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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at */
#include "2D.h"
#include "skia/include/core/SkCanvas.h"
#include "skia/include/core/SkFontTypes.h"
#include "skia/include/core/SkPathEffect.h"
#include "skia/include/core/SkPathTypes.h"
#include "skia/include/core/SkShader.h"
#include "skia/include/core/SkTileMode.h"
#include "skia/include/effects/SkDashPathEffect.h"
#include "mozilla/Assertions.h"
#include <cmath>
#include <vector>
#include "nsDebug.h"
namespace mozilla {
namespace gfx {
static inline SkColorType GfxFormatToSkiaColorType(SurfaceFormat format) {
switch (format) {
case SurfaceFormat::B8G8R8A8:
return kBGRA_8888_SkColorType;
case SurfaceFormat::B8G8R8X8:
// We probably need to do something here.
return kBGRA_8888_SkColorType;
case SurfaceFormat::R5G6B5_UINT16:
return kRGB_565_SkColorType;
case SurfaceFormat::A8:
return kAlpha_8_SkColorType;
case SurfaceFormat::R8G8B8A8:
return kRGBA_8888_SkColorType;
case SurfaceFormat::A8R8G8B8:
MOZ_DIAGNOSTIC_ASSERT(false, "A8R8G8B8 unsupported by Skia");
return kRGBA_8888_SkColorType;
MOZ_DIAGNOSTIC_ASSERT(false, "Unknown surface format");
return kRGBA_8888_SkColorType;
static inline SurfaceFormat SkiaColorTypeToGfxFormat(
SkColorType aColorType, SkAlphaType aAlphaType = kPremul_SkAlphaType) {
switch (aColorType) {
case kBGRA_8888_SkColorType:
return aAlphaType == kOpaque_SkAlphaType ? SurfaceFormat::B8G8R8X8
: SurfaceFormat::B8G8R8A8;
case kRGB_565_SkColorType:
return SurfaceFormat::R5G6B5_UINT16;
case kAlpha_8_SkColorType:
return SurfaceFormat::A8;
return SurfaceFormat::B8G8R8A8;
static inline SkAlphaType GfxFormatToSkiaAlphaType(SurfaceFormat format) {
switch (format) {
case SurfaceFormat::B8G8R8X8:
case SurfaceFormat::R5G6B5_UINT16:
return kOpaque_SkAlphaType;
return kPremul_SkAlphaType;
static inline SkImageInfo MakeSkiaImageInfo(const IntSize& aSize,
SurfaceFormat aFormat) {
return SkImageInfo::Make(aSize.width, aSize.height,
static inline void GfxMatrixToSkiaMatrix(const Matrix& mat, SkMatrix& retval) {
retval.setAll(SkFloatToScalar(mat._11), SkFloatToScalar(mat._21),
SkFloatToScalar(mat._31), SkFloatToScalar(mat._12),
SkFloatToScalar(mat._22), SkFloatToScalar(mat._32), 0, 0,
static inline void GfxMatrixToSkiaMatrix(const Matrix4x4& aMatrix,
SkMatrix& aResult) {
aResult.setAll(SkFloatToScalar(aMatrix._11), SkFloatToScalar(aMatrix._21),
SkFloatToScalar(aMatrix._41), SkFloatToScalar(aMatrix._12),
SkFloatToScalar(aMatrix._22), SkFloatToScalar(aMatrix._42),
SkFloatToScalar(aMatrix._14), SkFloatToScalar(aMatrix._24),
static inline SkPaint::Cap CapStyleToSkiaCap(CapStyle aCap) {
switch (aCap) {
case CapStyle::BUTT:
return SkPaint::kButt_Cap;
case CapStyle::ROUND:
return SkPaint::kRound_Cap;
case CapStyle::SQUARE:
return SkPaint::kSquare_Cap;
return SkPaint::kDefault_Cap;
static inline SkPaint::Join JoinStyleToSkiaJoin(JoinStyle aJoin) {
switch (aJoin) {
case JoinStyle::BEVEL:
return SkPaint::kBevel_Join;
case JoinStyle::ROUND:
return SkPaint::kRound_Join;
case JoinStyle::MITER:
case JoinStyle::MITER_OR_BEVEL:
return SkPaint::kMiter_Join;
return SkPaint::kDefault_Join;
static inline bool StrokeOptionsToPaint(SkPaint& aPaint,
const StrokeOptions& aOptions,
bool aUsePathEffects = true) {
// Skia renders 0 width strokes with a width of 1 (and in black),
// so we should just skip the draw call entirely.
