gecko-dev/gfx/thebes/gfxDrawable.cpp

/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*-
 * 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/. */

#include "gfxDrawable.h"
#include "gfxContext.h"
#include "gfxPlatform.h"
#include "gfx2DGlue.h"
#ifdef MOZ_X11
#  include "cairo.h"
#  include "gfxXlibSurface.h"
#endif
#include "mozilla/gfx/Logging.h"

using namespace mozilla;
using namespace mozilla::gfx;

gfxSurfaceDrawable::gfxSurfaceDrawable(SourceSurface* aSurface,
                                       const IntSize aSize,
                                       const gfxMatrix aTransform)
    : gfxDrawable(aSize), mSourceSurface(aSurface), mTransform(aTransform) {
  if (!mSourceSurface) {
    gfxWarning() << "Creating gfxSurfaceDrawable with null SourceSurface";
  }
}

bool gfxSurfaceDrawable::DrawWithSamplingRect(
    DrawTarget* aDrawTarget, CompositionOp aOp, AntialiasMode aAntialiasMode,
    const gfxRect& aFillRect, const gfxRect& aSamplingRect,
    ExtendMode aExtendMode, const SamplingFilter aSamplingFilter,
    gfxFloat aOpacity) {
  if (!mSourceSurface) {
    return true;
  }

  // When drawing with CLAMP we can expand the sampling rect to the nearest
  // pixel without changing the result.
  IntRect intRect =
      IntRect::RoundOut(aSamplingRect.X(), aSamplingRect.Y(),
                        aSamplingRect.Width(), aSamplingRect.Height());

  IntSize size = mSourceSurface->GetSize();
  if (!IntRect(IntPoint(), size).Contains(intRect)) {
    return false;
  }

  DrawInternal(aDrawTarget, aOp, aAntialiasMode, aFillRect, intRect,
               ExtendMode::CLAMP, aSamplingFilter, aOpacity, gfxMatrix());
  return true;
}

bool gfxSurfaceDrawable::Draw(gfxContext* aContext, const gfxRect& aFillRect,
                              ExtendMode aExtendMode,
                              const SamplingFilter aSamplingFilter,
                              gfxFloat aOpacity, const gfxMatrix& aTransform)

{
  if (!mSourceSurface) {
    return true;
  }

  DrawInternal(aContext->GetDrawTarget(), aContext->CurrentOp(),
               aContext->CurrentAntialiasMode(), aFillRect, IntRect(),
               aExtendMode, aSamplingFilter, aOpacity, aTransform);
  return true;
}

void gfxSurfaceDrawable::DrawInternal(
    DrawTarget* aDrawTarget, CompositionOp aOp, AntialiasMode aAntialiasMode,
    const gfxRect& aFillRect, const IntRect& aSamplingRect,
    ExtendMode aExtendMode, const SamplingFilter aSamplingFilter,
    gfxFloat aOpacity, const gfxMatrix& aTransform) {
  Matrix patternTransform = ToMatrix(aTransform * mTransform);
  patternTransform.Invert();

  SurfacePattern pattern(mSourceSurface, aExtendMode, patternTransform,
                         aSamplingFilter, aSamplingRect);

  Rect fillRect = ToRect(aFillRect);

  if (aOp == CompositionOp::OP_SOURCE && aOpacity == 1.0) {
    // Emulate cairo operator source which is bound by mask!
    aDrawTarget->ClearRect(fillRect);
    aDrawTarget->FillRect(fillRect, pattern);
  } else {
    aDrawTarget->FillRect(fillRect, pattern,
                          DrawOptions(aOpacity, aOp, aAntialiasMode));
  }
}

gfxCallbackDrawable::gfxCallbackDrawable(gfxDrawingCallback* aCallback,
                                         const IntSize aSize)
    : gfxDrawable(aSize), mCallback(aCallback) {}

already_AddRefed<gfxSurfaceDrawable> gfxCallbackDrawable::MakeSurfaceDrawable(
    gfxContext* aContext, const SamplingFilter aSamplingFilter) {
  SurfaceFormat format = gfxPlatform::GetPlatform()->Optimal2DFormatForContent(
      gfxContentType::COLOR_ALPHA);
  if (!aContext->GetDrawTarget()->CanCreateSimilarDrawTarget(mSize, format)) {
    return nullptr;
  }
  RefPtr<DrawTarget> dt =
      aContext->GetDrawTarget()->CreateSimilarDrawTarget(mSize, format);

  if (!dt || !dt->IsValid()) return nullptr;

