blob: d066915f0fabeac3877c2b91933493437c20657c [file] [log] [blame]
//========================================================================
//
// SplashXPath.cc
//
//========================================================================
//========================================================================
//
// Modified under the Poppler project - http://poppler.freedesktop.org
//
// All changes made under the Poppler project to this file are licensed
// under GPL version 2 or later
//
// Copyright (C) 2010 PaweĊ‚ Wiejacha <pawel.wiejacha@gmail.com>
// Copyright (C) 2010, 2011, 2018, 2019, 2021 Albert Astals Cid <aacid@kde.org>
// Copyright (C) 2013 Thomas Freitag <Thomas.Freitag@alfa.de>
// Copyright (C) 2017 Adrian Johnson <ajohnson@redneon.com>
//
// To see a description of the changes please see the Changelog file that
// came with your tarball or type make ChangeLog if you are building from git
//
//========================================================================
#include <config.h>
#include <cstdlib>
#include <cstring>
#include <algorithm>
#include "goo/gmem.h"
#include "goo/GooLikely.h"
#include "SplashMath.h"
#include "SplashPath.h"
#include "SplashXPath.h"
//------------------------------------------------------------------------
struct SplashXPathPoint
{
SplashCoord x, y;
};
struct SplashXPathAdjust
{
int firstPt, lastPt; // range of points
bool vert; // vertical or horizontal hint
SplashCoord x0a, x0b, // hint boundaries
xma, xmb, x1a, x1b;
SplashCoord x0, x1, xm; // adjusted coordinates
};
//------------------------------------------------------------------------
// Transform a point from user space to device space.
inline void SplashXPath::transform(SplashCoord *matrix, SplashCoord xi, SplashCoord yi, SplashCoord *xo, SplashCoord *yo)
{
// [ m[0] m[1] 0 ]
// [xo yo 1] = [xi yi 1] * [ m[2] m[3] 0 ]
// [ m[4] m[5] 1 ]
*xo = xi * matrix[0] + yi * matrix[2] + matrix[4];
*yo = xi * matrix[1] + yi * matrix[3] + matrix[5];
}
//------------------------------------------------------------------------
// SplashXPath
//------------------------------------------------------------------------
SplashXPath::SplashXPath(SplashPath *path, SplashCoord *matrix, SplashCoord flatness, bool closeSubpaths, bool adjustLines, int linePosI)
{
SplashPathHint *hint;
SplashXPathPoint *pts;
SplashXPathAdjust *adjusts, *adjust;
SplashCoord x0, y0, x1, y1, x2, y2, x3, y3, xsp, ysp;
SplashCoord adj0, adj1;
int curSubpath, i, j;
// transform the points
pts = (SplashXPathPoint *)gmallocn(path->length, sizeof(SplashXPathPoint));
for (i = 0; i < path->length; ++i) {
transform(matrix, path->pts[i].x, path->pts[i].y, &pts[i].x, &pts[i].y);
}
// set up the stroke adjustment hints
if (path->hints) {
adjusts = (SplashXPathAdjust *)gmallocn_checkoverflow(path->hintsLength, sizeof(SplashXPathAdjust));
if (adjusts) {
for (i = 0; i < path->hintsLength; ++i) {
hint = &path->hints[i];
if (hint->ctrl0 + 1 >= path->length || hint->ctrl1 + 1 >= path->length) {
gfree(adjusts);
adjusts = nullptr;
break;
}
x0 = pts[hint->ctrl0].x;
y0 = pts[hint->ctrl0].y;
x1 = pts[hint->ctrl0 + 1].x;
y1 = pts[hint->ctrl0 + 1].y;
x2 = pts[hint->ctrl1].x;
y2 = pts[hint->ctrl1].y;
x3 = pts[hint->ctrl1 + 1].x;
y3 = pts[hint->ctrl1 + 1].y;
if (x0 == x1 && x2 == x3) {
adjusts[i].vert = true;
adj0 = x0;
adj1 = x2;
} else if (y0 == y1 && y2 == y3) {
adjusts[i].vert = false;
adj0 = y0;
adj1 = y2;
} else {
gfree(adjusts);
adjusts = nullptr;
break;
}
if (adj0 > adj1) {
x0 = adj0;
adj0 = adj1;
adj1 = x0;
}
adjusts[i].x0a = adj0 - 0.01;
adjusts[i].x0b = adj0 + 0.01;
