Buffer: support for copying.

src/Buffer.cpp

@@ -0,0 +1,26 @@
+/*
+    Copyright © 2010, 2011, 2012 Vladimír Vondruš <mosra@centrum.cz>
+
+    This file is part of Magnum.
+
+    Magnum is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Lesser General Public License version 3
+    only, as published by the Free Software Foundation.
+
+    Magnum is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+    GNU Lesser General Public License version 3 for more details.
+*/
+
+#include "Buffer.h"
+
+namespace Magnum {
+
+void Buffer::copy(Buffer* read, Buffer* write, GLintptr readOffset, GLintptr writeOffset, GLsizeiptr size) {
+    read->bind(Target::CopyRead);
+    write->bind(Target::CopyWrite);
+    glCopyBufferSubData(static_cast<GLenum>(Target::CopyRead), static_cast<GLenum>(Target::CopyWrite), readOffset, writeOffset, size);
+}
+
+}

src/Buffer.h

@@ -25,6 +25,8 @@
 
 #include "Magnum.h"
 
+#include "magnumVisibility.h"
+
 namespace Magnum {
 
 /**
@@ -56,10 +58,9 @@ std::vector<Vector3> data;
 buffer.setData(data, Buffer::Usage::StaticDraw);
 @endcode
 
-@todo Support for buffer copying (OpenGL 3.1, @extension{ARB,copy_buffer})
 @todo Support for AMD's query buffer (@extension{AMD,query_buffer_object})
  */
-class Buffer {
+class MAGNUM_EXPORT Buffer {
     Buffer(const Buffer& other) = delete;
     Buffer(Buffer&& other) = delete;
     Buffer& operator=(const Buffer& other) = delete;
@@ -87,14 +88,14 @@ class Buffer {
             #endif
 
             /**
-             * Source for copies.
+             * Source for copies. See copy().
              * @requires_gl31 Extension @extension{ARB,copy_buffer}
              * @requires_gles30 (no extension providing this functionality)
              */
             CopyRead = GL_COPY_READ_BUFFER,
 
             /**
-             * Target for copies.
+             * Target for copies. See copy().
              * @requires_gl31 Extension @extension{ARB,copy_buffer}
              * @requires_gles30 (no extension providing this functionality)
              */
@@ -237,6 +238,22 @@ class Buffer {
             glBindBuffer(static_cast<GLenum>(target), 0);
         }
 
+        /**
+         * @brief Copy one buffer to another
+         * @param read          %Buffer from which to read
+         * @param write         %Buffer to which to copy
+         * @param readOffset    Offset in the read buffer
+         * @param writeOffset   Offset in the write buffer
+         * @param size          Data size
+         *
+         * Read buffer is bound to `Target::CopyRead`, write buffer to
+         * `Target::CopyWrite` and the copy is performed.
+         * @requires_gl31 Extension @extension{ARB,copy_buffer}
+         * @requires_gles30 (no extension providing this functionality)
+         * @see @fn_gl{CopyBufferSubData}
+         */
+        static void copy(Buffer* read, Buffer* write, GLintptr readOffset, GLintptr writeOffset, GLsizeiptr size);
+
         /**
          * @brief Constructor
          * @param defaultTarget Default target (used when calling bind()

src/CMakeLists.txt

@@ -21,6 +21,7 @@ set(Magnum_SRCS
     AbstractImage.cpp
     AbstractTexture.cpp
     AbstractShaderProgram.cpp
+    Buffer.cpp
     BufferedImage.cpp
     BufferedTexture.cpp
     Context.cpp