXTURE_SHADER_NV, GL_SHADER_OPERATION_NV, GL_NONE);
glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_NONE);
}
glActiveTexture(GL_TEXTURE0_ARB); { //not used
glDisable(GL_TEXTURE_2D);
glDisable(GL_TEXTURE_3D);
glTexEnvi(GL_TEXTURE_SHADER_NV, GL_SHADER_OPERATION_NV, GL_NONE);
glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);
}
glDisable(GL_TEXTURE_SHADER_NV);
}
//======================================================= Setup Reg Comb
//======================================================================
void NV20VolRen3D::setupRegComb()
{
if((gluvv.shade == gluvvShadeDiff) || (gluvv.shade == gluvvShadeDSpec)){
float vdir[3];
subV3(vdir, gluvv.env.eye, gluvv.env.at);
normalizeV3(vdir);
float ltdir[3];
subV3(ltdir, gluvv.light.pos, gluvv.env.at);
normalizeV3(ltdir);
float ltoe[3];
subV3(ltoe,vdir,ltdir);
scaleV3(.5, ltoe);
float half[4];
addV3(half,ltdir, ltoe);
half[3] = 1;
float vhalf[4];
float invx[16];
inverseMatrix(invx, gluvv.rinfo.xform);
translateV3(vhalf,invx,half);
negateV3(vhalf);
normalizeV3(vhalf);
vhalf[0] = vhalf[0]/2 + .5;
vhalf[1] = vhalf[1]/2 + .5;
vhalf[2] = vhalf[2]/2 + .5;
glFogfv(GL_FOG_COLOR, vhalf);
float lpos[4];
translateV3W(lpos, invx, ltdir);
negateV3(lpos);
normalizeV3(ltdir);
lpos[0] = lpos[0]/2 + .5;
lpos[1] = lpos[1]/2 + .5;
lpos[2] = lpos[2]/2 + .5;
lpos[3] = .3;
glCombinerParameterfvNV(GL_CONSTANT_COLOR1_NV, lpos); //set light direction
glEnable(GL_REGISTER_COMBINERS_NV);
glCombinerParameteriNV(GL_NUM_GENERAL_COMBINERS_NV, 8);
//diffuse dot product
glCombinerInputNV(GL_COMBINER0_NV, GL_RGB, GL_VARIABLE_A_NV, GL_TEXTURE2_ARB, GL_EXPAND_NORMAL_NV, GL_RGB);
glCombinerInputNV(GL_COMBINER0_NV, GL_RGB, GL_VARIABLE_B_NV, GL_CONSTANT_COLOR1_NV, GL_EXPAND_NORMAL_NV, GL_RGB);
glCombinerInputNV(GL_COMBINER0_NV, GL_RGB, GL_VARIABLE_C_NV, GL_TEXTURE2_ARB, GL_EXPAND_NORMAL_NV, GL_RGB);
glCombinerInputNV(GL_COMBINER0_NV, GL_RGB, GL_VARIABLE_D_NV, GL_CONSTANT_COLOR1_NV, GL_EXPAND_NEGATE_NV, GL_RGB);
glCombinerOutputNV(GL_COMBINER0_NV, GL_RGB,
GL_SPARE0_NV, GL_SPARE1_NV, GL_DISCARD_NV, GL_NONE, GL_NONE, GL_TRUE, GL_TRUE, GL_FALSE);
GlErr("nv20volren","gcom0.4");
//compute diffuse contribution
glCombinerInputNV(GL_COMBINER1_NV, GL_RGB, GL_VARIABLE_A_NV, GL_SPARE1_NV, GL_UNSIGNED_IDENTITY_NV, GL_RGB);
glCombinerInputNV(GL_COMBINER1_NV, GL_RGB, GL_VARIABLE_B_NV, GL_TEXTURE1_ARB, GL_UNSIGNED_IDENTITY_NV, GL_RGB);
glCombinerInputNV(GL_COMBINER1_NV, GL_RGB, GL_VARIABLE_C_NV, GL_SPARE0_NV, GL_UNSIGNED_IDENTITY_NV, GL_RGB);
