Added Framebuffer::detach().

doc/opengl-mapping.dox

@@ -142,7 +142,7 @@ OpenGL function                         | Matching API
 @fn_gl{Flush}                           | @ref Renderer::flush()
 @fn_gl{FlushMappedBufferRange}, \n `glFlushMappedNamedBufferRange()`, \n @fn_gl_extension{FlushMappedNamedBufferRange,EXT,direct_state_access} | @ref Buffer::flushMappedRange()
 @fn_gl2{FramebufferParameter,FramebufferParameteri}, \n `glNamedFramebufferParameter()`, \n @fn_gl_extension{NamedFramebufferParameter,EXT,direct_state_access} | |
-@fn_gl{FramebufferRenderbuffer}, \n `glNamedFramebufferRenderbuffer()`, \n @fn_gl_extension{NamedFramebufferRenderbuffer,EXT,direct_state_access} | @ref Framebuffer::attachRenderbuffer()
+@fn_gl{FramebufferRenderbuffer}, \n `glNamedFramebufferRenderbuffer()`, \n @fn_gl_extension{NamedFramebufferRenderbuffer,EXT,direct_state_access} | @ref Framebuffer::attachRenderbuffer(), \n @ref Framebuffer::detach()
 @fn_gl{FramebufferTexture}, \n `glNamedFramebufferTexture()`, \n @fn_gl_extension{NamedFramebufferTexture,EXT,direct_state_access} | not used, the functions below are used instead for compatibility reasons
 @fn_gl2{FramebufferTexture1D,FramebufferTexture}, \n @fn_gl_extension{NamedFramebufferTexture1D,EXT,direct_state_access}, \n `glFramebufferTexture2D()`, \n `glNamedFramebufferTexture2DEXT()` | @ref Framebuffer::attachTexture()
 @fn_gl2{FramebufferTexture3D,FramebufferTexture} | not used, @fn_gl{FramebufferTextureLayer} has more complete features

src/Magnum/Framebuffer.cpp

@@ -205,7 +205,7 @@ void Framebuffer::invalidate(std::initializer_list<InvalidationAttachment> attac
 #endif
 
 Framebuffer& Framebuffer::attachRenderbuffer(const BufferAttachment attachment, Renderbuffer& renderbuffer) {
-    (this->*Context::current()->state().framebuffer->renderbufferImplementation)(attachment, renderbuffer);
+    (this->*Context::current()->state().framebuffer->renderbufferImplementation)(attachment, renderbuffer.id());
     return *this;
 }
 
@@ -273,18 +273,23 @@ Framebuffer& Framebuffer::attachTextureLayer(const BufferAttachment attachment,
 }
 #endif
 
-void Framebuffer::renderbufferImplementationDefault(BufferAttachment attachment, Renderbuffer& renderbuffer) {
-    glFramebufferRenderbuffer(GLenum(bindInternal()), GLenum(attachment), GL_RENDERBUFFER, renderbuffer.id());
+Framebuffer& Framebuffer::detach(const BufferAttachment attachment) {
+    (this->*Context::current()->state().framebuffer->renderbufferImplementation)(attachment, 0);
+    return *this;
+}
+
+void Framebuffer::renderbufferImplementationDefault(const BufferAttachment attachment, const GLuint renderbufferId) {
+    glFramebufferRenderbuffer(GLenum(bindInternal()), GLenum(attachment), GL_RENDERBUFFER, renderbufferId);
 }
 
 #ifndef MAGNUM_TARGET_GLES
-void Framebuffer::renderbufferImplementationDSA(const BufferAttachment attachment, Renderbuffer& renderbuffer) {
-    glNamedFramebufferRenderbuffer(_id, GLenum(attachment), GL_RENDERBUFFER, renderbuffer.id());
+void Framebuffer::renderbufferImplementationDSA(const BufferAttachment attachment, const GLuint renderbufferId) {
+    glNamedFramebufferRenderbuffer(_id, GLenum(attachment), GL_RENDERBUFFER, renderbufferId);
 }
 
-void Framebuffer::renderbufferImplementationDSAEXT(BufferAttachment attachment, Renderbuffer& renderbuffer) {
+void Framebuffer::renderbufferImplementationDSAEXT(const BufferAttachment attachment, const GLuint renderbufferId) {
     _flags |= ObjectFlag::Created;
-    glNamedFramebufferRenderbufferEXT(_id, GLenum(attachment), GL_RENDERBUFFER, renderbuffer.id());
+    glNamedFramebufferRenderbufferEXT(_id, GLenum(attachment), GL_RENDERBUFFER, renderbufferId);
 }
 
 void Framebuffer::texture1DImplementationDefault(BufferAttachment attachment, GLuint textureId, GLint mipLevel) {

src/Magnum/Framebuffer.h

@@ -701,6 +701,21 @@ class MAGNUM_EXPORT Framebuffer: public AbstractFramebuffer, public AbstractObje
         Framebuffer& attachTextureLayer(BufferAttachment attachment, MultisampleTexture2DArray& texture, Int layer);
         #endif
 
