magnum/src/CubeMapTextureArray.h

#ifndef Magnum_CubeMapTextureArray_h
#define Magnum_CubeMapTextureArray_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.
*/

#ifndef MAGNUM_TARGET_GLES
/** @file
 * @brief Class Magnum::CubeMapTextureArray
 */
#endif

#include "AbstractTexture.h"

#ifndef MAGNUM_TARGET_GLES
namespace Magnum {

/**
@brief Cube map texture array

See CubeMapTexture documentation for introduction.

@section CubeMapTextureArray-usage Usage

Common usage is to specify each layer and face separately using setSubData().
You have to allocate the memory for all layers and faces first, possibly by
passing properly sized empty Image to setData(). Example: array with 16
layers of cube map faces, each face consisting of six 64x64 images:
@code
Image3D dummy({64, 64, 16*6}, Image3D::Components::RGBA, Image3D::ComponentType::UnsignedByte, nullptr);

CubeMapTextureArray texture;
texture.setMagnificationFilter(CubeMapTextureArray::Filter::Linear)
    // ...
    ->setData(0, CubeMapTextureArray::Format::RGBA8, &dummy);

for(std::size_t i = 0; i != 16; ++i) {
    void* dataPositiveX = ...;
    Image2D imagePositiveX({64, 64}, Image3D::Components::RGBA, Image3D::ComponentType::UnsignedByte, imagePositiveX);
    // ...

    texture->setSubData(i, CubeMapTextureArray::Coordinate::PositiveX, 0, imagePositiveX);
    texture->setSubData(i, CubeMapTextureArray::Coordinate::NegativeX, 0, imageNegativeX);
    // ...
}

// ...
@endcode

The texture is bound to layer specified by shader via bind(). In shader, the
texture is used via `samplerCubeArray`. Unlike in classic textures,
coordinates for cube map texture arrays is signed four-part vector. First
three parts define vector from the center of the cube which intersects with
one of the six sides of the cube map, fourth part is layer in the array. See
also AbstractShaderProgram for more information.

@see CubeMapTexture::setSeamless()
@requires_gl40 Extension @extension{ARB,texture_cube_map_array}
@requires_gl Cube map texture arrays are not available in OpenGL ES.
*/
class CubeMapTextureArray: public AbstractTexture {
    public:
        /** @brief Cube map coordinate */
        enum Coordinate: GLsizei {
            PositiveX = 0,  /**< +X cube side */
            NegativeX = 1,  /**< -X cube side */
            PositiveY = 2,  /**< +Y cube side */
            NegativeY = 3,  /**< -Y cube side */
            PositiveZ = 4,  /**< +Z cube side */
            NegativeZ = 5   /**< -Z cube side */
        };

        /**
         * @brief Constructor
         *
         * Creates one cube map OpenGL texture.
         * @see @def_gl{TEXTURE_CUBE_MAP_ARRAY}
         */
        inline CubeMapTextureArray(): AbstractTexture(GL_TEXTURE_CUBE_MAP_ARRAY) {}

        /**
         * @copydoc Texture::setWrapping()
         */
        inline CubeMapTextureArray* setWrapping(const Array3D<Wrapping>& wrapping) {
            DataHelper<3>::setWrapping(this, wrapping);
            return this;
        }

        /**
         * @copydoc Texture::setData(GLint, InternalFormat, Image*)
         *
         * Sets texture data from three-dimensional image for all cube faces
         * for all layers. Each group of 6 2D images is one cube map layer.
         * The images are ordered the same way as Coordinate enum.
         */
        template<class T> inline CubeMapTextureArray* setData(GLint mipLevel, InternalFormat internalFormat, T* image) {
            DataHelper<3>::set(this, GL_TEXTURE_CUBE_MAP_ARRAY, mipLevel, internalFormat, image);
            return this;
        }

        /**
         * @brief Set texture subdata from 3D image
         * @param mipLevel      Mip level
         * @param offset        Offset where to put data in the texture
         * @param image         Image3D, ImageWrapper3D, BufferImage3D or
         *      Trade::ImageData3D
         * @return Pointer to self (for method chaining)
         *
         * Sets texture subdata from given image. The image is not deleted
         * afterwards.
         *
         * Z coordinate of @p offset specifies layer and cube map face. If
         * you want to start at given face in layer *n*, you have to specify
         * Z coordinate as @f$ 6n + i @f$, where i is face index as specified
         * in Coordinate enum.
         *
         * @see setSubData(GLsizei, Coordinate, GLint, const Math::Vector<2, GLint>&, const Image*)
         */
        template<class Image> inline CubeMapTextureArray* setSubData(GLint mipLevel, const Vector3i& offset, const Image* image) {
            DataHelper<3>::setSub(this, GL_TEXTURE_CUBE_MAP_ARRAY, mipLevel, offset, image, Vector3i(Math::Vector<Image::Dimensions, GLsizei>()));
            return this;
        }

        /**
         * @brief Set texture subdata from 2D image
         * @param layer         Array layer
         * @param coordinate    Coordinate
         * @param mipLevel      Mip level
         * @param offset        Offset where to put data in the texture
         * @param image         Image2D, ImageWrapper2D, BufferImage2D or
         *      Trade::ImageData2D
         * @return Pointer to self (for method chaining)
         *
         * Sets texture subdata from given image. The image is not deleted
         * afterwards.
         *
         * @see setSubData(GLint, const Math::Vector<3, GLint>&, const Image*)
         */
        template<class Image> inline CubeMapTextureArray* setSubData(GLsizei layer, Coordinate coordinate, GLint mipLevel, const Vector2i& offset, const Image* image) {
            DataHelper<3>::setSub(this, GL_TEXTURE_CUBE_MAP_ARRAY, mipLevel, Vector3i(offset, layer*6+static_cast<GLsizei>(coordinate)), image, Vector2i(Math::Vector<Image::Dimensions, GLsizei>()));
            return this;
        }

        /* Overloads to remove WTF-factor from method chaining order */
        #ifndef DOXYGEN_GENERATING_OUTPUT
        inline CubeMapTextureArray* setMinificationFilter(Filter filter, Mipmap mipmap = Mipmap::BaseLevel) {
            AbstractTexture::setMinificationFilter(filter, mipmap);
            return this;
        }
        inline CubeMapTextureArray* setMagnificationFilter(Filter filter) {
            AbstractTexture::setMagnificationFilter(filter);
            return this;
        }
        inline CubeMapTextureArray* setBorderColor(const Color4<>& color) {
            AbstractTexture::setBorderColor(color);
            return this;
        }
        inline CubeMapTextureArray* setMaxAnisotropy(GLfloat anisotropy) {
            AbstractTexture::setMaxAnisotropy(anisotropy);
            return this;
        }
        inline CubeMapTextureArray* generateMipmap() {
            AbstractTexture::generateMipmap();
            return this;
        }
        #endif
};

}
#endif

#endif