glCombinerInputNV(GL_COMBINER1_NV, GL_RGB, GL_VARIABLE_D_NV, GL_TEXTURE1_ARB, GL_UNSIGNED_IDENTITY_NV, GL_RGB);
glCombinerOutputNV(GL_COMBINER1_NV, GL_RGB,
GL_DISCARD_NV, GL_DISCARD_NV, GL_SPARE0_NV, GL_NONE, GL_NONE, GL_FALSE, GL_FALSE, GL_FALSE);
GlErr("nv20volren","gcom1.4");
//add diffuse and ambiant
glCombinerInputNV(GL_COMBINER2_NV, GL_RGB, GL_VARIABLE_A_NV, GL_SPARE0_NV, GL_UNSIGNED_IDENTITY_NV, GL_RGB);
glCombinerInputNV(GL_COMBINER2_NV, GL_RGB, GL_VARIABLE_B_NV, GL_SPARE0_NV, GL_UNSIGNED_IDENTITY_NV, GL_RGB);
glCombinerInputNV(GL_COMBINER2_NV, GL_RGB, GL_VARIABLE_C_NV, GL_CONSTANT_COLOR1_NV, GL_UNSIGNED_IDENTITY_NV, GL_ALPHA);
glCombinerInputNV(GL_COMBINER2_NV, GL_RGB, GL_VARIABLE_D_NV, GL_TEXTURE1_ARB, GL_UNSIGNED_IDENTITY_NV, GL_RGB);
glCombinerOutputNV(GL_COMBINER2_NV, GL_RGB,
GL_DISCARD_NV, GL_DISCARD_NV, GL_TEXTURE1_ARB, GL_NONE, GL_NONE, GL_FALSE, GL_FALSE, GL_FALSE);
GlErr("nv20volren","gcom2.4");
//specular dod product
glCombinerInputNV(GL_COMBINER3_NV, GL_RGB, GL_VARIABLE_A_NV, GL_TEXTURE2_ARB, GL_EXPAND_NORMAL_NV, GL_RGB);
glCombinerInputNV(GL_COMBINER3_NV, GL_RGB, GL_VARIABLE_B_NV, GL_FOG, GL_EXPAND_NORMAL_NV, GL_RGB);
glCombinerInputNV(GL_COMBINER3_NV, GL_RGB, GL_VARIABLE_C_NV, GL_TEXTURE2_ARB, GL_EXPAND_NEGATE_NV, GL_RGB);
glCombinerInputNV(GL_COMBINER3_NV, GL_RGB, GL_VARIABLE_D_NV, GL_FOG, GL_EXPAND_NORMAL_NV, GL_RGB);
glCombinerOutputNV(GL_COMBINER3_NV, GL_RGB,
GL_TEXTURE2_ARB, GL_SPARE1_NV, GL_DISCARD_NV, GL_NONE, GL_NONE, GL_TRUE, GL_TRUE, GL_FALSE);
GlErr("nv20volren","gcom3.4");
//specular 2nd power
glCombinerInputNV(GL_COMBINER4_NV, GL_RGB, GL_VARIABLE_A_NV, GL_SPARE1_NV, GL_UNSIGNED_IDENTITY_NV, GL_RGB);
glCombinerInputNV(GL_COMBINER4_NV, GL_RGB, GL_VARIABLE_B_NV, GL_SPARE1_NV, GL_UNSIGNED_IDENTITY_NV, GL_RGB);
glCombinerInputNV(GL_COMBINER4_NV, GL_RGB, GL_VARIABLE_C_NV, GL_TEXTURE2_ARB, GL_UNSIGNED_IDENTITY_NV, GL_RGB);
glCombinerInputNV(GL_COMBINER4_NV, GL_RGB, GL_VARIABLE_D_NV, GL_TEXTURE2_ARB, GL_UNSIGNED_IDENTITY_NV, GL_RGB);
glCombinerOutputNV(GL_COMBINER4_NV, GL_RGB,
GL_SPARE1_NV, GL_TEXTURE2_ARB, GL_DISCARD_NV, GL_NONE, GL_NONE, GL_FALSE, GL_FALSE, GL_FALSE);
GlErr("nv20volren","gcom4.4");
//specular 4th power
glCombinerInputNV(GL_COMBINER5_NV, GL_RGB, GL_VARIABLE_A_NV, GL_SPARE1_NV, GL_UNSIGNED_IDENTITY_NV, GL_RGB);
glCombinerInputNV(GL_COMBINER5_NV, GL_RGB, GL_VARIABLE_B_NV, GL_SPARE1_NV, GL_UNSIGNED_IDENTITY_NV, GL_RGB);
