C++ Extensions3D::ensureEnabled方法代码示例

SharedGraphicsContext3D::SharedGraphicsContext3D(PassRefPtr<GraphicsContext3D> context, PassOwnPtr<SolidFillShader> solidFillShader, PassOwnPtr<TexShader> texShader, PassOwnPtr<BicubicShader> bicubicShader, PassOwnArrayPtr<OwnPtr<ConvolutionShader> > convolutionShaders, CreationFlags flags)
    : m_context(context)
    , m_bgraSupported(false)
    , m_quadVertices(0)
    , m_solidFillShader(solidFillShader)
    , m_texShader(texShader)
    , m_bicubicShader(bicubicShader)
    , m_convolutionShaders(convolutionShaders)
    , m_oesStandardDerivativesSupported(false)
    , m_flags(flags)
#if USE(SKIA)
    , m_grContext(0)
#endif
{
    allContexts()->add(this);
    Extensions3D* extensions = m_context->getExtensions();
    m_bgraSupported = extensions->supports("GL_EXT_texture_format_BGRA8888") && extensions->supports("GL_EXT_read_format_bgra");
    if (m_bgraSupported) {
        extensions->ensureEnabled("GL_EXT_texture_format_BGRA8888");
        extensions->ensureEnabled("GL_EXT_read_format_bgra");
    }
    m_oesStandardDerivativesSupported = extensions->supports("GL_OES_standard_derivatives");
    if (m_oesStandardDerivativesSupported)
        extensions->ensureEnabled("GL_OES_standard_derivatives");
}

bool FECustomFilter::createMultisampleBuffer()
{
    ASSERT(!m_triedMultisampleBuffer);
    m_triedMultisampleBuffer = true;

    Extensions3D* extensions = m_context->getExtensions();
    if (!extensions
            || !extensions->maySupportMultisampling()
            || !extensions->supports("GL_ANGLE_framebuffer_multisample")
            || !extensions->supports("GL_ANGLE_framebuffer_blit")
            || !extensions->supports("GL_OES_rgb8_rgba8"))
        return false;

    extensions->ensureEnabled("GL_ANGLE_framebuffer_blit");
    extensions->ensureEnabled("GL_ANGLE_framebuffer_multisample");
    extensions->ensureEnabled("GL_OES_rgb8_rgba8");

    if (!m_multisampleFrameBuffer)
        m_multisampleFrameBuffer = m_context->createFramebuffer();
    if (!m_multisampleRenderBuffer)
        m_multisampleRenderBuffer = m_context->createRenderbuffer();
    if (!m_multisampleDepthBuffer)
        m_multisampleDepthBuffer = m_context->createRenderbuffer();

    return true;
}

void GraphicsContext3D::validateAttributes()
{
    Extensions3D* extensions = getExtensions();
    if (m_attrs.stencil) {
        const char* packedDepthStencilExtension = isGLES2Compliant() ? "GL_OES_packed_depth_stencil" : "GL_EXT_packed_depth_stencil";
        if (extensions->supports(packedDepthStencilExtension)) {
            extensions->ensureEnabled(packedDepthStencilExtension);
            // Force depth if stencil is true.
            m_attrs.depth = true;
        } else
            m_attrs.stencil = false;
    }
    if (m_attrs.antialias) {
        bool isValidVendor = true;
        // Currently in Mac we only turn on antialias if vendor is NVIDIA,
        // or if ATI and on 10.7.2 and above.
        const char* vendor = reinterpret_cast<const char*>(::glGetString(GL_VENDOR));
        if (!std::strstr(vendor, "NVIDIA") && !(std::strstr(vendor, "ATI") && systemAllowsMultisamplingOnATICards()))
            isValidVendor = false;
        if (!isValidVendor || !extensions->supports("GL_ANGLE_framebuffer_multisample") || isGLES2Compliant())
            m_attrs.antialias = false;
        else
            extensions->ensureEnabled("GL_ANGLE_framebuffer_multisample");
    }
}

PassRefPtr<DrawingBuffer> DrawingBuffer::create(GraphicsContext3D* context, const IntSize& size)
{
    Extensions3D* extensions = context->getExtensions();
    bool multisampleSupported = extensions->supports("GL_ANGLE_framebuffer_blit") && extensions->supports("GL_ANGLE_framebuffer_multisample") && extensions->supports("GL_OES_rgb8_rgba8");
    if (multisampleSupported) {
        extensions->ensureEnabled("GL_ANGLE_framebuffer_blit");
        extensions->ensureEnabled("GL_ANGLE_framebuffer_multisample");
        extensions->ensureEnabled("GL_OES_rgb8_rgba8");
    }
    bool packedDepthStencilSupported = extensions->supports("GL_OES_packed_depth_stencil");
    if (packedDepthStencilSupported)
        extensions->ensureEnabled("GL_OES_packed_depth_stencil");
    RefPtr<DrawingBuffer> drawingBuffer = adoptRef(new DrawingBuffer(context, size, multisampleSupported, packedDepthStencilSupported));
    return (drawingBuffer->m_context) ? drawingBuffer.release() : 0;
}

bool LayerTextureUpdaterSkPicture::createFrameBuffer()
{
    ASSERT(!m_fbo);
    ASSERT(!m_bufferSize.isEmpty());

