#include <stdio.H>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <math.h>
#include "bresnham.h"
#include "hp2xx.h"
void fill(HPGL_Pt polygon[MAXPOLY], int numpoints,HPGL_Pt P1, HPGL_Pt P2,
int scale_flag,int filltype,float spacing,float hatchangle)
{
double pxmin,pxmax,pymin,pymax;
double scanx1,scanx2,scany1,scany2;
HPGL_Pt segment[MAXPOLY];
double segx,segy;
int i, j, k, jj;
int numlines;
double penwidth = 1.;
HPGL_Pt p;
double denominator;
double tmp,rot_ang;
float pxdiff=0.,pydiff=0.;
double A1,B1,C1,A2,B2,C2;
double tmp2;
if (filltype >2) penwidth=spacing;
/*fprintf(stderr,"edges to test : %d\n",numpoints);*/
pxmin=100000.;
pymin=100000.;
pxmax=-100000.;
pymax=-100000.;
if (hatchangle >89.9 && hatchangle < 180.) {
hatchangle = hatchangle-90.;
/*fprintf(stderr,"vertical fill\n");*/
goto FILL_VERT;
}
for (i = 0 ; i <= numpoints; i++ ) {
pxmin=MIN(pxmin,polygon[i].x);
pymin=MIN(pymin,polygon[i].y);
pxmax=MAX(pxmax,polygon[i].x);
pymax=MAX(pymax,polygon[i].y);
}
if (pxmin == pxmax && pymin == pymax){
fprintf(stderr,"zero area polygon\n");
return;
}
/*****?*pymin=P1.y-1.;pymax=P2.y+1.;*****?*/
pxdiff=pxmax-pxmin;
if (hatchangle != 0.) {
rot_ang=tan(M_PI*hatchangle/180.);
pymin=pymin-rot_ang*pxdiff;
pymax=pymax+rot_ang*pxdiff;
}
pxmin=pxmin-10.;
pxmax=pxmax+10.;
pymin=pymin-10.;
pymax=pymax+10.;
numlines = fabs(1. + ( pymax - pymin +penwidth) / penwidth);
#if 0
/* debug code to show shade box */
p.x=pxmin;
p.y=pymin;
Pen_action_to_tmpfile(MOVE_TO, &p, scale_flag);
p.x=pxmin;
p.y=pymax;
Pen_action_to_tmpfile(DRAW_TO, &p, scale_flag);
p.x=pxmax;
p.y=pymax;
Pen_action_to_tmpfile(DRAW_TO, &p, scale_flag);
p.x=pxmax;
p.y=pymin;
Pen_action_to_tmpfile(DRAW_TO, &p, scale_flag);
p.x=pxmin;
p.y=pymin;
Pen_action_to_tmpfile(DRAW_TO, &p, scale_flag);
#endif
/* start at lowest y , run scanlines parallel x across polygon */
/* looking for intersections with edges */
pydiff=0.;
if (hatchangle != 0.) pydiff=tan(M_PI*hatchangle/180.)*pxdiff;
for (i = 0; i <= numlines; ++i) { /* for all scanlines ...*/
k=-1;
scany1 = pymin + (double)i * penwidth;
scany2=scany1+pydiff;
/* coefficients for current scan line */
A1=scany2-scany1;
B1=pxmin-pxmax;
C1=pxmin*(scany1-scany2) + scany1*(pxmax-pxmin);
for (j =0 ; j <= numpoints ; j=j+2) { /*for all polygon edges*/
/* coefficients for this edge */
A2=polygon[j+1].y-polygon[j].y;
B2=polygon[j].x-polygon[j+1].x;
C2=polygon[j].x*(polygon[j].y-polygon[j+1].y) + polygon[j].y*(polygon[j+1].x-polygon[j].x);
#if 0
/* debug code to show outline */
p.x=polygon[j].x;
p.y=polygon[j].y;
Pen_action_to_tmpfile(MOVE_TO, &p, scale_flag);
p.x=polygon[j+1].x;
p.y=polygon[j+1].y;
Pen_action_to_tmpfile(DRAW_TO, &p, scale_flag);
#endif
/*determine coordinates of intersection */
denominator = A1*B2-A2*B1;
if (fabs(denominator)>1.e-20){ /* zero means parallel lines */
segx= (B1*C2-B2*C1) /denominator; /*x coordinate of intersection */
segy= (C1*A2-C2*A1) /denominator; /*y coordinate of intersection */
if ((segy < MIN(polygon[j].y,polygon[j+1].y)) ||
(segy > MAX(polygon[j].y,polygon[j+1].y)) ||
(segx < MIN(polygon[j].x,polygon[j+1].x)) ||
(segx > MAX(polygon[j].x,polygon[j+1].x)) ) {
/*fprintf(stderr,"intersection at %f %f is not within (%f,%f)-(%f,%f)\n",segx,segy,polygon[j].x,polygon[j].y,polygon[j+1].x,polygon[j+1].y ) ; */
}else{
k++;
segment[k].x=segx;
segment[k].y=segy;
/*fprintf(stderr,"fill: intersection %d with line %d at (%f %f)\n",k,j,segx,segy);*/
if (k >0) {
for (jj=0;jj<k;jj++){
if ( (fabs(segment[jj].x-segment[k].x) < 1.e-2 )
&& (fabs(segment[jj].y-segment[k].y) < 1.e-2) ){
k--;
break;
}
}
for (jj=0;jj<k;jj++){
if (segment[k].x<segment[jj].x){
tmp=segment[jj].x;
tmp2=segment[jj].y;
segment[jj].x=segment[k].x;
segment[jj].y=segment[k].y;
segment[k].x=tmp;
