/* -*- 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_layers_mlgpu_RenderViewMLGPU_h
#define mozilla_gfx_layers_mlgpu_RenderViewMLGPU_h

#include "LayerManagerMLGPU.h"
#include "ClearRegionHelper.h"
#include "RenderPassMLGPU.h"
#include "Units.h"
#include <deque>

namespace mozilla {
namespace layers {

class FrameBuilder;
class ContainerLayerMLGPU;
class MLGRenderTarget;

class RenderViewMLGPU {
 public:
  NS_INLINE_DECL_REFCOUNTING(RenderViewMLGPU)

  // Constructor for the widget render target.
  RenderViewMLGPU(FrameBuilder* aBuilder, MLGRenderTarget* aTarget,
                  const nsIntRegion& aInvalidRegion);

  // Constructor for intermediate surfaces.
  RenderViewMLGPU(FrameBuilder* aBuilder, ContainerLayerMLGPU* aContainer,
                  RenderViewMLGPU* aParent);

  void Prepare();
  void Render();
  void AddChild(RenderViewMLGPU* aParent);
  void AddItem(LayerMLGPU* aItem, const gfx::IntRect& aBounds,
               Maybe<gfx::Polygon>&& aGeometry);
  void FinishBuilding();

  const gfx::IntPoint& GetTargetOffset() const { return mTargetOffset; }
  RenderViewMLGPU* GetParent() const { return mParent; }
  bool HasDepthBuffer() const { return mUseDepthBuffer; }

  // Render after having previously delayed rendering due to the view
  // requiring a backdrop copy.
  void RenderAfterBackdropCopy();
  void RestoreDeviceState();

  // The size and render target cannot be read until the view has finished
  // building, since we try to right-size the render target to the visible
  // region.
  MLGRenderTarget* GetRenderTarget() const;
  gfx::IntSize GetSize() const;

  gfx::IntRect GetInvalidRect() const { return mInvalidBounds; }

 private:
  RenderViewMLGPU(FrameBuilder* aBuilder, RenderViewMLGPU* aParent);
  ~RenderViewMLGPU();

  void ExecuteRendering();
  bool UpdateVisibleRegion(ItemInfo& aItem);
  void AddItemFrontToBack(LayerMLGPU* aLayer, ItemInfo& aItem);
  void AddItemBackToFront(LayerMLGPU* aLayer, ItemInfo& aItem);

  void PrepareClears();
  void SetDeviceState();
  void SetDepthTestMode(MLGDepthTestMode aMode);

  void ExecutePass(RenderPassMLGPU* aPass);

  // Return the sorting index offset to use.
  int32_t PrepareDepthBuffer();

 private:
  std::deque<RefPtr<RenderPassMLGPU>> mFrontToBack;
  std::deque<RefPtr<RenderPassMLGPU>> mBackToFront;

  FrameBuilder* mBuilder;
  RefPtr<MLGDevice> mDevice;
  RenderViewMLGPU* mParent;
  std::vector<RefPtr<RenderViewMLGPU>> mChildren;

  // Shader data.
  ConstantBufferSection mWorldConstants;

  // Information for the initial target surface clear. This covers the area that
  // won't be occluded by opaque content.
  ClearRegionHelper mPreClear;

  // The post-clear region, that must be cleared after all drawing is done.
  nsIntRegion mPostClearRegion;
  ClearRegionHelper mPostClear;

  // Either an MLGSwapChain-derived render target, or an intermediate surface.
  RefPtr<MLGRenderTarget> mTarget;

  // For intermediate render targets only, this is the layer owning the render
  // target.
  ContainerLayerMLGPU* mContainer;

  // The offset adjustment from container layer space to render target space.
  // This is 0,0 for the root view.
  gfx::IntPoint mTargetOffset;

  // The invalid bounds as computed by LayerTreeInvalidation. This is the
  // initial render bounds size, if invalidation is disabled.
  gfx::IntRect mInvalidBounds;

  // The occluded region, which is updated every time we process an opaque,
  // rectangular item. This is not actually in LayerPixels, we do this to
  // avoid FromUnknownRegion which has array copies.
  LayerIntRegion mOccludedRegion;

  // True if we've finished adding layers to the view.
  bool mFinishedBuilding;

  // This state is used to avoid changing buffers while we execute batches.
  size_t mCurrentLayerBufferIndex;
  size_t mCurrentMaskRectBufferIndex;

  // This state is saved locally so it can be restored in RestoreDeviceState.
  MLGDepthTestMode mCurrentDepthMode;

  // Depth-buffer tracking.
  int32_t mNextSortIndex;
  bool mUseDepthBuffer;
  bool mDepthBufferNeedsClear;
};

}  // namespace layers
}  // namespace mozilla

#endif  // mozilla_gfx_layers_mlgpu_RenderViewMLGPU_h