/* -*- 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 http://mozilla.org/MPL/2.0/. */

#ifndef MOZILLA_GFX_HELPERSSKIA_H_

#define MOZILLA_GFX_HELPERSSKIA_H_

#include "2D.h"

#include "skia/include/core/SkCanvas.h"

#include "skia/include/effects/SkDashPathEffect.h"

#include "skia/include/core/SkShader.h"

#include "mozilla/Assertions.h"

#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;

    default:

      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;

    default:

      return SurfaceFormat::B8G8R8A8;

  }

}

static inline SkAlphaType

GfxFormatToSkiaAlphaType(SurfaceFormat format)

{

  switch (format)

  {

    case SurfaceFormat::B8G8R8X8:

    case SurfaceFormat::R5G6B5_UINT16:

      return kOpaque_SkAlphaType;

    default:

      return kPremul_SkAlphaType;

  }

}

static inline SkImageInfo

MakeSkiaImageInfo(const IntSize& aSize, SurfaceFormat aFormat)

{

  return SkImageInfo::Make(aSize.width, aSize.height,

                           GfxFormatToSkiaColorType(aFormat),

                           GfxFormatToSkiaAlphaType(aFormat));

}

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, SK_Scalar1);

}

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), SkFloatToScalar(aMatrix._44));

}

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)

{

  // 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 || !IsFinite(aOptions.mLineWidth)) {

    return false;

  }

  aPaint.setStrokeWidth(SkFloatToScalar(aOptions.mLineWidth));

  aPaint.setStrokeMiter(SkFloatToScalar(aOptions.mMiterLimit));

  aPaint.setStrokeCap(CapStyleToSkiaCap(aOptions.mLineCap));

  aPaint.setStrokeJoin(JoinStyleToSkiaJoin(aOptions.mLineJoin));

  if (aOptions.mDashLength > 0) {

    // 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;

    pattern.resize(dashCount);

    for (uint32_t i = 0; i < dashCount; i++) {

      pattern[i] = SkFloatToScalar(aOptions.mDashPattern[i % aOptions.mDashLength]);

    }

    sk_sp<SkPathEffect> dash = SkDashPathEffect::Make(&pattern.front(),

                                                      dashCount,

                                                      SkFloatToScalar(aOptions.mDashOffset));

    aPaint.setPathEffect(dash);

  }

  aPaint.setStyle(SkPaint::kStroke_Style);

  return true;

}

static inline SkBlendMode

GfxOpToSkiaOp(CompositionOp op)

{

  switch (op)

  {

    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;

    default:

      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 Color &color, Float aAlpha)

{

  return SkColorSetARGB(ColorFloatToByte(color.a*aAlpha), ColorFloatToByte(color.r),

                        ColorFloatToByte(color.g), ColorFloatToByte(color.b));

}

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()),

                          SkIntToScalar(aRect.Width()), SkIntToScalar(aRect.Height()));

}

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 SkShader::TileMode

ExtendModeToTileMode(ExtendMode aMode, Axis aAxis)

{

  switch (aMode)

  {

    case ExtendMode::CLAMP:

      return SkShader::kClamp_TileMode;

    case ExtendMode::REPEAT:

      return SkShader::kRepeat_TileMode;

    case ExtendMode::REFLECT:

      return SkShader::kMirror_TileMode;

    case ExtendMode::REPEAT_X:

    {

      return aAxis == Axis::X_AXIS

             ? SkShader::kRepeat_TileMode

             : SkShader::kClamp_TileMode;

    }

    case ExtendMode::REPEAT_Y:

    {

      return aAxis == Axis::Y_AXIS

             ? SkShader::kRepeat_TileMode

             : SkShader::kClamp_TileMode;

    }

  }

  return SkShader::kClamp_TileMode;

}

static inline SkPaint::Hinting

GfxHintingToSkiaHinting(FontHinting aHinting)

{

  switch (aHinting) {

    case FontHinting::NONE:

      return SkPaint::kNo_Hinting;

    case FontHinting::LIGHT:

      return SkPaint::kSlight_Hinting;

    case FontHinting::NORMAL:

      return SkPaint::kNormal_Hinting;

    case FontHinting::FULL:

      return SkPaint::kFull_Hinting;

  }

  return SkPaint::kNormal_Hinting;

}

static inline FillRule GetFillRule(SkPath::FillType aFillType)

{

  switch (aFillType)

  {

  case SkPath::kWinding_FillType:

    return FillRule::FILL_WINDING;

  case SkPath::kEvenOdd_FillType:

    return FillRule::FILL_EVEN_ODD;

  case SkPath::kInverseWinding_FillType:

  case SkPath::kInverseEvenOdd_FillType:

  default:

    NS_WARNING("Unsupported fill type\n");

    break;

  }

  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;

}

} // namespace gfx

} // namespace mozilla

#endif /* MOZILLA_GFX_HELPERSSKIA_H_ */