/*
    This file is part of Magnum.

    Copyright © 2010, 2011, 2012, 2013, 2014, 2015
              Vladimír Vondruš <mosra@centrum.cz>

    Permission is hereby granted, free of charge, to any person obtaining a
    copy of this software and associated documentation files (the "Software"),
    to deal in the Software without restriction, including without limitation
    the rights to use, copy, modify, merge, publish, distribute, sublicense,
    and/or sell copies of the Software, and to permit persons to whom the
    Software is furnished to do so, subject to the following conditions:

    The above copyright notice and this permission notice shall be included
    in all copies or substantial portions of the Software.

    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
    THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
    FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
    DEALINGS IN THE SOFTWARE.
*/

#include "AbstractTexture.h"

#ifndef MAGNUM_TARGET_GLES2
#include "Magnum/BufferImage.h"
#endif
#include "Magnum/Array.h"
#include "Magnum/Color.h"
#include "Magnum/ColorFormat.h"
#include "Magnum/Context.h"
#include "Magnum/Extensions.h"
#include "Magnum/Image.h"
#include "Magnum/TextureFormat.h"
#include "Magnum/Math/Range.h"

#ifdef MAGNUM_BUILD_DEPRECATED
#include "Magnum/Shader.h"
#endif

#ifndef MAGNUM_TARGET_WEBGL
#include "Implementation/DebugState.h"
#endif
#include "Implementation/State.h"
#include "Implementation/TextureState.h"

namespace Magnum {

#ifdef MAGNUM_BUILD_DEPRECATED
Int AbstractTexture::maxLayers() { return Shader::maxCombinedTextureImageUnits(); }
#endif

#ifndef MAGNUM_TARGET_GLES2
Float AbstractTexture::maxLodBias() {
    GLfloat& value = Context::current()->state().texture->maxLodBias;

    /* Get the value, if not already cached */
    if(value == 0.0f)
        glGetFloatv(GL_MAX_TEXTURE_LOD_BIAS, &value);

    return value;
}
#endif

#ifndef MAGNUM_TARGET_GLES2
Int AbstractTexture::maxColorSamples() {
    #ifndef MAGNUM_TARGET_GLES
    if(!Context::current()->isExtensionSupported<Extensions::GL::ARB::texture_multisample>())
    #else
    if(!Context::current()->isVersionSupported(Version::GLES310))
    #endif
        return 0;

    GLint& value = Context::current()->state().texture->maxColorSamples;

    /* Get the value, if not already cached */
    if(value == 0)
        glGetIntegerv(GL_MAX_COLOR_TEXTURE_SAMPLES, &value);

    return value;
}

Int AbstractTexture::maxDepthSamples() {
    #ifndef MAGNUM_TARGET_GLES
    if(!Context::current()->isExtensionSupported<Extensions::GL::ARB::texture_multisample>())
    #else
    if(!Context::current()->isVersionSupported(Version::GLES310))
    #endif
        return 0;

    GLint& value = Context::current()->state().texture->maxDepthSamples;

    /* Get the value, if not already cached */
    if(value == 0)
        glGetIntegerv(GL_MAX_DEPTH_TEXTURE_SAMPLES, &value);

    return value;
}

Int AbstractTexture::maxIntegerSamples() {
    #ifndef MAGNUM_TARGET_GLES
    if(!Context::current()->isExtensionSupported<Extensions::GL::ARB::texture_multisample>())
    #else
    if(!Context::current()->isVersionSupported(Version::GLES310))
    #endif
        return 0;

    GLint& value = Context::current()->state().texture->maxIntegerSamples;

    /* Get the value, if not already cached */
    if(value == 0)
        glGetIntegerv(GL_MAX_INTEGER_SAMPLES, &value);

    return value;
}
#endif

void AbstractTexture::unbind(const Int textureUnit) {
    Implementation::TextureState& textureState = *Context::current()->state().texture;

    /* If given texture unit is already unbound, nothing to do */
    if(textureState.bindings[textureUnit].second == 0) return;

    /* Unbind the texture, reset state tracker */
    Context::current()->state().texture->unbindImplementation(textureUnit);
    textureState.bindings[textureUnit] = {};
}

void AbstractTexture::unbindImplementationDefault(const GLint textureUnit) {
    Implementation::TextureState& textureState = *Context::current()->state().texture;

    /* Activate given texture unit if not already active, update state tracker */
    if(textureState.currentTextureUnit != textureUnit)
        glActiveTexture(GL_TEXTURE0 + (textureState.currentTextureUnit = textureUnit));

    CORRADE_INTERNAL_ASSERT(textureState.bindings[textureUnit].first != 0);
    glBindTexture(textureState.bindings[textureUnit].first, 0);
}

#ifndef MAGNUM_TARGET_GLES
void AbstractTexture::unbindImplementationMulti(const GLint textureUnit) {
    constexpr static GLuint zero = 0;
    glBindTextures(textureUnit, 1, &zero);
}

void AbstractTexture::unbindImplementationDSA(const GLint textureUnit) {
    Implementation::TextureState& textureState = *Context::current()->state().texture;

    CORRADE_INTERNAL_ASSERT(textureState.bindings[textureUnit].first != 0);
    glBindTextureUnit(textureUnit, 0);
}

void AbstractTexture::unbindImplementationDSAEXT(const GLint textureUnit) {
    Implementation::TextureState& textureState = *Context::current()->state().texture;

    CORRADE_INTERNAL_ASSERT(textureState.bindings[textureUnit].first != 0);
    glBindMultiTextureEXT(GL_TEXTURE0 + textureUnit, textureState.bindings[textureUnit].first, 0);
}
#endif

void AbstractTexture::unbind(const Int firstTextureUnit, const std::size_t count) {
    /* State tracker is updated in the implementations */
    Context::current()->state().texture->bindMultiImplementation(firstTextureUnit, {nullptr, count});
}

/** @todoc const std::initializer_list makes Doxygen grumpy */
void AbstractTexture::bind(const Int firstTextureUnit, std::initializer_list<AbstractTexture*> textures) {
    /* State tracker is updated in the implementations */
    Context::current()->state().texture->bindMultiImplementation(firstTextureUnit, {textures.begin(), textures.size()});
}

void AbstractTexture::bindImplementationFallback(const GLint firstTextureUnit, const Containers::ArrayReference<AbstractTexture* const> textures) {
    for(std::size_t i = 0; i != textures.size(); ++i)
        textures && textures[i] ? textures[i]->bind(firstTextureUnit + i) : unbind(firstTextureUnit + i);
}

#ifndef MAGNUM_TARGET_GLES
/** @todoc const Containers::ArrayReference makes Doxygen grumpy */
void AbstractTexture::bindImplementationMulti(const GLint firstTextureUnit, Containers::ArrayReference<AbstractTexture* const> textures) {
    Implementation::TextureState& textureState = *Context::current()->state().texture;

    /* Create array of IDs and also update bindings in state tracker */
    Containers::Array<GLuint> ids{textures ? textures.size() : 0};
    bool different = false;
    for(std::size_t i = 0; i != textures.size(); ++i) {
        const GLuint id = textures && textures[i] ? textures[i]->_id : 0;

        if(textures) {
            if(textures[i]) textures[i]->createIfNotAlready();
            ids[i] = id;
        }

        if(textureState.bindings[firstTextureUnit + i].second != id) {
            different = true;
            textureState.bindings[firstTextureUnit + i].second = id;
        }
    }

    /* Avoid doing the binding if there is nothing different */
    if(different) glBindTextures(firstTextureUnit, textures.size(), ids);
}
#endif

AbstractTexture::AbstractTexture(GLenum target): _target{target} {
    (this->*Context::current()->state().texture->createImplementation)();
    CORRADE_INTERNAL_ASSERT(_id != Implementation::State::DisengagedBinding);
}

void AbstractTexture::createImplementationDefault() {
    glGenTextures(1, &_id);
    _created = false;
}

#ifndef MAGNUM_TARGET_GLES
void AbstractTexture::createImplementationDSA() {
    glCreateTextures(_target, 1, &_id);
    _created = true;
}
#endif

AbstractTexture::~AbstractTexture() {
    /* Moved out, nothing to do */
    if(!_id) return;

    /* Remove all bindings */
    for(auto& binding: Context::current()->state().texture->bindings)
        if(binding.second == _id) binding = {};

    glDeleteTextures(1, &_id);
}

inline void AbstractTexture::createIfNotAlready() {
    if(_created) return;