+        /**
+         * @brief Detach any texture or renderbuffer bound to given buffer
+         * @param attachment        Buffer attachment
+         * @return Reference to self (for method chaining)
+         *
+         * If neither @extension{ARB,direct_state_access} (part of OpenGL 4.5)
+         * nor @extension{EXT,direct_state_access} desktop extension is
+         * available, the framebuffer is bound before the operation (if not
+         * already).
+         * @see @fn_gl2{NamedFramebufferRenderbuffer,FramebufferRenderbuffer},
+         *      @fn_gl_extension{NamedFramebufferRenderbuffer,EXT,direct_state_access},
+         *      eventually @fn_gl{BindFramebuffer} and @fn_gl{FramebufferRenderbuffer}
+         */
+        Framebuffer& detach(BufferAttachment attachment);
+
         /* Overloads to remove WTF-factor from method chaining order */
         #ifndef DOXYGEN_GENERATING_OUTPUT
         Framebuffer& setViewport(const Range2Di& rectangle) {
@@ -725,10 +740,10 @@ class MAGNUM_EXPORT Framebuffer: public AbstractFramebuffer, public AbstractObje
         Framebuffer& setLabelInternal(Containers::ArrayView<const char> label);
         #endif
 
-        void MAGNUM_LOCAL renderbufferImplementationDefault(BufferAttachment attachment, Renderbuffer& renderbuffer);
+        void MAGNUM_LOCAL renderbufferImplementationDefault(BufferAttachment attachment, GLuint renderbufferId);
         #ifndef MAGNUM_TARGET_GLES
-        void MAGNUM_LOCAL renderbufferImplementationDSA(BufferAttachment attachment, Renderbuffer& renderbuffer);
-        void MAGNUM_LOCAL renderbufferImplementationDSAEXT(BufferAttachment attachment, Renderbuffer& renderbuffer);
+        void MAGNUM_LOCAL renderbufferImplementationDSA(BufferAttachment attachment, GLuint renderbufferId);
+        void MAGNUM_LOCAL renderbufferImplementationDSAEXT(BufferAttachment attachment, GLuint renderbufferId);
         #endif
 
         #ifndef MAGNUM_TARGET_GLES

src/Magnum/Implementation/FramebufferState.h

@@ -60,7 +60,7 @@ struct FramebufferState {
     #endif
 
     void(Framebuffer::*createImplementation)();
-    void(Framebuffer::*renderbufferImplementation)(Framebuffer::BufferAttachment, Renderbuffer&);
+    void(Framebuffer::*renderbufferImplementation)(Framebuffer::BufferAttachment, GLuint);
     #ifndef MAGNUM_TARGET_GLES
     void(Framebuffer::*texture1DImplementation)(Framebuffer::BufferAttachment, GLuint, GLint);
     #endif

src/Magnum/Test/FramebufferGLTest.cpp

@@ -82,6 +82,7 @@ struct FramebufferGLTest: AbstractOpenGLTester {
     #ifndef MAGNUM_TARGET_GLES
     void attachCubeMapTextureArray();
     #endif
+    void detach();
 
     void multipleColorOutputs();
 
@@ -133,6 +134,7 @@ FramebufferGLTest::FramebufferGLTest() {
               #ifndef MAGNUM_TARGET_GLES
               &FramebufferGLTest::attachCubeMapTextureArray,
               #endif
+              &FramebufferGLTest::detach,
 
               &FramebufferGLTest::multipleColorOutputs,
 
@@ -630,6 +632,15 @@ void FramebufferGLTest::attachCubeMapTextureArray() {
 }
 #endif
 
+void FramebufferGLTest::detach() {
+    Framebuffer framebuffer({{}, Vector2i(128)});
+    framebuffer.detach(Framebuffer::ColorAttachment(0))
+               .detach(Framebuffer::BufferAttachment::Depth)
+               .detach(Framebuffer::BufferAttachment::Stencil);
+
+    MAGNUM_VERIFY_NO_ERROR();
+}
+
 void FramebufferGLTest::multipleColorOutputs() {
     #ifndef MAGNUM_TARGET_GLES
     if(!Context::current()->isExtensionSupported<Extensions::GL::ARB::framebuffer_object>())