GL: Mesh::draw() and MeshView::draw() return a reference to self as well.

So it's possible to chain the draw() calls (for example with a different
shader).

doc/changelog.dox

@@ -70,6 +70,9 @@ See also:
     @ref GL::Mesh::setIndexBuffer() can now take ownership of a passed
     @ref GL::Buffer to simplify resource management on user side. See
     @ref GL-Mesh-buffer-ownership for more information.
+-   @ref GL::Mesh::draw() and @ref GL::MeshView::draw() now return a reference
+    to self to make method-chained draws (for example using a different shader)
+    possible as well
 
 @subsubsection changelog-latest-changes-meshtools MeshTools library
 

src/Magnum/GL/Mesh.cpp

@@ -352,11 +352,11 @@ Mesh& Mesh::setIndexBuffer(Buffer& buffer, const GLintptr offset, const MeshInde
     return *this;
 }
 
-void Mesh::draw(AbstractShaderProgram& shader) {
+Mesh& Mesh::draw(AbstractShaderProgram& shader) {
-    CORRADE_ASSERT(_countSet, "GL::Mesh::draw(): setCount() was never called, probably a mistake?", );
+    CORRADE_ASSERT(_countSet, "GL::Mesh::draw(): setCount() was never called, probably a mistake?", *this);
 
     /* Nothing to draw, exit without touching any state */
-    if(!_count || !_instanceCount) return;
+    if(!_count || !_instanceCount) return *this;
 
     shader.use();
 
@@ -367,6 +367,8 @@ void Mesh::draw(AbstractShaderProgram& shader) {
     #else
     drawInternal(_count, _baseVertex, _instanceCount, _indexOffset);
     #endif
+
+    return *this;
 }
 
 #ifndef MAGNUM_TARGET_GLES
@@ -506,13 +508,13 @@ void Mesh::drawInternal(TransformFeedback& xfb, const UnsignedInt stream, const
     (this->*state.unbindImplementation)();
 }
 
-void Mesh::draw(AbstractShaderProgram& shader, TransformFeedback& xfb, UnsignedInt stream) {
+Mesh& Mesh::draw(AbstractShaderProgram& shader, TransformFeedback& xfb, UnsignedInt stream) {
     /* Nothing to draw, exit without touching any state */
-    if(!_instanceCount) return;
+    if(!_instanceCount) return *this;
 
     shader.use();
-
     drawInternal(xfb, stream, _instanceCount);
+    return *this;
 }
 #endif
 

src/Magnum/GL/Mesh.h

@@ -905,15 +905,14 @@ class MAGNUM_GL_EXPORT Mesh: public AbstractObject {
         Mesh& setIndexBuffer(Buffer&& buffer, GLintptr offset, MeshIndexType type) {
             return setIndexBuffer(std::move(buffer), offset, type, 0, 0);
         }
-
-        /** @overload */
         Mesh& setIndexBuffer(Buffer&& buffer, GLintptr offset, Magnum::MeshIndexType type) {
             return setIndexBuffer(std::move(buffer), offset, meshIndexType(type), 0, 0);
-        }
+        } /**< @overload */
 
         /**
          * @brief Draw the mesh
          * @param shader    Shader to use for drawing
+         * @return Reference to self (for method chaining)
          *
          * Expects that the shader is compatible with this mesh and is fully
          * set up. If vertex/index count or instance count is `0`, no draw
@@ -953,8 +952,10 @@ class MAGNUM_GL_EXPORT Mesh: public AbstractObject {
          * @requires_gl Specifying base vertex for indexed meshes is not
          *      available in OpenGL ES or WebGL.
          */
-        void draw(AbstractShaderProgram& shader);
+        Mesh& draw(AbstractShaderProgram& shader);
-        void draw(AbstractShaderProgram&& shader) { draw(shader); } /**< @overload */
+        Mesh& draw(AbstractShaderProgram&& shader) {
+            return draw(shader);
+        } /**< @overload */
 