    /* glGen*() does not create the object, just reserves the name. Some
       commands (such as glBindTextures() or glObjectLabel()) operate with IDs
       directly and they require the object to be created. Binding the texture
       to desired target finally creates it. Also all EXT DSA functions
       implicitly create it. */
    bindInternal();
    CORRADE_INTERNAL_ASSERT(_created);
}

#ifndef MAGNUM_TARGET_WEBGL
std::string AbstractTexture::label() {
    createIfNotAlready();
    return Context::current()->state().debug->getLabelImplementation(GL_TEXTURE, _id);
}

AbstractTexture& AbstractTexture::setLabelInternal(const Containers::ArrayReference<const char> label) {
    createIfNotAlready();
    Context::current()->state().debug->labelImplementation(GL_TEXTURE, _id, label);
    return *this;
}
#endif

void AbstractTexture::bind(Int textureUnit) {
    Implementation::TextureState& textureState = *Context::current()->state().texture;

    /* If already bound in given texture unit, nothing to do */
    if(textureState.bindings[textureUnit].second == _id) return;

    /* Update state tracker, bind the texture to the unit */
    textureState.bindings[textureUnit] = {_target, _id};
    (this->*textureState.bindImplementation)(textureUnit);
}

void AbstractTexture::bindImplementationDefault(GLint textureUnit) {
    Implementation::TextureState& textureState = *Context::current()->state().texture;

    /* Activate given texture unit if not already active, update state tracker */
    if(textureState.currentTextureUnit != textureUnit)
        glActiveTexture(GL_TEXTURE0 + (textureState.currentTextureUnit = textureUnit));

    /* Binding the texture finally creates it */
    _created = true;
    glBindTexture(_target, _id);
}

#ifndef MAGNUM_TARGET_GLES
void AbstractTexture::bindImplementationMulti(GLint textureUnit) {
    createIfNotAlready();
    glBindTextures(textureUnit, 1, &_id);
}

void AbstractTexture::bindImplementationDSA(const GLint textureUnit) {
    glBindTextureUnit(textureUnit, _id);
}

void AbstractTexture::bindImplementationDSAEXT(GLint textureUnit) {
    _created = true;
    glBindMultiTextureEXT(GL_TEXTURE0 + textureUnit, _target, _id);
}
#endif

#ifndef MAGNUM_TARGET_GLES2
void AbstractTexture::setBaseLevel(Int level) {
    (this->*Context::current()->state().texture->parameteriImplementation)(GL_TEXTURE_BASE_LEVEL, level);
}
#endif

void AbstractTexture::setMaxLevel(Int level) {
    (this->*Context::current()->state().texture->parameteriImplementation)(
        #ifndef MAGNUM_TARGET_GLES2
        GL_TEXTURE_MAX_LEVEL
        #else
        GL_TEXTURE_MAX_LEVEL_APPLE
        #endif
    , level);
}

void AbstractTexture::setMinificationFilter(Sampler::Filter filter, Sampler::Mipmap mipmap) {
    (this->*Context::current()->state().texture->parameteriImplementation)(GL_TEXTURE_MIN_FILTER, GLint(filter)|GLint(mipmap));
}

void AbstractTexture::setMagnificationFilter(const Sampler::Filter filter) {
    (this->*Context::current()->state().texture->parameteriImplementation)(GL_TEXTURE_MAG_FILTER, GLint(filter));
}

#ifndef MAGNUM_TARGET_GLES2
void AbstractTexture::setMinLod(const Float lod) {
    (this->*Context::current()->state().texture->parameterfImplementation)(GL_TEXTURE_MIN_LOD, lod);
}

void AbstractTexture::setMaxLod(const Float lod) {
    (this->*Context::current()->state().texture->parameterfImplementation)(GL_TEXTURE_MAX_LOD, lod);
}
#endif

#ifndef MAGNUM_TARGET_GLES
void AbstractTexture::setLodBias(const Float bias) {
    (this->*Context::current()->state().texture->parameterfImplementation)(GL_TEXTURE_LOD_BIAS, bias);
}
#endif

void AbstractTexture::setBorderColor(const Color4& color) {
    #ifndef MAGNUM_TARGET_GLES
    (this->*Context::current()->state().texture->parameterfvImplementation)(GL_TEXTURE_BORDER_COLOR, color.data());
    #else
    (this->*Context::current()->state().texture->parameterfvImplementation)(GL_TEXTURE_BORDER_COLOR_NV, color.data());
    #endif
}

#ifndef MAGNUM_TARGET_GLES
void AbstractTexture::setBorderColor(const Vector4ui& color) {
    (this->*Context::current()->state().texture->parameterIuivImplementation)(GL_TEXTURE_BORDER_COLOR, color.data());
}

void AbstractTexture::setBorderColor(const Vector4i& color) {
    (this->*Context::current()->state().texture->parameterIivImplementation)(GL_TEXTURE_BORDER_COLOR, color.data());
}
#endif

void AbstractTexture::setMaxAnisotropy(const Float anisotropy) {
    (this->*Context::current()->state().texture->setMaxAnisotropyImplementation)(anisotropy);
}

void AbstractTexture::setSRGBDecode(bool decode) {
    (this->*Context::current()->state().texture->parameteriImplementation)(GL_TEXTURE_SRGB_DECODE_EXT,
        decode ? GL_DECODE_EXT : GL_SKIP_DECODE_EXT);
}

#ifndef MAGNUM_TARGET_GLES2
void AbstractTexture::setSwizzleInternal(const GLint r, const GLint g, const GLint b, const GLint a) {
    #ifndef MAGNUM_TARGET_GLES
    const GLint rgba[] = {r, g, b, a};
    (this->*Context::current()->state().texture->parameterivImplementation)(GL_TEXTURE_SWIZZLE_RGBA, rgba);
    #else
    (this->*Context::current()->state().texture->parameteriImplementation)(GL_TEXTURE_SWIZZLE_R, r);
    (this->*Context::current()->state().texture->parameteriImplementation)(GL_TEXTURE_SWIZZLE_G, g);
    (this->*Context::current()->state().texture->parameteriImplementation)(GL_TEXTURE_SWIZZLE_B, b);
    (this->*Context::current()->state().texture->parameteriImplementation)(GL_TEXTURE_SWIZZLE_A, a);
    #endif
}
#endif

void AbstractTexture::setCompareMode(const Sampler::CompareMode mode) {
    (this->*Context::current()->state().texture->parameteriImplementation)(
        #ifndef MAGNUM_TARGET_GLES2
        GL_TEXTURE_COMPARE_MODE
        #else
        GL_TEXTURE_COMPARE_MODE_EXT
        #endif
        , GLenum(mode));
}

void AbstractTexture::setCompareFunction(const Sampler::CompareFunction function) {
    (this->*Context::current()->state().texture->parameteriImplementation)(
        #ifndef MAGNUM_TARGET_GLES2
        GL_TEXTURE_COMPARE_FUNC
        #else
        GL_TEXTURE_COMPARE_FUNC_EXT
        #endif
        , GLenum(function));
}

#ifndef MAGNUM_TARGET_GLES2
void AbstractTexture::setDepthStencilMode(const Sampler::DepthStencilMode mode) {
    (this->*Context::current()->state().texture->parameteriImplementation)(GL_DEPTH_STENCIL_TEXTURE_MODE, GLenum(mode));
}
#endif

void AbstractTexture::invalidateImage(const Int level) {
    (this->*Context::current()->state().texture->invalidateImageImplementation)(level);
}

void AbstractTexture::generateMipmap() {
    (this->*Context::current()->state().texture->mipmapImplementation)();
}

void AbstractTexture::mipmapImplementationDefault() {
    bindInternal();
    glGenerateMipmap(_target);
}

#ifndef MAGNUM_TARGET_GLES
void AbstractTexture::mipmapImplementationDSA() {
    glGenerateTextureMipmap(_id);
}

void AbstractTexture::mipmapImplementationDSAEXT() {
    _created = true;
    glGenerateTextureMipmapEXT(_id, _target);
}
#endif

void AbstractTexture::bindInternal() {
    /* Using glBindTextures() here is meaningless, because the non-DSA
       functions need to have the texture bound in *currently active* unit,
       so we would need to call glActiveTexture() afterwards anyway. */

    Implementation::TextureState& textureState = *Context::current()->state().texture;

    /* If the texture is already bound in current unit, nothing to do */
    if(textureState.bindings[textureState.currentTextureUnit].second == _id)
        return;

    /* Set internal unit as active if not already, update state tracker */
    CORRADE_INTERNAL_ASSERT(textureState.maxTextureUnits > 1);
    const GLint internalTextureUnit = textureState.maxTextureUnits-1;
    if(textureState.currentTextureUnit != internalTextureUnit)
        glActiveTexture(GL_TEXTURE0 + (textureState.currentTextureUnit = internalTextureUnit));

    /* Bind the texture to internal unit if not already, update state tracker */
    if(textureState.bindings[internalTextureUnit].second == _id) return;
    textureState.bindings[internalTextureUnit] = {_target, _id};

    /* Binding the texture finally creates it */
    _created = true;
    glBindTexture(_target, _id);
}

ColorFormat AbstractTexture::imageFormatForInternalFormat(const TextureFormat internalFormat) {
    switch(internalFormat) {
        case TextureFormat::Red:
        case TextureFormat::R8:
        #ifndef MAGNUM_TARGET_GLES2
        case TextureFormat::R8Snorm:
        #endif
        #ifndef MAGNUM_TARGET_GLES
        case TextureFormat::R16:
        case TextureFormat::R16Snorm:
        #endif
        #ifndef MAGNUM_TARGET_GLES2
        case TextureFormat::R16F:
        case TextureFormat::R32F:
        #endif
        #ifndef MAGNUM_TARGET_GLES
        case TextureFormat::CompressedRed:
        case TextureFormat::CompressedRedRgtc1:
        case TextureFormat::CompressedSignedRedRgtc1:
        #endif
            return ColorFormat::Red;

        #ifndef MAGNUM_TARGET_GLES2
        case TextureFormat::R8UI:
        case TextureFormat::R8I:
        case TextureFormat::R16UI:
        case TextureFormat::R16I:
        case TextureFormat::R32UI:
        case TextureFormat::R32I:
            return ColorFormat::RedInteger;
        #endif

        case TextureFormat::RG:
        case TextureFormat::RG8:
        #ifndef MAGNUM_TARGET_GLES2
        case TextureFormat::RG8Snorm:
        #endif
        #ifndef MAGNUM_TARGET_GLES
        case TextureFormat::RG16:
        case TextureFormat::RG16Snorm:
        #endif
        #ifndef MAGNUM_TARGET_GLES2
        case TextureFormat::RG16F:
        case TextureFormat::RG32F:
        #endif
        #ifndef MAGNUM_TARGET_GLES
        case TextureFormat::CompressedRG:
        case TextureFormat::CompressedRGRgtc2:
        case TextureFormat::CompressedSignedRGRgtc2:
        #endif
            return ColorFormat::RG;

        #ifndef MAGNUM_TARGET_GLES2
        case TextureFormat::RG8UI:
        case TextureFormat::RG8I:
        case TextureFormat::RG16UI:
        case TextureFormat::RG16I:
        case TextureFormat::RG32UI:
        case TextureFormat::RG32I:
            return ColorFormat::RGInteger;
        #endif

        case TextureFormat::RGB:
        case TextureFormat::RGB8:
        #ifndef MAGNUM_TARGET_GLES2
        case TextureFormat::RGB8Snorm:
        #endif
        #ifndef MAGNUM_TARGET_GLES
        case TextureFormat::RGB16:
        case TextureFormat::RGB16Snorm:
        #endif
        #ifndef MAGNUM_TARGET_GLES2
        case TextureFormat::RGB16F:
        case TextureFormat::RGB32F:
        #endif
        #ifndef MAGNUM_TARGET_GLES
        case TextureFormat::R3B3G2:
        case TextureFormat::RGB4:
        case TextureFormat::RGB5:
        #endif
        case TextureFormat::RGB565:
        #ifndef MAGNUM_TARGET_GLES3
        case TextureFormat::RGB10:
        #endif
        #ifndef MAGNUM_TARGET_GLES
        case TextureFormat::RGB12:
        #endif
        #ifndef MAGNUM_TARGET_GLES2
        case TextureFormat::R11FG11FB10F:
        case TextureFormat::RGB9E5:
        #endif
        case TextureFormat::SRGB:
        #ifndef MAGNUM_TARGET_GLES2
        case TextureFormat::SRGB8:
        #endif
        #ifndef MAGNUM_TARGET_GLES
        case TextureFormat::CompressedRGB:
        case TextureFormat::CompressedRGBBptcUnsignedFloat:
        case TextureFormat::CompressedRGBBptcSignedFloat:
        #endif
            return ColorFormat::RGB;

        #ifndef MAGNUM_TARGET_GLES2
        case TextureFormat::RGB8UI:
        case TextureFormat::RGB8I:
        case TextureFormat::RGB16UI:
        case TextureFormat::RGB16I:
        case TextureFormat::RGB32UI:
        case TextureFormat::RGB32I:
            return ColorFormat::RGBInteger;
        #endif

        case TextureFormat::RGBA:
        case TextureFormat::RGBA8:
        #ifndef MAGNUM_TARGET_GLES2
        case TextureFormat::RGBA8Snorm:
        #endif
        #ifndef MAGNUM_TARGET_GLES
        case TextureFormat::RGBA16:
        case TextureFormat::RGBA16Snorm:
        #endif
        #ifndef MAGNUM_TARGET_GLES2
        case TextureFormat::RGBA16F:
        case TextureFormat::RGBA32F:
        #endif
        #ifndef MAGNUM_TARGET_GLES
        case TextureFormat::RGBA2:
        #endif
        case TextureFormat::RGBA4:
        case TextureFormat::RGB5A1:
        case TextureFormat::RGB10A2:
        #ifndef MAGNUM_TARGET_GLES
        case TextureFormat::RGBA12:
        #endif
        case TextureFormat::SRGBAlpha:
        #ifndef MAGNUM_TARGET_GLES2
        case TextureFormat::SRGB8Alpha8:
        #endif
        #ifndef MAGNUM_TARGET_GLES
        case TextureFormat::CompressedRGBA:
        case TextureFormat::CompressedRGBABptcUnorm:
        case TextureFormat::CompressedSRGBAlphaBptcUnorm:
        #endif
            return ColorFormat::RGBA;

        #ifndef MAGNUM_TARGET_GLES2
        case TextureFormat::RGBA8UI:
        case TextureFormat::RGBA8I:
        case TextureFormat::RGBA16UI:
        case TextureFormat::RGBA16I:
        case TextureFormat::RGBA32UI:
        case TextureFormat::RGBA32I:
        case TextureFormat::RGB10A2UI:
            return ColorFormat::RGBAInteger;
        #endif

        #ifdef MAGNUM_TARGET_GLES2
        case TextureFormat::Luminance:
            return ColorFormat::Luminance;
        case TextureFormat::LuminanceAlpha:
            return ColorFormat::LuminanceAlpha;
        #endif

        case TextureFormat::DepthComponent:
        case TextureFormat::DepthComponent16:
        case TextureFormat::DepthComponent24:
        case TextureFormat::DepthComponent32:
        #ifndef MAGNUM_TARGET_GLES2
        case TextureFormat::DepthComponent32F:
        #endif
            return ColorFormat::DepthComponent;

        #ifndef MAGNUM_TARGET_GLES
        case TextureFormat::StencilIndex8:
            return ColorFormat::StencilIndex;
        #endif

        case TextureFormat::DepthStencil:
        case TextureFormat::Depth24Stencil8:
        #ifndef MAGNUM_TARGET_GLES2
        case TextureFormat::Depth32FStencil8:
        #endif
            return ColorFormat::DepthStencil;
    }

    CORRADE_ASSERT_UNREACHABLE();
}

ColorType AbstractTexture::imageTypeForInternalFormat(const TextureFormat internalFormat) {
    switch(internalFormat) {
        case TextureFormat::Red:
        case TextureFormat::RG:
        case TextureFormat::RGB:
        case TextureFormat::RGBA:
        case TextureFormat::R8:
        case TextureFormat::RG8:
        case TextureFormat::RGB8:
        case TextureFormat::RGBA8:
        #ifndef MAGNUM_TARGET_GLES2
        case TextureFormat::R8UI:
        case TextureFormat::RG8UI:
        case TextureFormat::RGB8UI:
        case TextureFormat::RGBA8UI:
        #endif
        #ifdef MAGNUM_TARGET_GLES2
        case TextureFormat::Luminance:
        case TextureFormat::LuminanceAlpha:
        #endif
        case TextureFormat::SRGB:
        case TextureFormat::SRGBAlpha:
        #ifndef MAGNUM_TARGET_GLES2
        case TextureFormat::SRGB8:
        case TextureFormat::SRGB8Alpha8:
        #endif
        #ifndef MAGNUM_TARGET_GLES
        case TextureFormat::RGBA2: /**< @todo really? */
        case TextureFormat::CompressedRed:
        case TextureFormat::CompressedRG:
        case TextureFormat::CompressedRGB:
        case TextureFormat::CompressedRGBA:
        case TextureFormat::CompressedRedRgtc1:
        case TextureFormat::CompressedRGRgtc2:
        case TextureFormat::CompressedRGBABptcUnorm:
        case TextureFormat::CompressedSRGBAlphaBptcUnorm:
        #endif
            return ColorType::UnsignedByte;

        #ifndef MAGNUM_TARGET_GLES2
        case TextureFormat::R8Snorm:
        case TextureFormat::RG8Snorm:
        case TextureFormat::RGB8Snorm:
        case TextureFormat::RGBA8Snorm:
        case TextureFormat::R8I:
        case TextureFormat::RG8I:
        case TextureFormat::RGB8I:
        case TextureFormat::RGBA8I:
        #ifndef MAGNUM_TARGET_GLES
        case TextureFormat::CompressedSignedRedRgtc1:
        case TextureFormat::CompressedSignedRGRgtc2:
        #endif
            return ColorType::Byte;
        #endif

        #ifndef MAGNUM_TARGET_GLES
        case TextureFormat::R16:
        case TextureFormat::RG16:
        case TextureFormat::RGB16:
        case TextureFormat::RGBA16:
        #endif
        #ifndef MAGNUM_TARGET_GLES2
        case TextureFormat::R16UI:
        case TextureFormat::RG16UI:
        case TextureFormat::RGB16UI:
        case TextureFormat::RGBA16UI:
        #endif
        #ifndef MAGNUM_TARGET_GLES
        case TextureFormat::RGB12: /**< @todo really? */
        #endif
        case TextureFormat::RGBA4: /**< @todo really? */
        #ifndef MAGNUM_TARGET_GLES
        case TextureFormat::RGBA12: /**< @todo really? */
        #endif
            return ColorType::UnsignedShort;

        #ifndef MAGNUM_TARGET_GLES2
        #ifndef MAGNUM_TARGET_GLES
        case TextureFormat::R16Snorm:
        case TextureFormat::RG16Snorm:
        case TextureFormat::RGB16Snorm:
        case TextureFormat::RGBA16Snorm:
        #endif
        case TextureFormat::R16I:
        case TextureFormat::RG16I:
        case TextureFormat::RGB16I:
        case TextureFormat::RGBA16I:
            return ColorType::Short;
        #endif

        #ifndef MAGNUM_TARGET_GLES2
        case TextureFormat::R16F:
        case TextureFormat::RG16F:
        case TextureFormat::RGB16F:
        case TextureFormat::RGBA16F:
            return ColorType::HalfFloat;

        case TextureFormat::R32UI:
        case TextureFormat::RG32UI:
        case TextureFormat::RGB32UI:
        case TextureFormat::RGBA32UI:
            return ColorType::UnsignedInt;

        case TextureFormat::R32I:
        case TextureFormat::RG32I:
        case TextureFormat::RGB32I:
        case TextureFormat::RGBA32I:
            return ColorType::Int;

        case TextureFormat::R32F:
        case TextureFormat::RG32F:
        case TextureFormat::RGB32F:
        case TextureFormat::RGBA32F:
        #ifndef MAGNUM_TARGET_GLES
        case TextureFormat::CompressedRGBBptcUnsignedFloat:
        case TextureFormat::CompressedRGBBptcSignedFloat:
        #endif
            return ColorType::Float;
        #endif

        #ifndef MAGNUM_TARGET_GLES
        case TextureFormat::R3B3G2:
            return ColorType::UnsignedByte332;
        case TextureFormat::RGB4:
            return ColorType::UnsignedShort4444;
        #endif

        #ifndef MAGNUM_TARGET_GLES
        case TextureFormat::RGB5:
        #endif
        case TextureFormat::RGB5A1:
            return ColorType::UnsignedShort5551;

        case TextureFormat::RGB565:
            return ColorType::UnsignedShort565;

        #ifndef MAGNUM_TARGET_GLES3
        case TextureFormat::RGB10:
        #endif
        case TextureFormat::RGB10A2:
        #ifndef MAGNUM_TARGET_GLES2
        case TextureFormat::RGB10A2UI:
        #endif
            return ColorType::UnsignedInt2101010Rev; /**< @todo Rev for all? */

        #ifndef MAGNUM_TARGET_GLES2
        case TextureFormat::R11FG11FB10F:
            return ColorType::UnsignedInt10F11F11FRev;
        case TextureFormat::RGB9E5:
            return ColorType::UnsignedInt5999Rev;
        #endif

        case TextureFormat::DepthComponent16:
            return ColorType::UnsignedShort;

        case TextureFormat::DepthComponent:
        case TextureFormat::DepthComponent24:
        case TextureFormat::DepthComponent32:
            return ColorType::UnsignedInt;

        #ifndef MAGNUM_TARGET_GLES2
        case TextureFormat::DepthComponent32F:
            return ColorType::Float;
        #endif

        #ifndef MAGNUM_TARGET_GLES
        case TextureFormat::StencilIndex8:
            return ColorType::UnsignedByte;
        #endif

        case TextureFormat::DepthStencil:
        case TextureFormat::Depth24Stencil8:
            return ColorType::UnsignedInt248;

        #ifndef MAGNUM_TARGET_GLES2
        case TextureFormat::Depth32FStencil8:
            return ColorType::Float32UnsignedInt248Rev;
        #endif
    }

    CORRADE_ASSERT_UNREACHABLE();
}

void AbstractTexture::parameterImplementationDefault(GLenum parameter, GLint value) {
    bindInternal();
    glTexParameteri(_target, parameter, value);
}

#ifndef MAGNUM_TARGET_GLES
void AbstractTexture::parameterImplementationDSA(const GLenum parameter, const GLint value) {
    glTextureParameteri(_id, parameter, value);
}

void AbstractTexture::parameterImplementationDSAEXT(GLenum parameter, GLint value) {
    _created = true;
    glTextureParameteriEXT(_id, _target, parameter, value);
}
#endif

void AbstractTexture::parameterImplementationDefault(GLenum parameter, GLfloat value) {
    bindInternal();
    glTexParameterf(_target, parameter, value);
}

#ifndef MAGNUM_TARGET_GLES
void AbstractTexture::parameterImplementationDSA(const GLenum parameter, const GLfloat value) {
    glTextureParameterf(_id, parameter, value);
}

void AbstractTexture::parameterImplementationDSAEXT(GLenum parameter, GLfloat value) {
    _created = true;
    glTextureParameterfEXT(_id, _target, parameter, value);
}
#endif

#ifndef MAGNUM_TARGET_GLES2
void AbstractTexture::parameterImplementationDefault(GLenum parameter, const GLint* values) {
    bindInternal();
    glTexParameteriv(_target, parameter, values);
}

#ifndef MAGNUM_TARGET_GLES
void AbstractTexture::parameterImplementationDSA(const GLenum parameter, const GLint* const values) {
    glTextureParameteriv(_id, parameter, values);
}

void AbstractTexture::parameterImplementationDSAEXT(GLenum parameter, const GLint* values) {
    _created = true;
    glTextureParameterivEXT(_id, _target, parameter, values);
}
#endif
#endif

void AbstractTexture::parameterImplementationDefault(GLenum parameter, const GLfloat* values) {
    bindInternal();
    glTexParameterfv(_target, parameter, values);
}

#ifndef MAGNUM_TARGET_GLES
void AbstractTexture::parameterImplementationDSA(const GLenum parameter, const GLfloat* const values) {
    glTextureParameterfv(_id, parameter, values);
}

void AbstractTexture::parameterImplementationDSAEXT(GLenum parameter, const GLfloat* values) {
    _created = true;
    glTextureParameterfvEXT(_id, _target, parameter, values);
}
#endif

#ifndef MAGNUM_TARGET_GLES
void AbstractTexture::parameterIImplementationDefault(GLenum parameter, const GLuint* values) {
    bindInternal();
    glTexParameterIuiv(_target, parameter, values);
}

void AbstractTexture::parameterIImplementationDSA(const GLenum parameter, const GLuint* const values) {
    glTextureParameterIuiv(_id, parameter, values);
}

void AbstractTexture::parameterIImplementationDSAEXT(GLenum parameter, const GLuint* values) {
    _created = true;
    glTextureParameterIuivEXT(_id, _target, parameter, values);
}

void AbstractTexture::parameterIImplementationDefault(GLenum parameter, const GLint* values) {
    bindInternal();
    glTexParameterIiv(_target, parameter, values);
}

void AbstractTexture::parameterIImplementationDSA(const GLenum parameter, const GLint* const values) {
    glTextureParameterIiv(_id, parameter, values);
}

void AbstractTexture::parameterIImplementationDSAEXT(GLenum parameter, const GLint* values) {
    _created = true;
    glTextureParameterIivEXT(_id, _target, parameter, values);
}
#endif

void AbstractTexture::setMaxAnisotropyImplementationNoOp(GLfloat) {}

void AbstractTexture::setMaxAnisotropyImplementationExt(GLfloat anisotropy) {
    (this->*Context::current()->state().texture->parameterfImplementation)(GL_TEXTURE_MAX_ANISOTROPY_EXT, anisotropy);
}

#ifndef MAGNUM_TARGET_GLES2
void AbstractTexture::getLevelParameterImplementationDefault(GLint level, GLenum parameter, GLint* values) {
    bindInternal();
    glGetTexLevelParameteriv(_target, level, parameter, values);
}

#ifndef MAGNUM_TARGET_GLES
void AbstractTexture::getLevelParameterImplementationDSA(const GLint level, const GLenum parameter, GLint* const values) {
    glGetTextureLevelParameteriv(_id, level, parameter, values);
}

void AbstractTexture::getLevelParameterImplementationDSAEXT(GLint level, GLenum parameter, GLint* values) {
    _created = true;
    glGetTextureLevelParameterivEXT(_id, _target, level, parameter, values);
}
#endif
#endif

#ifndef MAGNUM_TARGET_GLES
void AbstractTexture::storageImplementationFallback(const GLsizei levels, const TextureFormat internalFormat, const Math::Vector<1, GLsizei>& size) {
    const ColorFormat format = imageFormatForInternalFormat(internalFormat);
    const ColorType type = imageTypeForInternalFormat(internalFormat);

    for(GLsizei level = 0; level != levels; ++level)
        DataHelper<1>::setImage(*this, level, internalFormat,
            ImageReference1D{format, type, Math::max(Math::Vector<1, GLsizei>(1), size >> level)});
}

void AbstractTexture::storageImplementationDefault(GLsizei levels, TextureFormat internalFormat, const Math::Vector<1, GLsizei>& size) {
    bindInternal();
    glTexStorage1D(_target, levels, GLenum(internalFormat), size[0]);
}

void AbstractTexture::storageImplementationDSA(const GLsizei levels, const TextureFormat internalFormat, const Math::Vector<1, GLsizei>& size) {
    glTextureStorage1D(_id, levels, GLenum(internalFormat), size[0]);
}

void AbstractTexture::storageImplementationDSAEXT(GLsizei levels, TextureFormat internalFormat, const Math::Vector<1, GLsizei>& size) {
    _created = true;
    glTextureStorage1DEXT(_id, _target, levels, GLenum(internalFormat), size[0]);
}
#endif

void AbstractTexture::storageImplementationFallback(const GLsizei levels, const TextureFormat internalFormat, const Vector2i& size) {
    const ColorFormat format = imageFormatForInternalFormat(internalFormat);
    const ColorType type = imageTypeForInternalFormat(internalFormat);

    /* Common code for classic types */
    #ifndef MAGNUM_TARGET_GLES
    if(_target == GL_TEXTURE_2D || _target == GL_TEXTURE_RECTANGLE)
    #else
    if(_target == GL_TEXTURE_2D)
    #endif
    {
        for(GLsizei level = 0; level != levels; ++level)
            DataHelper<2>::setImage(*this, level, internalFormat,
                ImageReference2D{format, type, Math::max(Vector2i(1), size >> level)});

    /* Cube map additionally needs to specify all faces */
    } else if(_target == GL_TEXTURE_CUBE_MAP) {
        for(GLsizei level = 0; level != levels; ++level) {
            for(GLenum face: {GL_TEXTURE_CUBE_MAP_POSITIVE_X,
                              GL_TEXTURE_CUBE_MAP_NEGATIVE_X,
                              GL_TEXTURE_CUBE_MAP_POSITIVE_Y,
                              GL_TEXTURE_CUBE_MAP_NEGATIVE_Y,
                              GL_TEXTURE_CUBE_MAP_POSITIVE_Z,
                              GL_TEXTURE_CUBE_MAP_NEGATIVE_Z})
                DataHelper<2>::setImage(*this, face, level, internalFormat,
                    ImageReference2D{format, type, Math::max(Vector2i(1), size >> level)});
        }

    #ifndef MAGNUM_TARGET_GLES
    /* Array texture is not scaled in "layer" dimension */
    } else if(_target == GL_TEXTURE_1D_ARRAY) {
        for(GLsizei level = 0; level != levels; ++level)
            DataHelper<2>::setImage(*this, level, internalFormat,
                ImageReference2D{format, type, Vector2i{Math::max(1, size.x() >> level), size.y()}});
    #endif

    /* No other targets are available */
    } else CORRADE_ASSERT_UNREACHABLE();
}

void AbstractTexture::storageImplementationDefault(GLsizei levels, TextureFormat internalFormat, const Vector2i& size) {
    bindInternal();
    #ifndef MAGNUM_TARGET_GLES2
    glTexStorage2D(_target, levels, GLenum(internalFormat), size.x(), size.y());
    #elif !defined(CORRADE_TARGET_EMSCRIPTEN) && !defined(CORRADE_TARGET_NACL)
    glTexStorage2DEXT(_target, levels, GLenum(internalFormat), size.x(), size.y());
    #else
    static_cast<void>(levels);
    static_cast<void>(internalFormat);
    static_cast<void>(size);
    CORRADE_ASSERT_UNREACHABLE();
    #endif
}

#ifndef MAGNUM_TARGET_GLES
void AbstractTexture::storageImplementationDSA(const GLsizei levels, const TextureFormat internalFormat, const Vector2i& size) {
    glTextureStorage2D(_id, levels, GLenum(internalFormat), size.x(), size.y());
}

void AbstractTexture::storageImplementationDSAEXT(GLsizei levels, TextureFormat internalFormat, const Vector2i& size) {
    _created = true;
    glTextureStorage2DEXT(_id, _target, levels, GLenum(internalFormat), size.x(), size.y());
}
#endif

void AbstractTexture::storageImplementationFallback(GLsizei levels, TextureFormat internalFormat, const Vector3i& size) {
    const ColorFormat format = imageFormatForInternalFormat(internalFormat);
    const ColorType type = imageTypeForInternalFormat(internalFormat);

    /* Common code for classic type */
    #ifndef MAGNUM_TARGET_GLES2
    if(_target == GL_TEXTURE_3D)
    #else
    if(_target == GL_TEXTURE_3D_OES)
    #endif
        for(GLsizei level = 0; level != levels; ++level)
            DataHelper<3>::setImage(*this, level, internalFormat,
                ImageReference3D{format, type, Math::max(Vector3i(1), size >> level)});

    #ifndef MAGNUM_TARGET_GLES2
    /* Array texture is not scaled in "layer" dimension */
    #ifndef MAGNUM_TARGET_GLES
    else if(_target == GL_TEXTURE_2D_ARRAY || _target == GL_TEXTURE_CUBE_MAP_ARRAY)
    #else
    else if(_target == GL_TEXTURE_2D_ARRAY)
    #endif
        for(GLsizei level = 0; level != levels; ++level)
            DataHelper<3>::setImage(*this, level, internalFormat,
                ImageReference3D{format, type, Vector3i{Math::max(Vector2i{1}, size.xy() >> level), size.z()}});
    #endif

    /* No other targets are available */
    else CORRADE_ASSERT_UNREACHABLE();
}

void AbstractTexture::storageImplementationDefault(GLsizei levels, TextureFormat internalFormat, const Vector3i& size) {
    bindInternal();
    #ifndef MAGNUM_TARGET_GLES2
    glTexStorage3D(_target, levels, GLenum(internalFormat), size.x(), size.y(), size.z());
    #elif !defined(CORRADE_TARGET_EMSCRIPTEN) && !defined(CORRADE_TARGET_NACL)
    glTexStorage3DEXT(_target, levels, GLenum(internalFormat), size.x(), size.y(), size.z());
    #else
    static_cast<void>(levels);
    static_cast<void>(internalFormat);
    static_cast<void>(size);
    CORRADE_ASSERT_UNREACHABLE();
    #endif
}

#ifndef MAGNUM_TARGET_GLES
void AbstractTexture::storageImplementationDSA(const GLsizei levels, const TextureFormat internalFormat, const Vector3i& size) {
    glTextureStorage3D(_id, levels, GLenum(internalFormat), size.x(), size.y(), size.z());
}

void AbstractTexture::storageImplementationDSAEXT(GLsizei levels, TextureFormat internalFormat, const Vector3i& size) {
    _created = true;
    glTextureStorage3DEXT(_id, _target, levels, GLenum(internalFormat), size.x(), size.y(), size.z());
}
#endif

#ifndef MAGNUM_TARGET_GLES
void AbstractTexture::storageMultisampleImplementationFallback(const GLsizei samples, const TextureFormat internalFormat, const Vector2i& size, const GLboolean fixedSampleLocations) {
    bindInternal();
    glTexImage2DMultisample(_target, samples, GLenum(internalFormat), size.x(), size.y(), fixedSampleLocations);
}
#endif

#ifndef MAGNUM_TARGET_GLES2
void AbstractTexture::storageMultisampleImplementationDefault(const GLsizei samples, const TextureFormat internalFormat, const Vector2i& size, const GLboolean fixedSampleLocations) {
    bindInternal();
    glTexStorage2DMultisample(_target, samples, GLenum(internalFormat), size.x(), size.y(), fixedSampleLocations);
}
#endif

#ifndef MAGNUM_TARGET_GLES
void AbstractTexture::storageMultisampleImplementationDSA(const GLsizei samples, const TextureFormat internalFormat, const Vector2i& size, const GLboolean fixedSampleLocations) {
    glTextureStorage2DMultisample(_id, samples, GLenum(internalFormat), size.x(), size.y(), fixedSampleLocations);
}

void AbstractTexture::storageMultisampleImplementationDSAEXT(const GLsizei samples, const TextureFormat internalFormat, const Vector2i& size, const GLboolean fixedSampleLocations) {
    _created = true;
    glTextureStorage2DMultisampleEXT(_id, _target, samples, GLenum(internalFormat), size.x(), size.y(), fixedSampleLocations);
}

void AbstractTexture::storageMultisampleImplementationFallback(const GLsizei samples, const TextureFormat internalFormat, const Vector3i& size, const GLboolean fixedSampleLocations) {
    bindInternal();
    glTexImage3DMultisample(_target, samples, GLenum(internalFormat), size.x(), size.y(), size.z(), fixedSampleLocations);
}

void AbstractTexture::storageMultisampleImplementationDefault(const GLsizei samples, const TextureFormat internalFormat, const Vector3i& size, const GLboolean fixedSampleLocations) {
    bindInternal();
    glTexStorage3DMultisample(_target, samples, GLenum(internalFormat), size.x(), size.y(), size.z(), fixedSampleLocations);
}

void AbstractTexture::storageMultisampleImplementationDSA(const GLsizei samples, const TextureFormat internalFormat, const Vector3i& size, const GLboolean fixedSampleLocations) {
    glTextureStorage3DMultisample(_id, samples, GLenum(internalFormat), size.x(), size.y(), size.z(), fixedSampleLocations);
}

void AbstractTexture::storageMultisampleImplementationDSAEXT(const GLsizei samples, const TextureFormat internalFormat, const Vector3i& size, const GLboolean fixedSampleLocations) {
    _created = true;
    glTextureStorage3DMultisampleEXT(_id, _target, samples, GLenum(internalFormat), size.x(), size.y(), size.z(), fixedSampleLocations);
}
#endif

#ifndef MAGNUM_TARGET_GLES
void AbstractTexture::getImageImplementationDefault(const GLint level, const ColorFormat format, const ColorType type, const std::size_t, GLvoid* const data) {
    bindInternal();
    glGetTexImage(_target, level, GLenum(format), GLenum(type), data);
}

void AbstractTexture::getImageImplementationDSA(const GLint level, const ColorFormat format, const ColorType type, const std::size_t dataSize, GLvoid* const data) {
    glGetTextureImage(_id, level, GLenum(format), GLenum(type), dataSize, data);
}

void AbstractTexture::getImageImplementationDSAEXT(const GLint level, const ColorFormat format, const ColorType type, const std::size_t, GLvoid* const data) {
    _created = true;
    glGetTextureImageEXT(_id, _target, level, GLenum(format), GLenum(type), data);
}

void AbstractTexture::getImageImplementationRobustness(const GLint level, const ColorFormat format, const ColorType type, const std::size_t dataSize, GLvoid* const data) {
    bindInternal();
    glGetnTexImageARB(_target, level, GLenum(format), GLenum(type), dataSize, data);
}
#endif

#ifndef MAGNUM_TARGET_GLES
void AbstractTexture::subImageImplementationDefault(GLint level, const Math::Vector<1, GLint>& offset, const Math::Vector<1, GLsizei>& size, ColorFormat format, ColorType type, const GLvoid* data) {
    bindInternal();
    glTexSubImage1D(_target, level, offset[0], size[0], GLenum(format), GLenum(type), data);
}

void AbstractTexture::subImageImplementationDSA(const GLint level, const Math::Vector<1, GLint>& offset, const Math::Vector<1, GLsizei>& size, const ColorFormat format, const ColorType type, const GLvoid* const data) {
    glTextureSubImage1D(_id, level, offset[0], size[0], GLenum(format), GLenum(type), data);
}

void AbstractTexture::subImageImplementationDSAEXT(GLint level, const Math::Vector<1, GLint>& offset, const Math::Vector<1, GLsizei>& size, ColorFormat format, ColorType type, const GLvoid* data) {
    _created = true;
    glTextureSubImage1DEXT(_id, _target, level, offset[0], size[0], GLenum(format), GLenum(type), data);
}
#endif

void AbstractTexture::subImageImplementationDefault(GLint level, const Vector2i& offset, const Vector2i& size, ColorFormat format, ColorType type, const GLvoid* data) {
    bindInternal();
    glTexSubImage2D(_target, level, offset.x(), offset.y(), size.x(), size.y(), GLenum(format), GLenum(type), data);
}

#ifndef MAGNUM_TARGET_GLES
void AbstractTexture::subImageImplementationDSA(const GLint level, const Vector2i& offset, const Vector2i& size, const ColorFormat format, const ColorType type, const GLvoid* const data) {
    glTextureSubImage2D(_id, level, offset.x(), offset.y(), size.x(), size.y(), GLenum(format), GLenum(type), data);
}

void AbstractTexture::subImageImplementationDSAEXT(GLint level, const Vector2i& offset, const Vector2i& size, ColorFormat format, ColorType type, const GLvoid* data) {
    _created = true;
    glTextureSubImage2DEXT(_id, _target, level, offset.x(), offset.y(), size.x(), size.y(), GLenum(format), GLenum(type), data);
}
#endif

void AbstractTexture::subImageImplementationDefault(GLint level, const Vector3i& offset, const Vector3i& size, ColorFormat format, ColorType type, const GLvoid* data) {
    bindInternal();
    #ifndef MAGNUM_TARGET_GLES2
    glTexSubImage3D(_target, level, offset.x(), offset.y(), offset.z(), size.x(), size.y(), size.z(), GLenum(format), GLenum(type), data);
    #elif !defined(CORRADE_TARGET_EMSCRIPTEN) && !defined(CORRADE_TARGET_NACL)
    glTexSubImage3DOES(_target, level, offset.x(), offset.y(), offset.z(), size.x(), size.y(), size.z(), GLenum(format), GLenum(type), data);
    #else
    static_cast<void>(level);
    static_cast<void>(offset);
    static_cast<void>(size);
    static_cast<void>(format);
    static_cast<void>(type);
    static_cast<void>(data);
    CORRADE_ASSERT_UNREACHABLE();
    #endif
}

#ifndef MAGNUM_TARGET_GLES
void AbstractTexture::subImageImplementationDSA(const GLint level, const Vector3i& offset, const Vector3i& size, const ColorFormat format, const ColorType type, const GLvoid* const data) {
    glTextureSubImage3D(_id, level, offset.x(), offset.y(), offset.z(), size.x(), size.y(), size.z(), GLenum(format), GLenum(type), data);
}

void AbstractTexture::subImageImplementationDSAEXT(GLint level, const Vector3i& offset, const Vector3i& size, ColorFormat format, ColorType type, const GLvoid* data) {
    _created = true;
    glTextureSubImage3DEXT(_id, _target, level, offset.x(), offset.y(), offset.z(), size.x(), size.y(), size.z(), GLenum(format), GLenum(type), data);
}
#endif

void AbstractTexture::invalidateImageImplementationNoOp(GLint) {}

#ifndef MAGNUM_TARGET_GLES
void AbstractTexture::invalidateImageImplementationARB(GLint level) {
    createIfNotAlready();
    glInvalidateTexImage(_id, level);
}
#endif

void AbstractTexture::invalidateSubImageImplementationNoOp(GLint, const Vector3i&, const Vector3i&) {}