  RefPtr<gfxContext> ctx = gfxContext::CreateOrNull(dt);
  MOZ_ASSERT(ctx);  // already checked for target above
  Draw(ctx, gfxRect(0, 0, mSize.width, mSize.height), ExtendMode::CLAMP,
       aSamplingFilter);

  RefPtr<SourceSurface> surface = dt->Snapshot();
  if (surface) {
    RefPtr<gfxSurfaceDrawable> drawable =
        new gfxSurfaceDrawable(surface, mSize);
    return drawable.forget();
  }
  return nullptr;
}

static bool IsRepeatingExtendMode(ExtendMode aExtendMode) {
  switch (aExtendMode) {
    case ExtendMode::REPEAT:
    case ExtendMode::REPEAT_X:
    case ExtendMode::REPEAT_Y:
      return true;
    default:
      return false;
  }
}

bool gfxCallbackDrawable::Draw(gfxContext* aContext, const gfxRect& aFillRect,
                               ExtendMode aExtendMode,
                               const SamplingFilter aSamplingFilter,
                               gfxFloat aOpacity, const gfxMatrix& aTransform) {
  if ((IsRepeatingExtendMode(aExtendMode) || aOpacity != 1.0 ||
       aContext->CurrentOp() != CompositionOp::OP_OVER) &&
      !mSurfaceDrawable) {
    mSurfaceDrawable = MakeSurfaceDrawable(aContext, aSamplingFilter);
  }

  if (mSurfaceDrawable)
    return mSurfaceDrawable->Draw(aContext, aFillRect, aExtendMode,
                                  aSamplingFilter, aOpacity, aTransform);

  if (mCallback)
    return (*mCallback)(aContext, aFillRect, aSamplingFilter, aTransform);

  return false;
}

gfxPatternDrawable::gfxPatternDrawable(gfxPattern* aPattern,
                                       const IntSize aSize)
    : gfxDrawable(aSize), mPattern(aPattern) {}

gfxPatternDrawable::~gfxPatternDrawable() = default;

class DrawingCallbackFromDrawable : public gfxDrawingCallback {
 public:
  explicit DrawingCallbackFromDrawable(gfxDrawable* aDrawable)
      : mDrawable(aDrawable) {
    NS_ASSERTION(aDrawable, "aDrawable is null!");
  }

  virtual ~DrawingCallbackFromDrawable() = default;

  bool operator()(gfxContext* aContext, const gfxRect& aFillRect,
                  const SamplingFilter aSamplingFilter,
                  const gfxMatrix& aTransform = gfxMatrix()) override {
    return mDrawable->Draw(aContext, aFillRect, ExtendMode::CLAMP,
                           aSamplingFilter, 1.0, aTransform);
  }

 private:
  RefPtr<gfxDrawable> mDrawable;
};

already_AddRefed<gfxCallbackDrawable>
gfxPatternDrawable::MakeCallbackDrawable() {
  RefPtr<gfxDrawingCallback> callback = new DrawingCallbackFromDrawable(this);
  RefPtr<gfxCallbackDrawable> callbackDrawable =
      new gfxCallbackDrawable(callback, mSize);
  return callbackDrawable.forget();
}

bool gfxPatternDrawable::Draw(gfxContext* aContext, const gfxRect& aFillRect,
                              ExtendMode aExtendMode,
                              const SamplingFilter aSamplingFilter,
                              gfxFloat aOpacity, const gfxMatrix& aTransform) {
  DrawTarget& aDrawTarget = *aContext->GetDrawTarget();

  if (!mPattern) return false;

  if (IsRepeatingExtendMode(aExtendMode)) {
    // We can't use mPattern directly: We want our repeated tiles to have
    // the size mSize, which might not be the case in mPattern.
    // So we need to draw mPattern into a surface of size mSize, create
    // a pattern from the surface and draw that pattern.
    // gfxCallbackDrawable and gfxSurfaceDrawable already know how to do
    // those things, so we use them here. Drawing mPattern into the surface
    // will happen through this Draw() method with aRepeat = false.
    RefPtr<gfxCallbackDrawable> callbackDrawable = MakeCallbackDrawable();
    return callbackDrawable->Draw(aContext, aFillRect, aExtendMode,
                                  aSamplingFilter, aOpacity, aTransform);
  }

  gfxMatrix oldMatrix = mPattern->GetMatrix();
  mPattern->SetMatrix(aTransform * oldMatrix);
  DrawOptions drawOptions(aOpacity);
  aDrawTarget.FillRect(ToRect(aFillRect), *mPattern->GetPattern(&aDrawTarget),
                       drawOptions);
  mPattern->SetMatrix(oldMatrix);
  return true;
}