/* * Copyright 2011 Google Inc. * * Use of this source code is governed by a BSD-style license that can be * found in the LICENSE file. */ #include "SampleCode.h" #include "SkAnimTimer.h" #include "SkView.h" #include "SkBitmap.h" #include "SkCanvas.h" #include "SkGradientShader.h" #include "SkGraphics.h" #include "SkPath.h" #include "SkRegion.h" #include "SkShader.h" #include "SkUtils.h" #include "SkColorPriv.h" #include "SkColorFilter.h" #include "SkParsePath.h" #include "SkTime.h" #include "SkTypeface.h" #include "SkGeometry.h" #include // http://code.google.com/p/skia/issues/detail?id=32 static void test_cubic() { SkPoint src[4] = { { 556.25000f, 523.03003f }, { 556.23999f, 522.96002f }, { 556.21997f, 522.89001f }, { 556.21997f, 522.82001f } }; SkPoint dst[11]; dst[10].set(42, -42); // one past the end, that we don't clobber these SkScalar tval[] = { 0.33333334f, 0.99999994f }; SkChopCubicAt(src, dst, tval, 2); #if 0 for (int i = 0; i < 11; i++) { SkDebugf("--- %d [%g %g]\n", i, dst[i].fX, dst[i].fY); } #endif } static void test_cubic2() { const char* str = "M2242 -590088L-377758 9.94099e+07L-377758 9.94099e+07L2242 -590088Z"; SkPath path; SkParsePath::FromSVGString(str, &path); { SkRect r = path.getBounds(); SkIRect ir; r.round(&ir); SkDebugf("[%g %g %g %g] [%x %x %x %x]\n", SkScalarToDouble(r.fLeft), SkScalarToDouble(r.fTop), SkScalarToDouble(r.fRight), SkScalarToDouble(r.fBottom), ir.fLeft, ir.fTop, ir.fRight, ir.fBottom); } SkBitmap bitmap; bitmap.allocN32Pixels(300, 200); SkCanvas canvas(bitmap); SkPaint paint; paint.setAntiAlias(true); canvas.drawPath(path, paint); } class PathView : public SampleView { SkScalar fPrevSecs; public: SkScalar fDStroke, fStroke, fMinStroke, fMaxStroke; SkPath fPath[6]; bool fShowHairline; bool fOnce; PathView() { fPrevSecs = 0; fOnce = false; } void init() { if (fOnce) { return; } fOnce = true; test_cubic(); test_cubic2(); fShowHairline = false; fDStroke = 1; fStroke = 10; fMinStroke = 10; fMaxStroke = 180; const SkScalar V = 85; fPath[0].moveTo(40, 70); fPath[0].lineTo(70, 70 + SK_ScalarHalf); fPath[0].lineTo(110, 70); fPath[1].moveTo(40, 70); fPath[1].lineTo(70, 70 - SK_ScalarHalf); fPath[1].lineTo(110, 70); fPath[2].moveTo(V, V); fPath[2].lineTo(50, V); fPath[2].lineTo(50, 50); fPath[3].moveTo(50, 50); fPath[3].lineTo(50, V); fPath[3].lineTo(V, V); fPath[4].moveTo(50, 50); fPath[4].lineTo(50, V); fPath[4].lineTo(52, 50); fPath[5].moveTo(52, 50); fPath[5].lineTo(50, V); fPath[5].lineTo(50, 50); this->setBGColor(0xFFDDDDDD); } protected: // overrides from SkEventSink bool onQuery(SkEvent* evt) override { if (SampleCode::TitleQ(*evt)) { SampleCode::TitleR(evt, "Paths"); return true; } return this->INHERITED::onQuery(evt); } void drawPath(SkCanvas* canvas, const SkPath& path, SkPaint::Join j) { SkPaint paint; paint.setAntiAlias(true); paint.setStyle(SkPaint::kStroke_Style); paint.setStrokeJoin(j); paint.setStrokeWidth(fStroke); if (fShowHairline) { SkPath fill; paint.getFillPath(path, &fill); paint.setStrokeWidth(0); canvas->drawPath(fill, paint); } else { canvas->drawPath(path, paint); } paint.setColor(SK_ColorRED); paint.setStrokeWidth(0); canvas->drawPath(path, paint); } void onDrawContent(SkCanvas* canvas) override { this->init(); canvas->translate(50, 50); static const SkPaint::Join gJoins[] = { SkPaint::kBevel_Join, SkPaint::kMiter_Join, SkPaint::kRound_Join }; for (size_t i = 0; i < SK_ARRAY_COUNT(gJoins); i++) { canvas->save(); for (size_t j = 0; j < SK_ARRAY_COUNT(fPath); j++) { this->drawPath(canvas, fPath[j], gJoins[i]); canvas->translate(200, 0); } canvas->restore(); canvas->translate(0, 200); } } bool onAnimate(const SkAnimTimer& timer) override { SkScalar currSecs = timer.scaled(100); SkScalar delta = currSecs - fPrevSecs; fPrevSecs = currSecs; fStroke += fDStroke * delta; if (fStroke > fMaxStroke || fStroke < fMinStroke) { fDStroke = -fDStroke; } return true; } SkView::Click* onFindClickHandler(SkScalar x, SkScalar y, unsigned modi) override { fShowHairline = !fShowHairline; return this->INHERITED::onFindClickHandler(x, y, modi); } private: typedef SampleView INHERITED; }; DEF_SAMPLE( return new PathView; ) ////////////////////////////////////////////////////////////////////////////// #include "SkCornerPathEffect.h" #include "SkRandom.h" class ArcToView : public SampleView { bool fDoFrame, fDoCorner, fDoConic; SkPaint fPtsPaint, fSkeletonPaint, fCornerPaint; public: enum { N = 4 }; SkPoint fPts[N]; ArcToView() : fDoFrame(false), fDoCorner(false), fDoConic(false) { SkRandom rand; for (int i = 0; i < N; ++i) { fPts[i].fX = 20 + rand.nextUScalar1() * 640; fPts[i].fY = 20 + rand.nextUScalar1() * 480; } const SkScalar rad = 50; fPtsPaint.setAntiAlias(true); fPtsPaint.setStrokeWidth(15); fPtsPaint.setStrokeCap(SkPaint::kRound_Cap); fCornerPaint.setAntiAlias(true); fCornerPaint.setStyle(SkPaint::kStroke_Style); fCornerPaint.setStrokeWidth(13); fCornerPaint.setColor(SK_ColorGREEN); fCornerPaint.setPathEffect(SkCornerPathEffect::Make(rad*2)); fSkeletonPaint.setAntiAlias(true); fSkeletonPaint.setStyle(SkPaint::kStroke_Style); fSkeletonPaint.setColor(SK_ColorRED); } void toggle(bool& value) { value = !value; } protected: // overrides from SkEventSink bool onQuery(SkEvent* evt) override { if (SampleCode::TitleQ(*evt)) { SampleCode::TitleR(evt, "ArcTo"); return true; } SkUnichar uni; if (SampleCode::CharQ(*evt, &uni)) { switch (uni) { case '1': this->toggle(fDoFrame); return true; case '2': this->toggle(fDoCorner); return true; case '3': this->toggle(fDoConic); return true; default: break; } } return this->INHERITED::onQuery(evt); } void makePath(SkPath* path) { path->moveTo(fPts[0]); for (int i = 1; i < N; ++i) { path->lineTo(fPts[i]); } if (!fDoFrame) { path->close(); } } void onDrawContent(SkCanvas* canvas) override { canvas->drawPoints(SkCanvas::kPoints_PointMode, N, fPts, fPtsPaint); SkPath path; this->makePath(&path); if (fDoCorner) { canvas->drawPath(path, fCornerPaint); } canvas->drawPath(path, fSkeletonPaint); } bool onClick(Click* click) override { int32_t index; if (click->fMeta.findS32("index", &index)) { SkASSERT((unsigned)index < N); fPts[index] = click->fCurr; return true; } return false; } SkView::Click* onFindClickHandler(SkScalar x, SkScalar y, unsigned modi) override { const SkScalar tol = 4; const SkRect r = SkRect::MakeXYWH(x - tol, y - tol, tol * 2, tol * 2); for (int i = 0; i < N; ++i) { if (r.intersects(SkRect::MakeXYWH(fPts[i].fX, fPts[i].fY, 1, 1))) { Click* click = new Click(this); click->fMeta.setS32("index", i); return click; } } return this->INHERITED::onFindClickHandler(x, y, modi); } private: typedef SampleView INHERITED; }; DEF_SAMPLE( return new ArcToView; ) ///////////// class FatStroke : public SampleView { bool fClosed, fShowStroke, fShowHidden, fShowSkeleton; int fJoinType, fCapType; float fWidth = 30; SkPaint fPtsPaint, fHiddenPaint, fSkeletonPaint, fStrokePaint; public: enum { N = 4 }; SkPoint