#ifndef MAGNUM_TARGET_GLES
void AbstractTexture::invalidateSubImageImplementationARB(GLint level, const Vector3i& offset, const Vector3i& size) {
    createIfNotAlready();
    glInvalidateTexSubImage(_id, level, offset.x(), offset.y(), offset.z(), size.x(), size.y(), size.z());
}
#endif

#ifndef DOXYGEN_GENERATING_OUTPUT
#ifndef MAGNUM_TARGET_GLES
template<UnsignedInt dimensions> void AbstractTexture::image(GLint level, Image<dimensions>& image) {
    const Math::Vector<dimensions, Int> size = DataHelper<dimensions>::imageSize(*this, level);
    const std::size_t dataSize = image.dataSize(size);
    char* data = new char[dataSize];
    Buffer::unbindInternal(Buffer::TargetHint::PixelPack);
    (this->*Context::current()->state().texture->getImageImplementation)(level, image.format(), image.type(), dataSize, data);
    image.setData(image.format(), image.type(), size, data);
}

template void MAGNUM_EXPORT AbstractTexture::image<1>(GLint, Image<1>&);
template void MAGNUM_EXPORT AbstractTexture::image<2>(GLint, Image<2>&);
template void MAGNUM_EXPORT AbstractTexture::image<3>(GLint, Image<3>&);

template<UnsignedInt dimensions> void AbstractTexture::image(GLint level, BufferImage<dimensions>& image, BufferUsage usage) {
    const Math::Vector<dimensions, Int> size = DataHelper<dimensions>::imageSize(*this, level);
    const std::size_t dataSize = image.dataSize(size);
    if(image.size() != size)
        image.setData(image.format(), image.type(), size, nullptr, usage);

    image.buffer().bindInternal(Buffer::TargetHint::PixelPack);
    (this->*Context::current()->state().texture->getImageImplementation)(level, image.format(), image.type(), dataSize, nullptr);
}

template void MAGNUM_EXPORT AbstractTexture::image<1>(GLint, BufferImage<1>&, BufferUsage);
template void MAGNUM_EXPORT AbstractTexture::image<2>(GLint, BufferImage<2>&, BufferUsage);
template void MAGNUM_EXPORT AbstractTexture::image<3>(GLint, BufferImage<3>&, BufferUsage);

template<UnsignedInt dimensions> void AbstractTexture::subImage(const GLint level, const RangeTypeFor<dimensions, Int>& range, Image<dimensions>& image) {
    createIfNotAlready();

    const Math::Vector<dimensions, Int> size = range.size();
    const Vector3i paddedOffset = Vector3i::pad(range.min());
    const Vector3i paddedSize = Vector3i::pad(size, 1);
    const std::size_t dataSize = image.dataSize(size);
    char* data = new char[dataSize];

    Buffer::unbindInternal(Buffer::TargetHint::PixelPack);
    glGetTextureSubImage(_id, level, paddedOffset.x(), paddedOffset.y(), paddedOffset.z(), paddedSize.x(), paddedSize.y(), paddedSize.z(), GLenum(image.format()), GLenum(image.type()), dataSize, data);
    image.setData(image.format(), image.type(), size, data);
}

template void MAGNUM_EXPORT AbstractTexture::subImage<1>(GLint, const Range1Di&, Image<1>&);
template void MAGNUM_EXPORT AbstractTexture::subImage<2>(GLint, const Range2Di&, Image<2>&);
template void MAGNUM_EXPORT AbstractTexture::subImage<3>(GLint, const Range3Di&, Image<3>&);

template<UnsignedInt dimensions> void AbstractTexture::subImage(const GLint level, const RangeTypeFor<dimensions, Int>& range, BufferImage<dimensions>& image, const BufferUsage usage) {
    createIfNotAlready();

    const Math::Vector<dimensions, Int> size = range.size();
    const std::size_t dataSize = image.dataSize(size);
    const Vector3i paddedOffset = Vector3i::pad(range.min());
    const Vector3i paddedSize = Vector3i::pad(size, 1);
    if(image.size() != size)
        image.setData(image.format(), image.type(), size, nullptr, usage);

    image.buffer().bindInternal(Buffer::TargetHint::PixelPack);
    glGetTextureSubImage(_id, level, paddedOffset.x(), paddedOffset.y(), paddedOffset.z(), paddedSize.x(), paddedSize.y(), paddedSize.z(), GLenum(image.format()), GLenum(image.type()), dataSize, nullptr);
}

template void MAGNUM_EXPORT AbstractTexture::subImage<1>(GLint, const Range1Di&, BufferImage<1>&, BufferUsage);
template void MAGNUM_EXPORT AbstractTexture::subImage<2>(GLint, const Range2Di&, BufferImage<2>&, BufferUsage);
template void MAGNUM_EXPORT AbstractTexture::subImage<3>(GLint, const Range3Di&, BufferImage<3>&, BufferUsage);
#endif
#endif

#ifndef DOXYGEN_GENERATING_OUTPUT
#ifndef MAGNUM_TARGET_GLES
Math::Vector<1, GLint> AbstractTexture::DataHelper<1>::imageSize(AbstractTexture& texture, const GLint level) {
    Math::Vector<1, GLint> value;
    (texture.*Context::current()->state().texture->getLevelParameterivImplementation)(level, GL_TEXTURE_WIDTH, &value[0]);
    return value;
}
#endif

#ifndef MAGNUM_TARGET_GLES2
Vector2i AbstractTexture::DataHelper<2>::imageSize(AbstractTexture& texture, const GLint level) {
    const Implementation::TextureState& state = *Context::current()->state().texture;

    Vector2i value;
    (texture.*state.getLevelParameterivImplementation)(level, GL_TEXTURE_WIDTH, &value[0]);
    (texture.*state.getLevelParameterivImplementation)(level, GL_TEXTURE_HEIGHT, &value[1]);
    return value;
}

Vector3i AbstractTexture::DataHelper<3>::imageSize(AbstractTexture& texture, const GLint level) {
    const Implementation::TextureState& state = *Context::current()->state().texture;

    Vector3i value;
    (texture.*state.getLevelParameterivImplementation)(level, GL_TEXTURE_WIDTH, &value[0]);
    (texture.*state.getLevelParameterivImplementation)(level, GL_TEXTURE_HEIGHT, &value[1]);
    (texture.*state.getLevelParameterivImplementation)(level, GL_TEXTURE_DEPTH, &value[2]);
    return value;
}
#endif

#ifndef MAGNUM_TARGET_GLES
void AbstractTexture::DataHelper<1>::setStorage(AbstractTexture& texture, const GLsizei levels, const TextureFormat internalFormat, const Math::Vector< 1, GLsizei >& size) {
    (texture.*Context::current()->state().texture->storage1DImplementation)(levels, internalFormat, size);
}
#endif

void AbstractTexture::DataHelper<2>::setStorage(AbstractTexture& texture, const GLsizei levels, const TextureFormat internalFormat, const Vector2i& size) {
    (texture.*Context::current()->state().texture->storage2DImplementation)(levels, internalFormat, size);
}

void AbstractTexture::DataHelper<3>::setStorage(AbstractTexture& texture, const GLsizei levels, const TextureFormat internalFormat, const Vector3i& size) {
    (texture.*Context::current()->state().texture->storage3DImplementation)(levels, internalFormat, size);
}

#ifndef MAGNUM_TARGET_GLES2
void AbstractTexture::DataHelper<2>::setStorageMultisample(AbstractTexture& texture, const GLsizei samples, const TextureFormat internalFormat, const Vector2i& size, const GLboolean fixedSampleLocations) {
    (texture.*Context::current()->state().texture->storage2DMultisampleImplementation)(samples, internalFormat, size, fixedSampleLocations);
}
#endif

#ifndef MAGNUM_TARGET_GLES
void AbstractTexture::DataHelper<3>::setStorageMultisample(AbstractTexture& texture, const GLsizei samples, const TextureFormat internalFormat, const Vector3i& size, const GLboolean fixedSampleLocations) {
    (texture.*Context::current()->state().texture->storage3DMultisampleImplementation)(samples, internalFormat, size, fixedSampleLocations);
}
#endif

