/* -*- Mode: c++; c-basic-offset: 4; indent-tabs-mode: nil; tab-width: 40; -*- */
/* 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 "SharedSurfaceGL.h"

#include "GLContext.h"
#include "gfxImageSurface.h"

using namespace mozilla::gfx;

namespace mozilla {
namespace gl {

// |src| must begin and end locked, though we may
// temporarily unlock it if we need to.
void
SharedSurface_GL::Copy(SharedSurface_GL* src, SharedSurface_GL* dest,
                       SurfaceFactory_GL* factory)
{
    GLContext* gl = src->GL();

    if (src->AttachType() == AttachmentType::Screen &&
        dest->AttachType() == AttachmentType::Screen)
    {
        // Here, we actually need to blit through a temp surface, so let's make one.
        nsAutoPtr<SharedSurface_GLTexture> tempSurf(
            SharedSurface_GLTexture::Create(gl, gl,
                                            factory->Formats(),
                                            src->Size(),
                                            factory->Caps().alpha));

        Copy(src, tempSurf, factory);
        Copy(tempSurf, dest, factory);
        return;
    }

    if (src->AttachType() == AttachmentType::Screen) {
        SharedSurface* origLocked = gl->GetLockedSurface();
        bool srcNeedsUnlock = false;
        bool origNeedsRelock = false;
        if (origLocked != src) {
            if (origLocked) {
                origLocked->UnlockProd();
                origNeedsRelock = true;
            }

            src->LockProd();
            srcNeedsUnlock = true;
        }

        if (dest->AttachType() == AttachmentType::GLTexture) {
            GLuint destTex = dest->Texture();

            gl->BlitFramebufferToTexture(0, destTex, src->Size(), dest->Size());
        } else if (dest->AttachType() == AttachmentType::GLRenderbuffer) {
            GLuint destRB = dest->Renderbuffer();
            ScopedFramebufferForRenderbuffer destWrapper(gl, destRB);

            gl->BlitFramebufferToFramebuffer(0, destWrapper.FB(),
                                             src->Size(), dest->Size());
        } else {
            MOZ_NOT_REACHED("Unhandled dest->AttachType().");
            return;
        }

        if (srcNeedsUnlock)
            src->UnlockProd();

        if (origNeedsRelock)
            origLocked->LockProd();

        return;
    }

    if (dest->AttachType() == AttachmentType::Screen) {
        SharedSurface* origLocked = gl->GetLockedSurface();
        bool destNeedsUnlock = false;
        bool origNeedsRelock = false;
        if (origLocked != dest) {
            if (origLocked) {
                origLocked->UnlockProd();
                origNeedsRelock = true;
            }

            dest->LockProd();
            destNeedsUnlock = true;
        }

        if (src->AttachType() == AttachmentType::GLTexture) {
            GLuint srcTex = src->Texture();

            gl->BlitTextureToFramebuffer(srcTex, 0, src->Size(), dest->Size());
        } else if (src->AttachType() == AttachmentType::GLRenderbuffer) {
            GLuint srcRB = src->Renderbuffer();
            ScopedFramebufferForRenderbuffer srcWrapper(gl, srcRB);

            gl->BlitFramebufferToFramebuffer(srcWrapper.FB(), 0,
                                             src->Size(), dest->Size());
        } else {
            MOZ_NOT_REACHED("Unhandled src->AttachType().");
            return;
        }

        if (destNeedsUnlock)
            dest->UnlockProd();

        if (origNeedsRelock)
            origLocked->LockProd();

        return;
    }

    // Alright, done with cases involving Screen types.
    // Only {src,dest}x{texture,renderbuffer} left.

    if (src->AttachType() == AttachmentType::GLTexture) {
        GLuint srcTex = src->Texture();

        if (dest->AttachType() == AttachmentType::GLTexture) {
            GLuint destTex = dest->Texture();

            gl->BlitTextureToTexture(srcTex, destTex,
                                     src->Size(), dest->Size());

            return;
        }

        if (dest->AttachType() == AttachmentType::GLRenderbuffer) {
            GLuint destRB = dest->Renderbuffer();
            ScopedFramebufferForRenderbuffer destWrapper(gl, destRB);

            gl->BlitTextureToFramebuffer(srcTex, destWrapper.FB(),
                                         src->Size(), dest->Size());

            return;
        }

        MOZ_NOT_REACHED("Unhandled dest->AttachType().");
        return;
    }

    if (src->AttachType() == AttachmentType::GLRenderbuffer) {
        GLuint srcRB = src->Renderbuffer();
        ScopedFramebufferForRenderbuffer srcWrapper(gl, srcRB);

        if (dest->AttachType() == AttachmentType::GLTexture) {
            GLuint destTex = dest->Texture();

            gl->BlitFramebufferToTexture(srcWrapper.FB(), destTex,
                                         src->Size(), dest->Size());

            return;
        }

        if (dest->AttachType() == AttachmentType::GLRenderbuffer) {
            GLuint destRB = dest->Renderbuffer();
            ScopedFramebufferForRenderbuffer destWrapper(gl, destRB);

            gl->BlitFramebufferToFramebuffer(srcWrapper.FB(), destWrapper.FB(),
                                             src->Size(), dest->Size());

            return;
        }

        MOZ_NOT_REACHED("Unhandled dest->AttachType().");
        return;
    }

    MOZ_NOT_REACHED("Unhandled src->AttachType().");
    return;
}

void
SharedSurface_GL::LockProd()
{
    MOZ_ASSERT(!mIsLocked);

    LockProdImpl();

    mGL->LockSurface(this);
    mIsLocked = true;
}

void
SharedSurface_GL::UnlockProd()
{
    if (!mIsLocked)
        return;

