| /* |
| * Copyright 2019 Google LLC |
| * |
| * Use of this source code is governed by a BSD-style license that can be |
| * found in the LICENSE file. |
| */ |
| |
| #include "include/utils/SkRandom.h" |
| #include "modules/particles/include/SkCurve.h" |
| #include "modules/particles/include/SkReflected.h" |
| |
| constexpr SkFieldVisitor::EnumStringMapping gCurveSegmentTypeMapping[] = { |
| { kConstant_SegmentType, "Constant" }, |
| { kLinear_SegmentType, "Linear" }, |
| { kCubic_SegmentType, "Cubic" }, |
| }; |
| |
| static SkColor4f operator+(SkColor4f c1, SkColor4f c2) { |
| return { c1.fR + c2.fR, c1.fG + c2.fG, c1.fB + c2.fB, c1.fA + c2.fA }; |
| } |
| |
| static SkColor4f operator-(SkColor4f c1, SkColor4f c2) { |
| return { c1.fR - c2.fR, c1.fG - c2.fG, c1.fB - c2.fB, c1.fA - c2.fA }; |
| } |
| |
| template <typename T> |
| static T eval_cubic(const T* pts, float x) { |
| float ix = (1 - x); |
| return pts[0]*(ix*ix*ix) + pts[1]*(3*ix*ix*x) + pts[2]*(3*ix*x*x) + pts[3]*(x*x*x); |
| } |
| |
| template <typename T> |
| static T eval_segment(const T* pts, float x, int type) { |
| switch (type) { |
| case kLinear_SegmentType: |
| return pts[0] + (pts[3] - pts[0]) * x; |
| case kCubic_SegmentType: |
| return eval_cubic(pts, x); |
| case kConstant_SegmentType: |
| default: |
| return pts[0]; |
| } |
| } |
| |
| float SkCurveSegment::eval(float x, float t, bool negate) const { |
| float result = eval_segment(fMin, x, fType); |
| if (fRanged) { |
| result += (eval_segment(fMax, x, fType) - result) * t; |
| } |
| if (fBidirectional && negate) { |
| result = -result; |
| } |
| return result; |
| } |
| |
| void SkCurveSegment::visitFields(SkFieldVisitor* v) { |
| v->visit("Type", fType, gCurveSegmentTypeMapping, SK_ARRAY_COUNT(gCurveSegmentTypeMapping)); |
| v->visit("Ranged", fRanged); |
| v->visit("Bidirectional", fBidirectional); |
| v->visit("A0", fMin[0]); |
| if (fType == kCubic_SegmentType) { |
| v->visit("B0", fMin[1]); |
| v->visit("C0", fMin[2]); |
| } |
| if (fType != kConstant_SegmentType) { |
| v->visit("D0", fMin[3]); |
| } |
| if (fRanged) { |
| v->visit("A1", fMax[0]); |
| if (fType == kCubic_SegmentType) { |
| v->visit("B1", fMax[1]); |
| v->visit("C1", fMax[2]); |
| } |
| if (fType != kConstant_SegmentType) { |
| v->visit("D1", fMax[3]); |
| } |
| } |
| } |
| |
| float SkCurve::eval(float x, SkRandom& random) const { |
| SkASSERT(fSegments.count() == fXValues.count() + 1); |
| |
| int i = 0; |
| for (; i < fXValues.count(); ++i) { |
| if (x <= fXValues[i]) { |
| break; |
| } |
| } |
| |
| float rangeMin = (i == 0) ? 0.0f : fXValues[i - 1]; |
| float rangeMax = (i == fXValues.count()) ? 1.0f : fXValues[i]; |
| float segmentX = (x - rangeMin) / (rangeMax - rangeMin); |
| if (!sk_float_isfinite(segmentX)) { |
| segmentX = rangeMin; |
| } |
| SkASSERT(0.0f <= segmentX && segmentX <= 1.0f); |
| |
| // Always pull t and negate here, so that the stable generator behaves consistently, even if |
| // our segments use an inconsistent feature-set. |
| float t = random.nextF(); |
| bool negate = random.nextBool(); |
| return fSegments[i].eval(segmentX, t, negate); |
| } |
| |
| void SkCurve::visitFields(SkFieldVisitor* v) { |
| v->visit("XValues", fXValues); |
| v->visit("Segments", fSegments); |
| |
| // Validate and fixup |
| if (fSegments.empty()) { |
| fSegments.push_back().setConstant(0.0f); |
| } |
| fXValues.resize_back(fSegments.count() - 1); |
| for (int i = 0; i < fXValues.count(); ++i) { |
| fXValues[i] = SkTPin(fXValues[i], i > 0 ? fXValues[i - 1] : 0.0f, 1.0f); |
| } |
| } |
| |
| SkColor4f SkColorCurveSegment::eval(float x, float t) const { |
| SkColor4f result = eval_segment(fMin, x, fType); |
| if (fRanged) { |
| result = result + (eval_segment(fMax, x, fType) - result) * t; |
| } |
| return result; |
| } |
| |
| void SkColorCurveSegment::visitFields(SkFieldVisitor* v) { |
| v->visit("Type", fType, gCurveSegmentTypeMapping, SK_ARRAY_COUNT(gCurveSegmentTypeMapping)); |
| v->visit("Ranged", fRanged); |
| v->visit("A0", fMin[0]); |
| if (fType == kCubic_SegmentType) { |
| v->visit("B0", fMin[1]); |
| v->visit("C0", fMin[2]); |
| } |
| if (fType != kConstant_SegmentType) { |
| v->visit("D0", fMin[3]); |
| } |
| if (fRanged) { |
| v->visit("A1", fMax[0]); |
| if (fType == kCubic_SegmentType) { |
| v->visit("B1", fMax[1]); |
| v->visit("C1", fMax[2]); |
| } |
| if (fType != kConstant_SegmentType) { |
| v->visit("D1", fMax[3]); |
| } |
| } |
| } |
| |
| SkColor4f SkColorCurve::eval(float x, SkRandom& random) const { |
| SkASSERT(fSegments.count() == fXValues.count() + 1); |
| |
| int i = 0; |
| for (; i < fXValues.count(); ++i) { |
| if (x <= fXValues[i]) { |
| break; |
| } |
| } |
| |
| float rangeMin = (i == 0) ? 0.0f : fXValues[i - 1]; |
| float rangeMax = (i == fXValues.count()) ? 1.0f : fXValues[i]; |
| float segmentX = (x - rangeMin) / (rangeMax - rangeMin); |
| if (!sk_float_isfinite(segmentX)) { |
| segmentX = rangeMin; |
| } |
| SkASSERT(0.0f <= segmentX && segmentX <= 1.0f); |
| return fSegments[i].eval(segmentX, random.nextF()); |
| } |
| |
| void SkColorCurve::visitFields(SkFieldVisitor* v) { |
| v->visit("XValues", fXValues); |
| v->visit("Segments", fSegments); |
| |
| // Validate and fixup |
| if (fSegments.empty()) { |
| fSegments.push_back().setConstant(SkColor4f{ 1.0f, 1.0f, 1.0f, 1.0f }); |
| } |
| fXValues.resize_back(fSegments.count() - 1); |
| for (int i = 0; i < fXValues.count(); ++i) { |
| fXValues[i] = SkTPin(fXValues[i], i > 0 ? fXValues[i - 1] : 0.0f, 1.0f); |
| } |
| } |