/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* 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 "TextureImageEGL.h"
#include "GLLibraryEGL.h"
#include "GLContext.h"
#include "GLUploadHelpers.h"
#include "gfxPlatform.h"
#include "mozilla/gfx/Types.h"

namespace mozilla {
namespace gl {

static GLenum GLFormatForImage(gfx::SurfaceFormat aFormat) {
  switch (aFormat) {
    case gfx::SurfaceFormat::B8G8R8A8:
    case gfx::SurfaceFormat::B8G8R8X8:
      return LOCAL_GL_RGBA;
    case gfx::SurfaceFormat::R5G6B5_UINT16:
      return LOCAL_GL_RGB;
    case gfx::SurfaceFormat::A8:
      return LOCAL_GL_LUMINANCE;
    default:
      NS_WARNING("Unknown GL format for Surface format");
  }
  return 0;
}

static GLenum GLTypeForImage(gfx::SurfaceFormat aFormat) {
  switch (aFormat) {
    case gfx::SurfaceFormat::B8G8R8A8:
    case gfx::SurfaceFormat::B8G8R8X8:
    case gfx::SurfaceFormat::A8:
      return LOCAL_GL_UNSIGNED_BYTE;
    case gfx::SurfaceFormat::R5G6B5_UINT16:
      return LOCAL_GL_UNSIGNED_SHORT_5_6_5;
    default:
      NS_WARNING("Unknown GL format for Surface format");
  }
  return 0;
}

TextureImageEGL::TextureImageEGL(GLuint aTexture, const gfx::IntSize& aSize,
                                 GLenum aWrapMode, ContentType aContentType,
                                 GLContext* aContext, Flags aFlags,
                                 TextureState aTextureState,
                                 TextureImage::ImageFormat aImageFormat)
    : TextureImage(aSize, aWrapMode, aContentType, aFlags),
      mGLContext(aContext),
      mUpdateFormat(gfx::ImageFormatToSurfaceFormat(aImageFormat)),
      mEGLImage(nullptr),
      mTexture(aTexture),
      mSurface(nullptr),
      mConfig(nullptr),
      mTextureState(aTextureState),
      mBound(false) {
  if (mUpdateFormat == gfx::SurfaceFormat::UNKNOWN) {
    mUpdateFormat =
        gfxPlatform::GetPlatform()->Optimal2DFormatForContent(GetContentType());
  }

  if (mUpdateFormat == gfx::SurfaceFormat::R5G6B5_UINT16) {
    mTextureFormat = gfx::SurfaceFormat::R8G8B8X8;
  } else if (mUpdateFormat == gfx::SurfaceFormat::B8G8R8X8) {
    mTextureFormat = gfx::SurfaceFormat::B8G8R8X8;
  } else {
    mTextureFormat = gfx::SurfaceFormat::B8G8R8A8;
  }
}

TextureImageEGL::~TextureImageEGL() {
  if (mGLContext->IsDestroyed() || !mGLContext->IsOwningThreadCurrent()) {
    return;
  }

  // If we have a context, then we need to delete the texture;
  // if we don't have a context (either real or shared),
  // then they went away when the contex was deleted, because it
  // was the only one that had access to it.
  if (mGLContext->MakeCurrent()) {
    mGLContext->fDeleteTextures(1, &mTexture);
  }
  ReleaseTexImage();
  DestroyEGLSurface();
}

bool TextureImageEGL::DirectUpdate(
    gfx::DataSourceSurface* aSurf, const nsIntRegion& aRegion,
    const gfx::IntPoint& aFrom /* = gfx::IntPoint(0,0) */) {
  gfx::IntRect bounds = aRegion.GetBounds();

  nsIntRegion region;
  if (mTextureState != Valid) {
    bounds = gfx::IntRect(0, 0, mSize.width, mSize.height);
    region = nsIntRegion(bounds);
  } else {
    region = aRegion;
  }

  bool needInit = mTextureState == Created;
  size_t uploadSize = 0;
  mTextureFormat = UploadSurfaceToTexture(mGLContext, aSurf, region, mTexture,
                                          mSize, &uploadSize, needInit, aFrom);
  if (mTextureFormat == SurfaceFormat::UNKNOWN) {
    return false;
  }

