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#include "attachmentpack_p.h"
#include <Qt3DRender/private/rendertarget_p.h>
#include <Qt3DRender/private/rendertargetselectornode_p.h>

QT_BEGIN_NAMESPACE

namespace Qt3DRender {
namespace Render {

AttachmentPack::AttachmentPack()
{
}

AttachmentPack::AttachmentPack(const RenderTargetSelector *selector, const RenderTarget *target, AttachmentManager *attachmentManager)
{
    // Cache draw buffers list
    const QVector<QRenderTargetOutput::AttachmentPoint> selectedAttachmentPoints = selector->outputs();

    // Copy attachments
    const auto outputIds = target->renderOutputs();
    for (Qt3DCore::QNodeId outputId : outputIds) {
        const RenderTargetOutput *output = attachmentManager->lookupResource(outputId);
        if (output)
            m_attachments.append(*output->attachment());
    }

    // Create actual DrawBuffers list that is used for glDrawBuffers

    // If nothing is specified, use all the attachments as draw buffers
    if (selectedAttachmentPoints.isEmpty()) {
        m_drawBuffers.reserve(m_attachments.size());
        for (const Attachment &attachment : qAsConst(m_attachments))
            // only consider Color Attachments
            if (attachment.m_point <= QRenderTargetOutput::Color15)
                m_drawBuffers.push_back((int) attachment.m_point);
    } else {
        m_drawBuffers.reserve(selectedAttachmentPoints.size());
        for (QRenderTargetOutput::AttachmentPoint drawBuffer : selectedAttachmentPoints)
            if (drawBuffer <= QRenderTargetOutput::Color15)
                m_drawBuffers.push_back((int) drawBuffer);
    }
}

// return index of given attachment within actual draw buffers list
int AttachmentPack::getDrawBufferIndex(QRenderTargetOutput::AttachmentPoint attachmentPoint) const
{
    for (int i = 0; i < m_drawBuffers.size(); i++)
        if (m_drawBuffers.at(i) == (int)attachmentPoint)
            return i;
    return -1;
}

} // namespace Render
} // namespace Qt3DRender

QT_END_NAMESPACE