fPts[N]; FatStroke() : fClosed(false), fShowStroke(true), fShowHidden(false), fShowSkeleton(true), fJoinType(0), fCapType(0) { SkRandom rand; for (int i = 0; i < N; ++i) { fPts[i].fX = 20 + rand.nextUScalar1() * 640; fPts[i].fY = 20 + rand.nextUScalar1() * 480; } fPtsPaint.setAntiAlias(true); fPtsPaint.setStrokeWidth(10); fPtsPaint.setStrokeCap(SkPaint::kRound_Cap); fHiddenPaint.setAntiAlias(true); fHiddenPaint.setStyle(SkPaint::kStroke_Style); fHiddenPaint.setColor(0xFF0000FF); fStrokePaint.setAntiAlias(true); fStrokePaint.setStyle(SkPaint::kStroke_Style); fStrokePaint.setStrokeWidth(50); fStrokePaint.setColor(0x8000FF00); fSkeletonPaint.setAntiAlias(true); fSkeletonPaint.setStyle(SkPaint::kStroke_Style); fSkeletonPaint.setColor(SK_ColorRED); } void toggle(bool& value) { value = !value; } void toggle3(int& value) { value = (value + 1) % 3; } protected: // overrides from SkEventSink bool onQuery(SkEvent* evt) override { if (SampleCode::TitleQ(*evt)) { SampleCode::TitleR(evt, "FatStroke"); return true; } SkUnichar uni; if (SampleCode::CharQ(*evt, &uni)) { switch (uni) { case '1': this->toggle(fShowSkeleton); return true; case '2': this->toggle(fShowStroke); return true; case '3': this->toggle(fShowHidden); return true; case '4': this->toggle3(fJoinType); return true; case '5': this->toggle3(fCapType); return true; case '6': this->toggle(fClosed); return true; case '-': fWidth -= 5; return true; case '=': fWidth += 5; return true; default: break; } } return this->INHERITED::onQuery(evt); } void makePath(SkPath* path) { path->moveTo(fPts[0]); for (int i = 1; i < N; ++i) { path->lineTo(fPts[i]); } if (fClosed) { path->close(); } } void onDrawContent(SkCanvas* canvas) override { canvas->drawColor(0xFFEEEEEE); SkPath path; this->makePath(&path); fStrokePaint.setStrokeWidth(fWidth); fStrokePaint.setStrokeJoin((SkPaint::Join)fJoinType); fStrokePaint.setStrokeCap((SkPaint::Cap)fCapType); if (fShowStroke) { canvas->drawPath(path, fStrokePaint); } if (fShowHidden) { SkPath hidden; fStrokePaint.getFillPath(path, &hidden); canvas->drawPath(hidden, fHiddenPaint); } if (fShowSkeleton) { canvas->drawPath(path, fSkeletonPaint); } canvas->drawPoints(SkCanvas::kPoints_PointMode, N, fPts, fPtsPaint); } bool onClick(Click* click) override { int32_t index; if (click->fMeta.findS32("index", &index)) { SkASSERT((unsigned)index < N); fPts[index] = click->fCurr; return true; } return false; } SkView::Click* onFindClickHandler(SkScalar x, SkScalar y, unsigned modi) override { const SkScalar tol = 4; const SkRect r = SkRect::MakeXYWH(x - tol, y - tol, tol * 2, tol * 2); for (int i = 0; i < N; ++i) { if (r.intersects(SkRect::MakeXYWH(fPts[i].fX, fPts[i].fY, 1, 1))) { Click* click = new Click(this); click->fMeta.setS32("index", i); return click; } } return this->INHERITED::onFindClickHandler(x, y, modi); } private: typedef SampleView INHERITED; }; DEF_SAMPLE( return new FatStroke; ) static int compute_parallel_to_base(const SkPoint pts[4], SkScalar t[2]) { // F = At^3 + Bt^2 + Ct + D SkVector A = pts[3] - pts[0] + (pts[1] - pts[2]) * 3.0f; SkVector B = (pts[0] - pts[1] - pts[1] + pts[2]) * 3.0f; SkVector C = (pts[1] - pts[0]) * 3.0f; SkVector DA = pts[3] - pts[0]; // F' = 3At^2 + 2Bt + C SkScalar a = 3 * A.cross(DA); SkScalar b = 2 * B.cross(DA); SkScalar c = C.cross(DA); int n = SkFindUnitQuadRoots(a, b, c, t); SkString str; for (int i = 0; i < n; ++i) { str.appendf(" %g", t[i]); } SkDebugf("roots %s\n", str.c_str()); return n; } class CubicCurve : public SampleView { public: enum { N = 4 }; SkPoint fPts[N]; CubicCurve() { SkRandom rand; for (int i = 0; i < N; ++i) { fPts[i].fX = 20 + rand.nextUScalar1() * 640; fPts[i].fY = 20 + rand.nextUScalar1() * 480; } } protected: bool onQuery(SkEvent* evt) override { if (SampleCode::TitleQ(*evt)) { SampleCode::TitleR(evt, "CubicCurve"); return true; } return this->INHERITED::onQuery(evt); } void onDrawContent(SkCanvas* canvas) override { SkPaint paint; paint.setAntiAlias(true); { SkPath path; path.moveTo(fPts[0]); path.cubicTo(fPts[1], fPts[2], fPts[3]); paint.setStyle(SkPaint::kStroke_Style); canvas->drawPath(path, paint); } { paint.setColor(SK_ColorRED); SkScalar t[2]; int n = compute_parallel_to_base(fPts, t); SkPoint loc; SkVector tan; for (int i = 0; i < n; ++i) { SkEvalCubicAt(fPts, t[i], &loc, &tan, nullptr); tan.setLength(30); canvas->drawLine(loc - tan, loc + tan, paint); } paint.setStrokeWidth(0.5f); canvas->drawLine(fPts[0], fPts[3], paint); paint.setColor(SK_ColorBLUE); paint.setStrokeWidth(6); SkEvalCubicAt(fPts, 0.5f, &loc, nullptr, nullptr); canvas->drawPoint(loc, paint); paint.setColor(0xFF008800); SkEvalCubicAt(fPts, 1.0f/3, &loc, nullptr, nullptr); canvas->drawPoint(loc, paint); SkEvalCubicAt(fPts, 2.0f/3, &loc, nullptr, nullptr); canvas->drawPoint(loc, paint); // n = SkFindCubicInflections(fPts, t); // printf("inflections %d %g %g\n", n, t[0], t[1]); } { paint.setStyle(SkPaint::kFill_Style); paint.setColor(SK_ColorRED); for (SkPoint p : fPts) { canvas->drawCircle(p.fX, p.fY, 8, paint); } } } bool onClick(Click* click) override { int32_t index; if (click->fMeta.findS32("index", &index)) { SkASSERT((unsigned)index < N); fPts[index] = click->fCurr; return true; } return false; } SkView::Click* onFindClickHandler(SkScalar x, SkScalar y, unsigned modi) override { const SkScalar tol = 8; const SkRect r = SkRect::MakeXYWH(x - tol, y - tol, tol * 2, tol * 2); for (int i = 0; i < N; ++i) { if (r.intersects(SkRect::MakeXYWH(fPts[i].fX, fPts[i].fY, 1, 1))) { Click* click = new Click(this); click->fMeta.setS32("index", i); return click; } } return this->INHERITED::onFindClickHandler(x, y, modi); } private: typedef SampleView INHERITED; }; DEF_SAMPLE( return new CubicCurve; ) static SkPoint lerp(SkPoint a, SkPoint b, float t) { return a * (1 - t) + b * t; } static int find_max_deviation_cubic(const SkPoint src[4], SkScalar ts[2]) { // deviation = F' x (d - a) == 0, solve for t(s) // F = At^3 + Bt^2 + Ct + D // F' = 3At^2 + 2Bt + C // Z = d - a // F' x Z = 3(A x Z)t^2 + 2(B x Z)t + (C x Z) // SkVector A = src[3] + (src[1] - src[2]) * 3 - src[0]; SkVector B = (src[2] - src[1] - src[1] + src[0]) * 3; SkVector C = (src[1] - src[0]) * 3; SkVector Z = src[3] - src[0]; // now forumlate the quadratic coefficients we need to solve for t : F' x Z return SkFindUnitQuadRoots(3 * A.cross(Z), 2 * B.cross(Z), C.cross(Z), ts); } class CubicCurve2 : public SampleView { public: enum { N = 7 }; SkPoint fPts[N]; SkPoint* fQuad = fPts + 4; SkScalar fT = 0.5f; bool fShowSub = false; bool fShowFlatness = false; SkScalar fScale = 0.75; CubicCurve2() { fPts[0] = { 90, 300 }; fPts[1] = { 30, 60 }; fPts[2] = { 250, 30 }; fPts[3] = { 350, 200 }; fQuad[0] = fPts[0] + SkVector{ 300, 0}; fQuad[1] = fPts[1] + SkVector{ 300, 0}; fQuad[2] = fPts[2] + SkVector{ 300, 0}; } protected: bool onQuery(SkEvent* evt) override { if (SampleCode::TitleQ(*evt)) { SampleCode::TitleR(evt, "CubicCurve2"); return true; } SkUnichar uni; if (SampleCode::CharQ(*evt, &uni)) { switch (uni) { case 's': fShowSub = !fShowSub; break; case 'f': fShowFlatness = !fShowFlatness; break; case '-': fT -= 1.0f / 32; break; case '=': fT += 1.0f / 32; break; default: goto DONE; } fT = std::min(1.0f, std::max(0.0f, fT)); return true; } DONE: return this->INHERITED::onQuery(evt); } void showFrame(SkCanvas* canvas, const SkPoint pts[], int count, const SkPaint& p) { SkPaint paint(p); SkPoint storage[3 + 2 + 1]; SkPoint* tmp = storage; const SkPoint* prev = pts; int n = count; for (int n = count; n > 0; --n) { for (int i = 0; i < n; ++i) { canvas->drawLine(prev[i], prev[i+1], paint); tmp[i] = lerp(prev[i], prev[i+1], fT); } prev = tmp; tmp += n; } paint.setColor(SK_ColorBLUE); paint.setStyle(SkPaint::kFill_Style); n = tmp - storage; for (int i = 0; i < n; ++i) { canvas->drawCircle(storage[i].fX, storage[i].fY, 4, paint); } } void showFlattness(SkCanvas* canvas) { SkPaint paint; paint.setStyle(SkPaint::kStroke_Style); paint.setAntiAlias(true); SkPaint paint2(paint); paint2.setColor(0xFF008800); paint.setColor(0xFF888888); canvas->drawLine(fPts[0], fPts[3], paint); canvas->drawLine(fQuad[0], fQuad[2], paint); paint.setColor(0xFF0000FF); SkPoint pts[2]; pts[0] = (fQuad[0] + fQuad[1] + fQuad[1] + fQuad[2])*0.25; pts[1] = (fQuad[0] + fQuad[2]) * 0.5; canvas->drawLine(pts[0], pts[1], paint); // cubic SkVector v0 = (fPts[0] - fPts[1] - fPts[1] + fPts[2]) * fScale; SkVector v1 = (fPts[1] - fPts[2] - fPts[2] + fPts[3]) * fScale; SkVector v = (v0 + v1) * 0.5f; SkPoint anchor; SkScalar ts[2]; int n = find_max_deviation_cubic(fPts, ts); if (n > 0) { SkEvalCubicAt(fPts, ts[0], &anchor, nullptr, nullptr); canvas->drawLine(anchor, anchor + v, paint2); canvas->drawLine(anchor, anchor + v0, paint); if (n == 2) { SkEvalCubicAt(fPts, ts[1], &anchor, nullptr, nullptr); canvas->drawLine(anchor, anchor + v, paint2); } canvas->drawLine(anchor, anchor + v1, paint); } // not sure we can get here } void onDrawContent(SkCanvas* canvas) override { SkPaint paint; paint.setAntiAlias(true); { paint.setStyle(SkPaint::kStroke_Style); SkPath path; path.moveTo(fPts[0]); path.cubicTo(fPts[1], fPts[2], fPts[3]); path.moveTo(fQuad[0]); path.quadTo(fQuad[1], fQuad[2]); canvas->drawPath(path, paint); } if (fShowSub) { paint.setColor(SK_ColorRED); paint.setStrokeWidth(1.7f); this->showFrame(canvas, fPts, 3, paint); this->showFrame(canvas, fQuad, 2, paint); SkString str; str.printf("t = %g", fT); paint.setColor(SK_ColorBLACK); paint.setStyle(SkPaint::kFill_Style); paint.setTextSize(20); canvas->drawText(str.c_str(), str.size(), 20, 20, paint); } if (fShowFlatness) { this->showFlattness(canvas); } paint.setStyle(SkPaint::kFill_Style); paint.setColor(SK_ColorRED); for (SkPoint p : fPts) { canvas->drawCircle(p.fX, p.fY, 7, paint); } } bool onClick(Click* click) override { int32_t index; if (click->fMeta.findS32("index", &index)) { SkASSERT((unsigned)index < N); fPts[index] = click->fCurr; return true; } return false; } SkView::Click* onFindClickHandler(SkScalar x, SkScalar y, unsigned modi) override { const SkScalar tol = 8; const SkRect r = SkRect::MakeXYWH(x - tol, y - tol, tol * 2, tol * 2); for (int i = 0; i < N; ++i) { if (r.intersects(SkRect::MakeXYWH(fPts[i].fX, fPts[i].fY, 1, 1))) { Click* click = new Click(this); click->fMeta.setS32("index", i); return click; } } return this->INHERITED::onFindClickHandler(x, y, modi); } private: typedef SampleView INHERITED; }; DEF_SAMPLE( return new CubicCurve2; )