/****************************************************************************
**
** Copyright (C) 2016 The Qt Company Ltd.
** Contact: https://www.qt.io/licensing/
**
** This file is part of the QtQuick module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** Commercial License Usage
** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and The Qt Company. For licensing terms
** and conditions see https://www.qt.io/terms-conditions. For further
** information use the contact form at https://www.qt.io/contact-us.
**
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 3 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL3 included in the
** packaging of this file. Please review the following information to
** ensure the GNU Lesser General Public License version 3 requirements
** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 2.0 or (at your option) the GNU General
** Public license version 3 or any later version approved by the KDE Free
** Qt Foundation. The licenses are as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
** included in the packaging of this file. Please review the following
** information to ensure the GNU General Public License requirements will
** be met: https://www.gnu.org/licenses/gpl-2.0.html and
** https://www.gnu.org/licenses/gpl-3.0.html.
**
** $QT_END_LICENSE$
**
****************************************************************************/

#ifndef QSGRENDERER_P_H
#define QSGRENDERER_P_H

//
//  W A R N I N G
//  -------------
//
// This file is not part of the Qt API.  It exists purely as an
// implementation detail.  This header file may change from version to
// version without notice, or even be removed.
//
// We mean it.
//

#include "qsgabstractrenderer.h"
#include "qsgabstractrenderer_p.h"
#include "qsgnode.h"
#include "qsgmaterial.h"

#include <QtQuick/private/qsgcontext_p.h>

QT_BEGIN_NAMESPACE

class QSGBindable;
class QSGNodeUpdater;
class QRhiRenderTarget;
class QRhiCommandBuffer;
class QRhiRenderPassDescriptor;
class QRhiResourceUpdateBatch;

Q_QUICK_PRIVATE_EXPORT bool qsg_test_and_clear_fatal_render_error();
Q_QUICK_PRIVATE_EXPORT void qsg_set_fatal_renderer_error();

class Q_QUICK_PRIVATE_EXPORT QSGRenderer : public QSGAbstractRenderer
{
public:
    QSGRenderer(QSGRenderContext *context);
    virtual ~QSGRenderer();

    // Accessed by QSGMaterial[Rhi]Shader::RenderState.
    QMatrix4x4 currentProjectionMatrix() const { return m_current_projection_matrix; }
    QMatrix4x4 currentModelViewMatrix() const { return m_current_model_view_matrix; }
    QMatrix4x4 currentCombinedMatrix() const { return m_current_projection_matrix * m_current_model_view_matrix; }
    qreal currentOpacity() const { return m_current_opacity; }
    qreal determinant() const { return m_current_determinant; }

    void setDevicePixelRatio(qreal ratio) { m_device_pixel_ratio = ratio; }
    qreal devicePixelRatio() const { return m_device_pixel_ratio; }
    QSGRenderContext *context() const { return m_context; }

    bool isMirrored() const;
    void renderScene(const QSGBindable &bindable);
    void renderScene(uint fboId = 0) override;
    void nodeChanged(QSGNode *node, QSGNode::DirtyState state) override;

    QSGNodeUpdater *nodeUpdater() const;
    void setNodeUpdater(QSGNodeUpdater *updater);
    inline QSGMaterialShader::RenderState state(QSGMaterialShader::RenderState::DirtyStates dirty) const;
    inline QSGMaterialRhiShader::RenderState rhiState(QSGMaterialRhiShader::RenderState::DirtyStates dirty) const;
    virtual void setCustomRenderMode(const QByteArray &) { }
    virtual bool hasCustomRenderModeWithContinuousUpdate() const { return false; }
    virtual void releaseCachedResources() { }

    void clearChangedFlag() { m_changed_emitted = false; }

    // Accessed by QSGMaterialRhiShader::RenderState.
    QByteArray *currentUniformData() const { return m_current_uniform_data; }
    QRhiResourceUpdateBatch *currentResourceUpdateBatch() const { return m_current_resource_update_batch; }
    QRhi *currentRhi() const { return m_rhi; }