    UnlockProdImpl();

    mGL->UnlockSurface(this);
    mIsLocked = false;
}


SurfaceFactory_GL::SurfaceFactory_GL(GLContext* gl,
                                     SharedSurfaceType type,
                                     const SurfaceCaps& caps)
    : SurfaceFactory(type, caps)
    , mGL(gl)
    , mFormats(gl->ChooseGLFormats(caps))
{
    ChooseBufferBits(caps, mDrawCaps, mReadCaps);
}

void
SurfaceFactory_GL::ChooseBufferBits(const SurfaceCaps& caps,
                                    SurfaceCaps& drawCaps,
                                    SurfaceCaps& readCaps) const
{
    SurfaceCaps screenCaps;

    screenCaps.color = caps.color;
    screenCaps.alpha = caps.alpha;
    screenCaps.bpp16 = caps.bpp16;

    screenCaps.depth = caps.depth;
    screenCaps.stencil = caps.stencil;

    screenCaps.antialias = caps.antialias;
    screenCaps.preserve = caps.preserve;

    if (caps.antialias) {
        drawCaps = screenCaps;
        readCaps.Clear();

        // Color caps need to be duplicated in readCaps.
        readCaps.color = caps.color;
        readCaps.alpha = caps.alpha;
        readCaps.bpp16 = caps.bpp16;
    } else {
        drawCaps.Clear();
        readCaps = screenCaps;
    }
}


SharedSurface_Basic*
SharedSurface_Basic::Create(GLContext* gl,
                            const GLFormats& formats,
                            const gfxIntSize& size,
                            bool hasAlpha)
{
    gl->MakeCurrent();
    GLuint tex = gl->CreateTexture(formats.color_texInternalFormat,
                                   formats.color_texFormat,
                                   formats.color_texType,
                                   size);

    gfxASurface::gfxImageFormat format = gfxASurface::ImageFormatRGB24;
    switch (formats.color_texInternalFormat) {
    case LOCAL_GL_RGB:
    case LOCAL_GL_RGB8:
        if (formats.color_texType == LOCAL_GL_UNSIGNED_SHORT_5_6_5)
            format = gfxASurface::ImageFormatRGB16_565;
        else
            format = gfxASurface::ImageFormatRGB24;
        break;
    case LOCAL_GL_RGBA:
    case LOCAL_GL_RGBA8:
        format = gfxASurface::ImageFormatARGB32;
        break;
    default:
        MOZ_NOT_REACHED("Unhandled Tex format.");
        return nullptr;
    }
    return new SharedSurface_Basic(gl, size, hasAlpha, format, tex);
}

SharedSurface_Basic::SharedSurface_Basic(GLContext* gl,
                                         const gfxIntSize& size,
                                         bool hasAlpha,
                                         gfxASurface::gfxImageFormat format,
                                         GLuint tex)
    : SharedSurface_GL(SharedSurfaceType::Basic,
                       AttachmentType::GLTexture,
                       gl,
                       size,
                       hasAlpha)
    , mTex(tex)
{
    mData = new gfxImageSurface(size, format);
}

SharedSurface_Basic::~SharedSurface_Basic()
{
    if (!mGL->MakeCurrent())
        return;

    GLuint tex = mTex;
    mGL->fDeleteTextures(1, &tex);
}

void
SharedSurface_Basic::Fence()
{
    MOZ_ASSERT(mData->GetSize() == mGL->OffscreenSize());

    mGL->MakeCurrent();
    mData->Flush();
    mGL->ReadScreenIntoImageSurface(mData);
    mData->MarkDirty();
}



SharedSurface_GLTexture*
SharedSurface_GLTexture::Create(GLContext* prodGL,
                             GLContext* consGL,
                             const GLFormats& formats,
                             const gfxIntSize& size,
                             bool hasAlpha)
{
    MOZ_ASSERT(prodGL && consGL);
    MOZ_ASSERT(prodGL->SharesWith(consGL));

    prodGL->MakeCurrent();
    GLuint tex = prodGL->CreateTextureForOffscreen(formats, size);

    return new SharedSurface_GLTexture(prodGL, consGL, size, hasAlpha, tex);
}

SharedSurface_GLTexture::~SharedSurface_GLTexture()
{
    if (!mGL->MakeCurrent())
        return;

    GLuint tex = mTex;
    mGL->fDeleteTextures(1, &tex);

    if (mSync) {
        mGL->fDeleteSync(mSync);
    }
}

void
SharedSurface_GLTexture::Fence()
{
    mGL->MakeCurrent();

    if (mGL->IsExtensionSupported(GLContext::ARB_sync)) {
        if (mSync) {
            mGL->fDeleteSync(mSync);
            mSync = 0;
        }

        mSync = mGL->fFenceSync(LOCAL_GL_SYNC_GPU_COMMANDS_COMPLETE, 0);
        if (mSync) {
            mGL->fFlush();
            return;
        }
    }
    MOZ_ASSERT(!mSync);

    mGL->fFinish();
}

bool
SharedSurface_GLTexture::WaitSync()
{
    if (!mSync) {
        // We must have used glFinish instead of glFenceSync.
        return true;
    }
    MOZ_ASSERT(mGL->IsExtensionSupported(GLContext::ARB_sync));

    GLuint64 waitMS = 500;
    const GLuint64 nsPerMS = 1000 * 1000;
    GLuint64 waitNS = waitMS * nsPerMS;
    GLenum status = mGL->fClientWaitSync(mSync,
                                         0,
                                         waitNS);

    if (status != LOCAL_GL_CONDITION_SATISFIED &&
        status != LOCAL_GL_ALREADY_SIGNALED)
    {
        return false;
    }

    mGL->fDeleteSync(mSync);
    mSync = 0;

    return true;
}

} /* namespace gfx */
} /* namespace mozilla */