         #ifndef MAGNUM_TARGET_GLES
         /**
@@ -962,6 +963,7 @@ class MAGNUM_GL_EXPORT Mesh: public AbstractObject {
          * @param shader    Shader to use for drawing
          * @param xfb       Transform feedback to use for vertex count
          * @param stream    Transform feedback stream ID
+         * @return Reference to self (for method chaining)
          *
          * Expects that the @p shader is compatible with this mesh, is fully
          * set up and that the output buffer(s) from @p xfb are used as vertex
@@ -985,12 +987,10 @@ class MAGNUM_GL_EXPORT Mesh: public AbstractObject {
          * @requires_gl42 Extension @gl_extension{ARB,transform_feedback_instanced}
          *      if @ref instanceCount() is more than `1`.
          */
-        void draw(AbstractShaderProgram& shader, TransformFeedback& xfb, UnsignedInt stream = 0);
+        Mesh& draw(AbstractShaderProgram& shader, TransformFeedback& xfb, UnsignedInt stream = 0);
-
+        Mesh& draw(AbstractShaderProgram&& shader, TransformFeedback& xfb, UnsignedInt stream = 0) {
-        /** @overload */
+            return draw(shader, xfb, stream);
-        void draw(AbstractShaderProgram&& shader, TransformFeedback& xfb, UnsignedInt stream = 0) {
+        } /**< @overload */
-            draw(shader, xfb, stream);
-        }
         #endif
 
     private:

src/Magnum/GL/MeshView.cpp

@@ -145,11 +145,11 @@ MeshView& MeshView::setIndexRange(Int first) {
     return *this;
 }
 
-void MeshView::draw(AbstractShaderProgram& shader) {
+MeshView& MeshView::draw(AbstractShaderProgram& shader) {
-    CORRADE_ASSERT(_countSet, "GL::MeshView::draw(): setCount() was never called, probably a mistake?", );
+    CORRADE_ASSERT(_countSet, "GL::MeshView::draw(): setCount() was never called, probably a mistake?", *this);
 
     /* Nothing to draw, exit without touching any state */
-    if(!_count || !_instanceCount) return;
+    if(!_count || !_instanceCount) return *this;
 
     shader.use();
 
@@ -160,16 +160,18 @@ void MeshView::draw(AbstractShaderProgram& shader) {
     #else
     _original.get().drawInternal(_count, _baseVertex, _instanceCount, _indexOffset);
     #endif
+
+    return *this;
 }
 
 #ifndef MAGNUM_TARGET_GLES
-void MeshView::draw(AbstractShaderProgram& shader, TransformFeedback& xfb, UnsignedInt stream) {
+MeshView& MeshView::draw(AbstractShaderProgram& shader, TransformFeedback& xfb, UnsignedInt stream) {
     /* Nothing to draw, exit without touching any state */
-    if(!_instanceCount) return;
+    if(!_instanceCount) return *this;
 
     shader.use();
-
     _original.get().drawInternal(xfb, stream, _instanceCount);
+    return *this;
 }
 #endif
 

src/Magnum/GL/MeshView.h

@@ -235,6 +235,7 @@ class MAGNUM_GL_EXPORT MeshView {
 
         /**
          * @brief Draw the mesh
+         * @return Reference to self (for method chaining)
          *
          * See @ref Mesh::draw(AbstractShaderProgram&) for more information.
          * @see @ref draw(AbstractShaderProgram&, std::initializer_list<std::reference_wrapper<MeshView>>),
@@ -254,12 +255,15 @@ class MAGNUM_GL_EXPORT MeshView {
          * @requires_gl Specifying base vertex for indexed meshes is not
          *      available in OpenGL ES or WebGL.
          */
-        void draw(AbstractShaderProgram& shader);
+        MeshView& draw(AbstractShaderProgram& shader);
-        void draw(AbstractShaderProgram&& shader) { draw(shader); } /**< @overload */
+        MeshView& draw(AbstractShaderProgram&& shader) {
+            return draw(shader);
+        } /**< @overload */
 
         #ifndef MAGNUM_TARGET_GLES
         /**
          * @brief Draw the mesh with vertices coming out of transform feedback
+         * @return Reference to self (for method chaining)
          *
          * Everything set by @ref setCount(), @ref setBaseInstance(),
          * @ref setBaseVertex(), @ref setIndexRange() and @ref Mesh::setIndexBuffer()
@@ -274,12 +278,10 @@ class MAGNUM_GL_EXPORT MeshView {
          * @requires_gl42 Extension @gl_extension{ARB,transform_feedback_instanced}
          *      if @ref instanceCount() is more than `1`.
          */
-        void draw(AbstractShaderProgram& shader, TransformFeedback& xfb, UnsignedInt stream = 0);
+        MeshView& draw(AbstractShaderProgram& shader, TransformFeedback& xfb, UnsignedInt stream = 0);
-
+        MeshView& draw(AbstractShaderProgram&& shader, TransformFeedback& xfb, UnsignedInt stream = 0) {
-        /** @overload */
+            return draw(shader, xfb, stream);
-        void draw(AbstractShaderProgram&& shader, TransformFeedback& xfb, UnsignedInt stream = 0) {
+        } /**< @overload */
-            draw(shader, xfb, stream);
-        }
         #endif
 
     private: