Added Mesh::drawInternal().

Exposes explicit draw parameters like vertex/index offset etc.

src/Mesh.cpp

@@ -136,25 +136,25 @@ Mesh& Mesh::setIndexBuffer(Buffer& buffer, GLintptr offset, IndexType type, Unsi
     return *this;
 }
 
-void Mesh::draw() {
+void Mesh::drawInternal(Int firstVertex, Int vertexCount, GLintptr indexOffset, Int indexCount, Int indexStart, Int indexEnd) {
     /* Nothing to draw */
-    if(!_vertexCount && !_indexCount) return;
+    if(!vertexCount && !indexCount) return;
 
     (this->*bindImplementation)();
 
     /* Non-indexed mesh */
-    if(!_indexCount)
-        glDrawArrays(static_cast<GLenum>(_primitive), 0, _vertexCount);
+    if(!indexCount)
+        glDrawArrays(static_cast<GLenum>(_primitive), firstVertex, vertexCount);
 
     #ifndef MAGNUM_TARGET_GLES2
     /* Indexed mesh with specified range */
-    else if(_indexEnd)
-        glDrawRangeElements(static_cast<GLenum>(_primitive), _indexStart, _indexEnd, _indexCount, static_cast<GLenum>(_indexType), reinterpret_cast<GLvoid*>(_indexOffset));
+    else if(indexEnd)
+        glDrawRangeElements(static_cast<GLenum>(_primitive), indexStart, indexEnd, indexCount, static_cast<GLenum>(_indexType), reinterpret_cast<GLvoid*>(indexOffset));
     #endif
 
     /* Indexed mesh without specified range */
     else
-        glDrawElements(static_cast<GLenum>(_primitive), _indexCount, static_cast<GLenum>(_indexType), reinterpret_cast<GLvoid*>(_indexOffset));
+        glDrawElements(static_cast<GLenum>(_primitive), indexCount, static_cast<GLenum>(_indexType), reinterpret_cast<GLvoid*>(indexOffset));
 
     (this->*unbindImplementation)();
 }

src/Mesh.h

@@ -584,7 +584,9 @@ class MAGNUM_EXPORT Mesh {
          *      or @fn_gl{BindVertexArray} (if @extension{APPLE,vertex_array_object}
          *      is available), @fn_gl{DrawArrays} or @fn_gl{DrawElements}/@fn_gl{DrawRangeElements}.
          */
-        void draw();
+        void draw() {
+            drawInternal(0, _vertexCount, _indexOffset, _indexCount, _indexStart, _indexEnd);
+        }
 
     private:
         #ifndef DOXYGEN_GENERATING_OUTPUT
@@ -708,6 +710,8 @@ class MAGNUM_EXPORT Mesh {
         #endif
         #endif
 
+        void drawInternal(Int firstVertex, Int vertexCount, GLintptr indexOffset, Int indexCount, Int indexStart, Int indexEnd);
+
         typedef void(Mesh::*CreateImplementation)();
         void MAGNUM_LOCAL createImplementationDefault();
         void MAGNUM_LOCAL createImplementationVAO();
@@ -792,7 +796,6 @@ template<class ...T> inline Mesh& Mesh::addVertexBuffer(Buffer& buffer, GLintptr
     return *this;
 }
 
-
 }
 
 namespace Corrade { namespace Utility {