/*
    This file is part of Magnum.

    Copyright © 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019,
                2020, 2021, 2022, 2023, 2024, 2025
              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 "GlyphCacheGL.h"

#ifdef MAGNUM_BUILD_DEPRECATED
#include <Corrade/Containers/Optional.h>
#endif

#include "Magnum/Image.h"
#include "Magnum/ImageView.h"
#if (!defined(MAGNUM_TARGET_GLES) || (defined(MAGNUM_TARGET_GLES2) && !defined(MAGNUM_TARGET_WEBGL))) || defined(MAGNUM_BUILD_DEPRECATED)
#include "Magnum/PixelFormat.h"
#endif
#include "Magnum/Math/Vector2.h"
#if !defined(MAGNUM_TARGET_GLES) || (defined(MAGNUM_TARGET_GLES2) && !defined(MAGNUM_TARGET_WEBGL))
#include "Magnum/GL/Context.h"
#include "Magnum/GL/Extensions.h"
#endif
#if defined(MAGNUM_TARGET_GLES2) && !defined(MAGNUM_TARGET_WEBGL)
#include "Magnum/GL/PixelFormat.h"
#endif
#include "Magnum/GL/TextureFormat.h"
#include "Magnum/Text/Implementation/glyphCacheGLState.h"

namespace Magnum { namespace Text {

GlyphCacheGL::State::State(const PixelFormat format, const Vector2i& size, const PixelFormat processedFormat, const Vector2i& processedSize, const Vector2i& padding): AbstractGlyphCache::State{format, {size, 1}, processedFormat, processedSize, padding} {
    #ifndef MAGNUM_TARGET_GLES
    if(processedFormat == PixelFormat::R8Unorm)
        MAGNUM_ASSERT_GL_EXTENSION_SUPPORTED(GL::Extensions::ARB::texture_rg);
    #endif

    /* Initialize the texture */
    texture.setWrapping(GL::SamplerWrapping::ClampToEdge)
        .setMinificationFilter(GL::SamplerFilter::Linear)
        .setMagnificationFilter(GL::SamplerFilter::Linear);

    /* ES2 special-casing. WebGL 1 has neither EXT_texture_rg nor
       EXT_texture_storage so it can use the common code path without
       issues. */
    #if defined(MAGNUM_TARGET_GLES2) && !defined(MAGNUM_TARGET_WEBGL)
    /* Prefer to use Red instead of Luminance if available, as Luminance isn't
       renderable */
    GL::TextureFormat textureFormat = GL::textureFormat(processedFormat);
    GL::PixelFormat pixelFormat = GL::pixelFormat(processedFormat);
    if(textureFormat == GL::TextureFormat::Luminance && GL::Context::current().isExtensionSupported<GL::Extensions::EXT::texture_rg>()) {
        textureFormat = GL::TextureFormat::Red;
        pixelFormat = GL::PixelFormat::Red;
    }

    /* And use setImage() instead of setStorage() if the format is unsized, as
       EXT_texture_storage doesn't allow those */
    if(textureFormat == GL::TextureFormat::Red ||
       textureFormat == GL::TextureFormat::Luminance ||
       textureFormat == GL::TextureFormat::RG ||
       textureFormat == GL::TextureFormat::LuminanceAlpha ||
       textureFormat == GL::TextureFormat::RGB ||
       textureFormat == GL::TextureFormat::SRGB ||
       textureFormat == GL::TextureFormat::RGBA ||
       textureFormat == GL::TextureFormat::SRGBAlpha)
        texture.setImage(0, textureFormat, ImageView2D{pixelFormat, GL::PixelType::UnsignedByte, processedSize});
    else
        texture.setStorage(1, textureFormat, processedSize);
    #else
    texture.setStorage(1, GL::textureFormat(processedFormat), processedSize);
    #endif
}

GlyphCacheGL::GlyphCacheGL(PixelFormat format, const Vector2i& size, PixelFormat processedFormat, const Vector2i& processedSize, const Vector2i& padding): AbstractGlyphCache{Containers::pointer<State>(format, size, processedFormat, processedSize, padding)} {}

GlyphCacheGL::GlyphCacheGL(PixelFormat format, const Vector2i& size, PixelFormat processedFormat, const Vector2i& processedSize): GlyphCacheGL{format, size, processedFormat, processedSize, Vector2i{1}} {}

