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386BSD 0.1 development
[unix-history] / usr / src / usr.bin / groff / pic / common.cc
// -*- C++ -*-
/* Copyright (C) 1989, 1990 Free Software Foundation, Inc.
Written by James Clark (jjc@jclark.uucp)
This file is part of groff.
groff is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation; either version 1, or (at your option) any later
version.
groff 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 General Public License
for more details.
You should have received a copy of the GNU General Public License along
with groff; see the file LICENSE. If not, write to the Free Software
Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
#include "pic.h"
#include "common.h"
// output a dashed circle as a series of arcs
void common_output::dashed_circle(const position &cent, double rad,
const line_type &lt)
{
assert(lt.type == line_type::dashed);
line_type slt = lt;
slt.type = line_type::solid;
double dash_angle = lt.dash_width/rad;
int ndashes;
double gap_angle;
if (dash_angle >= M_PI/4.0) {
if (dash_angle < M_PI/2.0) {
gap_angle = M_PI/2.0 - dash_angle;
ndashes = 4;
}
else if (dash_angle < M_PI) {
gap_angle = M_PI - dash_angle;
ndashes = 2;
}
else {
circle(cent, rad, slt, -1.0);
return;
}
}
else {
ndashes = 4*int(ceil(M_PI/(4.0*dash_angle)));
gap_angle = (M_PI*2.0)/ndashes - dash_angle;
}
for (int i = 0; i < ndashes; i++) {
double start_angle = i*(dash_angle+gap_angle) - dash_angle/2.0;
solid_arc(cent, rad, start_angle, start_angle + dash_angle, lt);
}
}
// output a dotted circle as a series of dots
void common_output::dotted_circle(const position &cent, double rad,
const line_type &lt)
{
assert(lt.type == line_type::dotted);
double gap_angle = lt.dash_width/rad;
int ndots;
if (gap_angle >= M_PI/2.0) {
// always have at least 2 dots
gap_angle = M_PI;
ndots = 2;
}
else {
ndots = 4*int(M_PI/(2.0*gap_angle));
gap_angle = (M_PI*2.0)/ndots;
}
double ang = 0.0;
for (int i = 0; i < ndots; i++, ang += gap_angle)
dot(cent + position(cos(ang), sin(ang))*rad, lt);
}
// return non-zero iff we can compute a center
int compute_arc_center(const position &start, const position &cent,
const position &end, position *result)
{
// This finds the point along the vector from start to cent that
// is equidistant between start and end.
distance c = cent - start;
distance e = end - start;
double n = c*e;
if (n == 0.0)
return 0;
*result = start + c*((e*e)/(2.0*n));
return 1;
}
// output a dashed arc as a series of arcs
void common_output::dashed_arc(const position &start, const position &cent,
const position &end, const line_type &lt)
{
assert(lt.type == line_type::dashed);
position c;
if (!compute_arc_center(start, cent, end, &c)) {
line(start, &end, 1, lt);
return;
}
distance start_offset = start - c;
distance end_offset = end - c;
double start_angle = atan2(start_offset.y, start_offset.x);
double end_angle = atan2(end_offset.y, end_offset.x);
double rad = hypot(c - start);
double dash_angle = lt.dash_width/rad;
double total_angle = end_angle - start_angle;
if (total_angle <= dash_angle*2.0) {
solid_arc(cent, rad, start_angle, end_angle, lt);
return;
}
int ndashes = int((total_angle - dash_angle)/(dash_angle*2.0) + .5);
double dash_and_gap_angle = (total_angle - dash_angle)/ndashes;
for (int i = 0; i <= ndashes; i++)
solid_arc(cent, rad, start_angle + i*dash_and_gap_angle,
start_angle + i*dash_and_gap_angle + dash_angle, lt);
}
// output a dotted arc as a series of dots
void common_output::dotted_arc(const position &start, const position &cent,
const position &end, const line_type &lt)
{
assert(lt.type == line_type::dotted);
position c;
if (!compute_arc_center(start, cent, end, &c)) {
line(start, &end, 1, lt);
return;
}
