michael@0: /*
michael@0:  * Copyright 2012 Google Inc.
michael@0:  *
michael@0:  * Use of this source code is governed by a BSD-style license that can be
michael@0:  * found in the LICENSE file.
michael@0:  */
michael@0: #include "SkPathOpsPoint.h"
michael@0: #include "SkPathWriter.h"
michael@0: 
michael@0: // wrap path to keep track of whether the contour is initialized and non-empty
michael@0: SkPathWriter::SkPathWriter(SkPath& path)
michael@0:     : fPathPtr(&path)
michael@0:     , fCloses(0)
michael@0:     , fMoves(0)
michael@0: {
michael@0:     init();
michael@0: }
michael@0: 
michael@0: void SkPathWriter::close() {
michael@0:     if (!fHasMove) {
michael@0:         return;
michael@0:     }
michael@0:     bool callClose = isClosed();
michael@0:     lineTo();
michael@0:     if (fEmpty) {
michael@0:         return;
michael@0:     }
michael@0:     if (callClose) {
michael@0: #if DEBUG_PATH_CONSTRUCTION
michael@0:         SkDebugf("path.close();\n");
michael@0: #endif
michael@0:         fPathPtr->close();
michael@0:         fCloses++;
michael@0:     }
michael@0:     init();
michael@0: }
michael@0: 
michael@0: void SkPathWriter::cubicTo(const SkPoint& pt1, const SkPoint& pt2, const SkPoint& pt3) {
michael@0:     lineTo();
michael@0:     if (fEmpty && AlmostEqualUlps(fDefer[0], pt1) && AlmostEqualUlps(pt1, pt2)
michael@0:             && AlmostEqualUlps(pt2, pt3)) {
michael@0:         deferredLine(pt3);
michael@0:         return;
michael@0:     }
michael@0:     moveTo();
michael@0:     fDefer[1] = pt3;
michael@0:     nudge();
michael@0:     fDefer[0] = fDefer[1];
michael@0: #if DEBUG_PATH_CONSTRUCTION
michael@0:     SkDebugf("path.cubicTo(%1.9g,%1.9g, %1.9g,%1.9g, %1.9g,%1.9g);\n",
michael@0:             pt1.fX, pt1.fY, pt2.fX, pt2.fY, fDefer[1].fX, fDefer[1].fY);
michael@0: #endif
michael@0:     fPathPtr->cubicTo(pt1.fX, pt1.fY, pt2.fX, pt2.fY, fDefer[1].fX, fDefer[1].fY);
michael@0:     fEmpty = false;
michael@0: }
michael@0: 
michael@0: void SkPathWriter::deferredLine(const SkPoint& pt) {
michael@0:     if (pt == fDefer[1]) {
michael@0:         return;
michael@0:     }
michael@0:     if (changedSlopes(pt)) {
michael@0:         lineTo();
michael@0:         fDefer[0] = fDefer[1];
michael@0:     }
michael@0:     fDefer[1] = pt;
michael@0: }
michael@0: 
michael@0: void SkPathWriter::deferredMove(const SkPoint& pt) {
michael@0:     fMoved = true;
michael@0:     fHasMove = true;
michael@0:     fEmpty = true;
michael@0:     fDefer[0] = fDefer[1] = pt;
michael@0: }
michael@0: 
michael@0: void SkPathWriter::deferredMoveLine(const SkPoint& pt) {
michael@0:     if (!fHasMove) {
michael@0:         deferredMove(pt);
michael@0:     }
michael@0:     deferredLine(pt);
michael@0: }
michael@0: 
michael@0: bool SkPathWriter::hasMove() const {
michael@0:     return fHasMove;
michael@0: }
michael@0: 
michael@0: void SkPathWriter::init() {
michael@0:     fEmpty = true;
