magnum/src/IndexedMesh.h

#ifndef Magnum_IndexedMesh_h
#define Magnum_IndexedMesh_h
/*
    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.
*/

/** @file
 * @brief Class Magnum::IndexedMesh
 */

#include "Mesh.h"
#include "Buffer.h"

namespace Magnum {

/**
@brief Indexed mesh

@section IndexedMesh-configuration Indexed mesh configuration

Next to @ref Mesh-configuration "everything needed for non-indexed mesh" you
have to specify also index count and type (either in constructor or using
setIndexCount() and setIndexType()). Then fill index buffer or use
MeshTools::compressIndices() to conveniently fill the index buffer and set
index count and type.

@section IndexedMesh-drawing Rendering meshes

From user point-of-view the operation is the same as for
@ref Mesh-drawing "non-indexed meshes".

@section IndexedMesh-performance-optimization Performance optimizations

If @extension{APPLE,vertex_array_object} is supported, next to
@ref Mesh-performance-optimization "optimizations in Mesh itself" the index
buffer is bound on object construction instead of in every draw() call.
*/
class MAGNUM_EXPORT IndexedMesh: public Mesh {
    friend class Context;

    public:
        /**
         * @brief Implicit constructor
         * @param primitive     Primitive type
         *
         * @see @fn_gl{BindVertexArray} (if @extension{APPLE,vertex_array_object}
         *      is available)
         */
        IndexedMesh(Primitive primitive = Primitive::Triangles);

        /**
         * @brief Constructor
         * @param primitive     Primitive type
         * @param vertexCount   Count of unique vertices
         * @param indexCount    Count of indices
         * @param indexType     Type of indices (indexable, see TypeTraits)
         *
         * @see setPrimitive(), setVertexCount(), setIndexCount(),
         *      setIndexType(), @fn_gl{BindVertexArray} (if
         *      @extension{APPLE,vertex_array_object} is available)
         */
        IndexedMesh(Primitive primitive, GLsizei vertexCount, GLsizei indexCount, Type indexType = Type::UnsignedShort);

        /** @brief Index count */
        inline GLsizei indexCount() const { return _indexCount; }

        /**
         * @brief Set index count
         * @return Pointer to self (for method chaining)
         *
         * @see MeshTools::compressIndices()
         */
        inline IndexedMesh* setIndexCount(GLsizei count) {
            _indexCount = count;
            return this;
        }

        /** @brief Index type */
        inline Type indexType() const { return _indexType; }

        /**
         * @brief Set index type
         * @return Pointer to self (for method chaining)
         *
         * @see MeshTools::compressIndices()
         */
        inline IndexedMesh* setIndexType(Type type) {
            _indexType = type;
            return this;
        }

        /**
         * @brief Index buffer
         *
         * Returns pointer to index buffer, which should be then filled with
         * indices (of type specified in constructor).
         */
        inline Buffer* indexBuffer() { return &_indexBuffer; }

        /**
         * @brief Draw the mesh
         *
         * Expects an active shader with all uniforms set. See
         * @ref AbstractShaderProgram-rendering-workflow "AbstractShaderProgram documentation"
         * for more information.
         * @see @fn_gl{EnableVertexAttribArray}, @fn_gl{BindBuffer},
         *      @fn_gl{VertexAttribPointer}, @fn_gl{DisableVertexAttribArray}
         *      or @fn_gl{BindVertexArray} (if @extension{APPLE,vertex_array_object}
         *      is available), @fn_gl{DrawElements}
         */
        void draw();

    private:
        static void MAGNUM_LOCAL initializeContextBasedFunctionality(Context* context);

        void MAGNUM_LOCAL bind();

        typedef void(IndexedMesh::*CreateIndexedImplementation)();
        void MAGNUM_LOCAL createIndexedImplementationDefault();
        #ifndef MAGNUM_TARGET_GLES
        void MAGNUM_LOCAL createIndexedImplementationVAO();
        #endif
        static MAGNUM_LOCAL CreateIndexedImplementation createIndexedImplementation;

        typedef void(IndexedMesh::*BindIndexedImplementation)();
        void MAGNUM_LOCAL bindIndexedImplementationDefault();
        #ifndef MAGNUM_TARGET_GLES
        void MAGNUM_LOCAL bindIndexedImplementationVAO();
        #endif
        static MAGNUM_LOCAL BindIndexedImplementation bindIndexedImplementation;

        Buffer _indexBuffer;
        GLsizei _indexCount;
        Type _indexType;
};

}

#endif