glCombinerInputNV(GL_COMBINER5_NV, GL_RGB, GL_VARIABLE_C_NV, GL_TEXTURE2_ARB, GL_UNSIGNED_IDENTITY_NV, GL_RGB);
glCombinerInputNV(GL_COMBINER5_NV, GL_RGB, GL_VARIABLE_D_NV, GL_TEXTURE2_ARB, GL_UNSIGNED_IDENTITY_NV, GL_RGB);
glCombinerOutputNV(GL_COMBINER5_NV, GL_RGB,
GL_SPARE1_NV, GL_TEXTURE2_ARB, GL_DISCARD_NV, GL_NONE, GL_NONE, GL_FALSE, GL_FALSE, GL_FALSE);
GlErr("nv20volren","gcom5.4");
//specular 8th power
glCombinerInputNV(GL_COMBINER6_NV, GL_RGB, GL_VARIABLE_A_NV, GL_SPARE1_NV, GL_UNSIGNED_IDENTITY_NV, GL_RGB);
glCombinerInputNV(GL_COMBINER6_NV, GL_RGB, GL_VARIABLE_B_NV, GL_SPARE1_NV, GL_UNSIGNED_IDENTITY_NV, GL_RGB);
glCombinerInputNV(GL_COMBINER6_NV, GL_RGB, GL_VARIABLE_C_NV, GL_TEXTURE2_ARB, GL_UNSIGNED_IDENTITY_NV, GL_RGB);
glCombinerInputNV(GL_COMBINER6_NV, GL_RGB, GL_VARIABLE_D_NV, GL_TEXTURE2_ARB, GL_UNSIGNED_IDENTITY_NV, GL_RGB);
glCombinerOutputNV(GL_COMBINER6_NV, GL_RGB,
GL_SPARE1_NV, GL_TEXTURE2_ARB, GL_DISCARD_NV, GL_NONE, GL_NONE, GL_FALSE, GL_FALSE, GL_FALSE);
GlErr("nv20volren","gcom6.4");
//specular add them 2 sided lighting
glCombinerInputNV(GL_COMBINER7_NV, GL_RGB, GL_VARIABLE_A_NV, GL_SPARE1_NV, GL_UNSIGNED_IDENTITY_NV, GL_RGB);
glCombinerInputNV(GL_COMBINER7_NV, GL_RGB, GL_VARIABLE_B_NV, GL_ZERO, GL_UNSIGNED_INVERT_NV, GL_RGB);
glCombinerInputNV(GL_COMBINER7_NV, GL_RGB, GL_VARIABLE_C_NV, GL_TEXTURE2_ARB, GL_UNSIGNED_IDENTITY_NV, GL_RGB);
glCombinerInputNV(GL_COMBINER7_NV, GL_RGB, GL_VARIABLE_D_NV, GL_ZERO, GL_UNSIGNED_INVERT_NV, GL_RGB);
glCombinerOutputNV(GL_COMBINER7_NV, GL_RGB,
GL_DISCARD_NV, GL_DISCARD_NV, GL_TEXTURE2_ARB, GL_NONE, GL_NONE, GL_FALSE, GL_FALSE, GL_FALSE);
GlErr("nv20volren","gcom7.4");
glFinalCombinerInputNV(GL_VARIABLE_A_NV, GL_TEXTURE2_ARB, GL_UNSIGNED_IDENTITY_NV, GL_RGB);
glFinalCombinerInputNV(GL_VARIABLE_B_NV, GL_ZERO, GL_UNSIGNED_INVERT_NV, GL_RGB);
glFinalCombinerInputNV(GL_VARIABLE_C_NV, GL_ZERO, GL_UNSIGNED_IDENTITY_NV, GL_RGB);
glFinalCombinerInputNV(GL_VARIABLE_D_NV, GL_TEXTURE1_ARB, GL_UNSIGNED_IDENTITY_NV, GL_RGB);
glFinalCombinerInputNV(GL_VARIABLE_E_NV, GL_ZERO, GL_UNSIGNED_IDENTITY_NV, GL_RGB);
glFinalCombinerInputNV(GL_VARIABLE_F_NV, GL_ZERO, GL_UNSIGNED_IDENTITY_NV, GL_RGB);
glFinalCombinerInputNV(GL_VARIABLE_G_NV, GL_TEXTURE1_ARB, GL_UNSIGNED_IDENTITY_NV, GL_ALPHA);
GlErr("nv20volren","fcom.0");
}
else{ //no shading
switch(gluvv.dmode){ //third axis stuff
case GDM_VGH:
case GDM_V1GH:
case GDM_V2G:
case GDM_V2GH:
case GDM_V3:
case GDM_V3G:
