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/*
* MODULE NAME: segment.c
*
* FUNCTION:
* This module contains code that draws cylinder sections. There are a
* number of different segment routines presented: with and without colors,
* with and without normals, with and without front and back normals.
*
* HISTORY:
* written by Linas Vepstas August/September 1991
* split into multiple compile units, Linas, October 1991
* added normal vectors Linas, October 1991
* consoldated from other modules, Linas Vepstas, March 1993
*/
#include <malloc.h>
#include <stdlib.h>
#include <math.h>
#include <string.h> /* for the memcpy() subroutine */
#include "port.h"
#include "GL/tube.h"
#include "extrude.h"
#include "tube_gc.h"
#include "segment.h"
/* ============================================================ */
void draw_segment_plain (int ncp, /* number of contour points */
gleDouble front_contour[][3],
gleDouble back_contour[][3],
int inext, double len)
{
int j;
/* draw the tube segment */
BGNTMESH (inext, len);
for (j=0; j<ncp; j++) {
V3F (front_contour[j], j, FRONT);
V3F (back_contour[j], j, BACK);
}
if (__TUBE_CLOSE_CONTOUR) {
/* connect back up to first point of contour */
V3F (front_contour[0], 0, FRONT);
V3F (back_contour[0], 0, BACK);
}
ENDTMESH ();
}
/* ============================================================ */
void draw_segment_color (int ncp, /* number of contour points */
gleDouble front_contour[][3],
gleDouble back_contour[][3],
float color_last[3],
float color_next[3],
int inext, double len)
{
int j;
/* draw the tube segment */
BGNTMESH (inext, len);
for (j=0; j<ncp; j++) {
C3F (color_last);
V3F (front_contour[j], j, FRONT);
C3F (color_next);
V3F (back_contour[j], j, BACK);
}
if (__TUBE_CLOSE_CONTOUR) {
/* connect back up to first point of contour */
C3F (color_last);
V3F (front_contour[0], 0, FRONT);
C3F (color_next);
V3F (back_contour[0], 0, BACK);
}
ENDTMESH ();
}
/* ============================================================ */
void draw_segment_edge_n (int ncp, /* number of contour points */
gleDouble front_contour[][3],
gleDouble back_contour[][3],
double norm_cont[][3],
int inext, double len)
{
int j;
/* draw the tube segment */
BGNTMESH (inext,len);
for (j=0; j<ncp; j++) {
N3F_D (norm_cont[j]);
V3F (front_contour[j], j, FRONT);
V3F (back_contour[j], j, BACK);
}
if (__TUBE_CLOSE_CONTOUR) {
/* connect back up to first point of contour */
N3F_D (norm_cont[0]);
V3F (front_contour[0], 0, FRONT);
V3F (back_contour[0], 0, BACK);
}
ENDTMESH ();
}
/* ============================================================ */
void draw_segment_c_and_edge_n (int ncp, /* number of contour points */
gleDouble front_contour[][3],
gleDouble back_contour[][3],
double norm_cont[][3],
float color_last[3],
float color_next[3],
int inext, double len)
{
int j;
/* draw the tube segment */
BGNTMESH (inext, len);
for (j=0; j<ncp; j++) {
C3F (color_last);
N3F_D (norm_cont[j]);
