OpenGL Mathematics (GLM)
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#include <cstdio>
#include <glm/gtc/round.hpp>
#include "../load_ktx.hpp"
#include "file.hpp"
namespace gli{
namespace detail
{
inline texture::size_type compute_ktx_storage_size(texture const & Texture)
{
texture::size_type const BlockSize = block_size(Texture.format());
texture::size_type TotalSize = sizeof(detail::FOURCC_KTX10) + sizeof(detail::ktx_header10);
for(texture::size_type Level = 0, Levels = Texture.levels(); Level < Levels; ++Level)
{
TotalSize += sizeof(std::uint32_t);
for(texture::size_type Layer = 0, Layers = Texture.layers(); Layer < Layers; ++Layer)
for(texture::size_type Face = 0, Faces = Texture.faces(); Face < Faces; ++Face)
{
texture::size_type const FaceSize = Texture.size(Level);
texture::size_type const PaddedSize = std::max(BlockSize, glm::ceilMultiple(FaceSize, static_cast<texture::size_type>(4)));
TotalSize += PaddedSize;
}
}
return TotalSize;
}
}//namespace detail
inline bool save_ktx(texture const& Texture, std::vector<char>& Memory)
{
if(Texture.empty())
return false;
gl GL(gl::PROFILE_KTX);
gl::format const& Format = GL.translate(Texture.format(), Texture.swizzles());
target const Target = Texture.target();
detail::formatInfo const& Desc = detail::get_format_info(Texture.format());
Memory.resize(detail::compute_ktx_storage_size(Texture));
std::memcpy(&Memory[0], detail::FOURCC_KTX10, sizeof(detail::FOURCC_KTX10));
std::size_t Offset = sizeof(detail::FOURCC_KTX10);
detail::ktx_header10& Header = *reinterpret_cast<detail::ktx_header10*>(&Memory[0] + Offset);
Header.Endianness = 0x04030201;
Header.GLType = Format.Type;
Header.GLTypeSize = Format.Type == gl::TYPE_NONE ? 1 : Desc.BlockSize;
Header.GLFormat = Format.External;
Header.GLInternalFormat = Format.Internal;
Header.GLBaseInternalFormat = Format.External;
Header.PixelWidth = static_cast<std::uint32_t>(Texture.extent().x);
Header.PixelHeight = !is_target_1d(Target) ? static_cast<std::uint32_t>(Texture.extent().y) : 0;
Header.PixelDepth = Target == TARGET_3D ? static_cast<std::uint32_t>(Texture.extent().z) : 0;
Header.NumberOfArrayElements = is_target_array(Target) ? static_cast<std::uint32_t>(Texture.layers()) : 0;
Header.NumberOfFaces = is_target_cube(Target) ? static_cast<std::uint32_t>(Texture.faces()) : 1;
Header.NumberOfMipmapLevels = static_cast<std::uint32_t>(Texture.levels());
Header.BytesOfKeyValueData = 0;
Offset += sizeof(detail::ktx_header10);
for(texture::size_type Level = 0, Levels = Texture.levels(); Level < Levels; ++Level)
{
std::uint32_t& ImageSize = *reinterpret_cast<std::uint32_t*>(&Memory[0] + Offset);
Offset += sizeof(std::uint32_t);
for(texture::size_type Layer = 0, Layers = Texture.layers(); Layer < Layers; ++Layer)
for(texture::size_type Face = 0, Faces = Texture.faces(); Face < Faces; ++Face)
{
texture::size_type const FaceSize = Texture.size(Level);
std::memcpy(&Memory[0] + Offset, Texture.data(Layer, Face, Level), FaceSize);
texture::size_type const PaddedSize = glm::ceilMultiple(FaceSize, static_cast<texture::size_type>(4));
ImageSize += static_cast<std::uint32_t>(PaddedSize);
Offset += PaddedSize;
GLI_ASSERT(Offset <= Memory.size());
}
ImageSize = glm::ceilMultiple(ImageSize, static_cast<std::uint32_t>(4));
}
return true;
}
inline bool save_ktx(texture const& Texture, char const* Filename)
{
if(Texture.empty())
return false;
FILE* File = detail::open_file(Filename, "wb");
if(!File)
return false;
std::vector<char> Memory;
bool const Result = save_ktx(Texture, Memory);
std::fwrite(&Memory[0], 1, Memory.size(), File);
std::fclose(File);
return Result;
}
inline bool save_ktx(texture const& Texture, std::string const& Filename)
{
return save_ktx(Texture, Filename.c_str());
}
}//namespace gli