| /* |
| * 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 "include/core/SkBitmap.h" |
| #include "include/core/SkCanvas.h" |
| #include "include/core/SkColorFilter.h" |
| #include "include/core/SkColorPriv.h" |
| #include "include/core/SkFont.h" |
| #include "include/core/SkGraphics.h" |
| #include "include/core/SkPathBuilder.h" |
| #include "include/core/SkRegion.h" |
| #include "include/core/SkShader.h" |
| #include "include/core/SkTime.h" |
| #include "include/core/SkTypeface.h" |
| #include "include/effects/SkGradientShader.h" |
| #include "include/utils/SkParsePath.h" |
| #include "samplecode/Sample.h" |
| #include "src/utils/SkUTF.h" |
| #include "tools/timer/TimeUtils.h" |
| |
| #include "src/core/SkGeometry.h" |
| |
| #include <stdlib.h> |
| |
| // 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 Sample { |
| 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: |
| SkString name() override { return SkString("Paths"); } |
| |
| 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 < std::size(gJoins); i++) { |
| canvas->save(); |
| for (size_t j = 0; j < std::size(fPath); j++) { |
| this->drawPath(canvas, fPath[j], gJoins[i]); |
| canvas->translate(200, 0); |
| } |
| canvas->restore(); |
| |
| canvas->translate(0, 200); |
| } |
| } |
| |
| bool onAnimate(double nanos) override { |
| SkScalar currSecs = TimeUtils::Scaled(1e-9 * nanos, 100); |
| SkScalar delta = currSecs - fPrevSecs; |
| fPrevSecs = currSecs; |
| |
| fStroke += fDStroke * delta; |
| if (fStroke > fMaxStroke || fStroke < fMinStroke) { |
| fDStroke = -fDStroke; |
| } |
| return true; |
| } |
| |
| Sample::Click* onFindClickHandler(SkScalar x, SkScalar y, skui::ModifierKey modi) override { |
| fShowHairline = !fShowHairline; |
| return nullptr; |
| } |
| |
| private: |
| using INHERITED = Sample; |
| }; |
| DEF_SAMPLE( return new PathView; ) |
| |
| ////////////////////////////////////////////////////////////////////////////// |
| |
| #include "include/effects/SkCornerPathEffect.h" |
| #include "include/utils/SkRandom.h" |
| |
| class ArcToView : public Sample { |
| 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: |
| SkString name() override { return SkString("ArcTo"); } |
| |
| bool onChar(SkUnichar uni) override { |
| 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 false; |
| } |
| |
| 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); |
| } |
| |
| Sample::Click* onFindClickHandler(SkScalar x, SkScalar y, skui::ModifierKey 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))) { |
| return new Click([this, i](Click* c) { |
| fPts[i] = c->fCurr; |
| return true; |
| }); |
| } |
| } |
| return nullptr; |
| } |
| |
| private: |
| using INHERITED = Sample; |
| }; |
| DEF_SAMPLE( return new ArcToView; ) |
| |
| ///////////// |
| |
| class FatStroke : public Sample { |
| bool fClosed, fShowStroke, fShowHidden, fShowSkeleton, fAsCurves = false; |
| 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: |
| SkString name() override { return SkString("FatStroke"); } |
| |
| bool onChar(SkUnichar uni) override { |
| 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 'c': this->toggle(fAsCurves); return true; |
| case '-': fWidth -= 5; return true; |
| case '=': fWidth += 5; return true; |
| default: break; |
| } |
| return false; |
| } |
| |
| void makePath(SkPath* path) { |
| path->moveTo(fPts[0]); |
| if (fAsCurves) { |
| for (int i = 1; i < N-2; ++i) { |
| path->quadTo(fPts[i], (fPts[i+1] + fPts[i]) * 0.5f); |
| } |
| path->quadTo(fPts[N-2], fPts[N-1]); |
| } else { |
| 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); |
| } |
| |
| Sample::Click* onFindClickHandler(SkScalar x, SkScalar y, skui::ModifierKey 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))) { |
| return new Click([this, i](Click* c) { |
| fPts[i] = c->fCurr; |
| return true; |
| }); |
| } |
| } |
| return nullptr; |
| } |
| |
| private: |
| using INHERITED = Sample; |
| }; |
| 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 Sample { |