case GDM_V4:
glEnable(GL_REGISTER_COMBINERS_NV);
glCombinerParameteriNV(GL_NUM_GENERAL_COMBINERS_NV, 1);
glCombinerInputNV(GL_COMBINER0_NV, GL_ALPHA, GL_VARIABLE_A_NV, GL_TEXTURE1_ARB, GL_UNSIGNED_IDENTITY_NV, GL_ALPHA);
glCombinerInputNV(GL_COMBINER0_NV, GL_ALPHA, GL_VARIABLE_B_NV, GL_TEXTURE3_ARB, GL_UNSIGNED_IDENTITY_NV, GL_ALPHA);
glCombinerInputNV(GL_COMBINER0_NV, GL_ALPHA, GL_VARIABLE_C_NV, GL_ZERO, GL_UNSIGNED_IDENTITY_NV, GL_ALPHA);
glCombinerInputNV(GL_COMBINER0_NV, GL_ALPHA, GL_VARIABLE_D_NV, GL_ZERO, GL_UNSIGNED_IDENTITY_NV, GL_ALPHA);
glCombinerOutputNV(GL_COMBINER0_NV, GL_ALPHA,
GL_TEXTURE1_ARB, GL_DISCARD_NV, GL_DISCARD_NV, GL_NONE, GL_NONE, GL_FALSE, GL_FALSE, GL_FALSE);
GlErr("nv20volren","gcom7.4");
glFinalCombinerInputNV(GL_VARIABLE_A_NV, GL_ZERO, GL_UNSIGNED_IDENTITY_NV, GL_RGB);
glFinalCombinerInputNV(GL_VARIABLE_B_NV, GL_ZERO, GL_UNSIGNED_IDENTITY_NV, GL_RGB);
glFinalCombinerInputNV(GL_VARIABLE_C_NV, GL_ZERO, GL_UNSIGNED_IDENTITY_NV, GL_RGB);
glFinalCombinerInputNV(GL_VARIABLE_D_NV, GL_TEXTURE1_ARB, GL_UNSIGNED_IDENTITY_NV, GL_RGB);
glFinalCombinerInputNV(GL_VARIABLE_E_NV, GL_ZERO, GL_UNSIGNED_IDENTITY_NV, GL_RGB);
glFinalCombinerInputNV(GL_VARIABLE_F_NV, GL_ZERO, GL_UNSIGNED_IDENTITY_NV, GL_RGB);
glFinalCombinerInputNV(GL_VARIABLE_G_NV, GL_TEXTURE1_ARB, GL_UNSIGNED_IDENTITY_NV, GL_ALPHA);
GlErr("nv20volren","fcom.0");
break;
}
}
}
void NV20VolRen3D::resetRegComb()
{
glDisable(GL_REGISTER_COMBINERS_NV);
}
//=================================================== Render 3D Vec Algn
//======================================================================
void NV20VolRen3D::render3DVA(float sampleFrequency,
GLdouble mv[16],
unsigned int v,
float vo[8][3], //volume vertex coords model-space coords
float tx[8][3], //texture vertex coords tex-space coords
float axis[3]) //axis to slice along world-space coords
{
float rv[8][3]; //the rotated volume (may include a scale)
float maxval = -10; //(tmp)
float minval = 10;
int minvert = 0;
GLdouble mvinv[16];
inverseMatrix(mvinv, mv); //invert model view matrix
for(int i=0; i<8; ++i){ //translate model to world coords (view space)
translateV3(rv[i], mv, vo[i]);
if(maxval < MAX(maxval, rv[i][2])){
maxval = MAX(maxval, rv[i][2]);
}
if(minval > MIN(minval, rv[i][2])){
minval = MIN(minval, rv[i][2]);
minvert = i; //determine the starting point for slicing
}
}
// fix this function so that the eye is the universal reference point for all volumes!