    void setRenderTarget(QRhiRenderTarget *rt) { m_rt = rt; }
    QRhiRenderTarget *renderTarget() const { return m_rt; }

    void setCommandBuffer(QRhiCommandBuffer *cb) { m_cb = cb; }
    QRhiCommandBuffer *commandBuffer() const { return m_cb; }

    void setRenderPassDescriptor(QRhiRenderPassDescriptor *rpDesc) { m_rp_desc = rpDesc; }
    QRhiRenderPassDescriptor *renderPassDescriptor() const { return m_rp_desc; }

    void setRenderPassRecordingCallbacks(QSGRenderContext::RenderPassCallback start,
                                         QSGRenderContext::RenderPassCallback end,
                                         void *userData)
    {
        m_renderPassRecordingCallbacks.start = start;
        m_renderPassRecordingCallbacks.end = end;
        m_renderPassRecordingCallbacks.userData = userData;
    }

protected:
    virtual void render() = 0;

    const QSGBindable *bindable() const { return m_bindable; }

    virtual void preprocess();

    void addNodesToPreprocess(QSGNode *node);
    void removeNodesToPreprocess(QSGNode *node);

    QMatrix4x4 m_current_projection_matrix; // includes adjustment, where applicable, so can be treated as Y up in NDC always
    QMatrix4x4 m_current_projection_matrix_native_ndc; // Vulkan has Y down in normalized device coordinates, others Y up...
    QMatrix4x4 m_current_model_view_matrix;
    qreal m_current_opacity;
    qreal m_current_determinant;
    qreal m_device_pixel_ratio;

    QSGRenderContext *m_context;

    QByteArray *m_current_uniform_data;
    QRhiResourceUpdateBatch *m_current_resource_update_batch;
    QRhi *m_rhi;
    QRhiRenderTarget *m_rt;
    QRhiCommandBuffer *m_cb;
    QRhiRenderPassDescriptor *m_rp_desc;
    struct {
        QSGRenderContext::RenderPassCallback start = nullptr;
        QSGRenderContext::RenderPassCallback end = nullptr;
        void *userData = nullptr;
    } m_renderPassRecordingCallbacks;

private:
    QSGNodeUpdater *m_node_updater;

    QSet<QSGNode *> m_nodes_to_preprocess;
    QSet<QSGNode *> m_nodes_dont_preprocess;

    const QSGBindable *m_bindable;

    uint m_changed_emitted : 1;
    uint m_is_rendering : 1;
    uint m_is_preprocessing : 1;
};

class Q_QUICK_PRIVATE_EXPORT QSGBindable
{
public:
    virtual ~QSGBindable() { }
    virtual void bind() const = 0;
    virtual void clear(QSGAbstractRenderer::ClearMode mode) const;
    virtual void reactivate() const;
};
#if QT_CONFIG(opengl)
class QSGBindableFboId : public QSGBindable
{
public:
    QSGBindableFboId(GLuint);
    void bind() const override;
private:
    GLuint m_id;
};
#endif


QSGMaterialShader::RenderState QSGRenderer::state(QSGMaterialShader::RenderState::DirtyStates dirty) const
{
    QSGMaterialShader::RenderState s;
    s.m_dirty = dirty;
    s.m_data = this;
    return s;
}

QSGMaterialRhiShader::RenderState QSGRenderer::rhiState(QSGMaterialRhiShader::RenderState::DirtyStates dirty) const
{
    QSGMaterialRhiShader::RenderState s;
    s.m_dirty = dirty;
    s.m_data = this;
    return s;
}


class Q_QUICK_PRIVATE_EXPORT QSGNodeDumper : public QSGNodeVisitor {

public:
    static void dump(QSGNode *n);

    QSGNodeDumper() {}
    void visitNode(QSGNode *n) override;
    void visitChildren(QSGNode *n) override;

private:
    int m_indent = 0;
};



QT_END_NAMESPACE

#endif