distance start_offset = start - c;
distance end_offset = end - c;
double start_angle = atan2(start_offset.y, start_offset.x);
double total_angle = atan2(end_offset.y, end_offset.x) - start_angle;
double rad = hypot(c - start);
int ndots = int(total_angle/(lt.dash_width/rad) + .5);
if (ndots == 0)
dot(start, lt);
else {
for (int i = 0; i <= ndots; i++) {
double a = start_angle + (total_angle*i)/ndots;
dot(cent + position(cos(a), sin(a))*rad, lt);
}
}
}
void common_output::solid_arc(const position &cent, double rad,
double start_angle, double end_angle,
const line_type &lt)
{
line_type slt = lt;
slt.type = line_type::solid;
arc(cent + position(cos(start_angle), sin(start_angle))*rad,
cent,
cent + position(cos(end_angle), sin(end_angle))*rad,
slt);
}
void common_output::rounded_box(const position &cent, const distance &dim,
double rad, const line_type &lt, double fill)
{
if (fill >= 0.0)
filled_rounded_box(cent, dim, rad, fill);
switch (lt.type) {
case line_type::invisible:
break;
case line_type::dashed:
dashed_rounded_box(cent, dim, rad, lt);
break;
case line_type::dotted:
dotted_rounded_box(cent, dim, rad, lt);
break;
case line_type::solid:
solid_rounded_box(cent, dim, rad, lt);
break;
default:
assert(0);
}
}
void common_output::dashed_rounded_box(const position &cent,
const distance &dim, double rad,
const line_type &lt)
{
line_type slt = lt;
slt.type = line_type::solid;
double hor_length = dim.x + (M_PI/2.0 - 2.0)*rad;
int n_hor_dashes = int(hor_length/(lt.dash_width*2.0) + .5);
double hor_gap_width = (n_hor_dashes != 0
? hor_length/n_hor_dashes - lt.dash_width
: 0.0);
double vert_length = dim.y + (M_PI/2.0 - 2.0)*rad;
int n_vert_dashes = int(vert_length/(lt.dash_width*2.0) + .5);
double vert_gap_width = (n_vert_dashes != 0
? vert_length/n_vert_dashes - lt.dash_width
: 0.0);
// Note that each corner arc has to be split into two for dashing,
// because one part is dashed using vert_gap_width, and the other
// using hor_gap_width.
double offset = lt.dash_width/2.0;
dash_arc(cent + position(dim.x/2.0 - rad, -dim.y/2.0 + rad), rad,
-M_PI/4.0, 0, slt, lt.dash_width, vert_gap_width, &offset);
dash_line(cent + position(dim.x/2.0, -dim.y/2.0 + rad),
cent + position(dim.x/2.0, dim.y/2.0 - rad),
slt, lt.dash_width, vert_gap_width, &offset);
dash_arc(cent + position(dim.x/2.0 - rad, dim.y/2.0 - rad), rad,
0, M_PI/4.0, slt, lt.dash_width, vert_gap_width, &offset);
offset = lt.dash_width/2.0;
dash_arc(cent + position(dim.x/2.0 - rad, dim.y/2.0 - rad), rad,
M_PI/4.0, M_PI/2, slt, lt.dash_width, hor_gap_width, &offset);
dash_line(cent + position(dim.x/2.0 - rad, dim.y/2.0),
cent + position(-dim.x/2.0 + rad, dim.y/2.0),
slt, lt.dash_width, hor_gap_width, &offset);
dash_arc(cent + position(-dim.x/2.0 + rad, dim.y/2.0 - rad), rad,
M_PI/2, 3*M_PI/4.0, slt, lt.dash_width, hor_gap_width, &offset);
offset = lt.dash_width/2.0;
dash_arc(cent + position(-dim.x/2.0 + rad, dim.y/2.0 - rad), rad,
3.0*M_PI/4.0, M_PI, slt, lt.dash_width, vert_gap_width, &offset);
dash_line(cent + position(-dim.x/2.0, dim.y/2.0 - rad),
cent + position(-dim.x/2.0, -dim.y/2.0 + rad),
slt, lt.dash_width, vert_gap_width, &offset);
dash_arc(cent + position(-dim.x/2.0 + rad, -dim.y/2.0 + rad), rad,
M_PI, 5.0*M_PI/4.0, slt, lt.dash_width, vert_gap_width, &offset);
offset = lt.dash_width/2.0;
dash_arc(cent + position(-dim.x/2.0 + rad, -dim.y/2.0 + rad), rad,
5*M_PI/4.0, 3*M_PI/2.0, slt, lt.dash_width, hor_gap_width, &offset);
dash_line(cent + position(-dim.x/2.0 + rad, -dim.y/2.0),
cent + position(dim.x/2.0 - rad, -dim.y/2.0),
slt, lt.dash_width, hor_gap_width, &offset);
dash_arc(cent + position(dim.x/2.0 - rad, -dim.y/2.0 + rad), rad,
3*M_PI/2, 7*M_PI/4, slt, lt.dash_width, hor_gap_width, &offset);
}
// Used by dashed_rounded_box.