| 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: |
| SkString name() override { return SkString("CubicCurve"); } |
| |
| 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); |
| } |
| } |
| } |
| |
| Sample::Click* onFindClickHandler(SkScalar x, SkScalar y, skui::ModifierKey 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))) { |
| return new Click([this, i](Click* c) { |
| fPts[i] = c->fCurr; |
| return true; |
| }); |
| } |
| } |
| return this->INHERITED::onFindClickHandler(x, y, modi); |
| } |
| |
| private: |
| using INHERITED = Sample; |
| }; |
| 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 Sample { |
| public: |
| enum { |
| N = 7 |
| }; |
| SkPoint fPts[N]; |
| SkPoint* fQuad = fPts + 4; |
| SkScalar fT = 0.5f; |
| bool fShowSub = false; |
| bool fShowFlatness = false; |
| bool fShowInnerQuads = 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: |
| SkString name() override { return SkString("CubicCurve2"); } |
| |
| bool onChar(SkUnichar uni) override { |
| switch (uni) { |
| case 's': fShowSub = !fShowSub; break; |
| case 'f': fShowFlatness = !fShowFlatness; break; |
| case '-': fT -= 1.0f / 32; break; |
| case '=': fT += 1.0f / 32; break; |
| case 'q': fShowInnerQuads = !fShowInnerQuads; break; |
| default: return false; |
| } |
| fT = std::min(1.0f, std::max(0.0f, fT)); |
| return true; |
| } |
| |
| static void Dot(SkCanvas* canvas, SkPoint p, SkScalar radius, SkColor c) { |
| SkPaint paint; |
| paint.setAntiAlias(true); |
| paint.setColor(c); |
| canvas->drawCircle(p.fX, p.fY, radius, paint); |
| } |
| |
| 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; |
| 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); |
| int n = tmp - storage; |
| for (int i = 0; i < n; ++i) { |
| Dot(canvas, storage[i], 4, SK_ColorBLUE); |
| } |
| } |
| |
| 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 showInnerQuads(SkCanvas* canvas) { |
| auto draw_quad = [canvas](SkPoint a, SkPoint b, SkPoint c, SkColor color) { |
| SkPaint paint; |
| paint.setAntiAlias(true); |
| paint.setStroke(true); |
| paint.setColor(color); |
| |
| canvas->drawPath(SkPathBuilder().moveTo(a).quadTo(b, c).detach(), paint); |
| }; |
| |
| SkPoint p0 = SkEvalQuadAt(&fPts[0], fT), |
| p1 = SkEvalQuadAt(&fPts[1], fT), |
| p2 = lerp(p0, p1, fT); |
| |
| draw_quad(fPts[0], fPts[1], fPts[2], SK_ColorRED); |
| Dot(canvas, p0, 4, SK_ColorRED); |
| |
| draw_quad(fPts[1], fPts[2], fPts[3], SK_ColorBLUE); |
| Dot(canvas, p1, 4, SK_ColorBLUE); |
| |
| SkPaint paint; |
| paint.setAntiAlias(true); |
| paint.setColor(0xFF008800); |
| canvas->drawLine(p0, p1, paint); |
| Dot(canvas, p2, 4, 0xFF00AA00); |
| } |
| |
| 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); |
| |
| paint.setColor(SK_ColorBLACK); |
| paint.setStyle(SkPaint::kFill_Style); |
| SkFont font(nullptr, 20); |
| canvas->drawString(SkStringPrintf("t = %g", fT), 20, 20, font, paint); |
| } |
| |
| if (fShowFlatness) { |
| this->showFlattness(canvas); |
| } |
| |
| if (fShowInnerQuads) { |
| this->showInnerQuads(canvas); |
| } |
| |
| paint.setColor(SK_ColorGRAY); |
| paint.setStroke(true); |
| canvas->drawPath(SkPathBuilder().addPolygon(fPts, 4, false).detach(), paint); |
| canvas->drawPath(SkPathBuilder().addPolygon(fQuad, 3, false).detach(), paint); |
| |
| for (SkPoint p : fPts) { |
| Dot(canvas, p, 7, SK_ColorBLACK); |
| } |
| |
| if ((false)) { |
| SkScalar ts[2]; |
| int n = SkFindCubicInflections(fPts, ts); |
| for (int i = 0; i < n; ++i) { |
| SkPoint p; |
| SkEvalCubicAt(fPts, ts[i], &p, nullptr, nullptr); |
| canvas->drawCircle(p.fX, p.fY, 3, paint); |
| } |
| } |
| |
| } |
| |
| Sample::Click* onFindClickHandler(SkScalar x, SkScalar y, skui::ModifierKey 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))) { |
| return new Click([this, i](Click* c) { |
| fPts[i] = c->fCurr; |
| return true; |
| }); |
| } |
| } |
| return this->INHERITED::onFindClickHandler(x, y, modi); |
| } |
| |
| private: |
| using INHERITED = Sample; |
| }; |
| DEF_SAMPLE( return new CubicCurve2; ) |
| |