File indexing completed on 2024-05-12 05:31:41

 /*
     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 <QRect>
 #include <QStack>
 #include <epoxy/gl.h>
 
 namespace KWin
 {
 
 class GLTexture;
 class RenderTarget;
 class RenderViewport;
 
 // Cleans up all resources hold by the GL Context
 void KWIN_EXPORT cleanupGL();
 
 /**
  * @short OpenGL framebuffer object
  *
  * Framebuffer object enables you to render onto a texture. This texture can
  * later be used to e.g. do post-processing of the scene.
  *
  * @author Rivo Laks <rivolaks@hot.ee>
  */
 class KWIN_EXPORT GLFramebuffer
 {
 public:
     enum Attachment {
         NoAttachment,
         CombinedDepthStencil,
     };
 
     /**
      * Constructs a GLFramebuffer
      * @since 5.13
      */
     explicit GLFramebuffer();
 
     /**
      * Constructs a GLFramebuffer. Note that ensuring the color attachment outlives
      * the framebuffer is the responsibility of the caller.
      *
      * @param colorAttachment texture where the scene will be rendered onto
      */
     explicit GLFramebuffer(GLTexture *colorAttachment, Attachment attachment = NoAttachment);
 
     /**
      * Constructs a wrapper for an already created framebuffer object. The GLFramebuffer
      * does not take the ownership of the framebuffer object handle.
      */
     GLFramebuffer(GLuint handle, const QSize &size);
     ~GLFramebuffer();
 
     /**
      * Returns the framebuffer object handle to this framebuffer object.
      */
     GLuint handle() const
     {
         return m_handle;
     }
     /**
      * Returns the size of the color attachment to this framebuffer object.
      */
     QSize size() const
     {
         return m_size;
     }
     bool valid() const
     {
         return m_valid;
     }
 
     static void initStatic();
     static bool supported()
     {
         return s_supported;
     }
 
     /**
      * Returns the last bound framebuffer, or @c null if no framebuffer is current.
      */
     static GLFramebuffer *currentFramebuffer();
 
     static void pushFramebuffer(GLFramebuffer *fbo);
     static GLFramebuffer *popFramebuffer();
     /**
      * Whether the GL_EXT_framebuffer_blit extension is supported.
      * This functionality is not available in OpenGL ES 2.0.
      *
      * @returns whether framebuffer blitting is supported.
      * @since 4.8
      */
     static bool blitSupported();
 
     /**
      * Blits from @a source rectangle in the current framebuffer to the @a destination rectangle in
      * this framebuffer.
      *
      * Be aware that framebuffer blitting may not be supported on all hardware. Use blitSupported()
      * to check whether it is supported.
      *
      * The @a source and the @a destination rectangles can have different sizes. The @a filter indicates
      * what filter will be used in case scaling needs to be performed.
      *
      * @see blitSupported
      * @since 4.8
      */
     void blitFromFramebuffer(const QRect &source = QRect(), const QRect &destination = QRect(), GLenum filter = GL_LINEAR, bool flipX = false, bool flipY = false);
 
     /**
      * Blits from @a source rectangle in logical coordinates in the current framebuffer to the @a destination rectangle in texture-local coordinates
      * in this framebuffer, taking into account any transformations the source render target may have
      */
     bool blitFromRenderTarget(const RenderTarget &sourceRenderTarget, const RenderViewport &sourceViewport, const QRect &source, const QRect &destination);
 
     /**
      * @returns the color attachment of this fbo. May be nullptr
      */
     GLTexture *colorAttachment() const;
 
 protected:
     void initColorAttachment(GLTexture *colorAttachment);
     void initDepthStencilAttachment();
 
 private:
     bool bind();
 
     friend void KWin::cleanupGL();
     static void cleanup();
     inline static bool s_supported = false;
     inline static bool s_supportsPackedDepthStencil = false;
     inline static bool s_supportsDepth24 = false;
     inline static bool s_blitSupported = false;
     inline static QStack<GLFramebuffer *> s_fbos;
 
     GLuint m_handle = 0;
     GLuint m_depthBuffer = 0;
     GLuint m_stencilBuffer = 0;
     QSize m_size;
     bool m_valid = false;
     bool m_foreign = false;
     GLTexture *const m_colorAttachment;
 };
 
 }