gecko-dev/gfx/layers/opengl/CompositorOGL.h

/* -*- 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/. */

#ifndef MOZILLA_GFX_COMPOSITOROGL_H
#define MOZILLA_GFX_COMPOSITOROGL_H

#include "mozilla/layers/Compositor.h"
#include "GLContext.h"
#include "LayerManagerOGLProgram.h"
#include "mozilla/layers/Effects.h"
#include "nsTArray.h"

#include "mozilla/TimeStamp.h"

namespace mozilla {
namespace layers {

struct FPSState;
class CompositingRenderTargetOGL;
class GLManagerCompositor;

class CompositorOGL : public Compositor
{
  typedef mozilla::gl::GLContext GLContext;
  typedef mozilla::gl::ShaderProgramType ProgramType;
  
  friend class GLManagerCompositor;

public:
  CompositorOGL(nsIWidget *aWidget, int aSurfaceWidth = -1, int aSurfaceHeight = -1,
                bool aUseExternalSurfaceSize = false);

  virtual ~CompositorOGL();

  virtual bool Initialize() MOZ_OVERRIDE;

  virtual void Destroy() MOZ_OVERRIDE;

  virtual TextureFactoryIdentifier GetTextureFactoryIdentifier() MOZ_OVERRIDE
  {
    return TextureFactoryIdentifier(LAYERS_OPENGL,
                                    GetMaxTextureSize(),
                                    mFBOTextureTarget == LOCAL_GL_TEXTURE_2D,
                                    SupportsPartialTextureUpdate());
  }

  virtual TemporaryRef<CompositingRenderTarget> 
  CreateRenderTarget(const gfx::IntRect &aRect, SurfaceInitMode aInit) MOZ_OVERRIDE;

  virtual TemporaryRef<CompositingRenderTarget>
  CreateRenderTargetFromSource(const gfx::IntRect &aRect,
                               const CompositingRenderTarget *aSource) MOZ_OVERRIDE;

  virtual void SetRenderTarget(CompositingRenderTarget *aSurface) MOZ_OVERRIDE;
  virtual CompositingRenderTarget* GetCurrentRenderTarget() MOZ_OVERRIDE;

  virtual void DrawQuad(const gfx::Rect& aRect, const gfx::Rect& aClipRect,
                        const EffectChain &aEffectChain,
                        gfx::Float aOpacity, const gfx::Matrix4x4 &aTransform,
                        const gfx::Point& aOffset) MOZ_OVERRIDE;

  virtual void EndFrame() MOZ_OVERRIDE;
  virtual void EndFrameForExternalComposition(const gfxMatrix& aTransform) MOZ_OVERRIDE;
  virtual void AbortFrame() MOZ_OVERRIDE;

  virtual bool SupportsPartialTextureUpdate() MOZ_OVERRIDE
  {
    return mGLContext->CanUploadSubTextures();
  }

  virtual bool CanUseCanvasLayerForSize(const gfxIntSize &aSize) MOZ_OVERRIDE
  {
    if (!mGLContext)
      return false;
    int32_t maxSize = GetMaxTextureSize();
    return aSize <= gfxIntSize(maxSize, maxSize);
  }

  virtual int32_t GetMaxTextureSize() const MOZ_OVERRIDE
  {
    MOZ_ASSERT(mGLContext);
    GLint texSize = 0;
    mGLContext->fGetIntegerv(LOCAL_GL_MAX_TEXTURE_SIZE,
                             &texSize);
    MOZ_ASSERT(texSize != 0);
    return texSize;
  }

  /**
   * Set the size of the EGL surface we're rendering to, if we're rendering to
   * an EGL surface.
   */
  virtual void SetDestinationSurfaceSize(const gfx::IntSize& aSize) MOZ_OVERRIDE;

  virtual void SetScreenRenderOffset(const ScreenPoint& aOffset) MOZ_OVERRIDE {
    mRenderOffset = aOffset;
  }

  virtual void MakeCurrent(MakeCurrentFlags aFlags = 0) MOZ_OVERRIDE {
    if (mDestroyed) {
      NS_WARNING("Call on destroyed layer manager");
      return;
    }
    mGLContext->MakeCurrent(aFlags & ForceMakeCurrent);
  }

  virtual void SetTargetContext(gfxContext* aTarget) MOZ_OVERRIDE
  {
    mTarget = aTarget;
  }

  virtual void PrepareViewport(const gfx::IntSize& aSize,
                               const gfxMatrix& aWorldTransform) MOZ_OVERRIDE;