  if (uploadSize > 0) {
    UpdateUploadSize(uploadSize);
  }

  mTextureState = Valid;
  return true;
}

void TextureImageEGL::BindTexture(GLenum aTextureUnit) {
  // Ensure the texture is allocated before it is used.
  if (mTextureState == Created) {
    Resize(mSize);
  }

  mGLContext->fActiveTexture(aTextureUnit);
  mGLContext->fBindTexture(LOCAL_GL_TEXTURE_2D, mTexture);
  mGLContext->fActiveTexture(LOCAL_GL_TEXTURE0);
}

void TextureImageEGL::Resize(const gfx::IntSize& aSize) {
  if (mSize == aSize && mTextureState != Created) return;

  mGLContext->fBindTexture(LOCAL_GL_TEXTURE_2D, mTexture);

  mGLContext->fTexImage2D(LOCAL_GL_TEXTURE_2D, 0,
                          GLFormatForImage(mUpdateFormat), aSize.width,
                          aSize.height, 0, GLFormatForImage(mUpdateFormat),
                          GLTypeForImage(mUpdateFormat), nullptr);

  mTextureState = Allocated;
  mSize = aSize;
}

bool TextureImageEGL::BindTexImage() {
  if (mBound && !ReleaseTexImage()) return false;

  EGLBoolean success = sEGLLibrary.fBindTexImage(
      EGL_DISPLAY(), (EGLSurface)mSurface, LOCAL_EGL_BACK_BUFFER);

  if (success == LOCAL_EGL_FALSE) return false;

  mBound = true;
  return true;
}

bool TextureImageEGL::ReleaseTexImage() {
  if (!mBound) return true;

  EGLBoolean success = sEGLLibrary.fReleaseTexImage(
      EGL_DISPLAY(), (EGLSurface)mSurface, LOCAL_EGL_BACK_BUFFER);

  if (success == LOCAL_EGL_FALSE) return false;

  mBound = false;
  return true;
}

void TextureImageEGL::DestroyEGLSurface(void) {
  if (!mSurface) return;

  sEGLLibrary.fDestroySurface(EGL_DISPLAY(), mSurface);
  mSurface = nullptr;
}

already_AddRefed<TextureImage> CreateTextureImageEGL(
    GLContext* gl, const gfx::IntSize& aSize,
    TextureImage::ContentType aContentType, GLenum aWrapMode,
    TextureImage::Flags aFlags, TextureImage::ImageFormat aImageFormat) {
  RefPtr<TextureImage> t =
      new gl::TiledTextureImage(gl, aSize, aContentType, aFlags, aImageFormat);
  return t.forget();
}

already_AddRefed<TextureImage> TileGenFuncEGL(
    GLContext* gl, const gfx::IntSize& aSize,
    TextureImage::ContentType aContentType, TextureImage::Flags aFlags,
    TextureImage::ImageFormat aImageFormat) {
  gl->MakeCurrent();

  GLuint texture;
  gl->fGenTextures(1, &texture);

  RefPtr<TextureImageEGL> teximage =
      new TextureImageEGL(texture, aSize, LOCAL_GL_CLAMP_TO_EDGE, aContentType,
                          gl, aFlags, TextureImage::Created, aImageFormat);

  teximage->BindTexture(LOCAL_GL_TEXTURE0);

  GLint texfilter = aFlags & TextureImage::UseNearestFilter ? LOCAL_GL_NEAREST
                                                            : LOCAL_GL_LINEAR;
  gl->fTexParameteri(LOCAL_GL_TEXTURE_2D, LOCAL_GL_TEXTURE_MIN_FILTER,
                     texfilter);
  gl->fTexParameteri(LOCAL_GL_TEXTURE_2D, LOCAL_GL_TEXTURE_MAG_FILTER,
                     texfilter);
  gl->fTexParameteri(LOCAL_GL_TEXTURE_2D, LOCAL_GL_TEXTURE_WRAP_S,
                     LOCAL_GL_CLAMP_TO_EDGE);
  gl->fTexParameteri(LOCAL_GL_TEXTURE_2D, LOCAL_GL_TEXTURE_WRAP_T,
                     LOCAL_GL_CLAMP_TO_EDGE);

  return teximage.forget();
}

}  // namespace gl
}  // namespace mozilla