    // SKIA only needs color and stencil buffers, not depth buffer.
    // But it is very uncommon for cards to support color + stencil FBO config.
    // The most common config is color + packed-depth-stencil.
    // Instead of iterating through all possible FBO configs, we only try the
    // most common one here.
    // FIXME: Delegate the task of creating frame-buffer to SKIA.
    // It has all necessary code to iterate through all possible configs
    // and choose the one most suitable for its purposes.
    Extensions3D* extensions = context()->getExtensions();
    if (!extensions->supports("GL_OES_packed_depth_stencil"))
        return false;
    extensions->ensureEnabled("GL_OES_packed_depth_stencil");

    // Create and bind a frame-buffer-object.
    m_fbo = context()->createFramebuffer();
    if (!m_fbo)
        return false;
    context()->bindFramebuffer(GraphicsContext3D::FRAMEBUFFER, m_fbo);

    // We just need to create a stencil buffer for FBO.
    // The color buffer (texture) will be provided by tiles.
    // SKIA does not need depth buffer.
    m_depthStencilBuffer = context()->createRenderbuffer();
    if (!m_depthStencilBuffer) {
        deleteFrameBuffer();
        return false;
    }
    context()->bindRenderbuffer(GraphicsContext3D::RENDERBUFFER, m_depthStencilBuffer);
    context()->renderbufferStorage(GraphicsContext3D::RENDERBUFFER, Extensions3D::DEPTH24_STENCIL8, m_bufferSize.width(), m_bufferSize.height());
    context()->framebufferRenderbuffer(GraphicsContext3D::FRAMEBUFFER, GraphicsContext3D::DEPTH_ATTACHMENT, GraphicsContext3D::RENDERBUFFER, m_depthStencilBuffer);
    context()->framebufferRenderbuffer(GraphicsContext3D::FRAMEBUFFER, GraphicsContext3D::STENCIL_ATTACHMENT, GraphicsContext3D::RENDERBUFFER, m_depthStencilBuffer);

    // Create a skia gpu canvas.
    GrContext* skiaContext = m_context->grContext();
    GrPlatformSurfaceDesc targetDesc;
    targetDesc.reset();
    targetDesc.fSurfaceType = kRenderTarget_GrPlatformSurfaceType;
    targetDesc.fRenderTargetFlags = kNone_GrPlatformRenderTargetFlagBit;
    targetDesc.fWidth = m_bufferSize.width();
    targetDesc.fHeight = m_bufferSize.height();
    targetDesc.fConfig = kRGBA_8888_GrPixelConfig;
    targetDesc.fStencilBits = 8;
    targetDesc.fPlatformRenderTarget = m_fbo;
    SkAutoTUnref<GrRenderTarget> target(static_cast<GrRenderTarget*>(skiaContext->createPlatformSurface(targetDesc)));
    SkAutoTUnref<SkDevice> device(new SkGpuDevice(skiaContext, target.get()));
    m_canvas = adoptPtr(new SkCanvas(device.get()));

    context()->bindFramebuffer(GraphicsContext3D::FRAMEBUFFER, 0);
    return true;
}

PassRefPtr<DrawingBuffer> DrawingBuffer::create(GraphicsContext3D* context, const IntSize& size, PreserveDrawingBuffer preserve, AlphaRequirement alpha)
{

#if PLATFORM(JS)
	webkitTrace();
#endif
    Extensions3D* extensions = context->getExtensions();
    bool multisampleSupported = extensions->maySupportMultisampling()
        && extensions->supports("GL_ANGLE_framebuffer_blit")
        && extensions->supports("GL_ANGLE_framebuffer_multisample")
        && extensions->supports("GL_OES_rgb8_rgba8");
    if (multisampleSupported) {
        extensions->ensureEnabled("GL_ANGLE_framebuffer_blit");
        extensions->ensureEnabled("GL_ANGLE_framebuffer_multisample");
        extensions->ensureEnabled("GL_OES_rgb8_rgba8");
    }
    bool packedDepthStencilSupported = extensions->supports("GL_OES_packed_depth_stencil");
    if (packedDepthStencilSupported)
        extensions->ensureEnabled("GL_OES_packed_depth_stencil");
    RefPtr<DrawingBuffer> drawingBuffer = adoptRef(new DrawingBuffer(context, size, multisampleSupported, packedDepthStencilSupported, preserve, alpha));
    return (drawingBuffer->m_context) ? drawingBuffer.release() : 0;
}