skia2/tests/PathOpsTestCommon.cpp
Ben Wagner f08d1d0ce1 Stop using SkTSwap.
Use std::swap instead. It does not appear that any external user
specializes SkTSwap, but some may still use it. This removes all use in
Skia so that SkTSwap can later be removed in a smaller CL. After that
the <utility> include can be removed from SkTypes.h.

Change-Id: If03d4ee07dbecda961aa9f0dc34d171ef5168753
Reviewed-on: https://skia-review.googlesource.com/135578
Reviewed-by: Hal Canary <halcanary@google.com>
Reviewed-by: Mike Klein <mtklein@google.com>
Commit-Queue: Ben Wagner <bungeman@google.com>
2018-06-19 02:06:31 +00:00

332 lines
10 KiB
C++

/*
* Copyright 2012 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "PathOpsTestCommon.h"
#include "SkPathOpsBounds.h"
#include "SkPathOpsConic.h"
#include "SkPathOpsCubic.h"
#include "SkPathOpsLine.h"
#include "SkPathOpsQuad.h"
#include "SkPathOpsTSect.h"
#include "SkReduceOrder.h"
#include "SkTSort.h"
#include <utility>
static double calc_t_div(const SkDCubic& cubic, double precision, double start) {
const double adjust = sqrt(3.) / 36;
SkDCubic sub;
const SkDCubic* cPtr;
if (start == 0) {
cPtr = &cubic;
} else {
// OPTIMIZE: special-case half-split ?
sub = cubic.subDivide(start, 1);
cPtr = &sub;
}
const SkDCubic& c = *cPtr;
double dx = c[3].fX - 3 * (c[2].fX - c[1].fX) - c[0].fX;
double dy = c[3].fY - 3 * (c[2].fY - c[1].fY) - c[0].fY;
double dist = sqrt(dx * dx + dy * dy);
double tDiv3 = precision / (adjust * dist);
double t = SkDCubeRoot(tDiv3);
if (start > 0) {
t = start + (1 - start) * t;
}
return t;
}
static bool add_simple_ts(const SkDCubic& cubic, double precision, SkTArray<double, true>* ts) {
double tDiv = calc_t_div(cubic, precision, 0);
if (tDiv >= 1) {
return true;
}
if (tDiv >= 0.5) {
ts->push_back(0.5);
return true;
}
return false;
}
static void addTs(const SkDCubic& cubic, double precision, double start, double end,
SkTArray<double, true>* ts) {
double tDiv = calc_t_div(cubic, precision, 0);
double parts = ceil(1.0 / tDiv);
for (double index = 0; index < parts; ++index) {
double newT = start + (index / parts) * (end - start);
if (newT > 0 && newT < 1) {
ts->push_back(newT);
}
}
}
static void toQuadraticTs(const SkDCubic* cubic, double precision, SkTArray<double, true>* ts) {
SkReduceOrder reducer;
int order = reducer.reduce(*cubic, SkReduceOrder::kAllow_Quadratics);
if (order < 3) {
return;
}
double inflectT[5];
int inflections = cubic->findInflections(inflectT);
SkASSERT(inflections <= 2);
if (!cubic->endsAreExtremaInXOrY()) {
inflections += cubic->findMaxCurvature(&inflectT[inflections]);
SkASSERT(inflections <= 5);
}
SkTQSort<double>(inflectT, &inflectT[inflections - 1]);
// OPTIMIZATION: is this filtering common enough that it needs to be pulled out into its
// own subroutine?
while (inflections && approximately_less_than_zero(inflectT[0])) {
memmove(inflectT, &inflectT[1], sizeof(inflectT[0]) * --inflections);
}
int start = 0;
int next = 1;
while (next < inflections) {
if (!approximately_equal(inflectT[start], inflectT[next])) {
++start;
++next;
continue;
}
memmove(&inflectT[start], &inflectT[next], sizeof(inflectT[0]) * (--inflections - start));
}
while (inflections && approximately_greater_than_one(inflectT[inflections - 1])) {
--inflections;
}
SkDCubicPair pair;
if (inflections == 1) {
pair = cubic->chopAt(inflectT[0]);
int orderP1 = reducer.reduce(pair.first(), SkReduceOrder::kNo_Quadratics);
if (orderP1 < 2) {
--inflections;
} else {
int orderP2 = reducer.reduce(pair.second(), SkReduceOrder::kNo_Quadratics);
if (orderP2 < 2) {
--inflections;
}
}
}
if (inflections == 0 && add_simple_ts(*cubic, precision, ts)) {
return;
}
if (inflections == 1) {
pair = cubic->chopAt(inflectT[0]);
addTs(pair.first(), precision, 0, inflectT[0], ts);
addTs(pair.second(), precision, inflectT[0], 1, ts);
return;
}
if (inflections > 1) {
SkDCubic part = cubic->subDivide(0, inflectT[0]);
addTs(part, precision, 0, inflectT[0], ts);
int last = inflections - 1;
for (int idx = 0; idx < last; ++idx) {
part = cubic->subDivide(inflectT[idx], inflectT[idx + 1]);
addTs(part, precision, inflectT[idx], inflectT[idx + 1], ts);
}
part = cubic->subDivide(inflectT[last], 1);
addTs(part, precision, inflectT[last], 1, ts);
return;
}
addTs(*cubic, precision, 0, 1, ts);