GlyphCacheGL::GlyphCacheGL(const PixelFormat format, const Vector2i& size, const Vector2i& padding): GlyphCacheGL{format, size, format, size, padding} {}

GlyphCacheGL::GlyphCacheGL(const PixelFormat format, const Vector2i& size): GlyphCacheGL{format, size, Vector2i{1}} {}

#ifdef MAGNUM_BUILD_DEPRECATED
/* The unconditional Optional unwrap in these two may assert in rare cases.
   Let's hope it doesn't in practice. */

GlyphCacheGL::GlyphCacheGL(const GL::TextureFormat internalFormat, const Vector2i& size, const Vector2i& padding): GlyphCacheGL{*GL::genericPixelFormat(internalFormat), size, padding} {}

GlyphCacheGL::GlyphCacheGL(const GL::TextureFormat internalFormat, const Vector2i& size, const Vector2i& processedSize, const Vector2i& padding): GlyphCacheGL{*GL::genericPixelFormat(internalFormat), size, *GL::genericPixelFormat(internalFormat), processedSize, padding} {}

GlyphCacheGL::GlyphCacheGL(const Vector2i& size, const Vector2i& padding): GlyphCacheGL{PixelFormat::R8Unorm, size, padding} {}

GlyphCacheGL::GlyphCacheGL(const Vector2i& size, const Vector2i& processedSize, const Vector2i& padding): GlyphCacheGL{PixelFormat::R8Unorm, size, PixelFormat::R8Unorm, processedSize, padding} {}
#endif

GlyphCacheGL::GlyphCacheGL(Containers::Pointer<State>&& state) noexcept: AbstractGlyphCache{Utility::move(state)} {}

GlyphCacheGL::GlyphCacheGL(NoCreateT) noexcept: AbstractGlyphCache{NoCreate} {}

GL::Texture2D& GlyphCacheGL::texture() {
    return static_cast<State&>(*_state).texture;
}

GlyphCacheFeatures GlyphCacheGL::doFeatures() const { return {}; }

void GlyphCacheGL::doSetImage(const Vector2i& offset, const ImageView2D& image) {
    auto& state = static_cast<State&>(*_state);

    CORRADE_ASSERT(format() == processedFormat() && size() == processedSize(),
        "Text::GlyphCacheGL::flushImage(): subclass expected to provide a doSetImage() implementation to handle different processed format or size", );

    /* On ES2 without EXT_unpack_subimage and on WebGL 1 there's no possibility
       to upload just a slice of the input, upload the whole image instead by
       ignoring the PixelStorage properties of the input */
    #ifdef MAGNUM_TARGET_GLES2
    #ifndef MAGNUM_TARGET_WEBGL
    if(!GL::Context::current().isExtensionSupported<GL::Extensions::EXT::unpack_subimage>())
    #endif
    {
        /* On ES2 if EXT_texture_rg is present, the single-channel texture
           format is Red instead of Luminance. Have to duplicate the logic here
           in addition to below because it's easier than extracting
           formatExtra() and everything else from the view afterwards. */
        #ifndef MAGNUM_TARGET_WEBGL
        if(image.format() == PixelFormat::R8Unorm && GL::Context::current().isExtensionSupported<GL::Extensions::EXT::texture_rg>()) {
            state.texture.setSubImage(0, {}, ImageView2D{GL::PixelFormat::Red, GL::PixelType::UnsignedByte, size().xy(), image.data()});
        } else
        #endif
        {
            state.texture.setSubImage(0, {}, ImageView2D{image.format(), size().xy(), image.data()});
        }
        #ifdef MAGNUM_TARGET_WEBGL
        static_cast<void>(offset);
        #endif
    }
    #ifndef MAGNUM_TARGET_WEBGL
    else
    #endif
    #endif
    #if !(defined(MAGNUM_TARGET_GLES2) && defined(MAGNUM_TARGET_WEBGL))
    {
        /* On ES2 if EXT_texture_rg is present, the single-channel texture
           format is Red instead of Luminance */
        #ifdef MAGNUM_TARGET_GLES2
        if(image.format() == PixelFormat::R8Unorm && GL::Context::current().isExtensionSupported<GL::Extensions::EXT::texture_rg>()) {
            state.texture.setSubImage(0, offset, ImageView2D{image.storage(), GL::PixelFormat::Red, GL::PixelType::UnsignedByte, image.size(), image.data()});
        } else
        #endif
        {
            state.texture.setSubImage(0, offset, image);
        }
    }
    #endif
}

void GlyphCacheGL::doSetProcessedImage(const Vector2i& offset, const ImageView2D& image) {
    ImageView2D imageToUse = image;