segment[k].y=tmp2;
}
}
} /* if not the first intersection */
} /* if crossing withing range */
} /*if not parallel*/
} /*next edge */
if (k>0) {
/* fprintf(stderr, "%d segments for scanline %d\n",k,i);*/
for (j=0;j<k;j=j+2) {
/*fprintf(stderr, "segment (%f,%f)-(%f,%f)\n",segment[j].x,segment[j].y,segment[j+1].x,segment[j+1].y);*/
p.x=segment[j].x;
p.y=segment[j].y;
Pen_action_to_tmpfile(MOVE_TO, &p, scale_flag);
p.x=segment[j+1].x;
p.y=segment[j+1].y;
Pen_action_to_tmpfile(DRAW_TO, &p, scale_flag);
}
}else{
#if 0
/* debug code to show scanlines :*/
p.x=pxmin;
p.y=scany1;
Pen_action_to_tmpfile(MOVE_TO, &p, scale_flag);
p.x=pxmax;
p.y=scany2;
Pen_action_to_tmpfile(DRAW_TO, &p, scale_flag);
#endif
}
} /* next scanline */
if (filltype !=4) return;
FILL_VERT:
pxmin=P2.x;
pymin=P2.y;
pxmax=P1.x;
pymax=P1.y;
for (i = 0 ; i <= numpoints; i++ ) {
pxmin=MIN(pxmin,polygon[i].x);
pymin=MIN(pymin,polygon[i].y);
pxmax=MAX(pxmax,polygon[i].x);
pymax=MAX(pymax,polygon[i].y);
}
pxmin=P1.x-1.;pxmax=P2.x+1.;
pymin=P1.y-10.;pymax=P2.y+10.; /*???*/
pydiff=pymax-pymin;
if (hatchangle != 0.) {
rot_ang=tan(M_PI*hatchangle/180.);
pxmin=pxmin-rot_ang*pydiff;
pxmax=pxmax+rot_ang*pydiff;
}
pymin=pymin-1.;
pymax=pymax+1.;
numlines = fabs(1. + ( pxmax - pxmin +penwidth) / penwidth);
/*fprintf(stderr,"numlines = %d\n",numlines);*/
pxdiff=0.;
if (hatchangle != 0.) pxdiff=tan(M_PI*hatchangle/180.)*(pymax-pymin);
for (i = 0; i <= numlines; ++i) { /* for all scanlines ...*/
k=-1;
scanx1=pxmin + (double)i * penwidth;
scanx2=scanx1 - pxdiff;
/* coefficients for current scan line */
A1=pymax-pymin;
B1=scanx1-scanx2;
C1=scanx1*(pymin-pymax) + pymin*(scanx2-scanx1);
for (j =0 ; j <= numpoints ; j=j+2) { /*for all polygon edges*/
/* coefficients for this edge */
A2=polygon[j+1].y-polygon[j].y;
B2=polygon[j].x-polygon[j+1].x;
C2=polygon[j].x*(polygon[j].y-polygon[j+1].y) + polygon[j].y*(polygon[j+1].x-polygon[j].x);
/*determine coordinates of intersection */
denominator = A1*B2-A2*B1;
if (fabs(denominator)>0.){ /* zero means parallel lines */
segx= (B1*C2-B2*C1) /denominator; /*x coordinate of intersection */
segy= (C1*A2-C2*A1) /denominator; /*y coordinate of intersection */
if ((segy < MIN(polygon[j].y,polygon[j+1].y)) ||
(segy > MAX(polygon[j].y,polygon[j+1].y)) ||
(segx < MIN(polygon[j].x,polygon[j+1].x)) ||
(segx > MAX(polygon[j].x,polygon[j+1].x)) ) {
/*fprintf(stderr,"intersection at %f %f is not within (%f,%f)-(%f,%f)\n",segx,segy,polygon[j].x,polygon[j].y,polygon[j+1].x,polygon[j+1].y ) ; */
}else{
k++;
segment[k].x=segx;
segment[k].y=segy;
/*fprintf(stderr,"fill: intersection %d with line %d at (%f %f)\n",k,j,segx,segy);*/
if (k >0) {
for (jj=0;jj<k;jj++){
if ( (fabs(segment[jj].x-segment[k].x) < 1.e-10 )
&& (fabs(segment[jj].y-segment[k].y) < 1.e0) ){
k--;
break;
}
}
for (jj=0;jj<k;jj++){
if (segment[k].y<segment[jj].y){
tmp=segment[jj].x;
tmp2=segment[jj].y;
segment[jj].x=segment[k].x;
segment[jj].y=segment[k].y;
segment[k].x=tmp;
segment[k].y=tmp2;
}
}
} /* if not the first intersection */
} /* if crossing withing range */
} /*if not parallel*/
} /*next edge */
if (k>0) {
/* fprintf(stderr, "%d segments for scanline %d\n",k,i);*/
for (j=0;j<k;j=j+2) {
/*fprintf(stderr, "segment (%f,%f)-(%f,%f)\n",segment[j].x,segment[j].y,segment[j+1].x,segment[j+1].y);*/
p.x=segment[j].x;
p.y=segment[j].y;
Pen_action_to_tmpfile(MOVE_TO, &p, scale_flag);
p.x=segment[j+1].x;
p.y=segment[j+1].y;
Pen_action_to_tmpfile(DRAW_TO, &p, scale_flag);
}
}else{
#if 0
/* debug code to show scanlines :*/
p.x=pxmin;
p.y=scany1;
Pen_action_to_tmpfile(MOVE_TO, &p, scale_flag);
p.x=pxmax;
p.y=scany2;
Pen_action_to_tmpfile(DRAW_TO, &p, scale_flag);
#endif
}
} /* next scanline */
}
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