}
void CubicToQuads(const SkDCubic& cubic, double precision, SkTArray<SkDQuad, true>& quads) {
SkTArray<double, true> ts;
toQuadraticTs(&cubic, precision, &ts);
if (ts.count() <= 0) {
SkDQuad quad = cubic.toQuad();
quads.push_back(quad);
return;
}
double tStart = 0;
for (int i1 = 0; i1 <= ts.count(); ++i1) {
const double tEnd = i1 < ts.count() ? ts[i1] : 1;
SkDRect bounds;
bounds.setBounds(cubic);
SkDCubic part = cubic.subDivide(tStart, tEnd);
SkDQuad quad = part.toQuad();
if (quad[1].fX < bounds.fLeft) {
quad[1].fX = bounds.fLeft;
} else if (quad[1].fX > bounds.fRight) {
quad[1].fX = bounds.fRight;
}
if (quad[1].fY < bounds.fTop) {
quad[1].fY = bounds.fTop;
} else if (quad[1].fY > bounds.fBottom) {
quad[1].fY = bounds.fBottom;
}
quads.push_back(quad);
tStart = tEnd;
}
}
void CubicPathToQuads(const SkPath& cubicPath, SkPath* quadPath) {
quadPath->reset();
SkDCubic cubic;
SkTArray<SkDQuad, true> quads;
SkPath::RawIter iter(cubicPath);
uint8_t verb;
SkPoint pts[4];
while ((verb = iter.next(pts)) != SkPath::kDone_Verb) {
switch (verb) {
case SkPath::kMove_Verb:
quadPath->moveTo(pts[0].fX, pts[0].fY);
continue;
case SkPath::kLine_Verb:
quadPath->lineTo(pts[1].fX, pts[1].fY);
break;
case SkPath::kQuad_Verb:
quadPath->quadTo(pts[1].fX, pts[1].fY, pts[2].fX, pts[2].fY);
break;
case SkPath::kCubic_Verb:
quads.reset();
cubic.set(pts);
CubicToQuads(cubic, cubic.calcPrecision(), quads);
for (int index = 0; index < quads.count(); ++index) {
SkPoint qPts[2] = {
quads[index][1].asSkPoint(),
quads[index][2].asSkPoint()
};
quadPath->quadTo(qPts[0].fX, qPts[0].fY, qPts[1].fX, qPts[1].fY);
}
break;
case SkPath::kClose_Verb:
quadPath->close();
break;
default:
SkDEBUGFAIL("bad verb");
return;
}
}
}
void CubicPathToSimple(const SkPath& cubicPath, SkPath* simplePath) {
simplePath->reset();
SkDCubic cubic;
SkPath::RawIter iter(cubicPath);
uint8_t verb;
SkPoint pts[4];
while ((verb = iter.next(pts)) != SkPath::kDone_Verb) {
switch (verb) {
case SkPath::kMove_Verb:
simplePath->moveTo(pts[0].fX, pts[0].fY);
continue;
case SkPath::kLine_Verb:
simplePath->lineTo(pts[1].fX, pts[1].fY);
break;
case SkPath::kQuad_Verb:
simplePath->quadTo(pts[1].fX, pts[1].fY, pts[2].fX, pts[2].fY);
break;
case SkPath::kCubic_Verb: {
cubic.set(pts);
double tInflects[2];
int inflections = cubic.findInflections(tInflects);
if (inflections > 1 && tInflects[0] > tInflects[1]) {
using std::swap;
swap(tInflects[0], tInflects[1]);
}
double lo = 0;
for (int index = 0; index <= inflections; ++index) {
double hi = index < inflections ? tInflects[index] : 1;
SkDCubic part = cubic.subDivide(lo, hi);
SkPoint cPts[3];
cPts[0] = part[1].asSkPoint();
cPts[1] = part[2].asSkPoint();
cPts[2] = part[3].asSkPoint();
simplePath->cubicTo(cPts[0].fX, cPts[0].fY, cPts[1].fX, cPts[1].fY,
cPts[2].fX, cPts[2].fY);
lo = hi;
}
break;
}
case SkPath::kClose_Verb:
simplePath->close();
break;
default:
SkDEBUGFAIL("bad verb");
return;
}
}
}
bool ValidBounds(const SkPathOpsBounds& bounds) {
if (SkScalarIsNaN(bounds.fLeft)) {
return false;
}
if (SkScalarIsNaN(bounds.fTop)) {
return false;
}
if (SkScalarIsNaN(bounds.fRight)) {
return false;
}
return !SkScalarIsNaN(bounds.fBottom);
}
bool ValidConic(const SkDConic& conic) {
for (int index = 0; index < SkDConic::kPointCount; ++index) {
if (!ValidPoint(conic[index])) {
return false;
}
}
if (SkDoubleIsNaN(conic.fWeight)) {
return false;
}
return true;
}
bool ValidCubic(const SkDCubic& cubic) {
for (int index = 0; index < 4; ++index) {
if (!ValidPoint(cubic[index])) {
return false;
}
}
return true;
}
bool ValidLine(const SkDLine& line) {
for (int index = 0; index < 2; ++index) {
if (!ValidPoint(line[index])) {
return false;
}
}
return true;
}
bool ValidPoint(const SkDPoint& pt) {
if (SkDoubleIsNaN(pt.fX)) {
return false;
}
return !SkDoubleIsNaN(pt.fY);
}
bool ValidPoints(const SkPoint* pts, int count) {
for (int index = 0; index < count; ++index) {
if (SkScalarIsNaN(pts[index].fX)) {
return false;
}
if (SkScalarIsNaN(pts[index].fY)) {
return false;
}
}
return true;
}
bool ValidQuad(const SkDQuad& quad) {
for (int index = 0; index < 3; ++index) {
if (!ValidPoint(quad[index])) {
return false;
}
}
return true;
}
bool ValidVector(const SkDVector& v) {
if (SkDoubleIsNaN(v.fX)) {
return false;
}
return !SkDoubleIsNaN(v.fY);
}