glshadermanager.h

Go to the documentation of this file.

/*
    KWin - the KDE window manager
    This file is part of the KDE project.
 
    SPDX-FileCopyrightText: 2006-2007 Rivo Laks <rivolaks@hot.ee>
    SPDX-FileCopyrightText: 2010, 2011 Martin Gräßlin <mgraesslin@kde.org>
    SPDX-FileCopyrightText: 2023 Xaver Hugl <xaver.hugl@kde.org>
 
    SPDX-License-Identifier: GPL-2.0-or-later
*/
#pragma once
#include "kwin_export.h"
 
#include <QByteArray>
#include <QFlags>
#include <QStack>
#include <map>
#include <memory>
 
namespace KWin
{
 
class GLShader;
 
enum class ShaderTrait {
    MapTexture = (1 << 0),
    UniformColor = (1 << 1),
    Modulate = (1 << 2),
    AdjustSaturation = (1 << 3),
    TransformColorspace = (1 << 4),
    MapExternalTexture = (1 << 5),
};
 
Q_DECLARE_FLAGS(ShaderTraits, ShaderTrait)
 
 
class KWIN_EXPORT ShaderManager
{
public:
    explicit ShaderManager();
    ~ShaderManager();
 
    GLShader *shader(ShaderTraits traits);
 
    GLShader *getBoundShader() const;
 
    bool isShaderBound() const;
 
    GLShader *pushShader(ShaderTraits traits);
 
    void pushShader(GLShader *shader);
 
    void popShader();
 
    std::unique_ptr<GLShader> loadShaderFromCode(const QByteArray &vertexSource, const QByteArray &fragmentSource);
 
    std::unique_ptr<GLShader> generateCustomShader(ShaderTraits traits, const QByteArray &vertexSource = QByteArray(), const QByteArray &fragmentSource = QByteArray());
 
    std::unique_ptr<GLShader> generateShaderFromFile(ShaderTraits traits, const QString &vertexFile = QString(), const QString &fragmentFile = QString());
 
    static ShaderManager *instance();
 
    static void cleanup();
 
private:
    void bindFragDataLocations(GLShader *shader);
    void bindAttributeLocations(GLShader *shader) const;
 
    std::optional<QByteArray> preprocess(const QByteArray &src, int recursionDepth = 0) const;
    QByteArray generateVertexSource(ShaderTraits traits) const;
    QByteArray generateFragmentSource(ShaderTraits traits) const;
    std::unique_ptr<GLShader> generateShader(ShaderTraits traits);
 
    QStack<GLShader *> m_boundShaders;
    std::map<ShaderTraits, std::unique_ptr<GLShader>> m_shaderHash;
    static std::unique_ptr<ShaderManager> s_shaderManager;
};
 
class KWIN_EXPORT ShaderBinder
{
public:
    explicit ShaderBinder(GLShader *shader);
    explicit ShaderBinder(ShaderTraits traits);
    ~ShaderBinder();
 
    GLShader *shader();
 
private:
    GLShader *m_shader;
};
 
inline ShaderBinder::ShaderBinder(GLShader *shader)
    : m_shader(shader)
{
    ShaderManager::instance()->pushShader(shader);
}
 
inline ShaderBinder::ShaderBinder(ShaderTraits traits)
    : m_shader(nullptr)
{
    m_shader = ShaderManager::instance()->pushShader(traits);
}
 
inline ShaderBinder::~ShaderBinder()
{
    ShaderManager::instance()->popShader();
}
 
inline GLShader *ShaderBinder::shader()
{
    return m_shader;
}
 
}
 
Q_DECLARE_OPERATORS_FOR_FLAGS(KWin::ShaderTraits)