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Diffstat (limited to 'src/preproc/pic/common.cpp')
-rw-r--r-- | src/preproc/pic/common.cpp | 647 |
1 files changed, 647 insertions, 0 deletions
diff --git a/src/preproc/pic/common.cpp b/src/preproc/pic/common.cpp new file mode 100644 index 0000000..6a4a93e --- /dev/null +++ b/src/preproc/pic/common.cpp @@ -0,0 +1,647 @@ +// -*- C++ -*- +/* Copyright (C) 1989-2020 Free Software Foundation, Inc. + Written by James Clark (jjc@jclark.com) + +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 3 of the License, 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 this program. If not, see <http://www.gnu.org/licenses/>. */ + +#include "pic.h" +#include "common.h" + +// output a dashed circle as a series of arcs + +void common_output::dashed_circle(const position ¢, double rad, + const line_type <) +{ + 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 ¢, double rad, + const line_type <) +{ + 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); +} + +// recursive function for dash drawing, used by dashed_ellipse + +void common_output::ellipse_arc(const position ¢, + const position &z0, const position &z1, + const distance &dim, const line_type <) +{ + assert(lt.type == line_type::solid); + assert(dim.x != 0 && dim.y != 0); + double eps = 0.0001; + position zml = (z0 + z1) / 2; + // apply affine transformation (from ellipse to circle) to compute angle + // of new position, then invert transformation to get exact position + double psi = atan2(zml.y / dim.y, zml.x / dim.x); + position zm = position(dim.x * cos(psi), dim.y * sin(psi)); + // to approximate the ellipse arc with one or more circle arcs, we + // first compute the radius of curvature in zm + double a_2 = dim.x * dim.x; + double a_4 = a_2 * a_2; + double b_2 = dim.y * dim.y; + double b_4 = b_2 * b_2; + double e_2 = a_2 - b_2; + double temp = a_4 * zm.y * zm.y + b_4 * zm.x * zm.x; + double rho = sqrt(temp / a_4 / b_4 * temp / a_4 / b_4 * temp); + // compute center of curvature circle + position M = position(e_2 * zm.x / a_2 * zm.x / a_2 * zm.x, + -e_2 * zm.y / b_2 * zm.y / b_2 * zm.y); + // compute distance between circle and ellipse arc at start and end + double phi0 = atan2(z0.y - M.y, z0.x - M.x); + double phi1 = atan2(z1.y - M.y, z1.x - M.x); + position M0 = position(rho * cos(phi0), rho * sin(phi0)) + M; + position M1 = position(rho * cos(phi1), rho * sin(phi1)) + M; + double dist0 = hypot(z0 - M0) / sqrt(z0 * z0); + double dist1 = hypot(z1 - M1) / sqrt(z1 * z1); + if (dist0 < eps && dist1 < eps) + solid_arc(M + cent, rho, phi0, phi1, lt); + else { + ellipse_arc(cent, z0, zm, dim, lt); + ellipse_arc(cent, zm, z1, dim, lt); + } +} + +// output a dashed ellipse as a series of arcs + +void common_output::dashed_ellipse(const position ¢, const distance &dim, + const line_type <) +{ + assert(lt.type == line_type::dashed); + double dim_x = dim.x / 2; + double dim_y = dim.y / 2; + line_type slt = lt; + slt.type = line_type::solid; + double dw = lt.dash_width; + // we use an approximation to compute the ellipse length (found in: + // Bronstein, Semendjajew, Taschenbuch der Mathematik) + double lambda = (dim.x - dim.y) / (dim.x + dim.y); + double le = M_PI / 2 * (dim.x + dim.y) + * ((64 - 3 * lambda * lambda * lambda * lambda ) + / (64 - 16 * lambda * lambda)); + // for symmetry we make nmax a multiple of 8 + int nmax = 8 * int(le / dw / 8 + 0.5); + if (nmax < 8) { + nmax = 8; + dw = le / 8; + } + int ndash = nmax / 2; + double gapwidth = (le - dw * ndash) / ndash; + double l = 0; + position z = position(dim_x, 0); + position zdot = z; + int j = 0; + int jmax = int(10 / lt.dash_width); + for (int i = 0; i <= nmax; i++) { + position zold = z; + position zpre = zdot; + double ld = (int(i / 2) + 0.5) * dw + int((i + 1) / 2) * gapwidth; + double lold = 0; + double dl = 1; + // find next position for fixed arc length + while (l < ld) { + j++; + lold = l; + zold = z; + double phi = j * 2 * M_PI / jmax; + z = position(dim_x * cos(phi), dim_y * sin(phi)); + dl = hypot(z - zold); + l += dl; + } + // interpolate linearly