Florin Malita | df007e1 | 2017-10-09 15:14:13 -0400 | [diff] [blame] | 1 | /* |
| 2 | * Copyright 2017 Google Inc. |
| 3 | * |
| 4 | * Use of this source code is governed by a BSD-style license that can be |
| 5 | * found in the LICENSE file. |
| 6 | */ |
| 7 | |
| 8 | #include "SkSVGGradient.h" |
| 9 | #include "SkSVGRenderContext.h" |
| 10 | #include "SkSVGStop.h" |
| 11 | #include "SkSVGValue.h" |
| 12 | |
| 13 | void SkSVGGradient::setHref(const SkSVGStringType& href) { |
| 14 | fHref = std::move(href); |
| 15 | } |
| 16 | |
| 17 | void SkSVGGradient::setGradientTransform(const SkSVGTransformType& t) { |
| 18 | fGradientTransform = t; |
| 19 | } |
| 20 | |
| 21 | void SkSVGGradient::setSpreadMethod(const SkSVGSpreadMethod& spread) { |
| 22 | fSpreadMethod = spread; |
| 23 | } |
| 24 | |
| 25 | void SkSVGGradient::onSetAttribute(SkSVGAttribute attr, const SkSVGValue& v) { |
| 26 | switch (attr) { |
| 27 | case SkSVGAttribute::kGradientTransform: |
| 28 | if (const auto* t = v.as<SkSVGTransformValue>()) { |
| 29 | this->setGradientTransform(*t); |
| 30 | } |
| 31 | break; |
| 32 | case SkSVGAttribute::kHref: |
| 33 | if (const auto* href = v.as<SkSVGStringValue>()) { |
| 34 | this->setHref(*href); |
| 35 | } |
| 36 | break; |
| 37 | case SkSVGAttribute::kSpreadMethod: |
| 38 | if (const auto* spread = v.as<SkSVGSpreadMethodValue>()) { |
| 39 | this->setSpreadMethod(*spread); |
| 40 | } |
| 41 | break; |
| 42 | default: |
| 43 | this->INHERITED::onSetAttribute(attr, v); |
| 44 | } |
| 45 | } |
| 46 | |
| 47 | // https://www.w3.org/TR/SVG/pservers.html#LinearGradientElementHrefAttribute |
| 48 | void SkSVGGradient::collectColorStops(const SkSVGRenderContext& ctx, |
| 49 | StopPositionArray* pos, |
| 50 | StopColorArray* colors) const { |
| 51 | // Used to resolve percentage offsets. |
| 52 | const SkSVGLengthContext ltx(SkSize::Make(1, 1)); |
| 53 | |
| 54 | for (const auto& child : fChildren) { |
| 55 | if (child->tag() != SkSVGTag::kStop) { |
| 56 | continue; |
| 57 | } |
| 58 | |
| 59 | const auto& stop = static_cast<const SkSVGStop&>(*child); |
| 60 | colors->push_back(SkColorSetA(stop.stopColor(), |
| 61 | SkScalarRoundToInt(stop.stopOpacity() * 255))); |
| 62 | pos->push_back(SkTPin(ltx.resolve(stop.offset(), SkSVGLengthContext::LengthType::kOther), |
| 63 | 0.f, 1.f)); |
| 64 | } |
| 65 | |
| 66 | SkASSERT(colors->count() == pos->count()); |
| 67 | |
| 68 | if (pos->empty() && !fHref.value().isEmpty()) { |
| 69 | const auto* ref = ctx.findNodeById(fHref); |
Florin Malita | 532a091 | 2017-10-09 22:11:50 -0400 | [diff] [blame] | 70 | if (ref && (ref->tag() == SkSVGTag::kLinearGradient || |
| 71 | ref->tag() == SkSVGTag::kRadialGradient)) { |
Florin Malita | df007e1 | 2017-10-09 15:14:13 -0400 | [diff] [blame] | 72 | static_cast<const SkSVGGradient*>(ref)->collectColorStops(ctx, pos, colors); |
| 73 | } |
| 74 | } |
| 75 | } |
| 76 | |
| 77 | bool SkSVGGradient::onAsPaint(const SkSVGRenderContext& ctx, SkPaint* paint) const { |
| 78 | StopColorArray colors; |
| 79 | StopPositionArray pos; |
| 80 | |
| 81 | this->collectColorStops(ctx, &pos, &colors); |
| 82 | |
| 83 | // TODO: |
| 84 | // * stop (lazy?) sorting |
| 85 | // * href loop detection |
| 86 | // * href attribute inheritance (not just color stops) |
| 87 | // * objectBoundingBox units support |
| 88 | |
| 89 | static_assert(static_cast<SkShader::TileMode>(SkSVGSpreadMethod::Type::kPad) == |
| 90 | SkShader::kClamp_TileMode, "SkSVGSpreadMethod::Type is out of sync"); |
| 91 | static_assert(static_cast<SkShader::TileMode>(SkSVGSpreadMethod::Type::kRepeat) == |
| 92 | SkShader::kRepeat_TileMode, "SkSVGSpreadMethod::Type is out of sync"); |
| 93 | static_assert(static_cast<SkShader::TileMode>(SkSVGSpreadMethod::Type::kReflect) == |
| 94 | SkShader::kMirror_TileMode, "SkSVGSpreadMethod::Type is out of sync"); |
| 95 | const auto tileMode = static_cast<SkShader::TileMode>(fSpreadMethod.type()); |
| 96 | |
| 97 | paint->setShader(this->onMakeShader(ctx, colors.begin(), pos.begin(), colors.count(), tileMode, |
| 98 | fGradientTransform.value())); |
| 99 | return true; |
| 100 | } |