/* -*- Mode: C++; tab-width: 2; 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/. */

#ifndef mozilla_image_ImageRegion_h

#define mozilla_image_ImageRegion_h

#include "gfxRect.h"

#include "mozilla/gfx/Types.h"

namespace mozilla {

namespace image {

/**

 * An axis-aligned rectangle in tiled image space, with an optional sampling

 * restriction rect. The drawing code ensures that if a sampling restriction

 * rect is present, any pixels sampled during the drawing process are found

 * within that rect.

 *

 * The sampling restriction rect exists primarily for callers which perform

 * pixel snapping. Other callers should generally use one of the Create()

 * overloads.

 */

class ImageRegion {

  typedef mozilla::gfx::ExtendMode ExtendMode;

 public:

  static ImageRegion Empty() {

    return ImageRegion(gfxRect(), ExtendMode::CLAMP);

  }

  static ImageRegion Create(const gfxRect& aRect,

                            ExtendMode aExtendMode = ExtendMode::CLAMP) {

    return ImageRegion(aRect, aExtendMode);

  }

  static ImageRegion Create(const gfxSize& aSize,

                            ExtendMode aExtendMode = ExtendMode::CLAMP) {

    return ImageRegion(gfxRect(0, 0, aSize.width, aSize.height), aExtendMode);

  }

  static ImageRegion Create(const nsIntSize& aSize,

                            ExtendMode aExtendMode = ExtendMode::CLAMP) {

    return ImageRegion(gfxRect(0, 0, aSize.width, aSize.height), aExtendMode);

  }

  static ImageRegion CreateWithSamplingRestriction(

      const gfxRect& aRect, const gfxRect& aRestriction,

      ExtendMode aExtendMode = ExtendMode::CLAMP) {

    return ImageRegion(aRect, aRestriction, aExtendMode);

  }

  bool IsRestricted() const { return mIsRestricted; }

  const gfxRect& Rect() const { return mRect; }

  const gfxRect& Restriction() const {

    MOZ_ASSERT(mIsRestricted);

    return mRestriction;

  }

  bool RestrictionContains(const gfxRect& aRect) const {

    if (!mIsRestricted) {

      return true;

    }

    return mRestriction.Contains(aRect);

  }

  ImageRegion Intersect(const gfxRect& aRect) const {

    if (mIsRestricted) {

      return CreateWithSamplingRestriction(aRect.Intersect(mRect),

                                           aRect.Intersect(mRestriction));

    }

    return Create(aRect.Intersect(mRect));

  }

  gfxRect IntersectAndRestrict(const gfxRect& aRect) const {

    gfxRect intersection = mRect.Intersect(aRect);

    if (mIsRestricted) {

      intersection = mRestriction.Intersect(intersection);

    }

    return intersection;

  }

  void MoveBy(gfxFloat dx, gfxFloat dy) {

    mRect.MoveBy(dx, dy);

    if (mIsRestricted) {

      mRestriction.MoveBy(dx, dy);

    }

  }

  void Scale(gfxFloat sx, gfxFloat sy) {

    mRect.Scale(sx, sy);

    if (mIsRestricted) {

      mRestriction.Scale(sx, sy);

    }

  }

  void TransformBy(const gfxMatrix& aMatrix) {

    mRect = aMatrix.TransformRect(mRect);

    if (mIsRestricted) {

      mRestriction = aMatrix.TransformRect(mRestriction);

    }

  }

  void TransformBoundsBy(const gfxMatrix& aMatrix) {

    mRect = aMatrix.TransformBounds(mRect);

    if (mIsRestricted) {

      mRestriction = aMatrix.TransformBounds(mRestriction);

    }

  }

  ImageRegion operator-(const gfxPoint& aPt) const {

    if (mIsRestricted) {

      return CreateWithSamplingRestriction(mRect - aPt, mRestriction - aPt);

    }

    return Create(mRect - aPt);

  }

  ImageRegion operator+(const gfxPoint& aPt) const {

    if (mIsRestricted) {

      return CreateWithSamplingRestriction(mRect + aPt, mRestriction + aPt);

    }

    return Create(mRect + aPt);

  }

  gfx::ExtendMode GetExtendMode() const { return mExtendMode; }

  /* ImageRegion() : mIsRestricted(false) { } */

 private:

  explicit ImageRegion(const gfxRect& aRect, ExtendMode aExtendMode)

      : mRect(aRect), mExtendMode(aExtendMode), mIsRestricted(false) {}

  ImageRegion(const gfxRect& aRect, const gfxRect& aRestriction,

              ExtendMode aExtendMode)

      : mRect(aRect),

        mRestriction(aRestriction),

        mExtendMode(aExtendMode),

        mIsRestricted(true) {}

  gfxRect mRect;

  gfxRect mRestriction;

  ExtendMode mExtendMode;

  bool mIsRestricted;

};

}  // namespace image

}  // namespace mozilla

#endif  // mozilla_image_ImageRegion_h