// we will get artifacts at brick boundaries otherwise!
//find the slice plane point 'sp' (initial) and the slice plane normal 'sn'
//sp is the sliceing starting point, simply the vertex farthest from the eye
float sp[3] = {vo[minvert][0], vo[minvert][1], vo[minvert][2]};
//float vpn[3] = {0,0,1}; //view plane normal, points to eye (temp variable)
float vpn[3];
vpn[0] = axis[0]; vpn[1] = axis[1]; vpn[2] = axis[2];
float sn[3]; //slice plane normal
translateV3(sn, mvinv, vpn); //move vpn to sn (model space);
//note: sn & sp are defined in Model Space, ie the space where the volume
// is alligned with the (x,y,z) axies
float normsn = (float)sqrt(sn[0]*sn[0] + sn[1]*sn[1] + sn[2]*sn[2]); //normalize
sn[0]/=normsn;
sn[1]/=normsn;
sn[2]/=normsn;
//now find the distance we need to slice (|max_vertex - min_vertex|)
float maxd[3] = {0, 0, maxval}; //(tmp) only use z-coord (view space)
float mind[3] = {0, 0, minval}; //(tmp) ditto (view space)
float maxv[3], minv[3]; //(tmp)
translateV3(maxv, mvinv, maxd); //translate back to model space
translateV3(minv, mvinv, mind); //ditto
maxv[0] -= minv[0]; //subtract
maxv[1] -= minv[1];
maxv[2] -= minv[2];
//now take the norm of this vector... we have the distance to be sampled
float dist = (float)sqrt(maxv[0]*maxv[0] + maxv[1]*maxv[1] + maxv[2]*maxv[2]);
//draw a red bounding box
//if(m_bbb) renderBBoxBrackets(sizef[0], sizef[1], sizef[2]);
//if(m_bb) renderBBox(sizef[0], sizef[1], sizef[2]);
glDisable(GL_LIGHTING); //light makes it look bad!
glDisable(GL_CULL_FACE);
glPolygonMode(GL_FRONT, GL_FILL);
glPolygonMode(GL_BACK, GL_FILL);
//glEnable(GL_TEXTURE_3D_EXT);
glActiveTexture(GL_TEXTURE2_ARB);
glBindTexture(GL_TEXTURE_3D, shadeNames[v]);
glActiveTexture(GL_TEXTURE0_ARB);
glBindTexture(GL_TEXTURE_3D, texNames[v]);
glEnable(GL_BLEND);
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
glColor4f(1, 1, 1, 1);
GlErr("NV20VolRen3D","drawVA");
//distance between samples
float dis = gluvv.mv->xfSize / (gluvv.mv->xiSize * sampleFrequency);
float del[3] = {sn[0]*dis, sn[1]*dis, sn[2]*dis};
int samples = (int)((dist) / dis);//(total distance to be sampled)/(sample spacing)
//samples /= 40;
//del[0] *= 40;
//del[1] *= 40;
//del[2] *= 40;
float poly[6][3]; // for edge intersections
float tcoord[6][3]; // for texture intersections
float tpoly[6][3]; // for transformed edge intersections
int edges; // total number of edge intersections
//highly un-optimized!!!!!!!!!
for(i = 0 ; i < samples; ++i){ //for each slice
//increment the slice plane point by the slice distance
sp[0] += del[0];
sp[1] += del[1];
sp[2] += del[2];
edges = 0;
//now check each edge of the volume for intersection with..