between the last two points, + // using the length difference as the scaling factor + double delta = (ld - lold) / dl; + zdot = zold + (z - zold) * delta; + // compute angle of new position on the affine circle + // and use it to get the exact value on the ellipse + double psi = atan2(zdot.y / dim_y, zdot.x / dim_x); + zdot = position(dim_x * cos(psi), dim_y * sin(psi)); + if ((i % 2 == 0) && (i > 1)) + ellipse_arc(cent, zpre, zdot, dim / 2, slt); + } +} + +// output a dotted ellipse as a series of dots + +void common_output::dotted_ellipse(const position ¢, const distance &dim, + const line_type <) +{ + assert(lt.type == line_type::dotted); + double dim_x = dim.x / 2; + double dim_y = dim.y / 2; + line_type slt = lt; + slt.type = line_type::solid; + // we use an approximation to compute the ellipse length (found in: + // Bronstein, Semendjajew, Taschenbuch der Mathematik) + double lambda = (dim.x - dim.y) / (dim.x + dim.y); + double le = M_PI / 2 * (dim.x + dim.y) + * ((64 - 3 * lambda * lambda * lambda * lambda ) + / (64 - 16 * lambda * lambda)); + // for symmetry we make nmax a multiple of 4 + int ndots = 4 * int(le / lt.dash_width / 4 + 0.5); + if (ndots < 4) + ndots = 4; + double l = 0; + position z = position(dim_x, 0); + int j = 0; + int jmax = int(10 / lt.dash_width); + for (int i = 1; i <= ndots; i++) { + position zold = z; + double lold = l; + double ld = i * le / ndots; + double dl = 1; + // find next position for fixed arc length + while (l < ld) { + j++; + lold = l; + zold = z; + double phi = j * 2 * M_PI / jmax; + z = position(dim_x * cos(phi), dim_y * sin(phi)); + dl = hypot(z - zold); + l += dl; + } + // interpolate linearly between the last two points, + // using the length difference as the scaling factor + double delta = (ld - lold) / dl; + position zdot = zold + (z - zold) * delta; + // compute angle of new position on the affine circle + // and use it to get the exact value on the ellipse + double psi = atan2(zdot.y / dim_y, zdot.x / dim_x); + zdot = position(dim_x * cos(psi), dim_y * sin(psi)); + dot(cent + zdot, slt); + } +} + +// return non-zero iff we can compute a center + +int compute_arc_center(const position &start, const position ¢, + 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 ¢, + const position &end, const line_type <) +{ + 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; + while (total_angle < 0) + total_angle += M_PI + M_PI; + 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 ¢, + const position &end, const line_type <) +{ + 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; + while (total_angle < 0) + total_angle += M_PI + M_PI; + 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 ¢, double rad, + double start_angle, double end_angle, + const line_type <) +{ + 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 ¢, const distance &dim, + double rad, const line_type <, + double fill, char *color_fill) +{ + if (fill >= 0.0 || color_fill) + 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 ¢, + const distance &dim, double rad, + const line_type <) +{ + 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 ¢, double rad, + double start_angle, double end_angle, + const line_type <, + 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 <, + double dash_width, double gap_width, + double *offsetp) +{ + distance dist = end - start; + double length = hypot(dist); + if (length == 0.0) + return; + 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 ¢, + const distance &dim, double rad, + const line_type <) +{ + 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 ¢, double rad, + double start_angle, double end_angle, + const line_type <, 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 <, double gap_width, + double *offsetp) +{ + distance dist = end - start; + double length = hypot(dist); + if (length == 0.0) + return; + 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 ¢, + const distance &dim, double rad, + const line_type <) +{ + 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 ¢, + 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); +} |