void common_output::dash_arc(const position &cent, double rad,
double start_angle, double end_angle,
const line_type &lt,
double dash_width, double gap_width,
double *offsetp)
{
double length = (end_angle - start_angle)*rad;
double pos = 0.0;
for (;;) {
if (*offsetp >= dash_width) {
double rem = dash_width + gap_width - *offsetp;
if (pos + rem > length) {
*offsetp += length - pos;
break;
}
else {
pos += rem;
*offsetp = 0.0;
}
}
else {
double rem = dash_width - *offsetp;
if (pos + rem > length) {
solid_arc(cent, rad, start_angle + pos/rad, end_angle, lt);
*offsetp += length - pos;
break;
}
else {
solid_arc(cent, rad, start_angle + pos/rad,
start_angle + (pos + rem)/rad, lt);
pos += rem;
*offsetp = dash_width;
}
}
}
}
// Used by dashed_rounded_box.
void common_output::dash_line(const position &start, const position &end,
const line_type &lt,
double dash_width, double gap_width,
double *offsetp)
{
distance dist = end - start;
double length = hypot(dist);
double pos = 0.0;
for (;;) {
if (*offsetp >= dash_width) {
double rem = dash_width + gap_width - *offsetp;
if (pos + rem > length) {
*offsetp += length - pos;
break;
}
else {
pos += rem;
*offsetp = 0.0;
}
}
else {
double rem = dash_width - *offsetp;
if (pos + rem > length) {
line(start + dist*(pos/length), &end, 1, lt);
*offsetp += length - pos;
break;
}
else {
position p(start + dist*((pos + rem)/length));
line(start + dist*(pos/length), &p, 1, lt);
pos += rem;
*offsetp = dash_width;
}
}
}
}
void common_output::dotted_rounded_box(const position &cent,
const distance &dim, double rad,
const line_type &lt)
{
line_type slt = lt;
slt.type = line_type::solid;
double hor_length = dim.x + (M_PI/2.0 - 2.0)*rad;
int n_hor_dots = int(hor_length/lt.dash_width + .5);
double hor_gap_width = (n_hor_dots != 0
? hor_length/n_hor_dots
: lt.dash_width);
double vert_length = dim.y + (M_PI/2.0 - 2.0)*rad;
int n_vert_dots = int(vert_length/lt.dash_width + .5);
double vert_gap_width = (n_vert_dots != 0
? vert_length/n_vert_dots
: lt.dash_width);
double epsilon = lt.dash_width/(rad*100.0);
double offset = 0.0;
dot_arc(cent + position(dim.x/2.0 - rad, -dim.y/2.0 + rad), rad,
-M_PI/4.0, 0, slt, vert_gap_width, &offset);
dot_line(cent + position(dim.x/2.0, -dim.y/2.0 + rad),
cent + position(dim.x/2.0, dim.y/2.0 - rad),
slt, vert_gap_width, &offset);
dot_arc(cent + position(dim.x/2.0 - rad, dim.y/2.0 - rad), rad,
0, M_PI/4.0 - epsilon, slt, vert_gap_width, &offset);
offset = 0.0;
dot_arc(cent + position(dim.x/2.0 - rad, dim.y/2.0 - rad), rad,
M_PI/4.0, M_PI/2, slt, hor_gap_width, &offset);
dot_line(cent + position(dim.x/2.0 - rad, dim.y/2.0),
cent + position(-dim.x/2.0 + rad, dim.y/2.0),
slt, hor_gap_width, &offset);
dot_arc(cent + position(-dim.x/2.0 + rad, dim.y/2.0 - rad), rad,
M_PI/2, 3*M_PI/4.0 - epsilon, slt, hor_gap_width, &offset);
offset = 0.0;
dot_arc(cent + position(-dim.x/2.0 + rad, dim.y/2.0 - rad), rad,
3.0*M_PI/4.0, M_PI, slt, vert_gap_width, &offset);
dot_line(cent + position(-dim.x/2.0, dim.y/2.0 - rad),
cent + position(-dim.x/2.0, -dim.y/2.0 + rad),
slt, vert_gap_width, &offset);
dot_arc(cent + position(-dim.x/2.0 + rad, -dim.y/2.0 + rad), rad,
M_PI, 5.0*M_PI/4.0 - epsilon, slt, vert_gap_width, &offset);
offset = 0.0;
dot_arc(cent + position(-dim.x/2.0 + rad, -dim.y/2.0 + rad), rad,
5*M_PI/4.0, 3*M_PI/2.0, slt, hor_gap_width, &offset);
dot_line(cent + position(-dim.x/2.0 + rad, -dim.y/2.0),
cent + position(dim.x/2.0 - rad, -dim.y/2.0),
slt, hor_gap_width, &offset);
dot_arc(cent + position(dim.x/2.0 - rad, -dim.y/2.0 + rad), rad,
3*M_PI/2, 7*M_PI/4 - epsilon, slt, hor_gap_width, &offset);
}
// Used by dotted_rounded_box.