//the plane defined by sp & sn
//front bottom edge
edges += intersect(vo[0], vo[1], tx[0], tx[1], rv[0], rv[1], sp, sn,
poly[edges], tcoord[edges], tpoly[edges]);
//front left edge
edges += intersect(vo[0], vo[2], tx[0], tx[2], rv[0], rv[2], sp, sn,
poly[edges], tcoord[edges], tpoly[edges]);
//front right edge
edges += intersect(vo[1], vo[3], tx[1], tx[3], rv[1], rv[3], sp, sn,
poly[edges], tcoord[edges], tpoly[edges]);
//left bottom edge
edges += intersect(vo[4], vo[0], tx[4], tx[0], rv[4], rv[0], sp, sn,
poly[edges], tcoord[edges], tpoly[edges]);
//right bottom edge
edges += intersect(vo[1], vo[5], tx[1], tx[5], rv[1], rv[5], sp, sn,
poly[edges], tcoord[edges], tpoly[edges]);
//front top edge
edges += intersect(vo[2], vo[3], tx[2], tx[3], rv[2], rv[3], sp, sn,
poly[edges], tcoord[edges], tpoly[edges]);
//back bottom edge
edges += intersect(vo[4], vo[5], tx[4], tx[5], rv[4], rv[5], sp, sn,
poly[edges], tcoord[edges], tpoly[edges]);
//back left edge
edges += intersect(vo[4], vo[6], tx[4], tx[6], rv[4], rv[6], sp, sn,
poly[edges], tcoord[edges], tpoly[edges]);
//back right edge
edges += intersect(vo[5], vo[7], tx[5], tx[7], rv[5], rv[7], sp, sn,
poly[edges], tcoord[edges], tpoly[edges]);
//back top edge
edges += intersect(vo[6], vo[7], tx[6], tx[7], rv[6], rv[7], sp, sn,
poly[edges], tcoord[edges], tpoly[edges]);
//left top edge
edges += intersect(vo[2], vo[6], tx[2], tx[6], rv[2], rv[6], sp, sn,
poly[edges], tcoord[edges], tpoly[edges]);
//right top edge
edges += intersect(vo[3], vo[7], tx[3], tx[7], rv[3], rv[7], sp, sn,
poly[edges], tcoord[edges], tpoly[edges]);
#if 0
if(edges == 3){ //no sort required for triangles
//cerr << "doing a triangle" <<endl;
glBegin(GL_TRIANGLES);
{
glTexCoord3fv(tcoord[0]);
glVertex3fv(poly[0]);
glTexCoord3fv(tcoord[1]);
glVertex3fv(poly[1]);
glTexCoord3fv(tcoord[2]);
glVertex3fv(poly[2]);
}
glEnd();
}
else { //compute convex hull and sort, a little piece of magic from:
#endif
// B.M.E. Moret & H.D. Shapiro "P to NP" pp. 453
float dx, dy, tt ,theta, cen[2]; //tt= TempTheta
cen[0] = cen[1] = 0.0;
int next;
//rather than swap 3 arrays, only one?
int order[6] ={0,1,2,3,4,5};
// order[6] could be an extreemly inefficient way to do this
for( int j=0; j<edges; ++j){ //find the center of the points
cen[0] += tpoly[j][0];
cen[1] += tpoly[j][1];
} //by averaging
cen[0]/= edges;
cen[1]/= edges;
for(j=0; j<edges; ++j){ //for each vertex
theta = -10; //find one with largest angle from center..
next = j;
for ( int k= j; k<edges; ++k){
//... and check angle made between other edges
dx = tpoly[order[k]][0] - cen[0];
dy = tpoly[order[k]][1] - cen[1];
if( (dx == 0) && (dy == 0)){ //same as center?
next = k;
cout << "what teh " << endl;
break; //out of this for-loop
}
tt = dy/(ABS(dx) + ABS(dy)); //else compute theta [0-4]
if( dx < 0.0 ) tt = (float)(2.0 - tt); //check quadrants 2&3
else if( dy < 0.0 ) tt = (float)(4.0 + tt); //quadrant 4
if( theta <= tt ){ //grab the max theta
next = k;
theta = tt;
}
} //end for(k) angle checking
// i am using 'tt' as a temp
// swap polygon vertex ( is this better than another branch?)
// I am not sure wich is worse: swapping 3 vectors for every edge
// or: using an array to index into another array??? hmmm....
// should have payed more attention in class
int tmp = order[j];
order[j] = order[next];
order[next] = tmp;
} //end for(j) edge /angle sort
#if 0
glBegin(GL_POLYGON); //draw slice and texture map it
{
for(int j=0; j< edges; ++j){
glTexCoord3fv(tcoord[order[j]]);
glVertex3fv(poly[order[j]]);
}
}
glEnd();
#else
volSlice(edges, tcoord, poly, order);