// Skia does not handle non-finite line widths.
if (!aOptions.mLineWidth || !std::isfinite(aOptions.mLineWidth)) {
return false;
if (aOptions.mDashLength > 0 && aUsePathEffects) {
// Skia only supports dash arrays that are multiples of 2.
uint32_t dashCount;
if (aOptions.mDashLength % 2 == 0) {
dashCount = aOptions.mDashLength;
} else {
dashCount = aOptions.mDashLength * 2;
std::vector<SkScalar> pattern;
for (uint32_t i = 0; i < dashCount; i++) {
pattern[i] =
SkFloatToScalar(aOptions.mDashPattern[i % aOptions.mDashLength]);
auto dash = SkDashPathEffect::Make(&pattern.front(), dashCount,
return true;
static inline SkBlendMode GfxOpToSkiaOp(CompositionOp op) {
switch (op) {
case CompositionOp::OP_CLEAR:
return SkBlendMode::kClear;
case CompositionOp::OP_OVER:
return SkBlendMode::kSrcOver;
case CompositionOp::OP_ADD:
return SkBlendMode::kPlus;
case CompositionOp::OP_ATOP:
return SkBlendMode::kSrcATop;
case CompositionOp::OP_OUT:
return SkBlendMode::kSrcOut;
case CompositionOp::OP_IN:
return SkBlendMode::kSrcIn;
case CompositionOp::OP_SOURCE:
return SkBlendMode::kSrc;
case CompositionOp::OP_DEST_IN:
return SkBlendMode::kDstIn;
case CompositionOp::OP_DEST_OUT:
return SkBlendMode::kDstOut;
case CompositionOp::OP_DEST_OVER:
return SkBlendMode::kDstOver;
case CompositionOp::OP_DEST_ATOP:
return SkBlendMode::kDstATop;
case CompositionOp::OP_XOR:
return SkBlendMode::kXor;
case CompositionOp::OP_MULTIPLY:
return SkBlendMode::kMultiply;
case CompositionOp::OP_SCREEN:
return SkBlendMode::kScreen;
case CompositionOp::OP_OVERLAY:
return SkBlendMode::kOverlay;
case CompositionOp::OP_DARKEN:
return SkBlendMode::kDarken;
case CompositionOp::OP_LIGHTEN:
return SkBlendMode::kLighten;
case CompositionOp::OP_COLOR_DODGE:
return SkBlendMode::kColorDodge;
case CompositionOp::OP_COLOR_BURN:
return SkBlendMode::kColorBurn;
case CompositionOp::OP_HARD_LIGHT:
return SkBlendMode::kHardLight;
case CompositionOp::OP_SOFT_LIGHT:
return SkBlendMode::kSoftLight;
case CompositionOp::OP_DIFFERENCE:
return SkBlendMode::kDifference;
case CompositionOp::OP_EXCLUSION:
return SkBlendMode::kExclusion;
case CompositionOp::OP_HUE:
return SkBlendMode::kHue;
case CompositionOp::OP_SATURATION:
return SkBlendMode::kSaturation;
case CompositionOp::OP_COLOR:
return SkBlendMode::kColor;
case CompositionOp::OP_LUMINOSITY:
return SkBlendMode::kLuminosity;
case CompositionOp::OP_COUNT:
return SkBlendMode::kSrcOver;
/* There's quite a bit of inconsistency about
* whether float colors should be rounded with .5f.