V3F (front_contour[j], j, FRONT);
C3F (color_next);
N3F_D (norm_cont[j]);
V3F (back_contour[j], j, BACK);
}
if (__TUBE_CLOSE_CONTOUR) {
/* connect back up to first point of contour */
C3F (color_last);
N3F_D (norm_cont[0]);
V3F (front_contour[0], 0, FRONT);
C3F (color_next);
N3F_D (norm_cont[0]);
V3F (back_contour[0], 0, BACK);
}
ENDTMESH ();
}
/* ============================================================ */
void draw_segment_facet_n (int ncp, /* number of contour points */
gleDouble front_contour[][3],
gleDouble back_contour[][3],
double norm_cont[][3],
int inext, double len)
{
int j;
/* draw the tube segment */
BGNTMESH (inext, len);
for (j=0; j<ncp-1; j++) {
N3F_D (norm_cont[j]);
V3F (front_contour[j], j, FRONT);
V3F (back_contour[j], j, BACK);
V3F (front_contour[j+1], j+1, FRONT);
V3F (back_contour[j+1], j+1, BACK);
}
if (__TUBE_CLOSE_CONTOUR) {
/* connect back up to first point of contour */
N3F_D (norm_cont[ncp-1]);
V3F (front_contour[ncp-1], ncp-1, FRONT);
V3F (back_contour[ncp-1], ncp-1, BACK);
V3F (front_contour[0], 0, FRONT);
V3F (back_contour[0], 0, BACK);
}
ENDTMESH ();
}
/* ============================================================ */
void draw_segment_c_and_facet_n (int ncp, /* number of contour points */
gleDouble front_contour[][3],
gleDouble back_contour[][3],
double norm_cont[][3],
float color_last[3],
float color_next[3],
int inext, double len)
{
int j;
/* Note about this code:
* At first, when looking at this code, it appears to be really dumb:
* the N3F() call appears to be repeated multiple times, for no
* apparent purpose. It would seem that a performance improvement
* would be gained by stripping it out. !DONT DO IT!
* When there are no local lights or viewers, the V3F() subroutine
* does not trigger a recalculation of the lighting equations.
* However, we MUST trigger lighting, since otherwise colors come out
* wrong. Trigger lighting by doing an N3F call.
*/
/* draw the tube segment */
BGNTMESH (inext, len);
for (j=0; j<ncp-1; j++) {
C3F (color_last);
N3F_D (norm_cont[j]);
V3F (front_contour[j], j, FRONT);
C3F (color_next);
N3F_D (norm_cont[j]);
V3F (back_contour[j], j, BACK);
C3F (color_last);
N3F_D (norm_cont[j]);
V3F (front_contour[j+1], j+1, FRONT);
C3F (color_next);
N3F_D (norm_cont[j]);
V3F (back_contour[j+1], j+1, BACK);
}
if (__TUBE_CLOSE_CONTOUR) {
/* connect back up to first point of contour */
C3F (color_last);
N3F_D (norm_cont[ncp-1]);
V3F (front_contour[ncp-1], ncp-1, FRONT);
C3F (color_next);
N3F_D (norm_cont[ncp-1]);
V3F (back_contour[ncp-1], ncp-1, BACK);
C3F (color_last);
N3F_D (norm_cont[ncp-1]);
V3F (front_contour[0], 0, FRONT);
C3F (color_next);
N3F_D (norm_cont[ncp-1]);
V3F (back_contour[0], 0, BACK);
}
ENDTMESH ();
}
/* ============================================================ */
/* ============================================================ */
/*
* This routine draws a segment with normals specified at each end.
*/
void draw_binorm_segment_edge_n (int ncp, /* number of contour points */
double front_contour[][3],
double back_contour[][3],
double front_norm[][3],
double back_norm[][3],
int inext, double len)
{
int j;
/* draw the tube segment */
BGNTMESH (inext, len);
for (j=0; j<ncp; j++) {
N3F_D (front_norm[j]);
V3F_D (front_contour[j], j, FRONT);
N3F_D (back_norm[j]);
V3F_D (back_contour[j], j, BACK);
}
if (__TUBE_CLOSE_CONTOUR) {
/* connect back up to first point of contour */
N3F_D (front_norm[0]);
V3F_D (front_contour[0], 0, FRONT);
N3F_D (back_norm[0]);
V3F_D (back_contour[0], 0, BACK);
}
ENDTMESH ();
}
/* ============================================================ */
void draw_binorm_segment_c_and_edge_n (int ncp, /* number of contour points */
double front_contour[][3],
double back_contour[][3],
double front_norm[][3],
double back_norm[][3],
float color_last[3],
float color_next[3],
int inext, double len)
{
int j;
/* draw the tube segment */
BGNTMESH (inext, len);
for (j=0; j<ncp; j++) {
C3F (color_last);
N3F_D (front_norm[j]);
V3F_D (front_contour[j], j, FRONT);
C3F (color_next);
N3F_D (back_norm[j]);
V3F_D (back_contour[j], j, BACK);
}
if (__TUBE_CLOSE_CONTOUR) {
/* connect back up to first point of contour */
C3F (color_last);
N3F_D (front_norm[0]);
V3F_D (front_contour[0], 0, FRONT);
C3F (color_next);
N3F_D (back_norm[0]);
V3F_D (back_contour[0], 0, BACK);
}
ENDTMESH ();
}
/* ============================================================ */
/*
* This routine draws a piece of the round segment with psuedo-facet
* normals. I say "psuedo-facet" because the resulting object looks
* much, much better than real facet normals, and is what the round
* join style was meant to accomplish for face normals.
*/
void draw_binorm_segment_facet_n (int ncp, /* number of contour points */
double front_contour[][3],
double back_contour[][3],
double front_norm[][3],
double back_norm[][3],
int inext, double len)
{
int j;
/* draw the tube segment */
BGNTMESH (inext, len);
for (j=0; j<ncp-1; j++) {
N3F_D (front_norm[j]);
V3F_D (front_contour[j], j, FRONT);
N3F_D (back_norm[j]);
V3F_D (back_contour[j], j, BACK);
N3F_D (front_norm[j]);
V3F_D (front_contour[j+1], j+1, FRONT);
N3F_D (back_norm[j]);
V3F_D (back_contour[j+1], j+1, BACK);
}
if (__TUBE_CLOSE_CONTOUR) {
/* connect back up to first point of contour */
N3F_D (front_norm[ncp-1]);
V3F_D (front_contour[ncp-1], ncp-1, FRONT);
N3F_D (back_norm[ncp-1]);
V3F_D (back_contour[ncp-1], ncp-1, BACK);
N3F_D (front_norm[ncp-1]);
V3F_D (front_contour[0], 0, FRONT);
N3F_D (back_norm[ncp-1]);
V3F_D (back_contour[0], 0, BACK);
}
ENDTMESH ();
}
/* ============================================================ */
void draw_binorm_segment_c_and_facet_n (int ncp,
double front_contour[][3],
double back_contour[][3],
double front_norm[][3],
double back_norm[][3],
float color_last[3],
float color_next[3],
int inext, double len)
{
int j;
/* draw the tube segment */
BGNTMESH (inext, len);
for (j=0; j<ncp-1; j++) {
C3F (color_last);
N3F_D (front_norm[j]);
V3F_D (front_contour[j], j, FRONT);
C3F (color_next);
N3F_D (back_norm[j]);
V3F_D (back_contour[j], j, BACK);
C3F (color_last);
N3F_D (front_norm[j]);
V3F_D (front_contour[j+1], j+1, FRONT);
C3F (color_next);
N3F_D (back_norm[j]);
V3F_D (back_contour[j+1], j+1, BACK);
}
if (__TUBE_CLOSE_CONTOUR) {
/* connect back up to first point of contour */
C3F (color_last);
N3F_D (front_norm[ncp-1]);
V3F_D (front_contour[ncp-1], ncp-1, FRONT);
C3F (color_next);
N3F_D (back_norm[ncp-1]);
V3F_D (back_contour[ncp-1], ncp-1, BACK);
C3F (color_last);
N3F_D (front_norm[ncp-1]);
V3F_D (front_contour[0], 0, FRONT);
C3F (color_next);
N3F_D (back_norm[ncp-1]);
V3F_D (back_contour[0], 0, BACK);
}
ENDTMESH ();
}
/* ==================== END OF FILE =========================== */
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