#ifndef MAGNUM_TARGET_GLES
void AbstractTexture::DataHelper<1>::setImage(AbstractTexture& texture, const GLint level, const TextureFormat internalFormat, const ImageReference1D& image) {
    Buffer::unbindInternal(Buffer::TargetHint::PixelUnpack);
    texture.bindInternal();
    glTexImage1D(texture._target, level, GLint(internalFormat), image.size()[0], 0, GLenum(image.format()), GLenum(image.type()), image.data());
}

void AbstractTexture::DataHelper<1>::setImage(AbstractTexture& texture, const GLint level, const TextureFormat internalFormat, BufferImage1D& image) {
    image.buffer().bindInternal(Buffer::TargetHint::PixelUnpack);
    texture.bindInternal();
    glTexImage1D(texture._target, level, GLint(internalFormat), image.size()[0], 0, GLenum(image.format()), GLenum(image.type()), nullptr);
}

void AbstractTexture::DataHelper<1>::setSubImage(AbstractTexture& texture, const GLint level, const Math::Vector<1, GLint>& offset, const ImageReference1D& image) {
    Buffer::unbindInternal(Buffer::TargetHint::PixelUnpack);
    (texture.*Context::current()->state().texture->subImage1DImplementation)(level, offset, image.size(), image.format(), image.type(), image.data());
}

void AbstractTexture::DataHelper<1>::setSubImage(AbstractTexture& texture, const GLint level, const Math::Vector<1, GLint>& offset, BufferImage1D& image) {
    image.buffer().bindInternal(Buffer::TargetHint::PixelUnpack);
    (texture.*Context::current()->state().texture->subImage1DImplementation)(level, offset, image.size(), image.format(), image.type(), nullptr);
}
#endif

void AbstractTexture::DataHelper<2>::setImage(AbstractTexture& texture, const GLenum target, const GLint level, const TextureFormat internalFormat, const ImageReference2D& image) {
    #ifndef MAGNUM_TARGET_GLES2
    Buffer::unbindInternal(Buffer::TargetHint::PixelUnpack);
    #endif
    texture.bindInternal();
    glTexImage2D(target, level, GLint(internalFormat), image.size().x(), image.size().y(), 0, GLenum(image.format()), GLenum(image.type()), image.data());
}

#ifndef MAGNUM_TARGET_GLES2
void AbstractTexture::DataHelper<2>::setImage(AbstractTexture& texture, const GLenum target, const GLint level, const TextureFormat internalFormat, BufferImage2D& image) {
    image.buffer().bindInternal(Buffer::TargetHint::PixelUnpack);
    texture.bindInternal();
    glTexImage2D(target, level, GLint(internalFormat), image.size().x(), image.size().y(), 0, GLenum(image.format()), GLenum(image.type()), nullptr);
}
#endif

void AbstractTexture::DataHelper<2>::setSubImage(AbstractTexture& texture, const GLint level, const Vector2i& offset, const ImageReference2D& image) {
    #ifndef MAGNUM_TARGET_GLES2
    Buffer::unbindInternal(Buffer::TargetHint::PixelUnpack);
    #endif
    (texture.*Context::current()->state().texture->subImage2DImplementation)(level, offset, image.size(), image.format(), image.type(), image.data());
}

#ifndef MAGNUM_TARGET_GLES2
void AbstractTexture::DataHelper<2>::setSubImage(AbstractTexture& texture, const GLint level, const Vector2i& offset, BufferImage2D& image) {
    image.buffer().bindInternal(Buffer::TargetHint::PixelUnpack);
    (texture.*Context::current()->state().texture->subImage2DImplementation)(level, offset, image.size(), image.format(), image.type(), nullptr);
}
#endif

void AbstractTexture::DataHelper<3>::setImage(AbstractTexture& texture, const GLint level, const TextureFormat internalFormat, const ImageReference3D& image) {
    #ifndef MAGNUM_TARGET_GLES2
    Buffer::unbindInternal(Buffer::TargetHint::PixelUnpack);
    #endif
    texture.bindInternal();
    #ifndef MAGNUM_TARGET_GLES2
    glTexImage3D(texture._target, level, GLint(internalFormat), image.size().x(), image.size().y(), image.size().z(), 0, GLenum(image.format()), GLenum(image.type()), image.data());
    #elif !defined(CORRADE_TARGET_EMSCRIPTEN) && !defined(CORRADE_TARGET_NACL)
    glTexImage3DOES(texture._target, level, GLint(internalFormat), image.size().x(), image.size().y(), image.size().z(), 0, GLenum(image.format()), GLenum(image.type()), image.data());
    #else
    static_cast<void>(level);
    static_cast<void>(internalFormat);
    static_cast<void>(image);
    CORRADE_ASSERT_UNREACHABLE();
    #endif
}

#ifndef MAGNUM_TARGET_GLES2
void AbstractTexture::DataHelper<3>::setImage(AbstractTexture& texture, const GLint level, const TextureFormat internalFormat, BufferImage3D& image) {
    image.buffer().bindInternal(Buffer::TargetHint::PixelUnpack);
    texture.bindInternal();
    glTexImage3D(texture._target, level, GLint(internalFormat), image.size().x(), image.size().y(), image.size().z(), 0, GLenum(image.format()), GLenum(image.type()), nullptr);
}
#endif

void AbstractTexture::DataHelper<3>::setSubImage(AbstractTexture& texture, const GLint level, const Vector3i& offset, const ImageReference3D& image) {
    #ifndef MAGNUM_TARGET_GLES2
    Buffer::unbindInternal(Buffer::TargetHint::PixelUnpack);
    #endif
    (texture.*Context::current()->state().texture->subImage3DImplementation)(level, offset, image.size(), image.format(), image.type(), image.data());
}

#ifndef MAGNUM_TARGET_GLES2
void AbstractTexture::DataHelper<3>::setSubImage(AbstractTexture& texture, const GLint level, const Vector3i& offset, BufferImage3D& image) {
    image.buffer().bindInternal(Buffer::TargetHint::PixelUnpack);
    (texture.*Context::current()->state().texture->subImage3DImplementation)(level, offset, image.size(), image.format(), image.type(), nullptr);
}
#endif

#ifndef MAGNUM_TARGET_GLES
void AbstractTexture::DataHelper<1>::invalidateSubImage(AbstractTexture& texture, const GLint level, const Math::Vector<1, GLint>& offset, const Math::Vector<1, GLint>& size) {
    (texture.*Context::current()->state().texture->invalidateSubImageImplementation)(level, {offset[0], 0, 0}, {size[0], 1, 1});
}
#endif

void AbstractTexture::DataHelper<2>::invalidateSubImage(AbstractTexture& texture, const GLint level, const Vector2i& offset, const Vector2i& size) {
    (texture.*Context::current()->state().texture->invalidateSubImageImplementation)(level, {offset, 0}, {size, 1});
}

void AbstractTexture::DataHelper<3>::invalidateSubImage(AbstractTexture& texture, const GLint level, const Vector3i& offset, const Vector3i& size) {
    (texture.*Context::current()->state().texture->invalidateSubImageImplementation)(level, offset, size);
}

#ifndef MAGNUM_TARGET_GLES
void AbstractTexture::DataHelper<1>::setWrapping(AbstractTexture& texture, const Array1D<Sampler::Wrapping>& wrapping) {
    (texture.*Context::current()->state().texture->parameteriImplementation)(GL_TEXTURE_WRAP_S, GLint(wrapping.x()));
}
#endif

void AbstractTexture::DataHelper<2>::setWrapping(AbstractTexture& texture, const Array2D<Sampler::Wrapping>& wrapping) {
    const Implementation::TextureState& state = *Context::current()->state().texture;

    (texture.*state.parameteriImplementation)(GL_TEXTURE_WRAP_S, GLint(wrapping.x()));
    (texture.*state.parameteriImplementation)(GL_TEXTURE_WRAP_T, GLint(wrapping.y()));
}

void AbstractTexture::DataHelper<3>::setWrapping(AbstractTexture& texture, const Array3D<Sampler::Wrapping>& wrapping) {
    const Implementation::TextureState& state = *Context::current()->state().texture;

    (texture.*state.parameteriImplementation)(GL_TEXTURE_WRAP_S, GLint(wrapping.x()));
    (texture.*state.parameteriImplementation)(GL_TEXTURE_WRAP_T, GLint(wrapping.y()));
    #ifndef MAGNUM_TARGET_GLES
    (texture.*state.parameteriImplementation)(GL_TEXTURE_WRAP_R, GLint(wrapping.z()));
    #endif
}
#endif

}