#ifdef MOZ_DUMP_PAINTING
  virtual const char* Name() const MOZ_OVERRIDE { return "OGL"; }
#endif // MOZ_DUMP_PAINTING

  virtual void NotifyLayersTransaction() MOZ_OVERRIDE;

  virtual void Pause() MOZ_OVERRIDE;
  virtual bool Resume() MOZ_OVERRIDE;

  virtual nsIWidget* GetWidget() const MOZ_OVERRIDE { return mWidget; }
  virtual const nsIntSize& GetWidgetSize() MOZ_OVERRIDE {
    return mWidgetSize;
  }

  GLContext* gl() const { return mGLContext; }
  gl::ShaderProgramType GetFBOLayerProgramType() const {
    return mFBOTextureTarget == LOCAL_GL_TEXTURE_RECTANGLE_ARB ?
           gl::RGBARectLayerProgramType : gl::RGBALayerProgramType;
  }

  /**
   * The compositor provides with temporary textures for use with direct
   * textruing like gralloc texture.
   * Doing so lets us use gralloc the way it has been designed to be used
   * (see https://wiki.mozilla.org/Platform/GFX/Gralloc)
   */
  GLuint GetTemporaryTexture(GLenum aUnit);
private:
  /** 
   * Context target, nullptr when drawing directly to our swap chain.
   */
  nsRefPtr<gfxContext> mTarget;

  /** Widget associated with this compositor */
  nsIWidget *mWidget;
  nsIntSize mWidgetSize;
  nsRefPtr<GLContext> mGLContext;

  /** The size of the surface we are rendering to */
  nsIntSize mSurfaceSize;

  ScreenPoint mRenderOffset;

  /** Helper-class used by Initialize **/
  class ReadDrawFPSPref MOZ_FINAL : public nsRunnable {
  public:
    NS_IMETHOD Run() MOZ_OVERRIDE;
  };

  already_AddRefed<mozilla::gl::GLContext> CreateContext();

  /** Shader Programs */
  struct ShaderProgramVariations {
    nsAutoTArray<nsAutoPtr<ShaderProgramOGL>, NumMaskTypes> mVariations;
    ShaderProgramVariations() {
      MOZ_COUNT_CTOR(ShaderProgramVariations);
      mVariations.SetLength(NumMaskTypes);
    }
    ~ShaderProgramVariations() {
      MOZ_COUNT_DTOR(ShaderProgramVariations);
    }
  };
  nsTArray<ShaderProgramVariations> mPrograms;

  /** Texture target to use for FBOs */
  GLenum mFBOTextureTarget;

  /** Currently bound render target */
  RefPtr<CompositingRenderTargetOGL> mCurrentRenderTarget;
#ifdef DEBUG
  CompositingRenderTargetOGL* mWindowRenderTarget;
#endif

  /** VBO that has some basics in it for a textured quad,
   *  including vertex coords and texcoords for both
   *  flipped and unflipped textures */
  GLuint mQuadVBO;

  bool mHasBGRA;

  /**
   * When rendering to some EGL surfaces (e.g. on Android), we rely on being told
   * about size changes (via SetSurfaceSize) rather than pulling this information
   * from the widget.
   */
  bool mUseExternalSurfaceSize;

  /**
   * Have we had DrawQuad calls since the last frame was rendered?
   */
  bool mFrameInProgress;

  /* Start a new frame. If aClipRectIn is null and aClipRectOut is non-null,
   * sets *aClipRectOut to the screen dimensions.
   */
  virtual void BeginFrame(const gfx::Rect *aClipRectIn,
                          const gfxMatrix& aTransform,
                          const gfx::Rect& aRenderBounds, 
                          gfx::Rect *aClipRectOut = nullptr,
                          gfx::Rect *aRenderBoundsOut = nullptr) MOZ_OVERRIDE;

  gl::ShaderProgramType GetProgramTypeForEffect(Effect* aEffect) const;

  /**
   * Updates all layer programs with a new projection matrix.
   */
  void SetLayerProgramProjectionMatrix(const gfx3DMatrix& aMatrix);

  /**
   * Helper method for Initialize, creates all valid variations of a program
   * and adds them to mPrograms
   */
  void AddPrograms(gl::ShaderProgramType aType);