adjusts[i].xma = (SplashCoord)0.5 * (adj0 + adj1) - 0.01;
adjusts[i].xmb = (SplashCoord)0.5 * (adj0 + adj1) + 0.01;
adjusts[i].x1a = adj1 - 0.01;
adjusts[i].x1b = adj1 + 0.01;
// rounding both edge coordinates can result in lines of
// different widths (e.g., adj=10.1, adj1=11.3 --> x0=10, x1=11;
// adj0=10.4, adj1=11.6 --> x0=10, x1=12), but it has the
// benefit of making adjacent strokes/fills line up without any
// gaps between them
x0 = splashRound(adj0);
x1 = splashRound(adj1);
if (x1 == x0) {
if (adjustLines) {
// the adjustment moves thin lines (clip rectangle with
// empty width or height) out of clip area, here we need
// a special adjustment:
x0 = linePosI;
x1 = x0 + 1;
} else {
x1 = x1 + 1;
}
}
adjusts[i].x0 = (SplashCoord)x0;
adjusts[i].x1 = (SplashCoord)x1 - 0.01;
adjusts[i].xm = (SplashCoord)0.5 * (adjusts[i].x0 + adjusts[i].x1);
adjusts[i].firstPt = hint->firstPt;
adjusts[i].lastPt = hint->lastPt;
}
}
} else {
adjusts = nullptr;
}
// perform stroke adjustment
if (adjusts) {
for (i = 0, adjust = adjusts; i < path->hintsLength; ++i, ++adjust) {
for (j = adjust->firstPt; j <= adjust->lastPt; ++j) {
strokeAdjust(adjust, &pts[j].x, &pts[j].y);
}
}
gfree(adjusts);
}
segs = nullptr;
length = size = 0;
x0 = y0 = xsp = ysp = 0; // make gcc happy
adj0 = adj1 = 0; // make gcc happy
curSubpath = 0;
i = 0;
while (i < path->length) {
// first point in subpath - skip it
if (path->flags[i] & splashPathFirst) {
x0 = pts[i].x;
y0 = pts[i].y;
xsp = x0;
ysp = y0;
curSubpath = i;
++i;
} else {
// curve segment
if (path->flags[i] & splashPathCurve) {
x1 = pts[i].x;
y1 = pts[i].y;
x2 = pts[i + 1].x;
y2 = pts[i + 1].y;
x3 = pts[i + 2].x;
y3 = pts[i + 2].y;
addCurve(x0, y0, x1, y1, x2, y2, x3, y3, flatness, (path->flags[i - 1] & splashPathFirst), (path->flags[i + 2] & splashPathLast),
!closeSubpaths && (path->flags[i - 1] & splashPathFirst) && !(path->flags[i - 1] & splashPathClosed), !closeSubpaths && (path->flags[i + 2] & splashPathLast) && !(path->flags[i + 2] & splashPathClosed));
x0 = x3;
y0 = y3;
i += 3;
// line segment
} else {
x1 = pts[i].x;
y1 = pts[i].y;
addSegment(x0, y0, x1, y1);
x0 = x1;
y0 = y1;
++i;
}
// close a subpath
if (closeSubpaths && (path->flags[i - 1] & splashPathLast) && (pts[i - 1].x != pts[curSubpath].x || pts[i - 1].y != pts[curSubpath].y)) {
addSegment(x0, y0, xsp, ysp);
}
}
}
gfree(pts);
}
// Apply the stroke adjust hints to point <pt>: (*<xp>, *<yp>).
void SplashXPath::strokeAdjust(SplashXPathAdjust *adjust, SplashCoord *xp, SplashCoord *yp)
{
SplashCoord x, y;
if (adjust->vert) {
x = *xp;
if (x > adjust->x0a && x < adjust->x0b) {
*xp = adjust->x0;
} else if (x > adjust->xma && x < adjust->xmb) {
*xp = adjust->xm;
} else if (x > adjust->x1a && x < adjust->x1b) {
*xp = adjust->x1;
}
} else {
y = *yp;
if (y > adjust->x0a && y < adjust->x0b) {
*yp = adjust->x0;
} else if (y > adjust->xma && y < adjust->xmb) {
*yp = adjust->xm;
} else if (y > adjust->x1a && y < adjust->x1b) {
*yp = adjust->x1;
}
}
}
SplashXPath::~SplashXPath()
{
gfree(segs);
}
// Add space for <nSegs> more segments
void SplashXPath::grow(int nSegs)
{
if (length + nSegs > size) {
if (size == 0) {
size = 32;
}
while (size < length + nSegs) {
size *= 2;
}
segs = (SplashXPathSeg *)greallocn_checkoverflow(segs, size, sizeof(SplashXPathSeg));
if (unlikely(!segs)) {
length = 0;
size = 0;
}
}
}
void SplashXPath::addCurve(SplashCoord x0, SplashCoord y0, SplashCoord x1, SplashCoord y1, SplashCoord x2, SplashCoord y2, SplashCoord x3, SplashCoord y3, SplashCoord flatness, bool first, bool last, bool end0, bool end1)
{
SplashCoord *cx = new SplashCoord[(splashMaxCurveSplits + 1) * 3];
SplashCoord *cy = new SplashCoord[(splashMaxCurveSplits + 1) * 3];
int *cNext = new int[splashMaxCurveSplits + 1];
SplashCoord xl0, xl1, xl2, xr0, xr1, xr2, xr3, xx1, xx2, xh;
SplashCoord yl0, yl1, yl2, yr0, yr1, yr2, yr3, yy1, yy2, yh;
SplashCoord dx, dy, mx, my, d1, d2, flatness2;
int p1, p2, p3;
flatness2 = flatness * flatness;
// initial segment
p1 = 0;
p2 = splashMaxCurveSplits;
*(cx + p1 * 3 + 0) = x0;
*(cx + p1 * 3 + 1) = x1;
*(cx + p1 * 3 + 2) = x2;
*(cx + p2 * 3 + 0) = x3;
*(cy + p1 * 3 + 0) = y0;
*(cy + p1 * 3 + 1) = y1;
*(cy + p1 * 3 + 2) = y2;
*(cy + p2 * 3 + 0) = y3;
*(cNext + p1) = p2;
while (p1 < splashMaxCurveSplits) {
// get the next segment
xl0 = *(cx + p1 * 3 + 0);
xx1 = *(cx + p1 * 3 + 1);
xx2 = *(cx + p1 * 3 + 2);
yl0 = *(cy + p1 * 3 + 0);
yy1 = *(cy + p1 * 3 + 1);
yy2 = *(cy + p1 * 3 + 2);
p2 = *(cNext + p1);
xr3 = *(cx + p2 * 3 + 0);
yr3 = *(cy + p2 * 3 + 0);
// compute the distances from the control points to the
// midpoint of the straight line (this is a bit of a hack, but
// it's much faster than computing the actual distances to the
// line)
mx = (xl0 + xr3) * 0.5;
my = (yl0 + yr3) * 0.5;
dx = xx1 - mx;
dy = yy1 - my;
d1 = dx * dx + dy * dy;
dx = xx2 - mx;
dy = yy2 - my;
d2 = dx * dx + dy * dy;
// if the curve is flat enough, or no more subdivisions are
// allowed, add the straight line segment
if (p2 - p1 == 1 || (d1 <= flatness2 && d2 <= flatness2)) {
addSegment(xl0, yl0, xr3, yr3);
p1 = p2;
// otherwise, subdivide the curve
} else {
xl1 = (xl0 + xx1) * 0.5;
yl1 = (yl0 + yy1) * 0.5;
xh = (xx1 + xx2) * 0.5;
yh = (yy1 + yy2) * 0.5;
xl2 = (xl1 + xh) * 0.5;
yl2 = (yl1 + yh) * 0.5;
xr2 = (xx2 + xr3) * 0.5;
yr2 = (yy2 + yr3) * 0.5;
xr1 = (xh + xr2) * 0.5;
yr1 = (yh + yr2) * 0.5;
xr0 = (xl2 + xr1) * 0.5;
yr0 = (yl2 + yr1) * 0.5;
// add the new subdivision points
p3 = (p1 + p2) / 2;
*(cx + p1 * 3 + 1) = xl1;
*(cx + p1 * 3 + 2) = xl2;
*(cy + p1 * 3 + 1) = yl1;
*(cy + p1 * 3 + 2) = yl2;
*(cNext + p1) = p3;
*(cx + p3 * 3 + 0) = xr0;
*(cx + p3 * 3 + 1) = xr1;
*(cx + p3 * 3 + 2) = xr2;
*(cy + p3 * 3 + 0) = yr0;
*(cy + p3 * 3 + 1) = yr1;
*(cy + p3 * 3 + 2) = yr2;
*(cNext + p3) = p2;
}
}
delete[] cx;
delete[] cy;
delete[] cNext;
}
void SplashXPath::addSegment(SplashCoord x0, SplashCoord y0, SplashCoord x1, SplashCoord y1)
{
grow(1);
if (unlikely(!segs)) {
return;
}
segs[length].x0 = x0;
segs[length].y0 = y0;
segs[length].x1 = x1;
segs[length].y1 = y1;
segs[length].flags = 0;
if (y1 == y0) {
segs[length].dxdy = segs[length].dydx = 0;
segs[length].flags |= splashXPathHoriz;
if (x1 == x0) {
segs[length].flags |= splashXPathVert;
}
} else if (x1 == x0) {
segs[length].dxdy = segs[length].dydx = 0;
segs[length].flags |= splashXPathVert;
} else {
segs[length].dxdy = (x1 - x0) / (y1 - y0);
segs[length].dydx = (SplashCoord)1 / segs[length].dxdy;
}
if (y0 > y1) {
segs[length].flags |= splashXPathFlip;
}
++length;
}
struct cmpXPathSegsFunctor
{
bool operator()(const SplashXPathSeg &seg0, const SplashXPathSeg &seg1)
{
SplashCoord x0, y0, x1, y1;
if (seg0.flags & splashXPathFlip) {
x0 = seg0.x1;
y0 = seg0.y1;
} else {
x0 = seg0.x0;
y0 = seg0.y0;
}
if (seg1.flags & splashXPathFlip) {
x1 = seg1.x1;
y1 = seg1.y1;
} else {
x1 = seg1.x0;
y1 = seg1.y0;
}
return (y0 != y1) ? (y0 < y1) : (x0 < x1);
}
};
void SplashXPath::aaScale()
{
SplashXPathSeg *seg;
int i;
for (i = 0, seg = segs; i < length; ++i, ++seg) {
seg->x0 *= splashAASize;
seg->y0 *= splashAASize;
seg->x1 *= splashAASize;
seg->y1 *= splashAASize;
}
}
void SplashXPath::sort()
{
std::sort(segs, segs + length, cmpXPathSegsFunctor());
}