    /* On ES2, R8Unorm maps to Luminance, but here it's actually Red if
       EXT_texture_rg is supported. Reinterpret the image format in that
       case. If the format is something else (such as RGBA8Unorm), no
       reinterpret is done. WebGL doesn't have the EXT_texture_rg extension so
       there it isn't done either. */
    #if defined(MAGNUM_TARGET_GLES2) && !defined(MAGNUM_TARGET_WEBGL)
    if(processedFormat() == PixelFormat::R8Unorm && GL::Context::current().isExtensionSupported<GL::Extensions::EXT::texture_rg>()) {
        /* This is checked inside setProcessedImage() already */
        CORRADE_INTERNAL_ASSERT(image.format() == PixelFormat::R8Unorm);
        imageToUse = ImageView2D{image.storage(), GL::PixelFormat::Red, GL::PixelType::UnsignedByte, image.size(), image.data()};
    }
    #endif

    static_cast<State&>(*_state).texture.setSubImage(0, offset, imageToUse);
}

#ifndef MAGNUM_TARGET_GLES
Image3D GlyphCacheGL::doProcessedImage() {
    Image2D out = static_cast<State&>(*_state).texture.image(0, processedFormat());
    return Image3D{out.format(), {out.size(), 1}, out.release()};
}
#endif

#ifndef MAGNUM_TARGET_GLES2
GlyphCacheArrayGL::State::State(const PixelFormat format, const Vector3i& size, const PixelFormat processedFormat, const Vector2i& processedSize, const Vector2i& padding): AbstractGlyphCache::State{format, size, processedFormat, processedSize, padding} {
    #ifndef MAGNUM_TARGET_GLES
    if(processedFormat == PixelFormat::R8Unorm)
        MAGNUM_ASSERT_GL_EXTENSION_SUPPORTED(GL::Extensions::ARB::texture_rg);
    #endif

    /* Initialize the texture */
    texture.setWrapping(GL::SamplerWrapping::ClampToEdge)
        .setMinificationFilter(GL::SamplerFilter::Linear)
        .setMagnificationFilter(GL::SamplerFilter::Linear)
        .setStorage(1, GL::textureFormat(processedFormat), {processedSize, size.z()});
}

GlyphCacheArrayGL::GlyphCacheArrayGL(PixelFormat format, const Vector3i& size, PixelFormat processedFormat, const Vector2i& processedSize, const Vector2i& padding): AbstractGlyphCache{Containers::pointer<State>(format, size, processedFormat, processedSize, padding)} {}

GlyphCacheArrayGL::GlyphCacheArrayGL(PixelFormat format, const Vector3i& size, PixelFormat processedFormat, const Vector2i& processedSize): GlyphCacheArrayGL{format, size, processedFormat, processedSize, Vector2i{1}} {}

GlyphCacheArrayGL::GlyphCacheArrayGL(const PixelFormat format, const Vector3i& size, const Vector2i& padding): GlyphCacheArrayGL{format, size, format, size.xy(), padding} {}

GlyphCacheArrayGL::GlyphCacheArrayGL(const PixelFormat format, const Vector3i& size): GlyphCacheArrayGL{format, size, Vector2i{1}} {}

GlyphCacheArrayGL::GlyphCacheArrayGL(NoCreateT) noexcept: AbstractGlyphCache{NoCreate} {}

GL::Texture2DArray& GlyphCacheArrayGL::texture() {
    return static_cast<State&>(*_state).texture;
}

GlyphCacheFeatures GlyphCacheArrayGL::doFeatures() const { return {}; }

void GlyphCacheArrayGL::doSetImage(const Vector3i& offset, const ImageView3D& image) {
    CORRADE_ASSERT(format() == processedFormat() && size() == processedSize(),
        "Text::GlyphCacheArrayGL::flushImage(): subclass expected to provide a doSetImage() implementation to handle different processed format or size", );

    static_cast<State&>(*_state).texture.setSubImage(0, offset, image);
}
#endif

}}