  ShaderProgramOGL* GetProgram(gl::ShaderProgramType aType,
                               MaskType aMask = MaskNone) {
    MOZ_ASSERT(ProgramProfileOGL::ProgramExists(aType, aMask),
               "Invalid program type.");
    return mPrograms[aType].mVariations[aMask];
  }

  /**
   * Create a FBO backed by a texture.
   * Note that the texture target type will be
   * of the type returned by FBOTextureTarget; different
   * shaders are required to sample from the different
   * texture types.
   */
  void CreateFBOWithTexture(const gfx::IntRect& aRect, SurfaceInitMode aInit,
                            GLuint aSourceFrameBuffer,
                            GLuint *aFBO, GLuint *aTexture);

  GLintptr QuadVBOVertexOffset() { return 0; }
  GLintptr QuadVBOTexCoordOffset() { return sizeof(float)*4*2; }
  GLintptr QuadVBOFlippedTexCoordOffset() { return sizeof(float)*8*2; }

  void BindQuadVBO() {
    mGLContext->fBindBuffer(LOCAL_GL_ARRAY_BUFFER, mQuadVBO);
  }

  void QuadVBOVerticesAttrib(GLuint aAttribIndex) {
    mGLContext->fVertexAttribPointer(aAttribIndex, 2,
                                     LOCAL_GL_FLOAT, LOCAL_GL_FALSE, 0,
                                     (GLvoid*) QuadVBOVertexOffset());
  }

  void QuadVBOTexCoordsAttrib(GLuint aAttribIndex) {
    mGLContext->fVertexAttribPointer(aAttribIndex, 2,
                                     LOCAL_GL_FLOAT, LOCAL_GL_FALSE, 0,
                                     (GLvoid*) QuadVBOTexCoordOffset());
  }

  void QuadVBOFlippedTexCoordsAttrib(GLuint aAttribIndex) {
    mGLContext->fVertexAttribPointer(aAttribIndex, 2,
                                     LOCAL_GL_FLOAT, LOCAL_GL_FALSE, 0,
                                     (GLvoid*) QuadVBOFlippedTexCoordOffset());
  }

  void BindAndDrawQuad(GLuint aVertAttribIndex,
                       GLuint aTexCoordAttribIndex,
                       bool aFlipped = false)
  {
    BindQuadVBO();
    QuadVBOVerticesAttrib(aVertAttribIndex);

    if (aTexCoordAttribIndex != GLuint(-1)) {
      if (aFlipped)
        QuadVBOFlippedTexCoordsAttrib(aTexCoordAttribIndex);
      else
        QuadVBOTexCoordsAttrib(aTexCoordAttribIndex);

      mGLContext->fEnableVertexAttribArray(aTexCoordAttribIndex);
    }

    mGLContext->fEnableVertexAttribArray(aVertAttribIndex);
    mGLContext->fDrawArrays(LOCAL_GL_TRIANGLE_STRIP, 0, 4);
    mGLContext->fDisableVertexAttribArray(aVertAttribIndex);

    if (aTexCoordAttribIndex != GLuint(-1)) {
      mGLContext->fDisableVertexAttribArray(aTexCoordAttribIndex);
    }
  }

  void BindAndDrawQuad(ShaderProgramOGL *aProg,
                       bool aFlipped = false)
  {
    NS_ASSERTION(aProg->HasInitialized(), "Shader program not correctly initialized");
    BindAndDrawQuad(aProg->AttribLocation(ShaderProgramOGL::VertexCoordAttrib),
                    aProg->AttribLocation(ShaderProgramOGL::TexCoordAttrib),
                    aFlipped);
  }

  void BindAndDrawQuadWithTextureRect(ShaderProgramOGL *aProg,
                                      const gfx::Rect& aTexCoordRect,
                                      TextureSource *aTexture);

  void CleanupResources();

  /**
   * Copies the content of our backbuffer to the set transaction target.
   * Does not restore the target FBO, so only call from EndFrame.
   */
  void CopyToTarget(gfxContext *aTarget, const gfxMatrix& aWorldMatrix);

  /**
   * Records the passed frame timestamp and returns the current estimated FPS.
   */
  double AddFrameAndGetFps(const TimeStamp& timestamp);

  bool mDestroyed;

  nsAutoPtr<FPSState> mFPS;
  // Textures used for direct texturing of buffers like gralloc.
  // The index of the texture in this array must correspond to the texture unit.
  nsTArray<GLuint> mTextures;
  static bool sDrawFPS;
  static bool sFrameCounter;
};

}
}

#endif /* MOZILLA_GFX_COMPOSITOROGL_H */