It is possible to draw into a QOpenGLFramebufferObject using QPainter and QOpenGLPaintDevice in a separate thread. If you want to use a framebuffer object with multisampling enabled as a texture, you first need to copy from it to a regular framebuffer object using QOpenGLContext::blitFramebuffer(). Here there will be multiple textures (or, in case of multisampling, renderbuffers) present and each of them will get attached to GL_COLOR_ATTACHMENT0, 1, 2. Multiple render targets are also supported, in case the OpenGL implementation supports this. The color render buffer or texture will have the specified internal format, and will be bound to the GL_COLOR_ATTACHMENT0 attachment in the framebuffer object. To create a multisample framebuffer object you should use one of the constructors that take a QOpenGLFramebufferObjectFormat parameter, and set the QOpenGLFramebufferObjectFormat::samples() property to a non-zero value.įor multisample framebuffer objects a color render buffer is created, otherwise a texture with the specified texture target is created. Note that you need to create a QOpenGLFramebufferObject with more than one sample per pixel for primitives to be antialiased when drawing using a QPainter. It is important to have a current OpenGL context when creating a QOpenGLFramebufferObject, otherwise initialization will fail.Ĭreate the QOpenGLFrameBufferObject instance with the CombinedDepthStencil attachment if you want QPainter to render correctly. By default, the QOpenGLFramebufferObject class generates a 2D OpenGL texture (using the GL_TEXTURE_2D target), which is used as the internal rendering target. This surface can be bound and used as a regular texture in your own OpenGL drawing code. It provides a rendering surface that can be painted on with a QPainter with the help of QOpenGLPaintDevice, or rendered to using native OpenGL calls. The QOpenGLFramebufferObject class encapsulates an OpenGL framebuffer object, defined by the GL_EXT_framebuffer_object extension. The QOpenGLFramebufferObject class encapsulates an OpenGL framebuffer object. ToImage(bool flipped, int colorAttachmentIndex) const QOpenGLFramebufferObject(int width, int height, const QOpenGLFramebufferObjectFormat & format)ĪddColorAttachment(const QSize & size, GLenum internalFormat = 0)ĪddColorAttachment(int width, int height, GLenum internalFormat = 0)

QOpenGLFramebufferObject(const QSize & size, const QOpenGLFramebufferObjectFormat & format) QOpenGLFramebufferObject(int width, int height, Attachment attachment, GLenum target = GL_TEXTURE_2D, GLenum internalFormat = 0)

QOpenGLFramebufferObject(const QSize & size, Attachment attachment, GLenum target = GL_TEXTURE_2D, GLenum internalFormat = 0) QOpenGLFramebufferObject(int width, int height, GLenum target = GL_TEXTURE_2D) QOpenGLFramebufferObject(const QSize & size, GLenum target = GL_TEXTURE_2D)

Opengl es 2.0 merge framebuffer object