void common_output::dot_arc(const position &cent, double rad,
double start_angle, double end_angle,
const line_type &lt, double gap_width,
double *offsetp)
{
double length = (end_angle - start_angle)*rad;
double pos = 0.0;
for (;;) {
if (*offsetp == 0.0) {
double ang = start_angle + pos/rad;
dot(cent + position(cos(ang), sin(ang))*rad, lt);
}
double rem = gap_width - *offsetp;
if (pos + rem > length) {
*offsetp += length - pos;
break;
}
else {
pos += rem;
*offsetp = 0.0;
}
}
}
// Used by dotted_rounded_box.
void common_output::dot_line(const position &start, const position &end,
const line_type &lt, double gap_width,
double *offsetp)
{
distance dist = end - start;
double length = hypot(dist);
double pos = 0.0;
for (;;) {
if (*offsetp == 0.0)
dot(start + dist*(pos/length), lt);
double rem = gap_width - *offsetp;
if (pos + rem > length) {
*offsetp += length - pos;
break;
}
else {
pos += rem;
*offsetp = 0.0;
}
}
}
void common_output::solid_rounded_box(const position &cent,
const distance &dim, double rad,
const line_type &lt)
{
position tem = cent - dim/2.0;
arc(tem + position(0.0, rad),
tem + position(rad, rad),
tem + position(rad, 0.0),
lt);
tem = cent + position(-dim.x/2.0, dim.y/2.0);
arc(tem + position(rad, 0.0),
tem + position(rad, -rad),
tem + position(0.0, -rad),
lt);
tem = cent + dim/2.0;
arc(tem + position(0.0, -rad),
tem + position(-rad, -rad),
tem + position(-rad, 0.0),
lt);
tem = cent + position(dim.x/2.0, -dim.y/2.0);
arc(tem + position(-rad, 0.0),
tem + position(-rad, rad),
tem + position(0.0, rad),
lt);
position end;
end = cent + position(-dim.x/2.0, dim.y/2.0 - rad);
line(cent - dim/2.0 + position(0.0, rad), &end, 1, lt);
end = cent + position(dim.x/2.0 - rad, dim.y/2.0);
line(cent + position(-dim.x/2.0 + rad, dim.y/2.0), &end, 1, lt);
end = cent + position(dim.x/2.0, -dim.y/2.0 + rad);
line(cent + position(dim.x/2.0, dim.y/2.0 - rad), &end, 1, lt);
end = cent + position(-dim.x/2.0 + rad, -dim.y/2.0);
line(cent + position(dim.x/2.0 - rad, -dim.y/2.0), &end, 1, lt);
}
void common_output::filled_rounded_box(const position &cent,
const distance &dim, double rad,
double fill)
{
line_type ilt;
ilt.type = line_type::invisible;
circle(cent + position(dim.x/2.0 - rad, dim.y/2.0 - rad), rad, ilt, fill);
circle(cent + position(-dim.x/2.0 + rad, dim.y/2.0 - rad), rad, ilt, fill);
circle(cent + position(-dim.x/2.0 + rad, -dim.y/2.0 + rad), rad, ilt, fill);
circle(cent + position(dim.x/2.0 - rad, -dim.y/2.0 + rad), rad, ilt, fill);
position vec[4];
vec[0] = cent + position(dim.x/2.0, dim.y/2.0 - rad);
vec[1] = cent + position(-dim.x/2.0, dim.y/2.0 - rad);
vec[2] = cent + position(-dim.x/2.0, -dim.y/2.0 + rad);
vec[3] = cent + position(dim.x/2.0, -dim.y/2.0 + rad);
polygon(vec, 4, ilt, fill);
vec[0] = cent + position(dim.x/2.0 - rad, dim.y/2.0);
vec[1] = cent + position(-dim.x/2.0 + rad, dim.y/2.0);
vec[2] = cent + position(-dim.x/2.0 + rad, -dim.y/2.0);
vec[3] = cent + position(dim.x/2.0 - rad, -dim.y/2.0);
polygon(vec, 4, ilt, fill);
}
Continuous source code history from original PDP-7 UNIX to FreeBSD 2, the first fully unencumbered FreeBSD release.