michael@0:     fHasMove = false;
michael@0:     fMoved = false;
michael@0: }
michael@0: 
michael@0: bool SkPathWriter::isClosed() const {
michael@0:     return !fEmpty && SkDPoint::ApproximatelyEqual(fFirstPt, fDefer[1]);
michael@0: }
michael@0: 
michael@0: void SkPathWriter::lineTo() {
michael@0:     if (fDefer[0] == fDefer[1]) {
michael@0:         return;
michael@0:     }
michael@0:     moveTo();
michael@0:     nudge();
michael@0:     fEmpty = false;
michael@0: #if DEBUG_PATH_CONSTRUCTION
michael@0:     SkDebugf("path.lineTo(%1.9g,%1.9g);\n", fDefer[1].fX, fDefer[1].fY);
michael@0: #endif
michael@0:     fPathPtr->lineTo(fDefer[1].fX, fDefer[1].fY);
michael@0:     fDefer[0] = fDefer[1];
michael@0: }
michael@0: 
michael@0: const SkPath* SkPathWriter::nativePath() const {
michael@0:     return fPathPtr;
michael@0: }
michael@0: 
michael@0: void SkPathWriter::nudge() {
michael@0:     if (fEmpty || !AlmostEqualUlps(fDefer[1].fX, fFirstPt.fX)
michael@0:             || !AlmostEqualUlps(fDefer[1].fY, fFirstPt.fY)) {
michael@0:         return;
michael@0:     }
michael@0:     fDefer[1] = fFirstPt;
michael@0: }
michael@0: 
michael@0: void SkPathWriter::quadTo(const SkPoint& pt1, const SkPoint& pt2) {
michael@0:     lineTo();
michael@0:     if (fEmpty && AlmostEqualUlps(fDefer[0], pt1) && AlmostEqualUlps(pt1, pt2)) {
michael@0:         deferredLine(pt2);
michael@0:         return;
michael@0:     }
michael@0:     moveTo();
michael@0:     fDefer[1] = pt2;
michael@0:     nudge();
michael@0:     fDefer[0] = fDefer[1];
michael@0: #if DEBUG_PATH_CONSTRUCTION
michael@0:     SkDebugf("path.quadTo(%1.9g,%1.9g, %1.9g,%1.9g);\n",
michael@0:             pt1.fX, pt1.fY, fDefer[1].fX, fDefer[1].fY);
michael@0: #endif
michael@0:     fPathPtr->quadTo(pt1.fX, pt1.fY, fDefer[1].fX, fDefer[1].fY);
michael@0:     fEmpty = false;
michael@0: }
michael@0: 
michael@0: bool SkPathWriter::someAssemblyRequired() const {
michael@0:     return fCloses < fMoves;
michael@0: }
michael@0: 
michael@0: bool SkPathWriter::changedSlopes(const SkPoint& pt) const {
michael@0:     if (fDefer[0] == fDefer[1]) {
michael@0:         return false;
michael@0:     }
michael@0:     SkScalar deferDx = fDefer[1].fX - fDefer[0].fX;
michael@0:     SkScalar deferDy = fDefer[1].fY - fDefer[0].fY;
michael@0:     SkScalar lineDx = pt.fX - fDefer[1].fX;
michael@0:     SkScalar lineDy = pt.fY - fDefer[1].fY;
michael@0:     return deferDx * lineDy != deferDy * lineDx;
michael@0: }
michael@0: 
michael@0: void SkPathWriter::moveTo() {
michael@0:     if (!fMoved) {
michael@0:         return;
michael@0:     }
michael@0:     fFirstPt = fDefer[0];
michael@0: #if DEBUG_PATH_CONSTRUCTION
michael@0:     SkDebugf("path.moveTo(%1.9g,%1.9g);\n", fDefer[0].fX, fDefer[0].fY);
michael@0: #endif
michael@0:     fPathPtr->moveTo(fDefer[0].fX, fDefer[0].fY);
michael@0:     fMoved = false;
michael@0:     fMoves++;
michael@0: }