* We choose to do it to match cairo which also
* happens to match the Direct3D specs */
static inline U8CPU ColorFloatToByte(Float color) {
// XXX: do a better job converting to int
return U8CPU(color * 255.f + .5f);
static inline SkColor ColorToSkColor(const DeviceColor& color, Float aAlpha) {
return SkColorSetARGB(ColorFloatToByte(color.a * aAlpha),
ColorFloatToByte(color.r), ColorFloatToByte(color.g),
static inline SkPoint PointToSkPoint(const Point& aPoint) {
return SkPoint::Make(SkFloatToScalar(aPoint.x), SkFloatToScalar(aPoint.y));
static inline SkRect RectToSkRect(const Rect& aRect) {
return SkRect::MakeXYWH(
SkFloatToScalar(aRect.X()), SkFloatToScalar(aRect.Y()),
SkFloatToScalar(aRect.Width()), SkFloatToScalar(aRect.Height()));
static inline SkRect IntRectToSkRect(const IntRect& aRect) {
return SkRect::MakeXYWH(SkIntToScalar(aRect.X()), SkIntToScalar(aRect.Y()),
static inline SkIRect RectToSkIRect(const Rect& aRect) {
return SkIRect::MakeXYWH(int32_t(aRect.X()), int32_t(aRect.Y()),
int32_t(aRect.Width()), int32_t(aRect.Height()));
static inline SkIRect IntRectToSkIRect(const IntRect& aRect) {
return SkIRect::MakeXYWH(aRect.X(), aRect.Y(), aRect.Width(), aRect.Height());
static inline IntRect SkIRectToIntRect(const SkIRect& aRect) {
return IntRect(aRect.x(), aRect.y(), aRect.width(), aRect.height());
static inline Point SkPointToPoint(const SkPoint& aPoint) {
return Point(SkScalarToFloat(aPoint.x()), SkScalarToFloat(aPoint.y()));
static inline Rect SkRectToRect(const SkRect& aRect) {
return Rect(SkScalarToFloat(aRect.x()), SkScalarToFloat(aRect.y()),
SkScalarToFloat(aRect.width()), SkScalarToFloat(aRect.height()));
static inline SkTileMode ExtendModeToTileMode(ExtendMode aMode, Axis aAxis) {
switch (aMode) {
case ExtendMode::CLAMP:
return SkTileMode::kClamp;
case ExtendMode::REPEAT:
return SkTileMode::kRepeat;
case ExtendMode::REFLECT:
return SkTileMode::kMirror;
case ExtendMode::REPEAT_X: {
return aAxis == Axis::X_AXIS ? SkTileMode::kRepeat : SkTileMode::kClamp;
case ExtendMode::REPEAT_Y: {
return aAxis == Axis::Y_AXIS ? SkTileMode::kRepeat : SkTileMode::kClamp;
return SkTileMode::kClamp;
static inline SkFontHinting GfxHintingToSkiaHinting(FontHinting aHinting) {
switch (aHinting) {
case FontHinting::NONE:
return SkFontHinting::kNone;
case FontHinting::LIGHT:
return SkFontHinting::kSlight;
case FontHinting::NORMAL:
return SkFontHinting::kNormal;
case FontHinting::FULL:
return SkFontHinting::kFull;
return SkFontHinting::kNormal;
static inline FillRule GetFillRule(SkPathFillType aFillType) {
switch (aFillType) {
case SkPathFillType::kWinding:
return FillRule::FILL_WINDING;
case SkPathFillType::kEvenOdd:
return FillRule::FILL_EVEN_ODD;
case SkPathFillType::kInverseWinding:
case SkPathFillType::kInverseEvenOdd:
NS_WARNING("Unsupported fill type\n");
return FillRule::FILL_EVEN_ODD;
* Returns true if the canvas is backed by pixels. Returns false if the canvas
* wraps an SkPDFDocument, for example.
* Note: It is not clear whether the test used to implement this function may
* result in it returning false in some circumstances even when the canvas
* _is_ pixel backed. In other words maybe it is possible for such a canvas to
* have kUnknown_SkPixelGeometry?
static inline bool IsBackedByPixels(const SkCanvas* aCanvas) {
SkSurfaceProps props(0, kUnknown_SkPixelGeometry);
if (!aCanvas->getProps(&props) ||
props.pixelGeometry() == kUnknown_SkPixelGeometry) {
return false;
return true;
* Computes appropriate resolution scale to be used with SkPath::getFillPath
* based on the scaling of the supplied transform.
float ComputeResScaleForStroking(const Matrix& aTransform);
* This is a wrapper around SkGeometry's SkConic that can be used to convert
* conic sections in an SkPath to a sequence of quadratic curves. The quads
* vector is organized such that for the Nth quad, it's control points are
* 2*N, 2*N+1, 2*N+2. This function returns the resulting number of quads.
int ConvertConicToQuads(const Point& aP0, const Point& aP1, const Point& aP2,
float aWeight, std::vector<Point>& aQuads);
} // namespace gfx
} // namespace mozilla