unity/crnlib/crn_ktx_texture.h

// File: crn_ktx_texture.h
#ifndef _KTX_TEXTURE_H_
#define _KTX_TEXTURE_H_
#ifdef _MSC_VER
#pragma once
#endif

#include "crn_data_stream_serializer.h"

#define KTX_ENDIAN 0x04030201
#define KTX_OPPOSITE_ENDIAN 0x01020304

namespace crnlib {
extern const uint8 s_ktx_file_id[12];

struct ktx_header {
  uint8 m_identifier[12];
  uint32 m_endianness;
  uint32 m_glType;
  uint32 m_glTypeSize;
  uint32 m_glFormat;
  uint32 m_glInternalFormat;
  uint32 m_glBaseInternalFormat;
  uint32 m_pixelWidth;
  uint32 m_pixelHeight;
  uint32 m_pixelDepth;
  uint32 m_numberOfArrayElements;
  uint32 m_numberOfFaces;
  uint32 m_numberOfMipmapLevels;
  uint32 m_bytesOfKeyValueData;

  void clear() {
    memset(this, 0, sizeof(*this));
  }

  void endian_swap() {
    utils::endian_swap_mem32(&m_endianness, (sizeof(*this) - sizeof(m_identifier)) / sizeof(uint32));
  }
};

typedef crnlib::vector<uint8_vec> ktx_key_value_vec;
typedef crnlib::vector<uint8_vec> ktx_image_data_vec;

// Compressed pixel data formats: ETC1, DXT1, DXT3, DXT5
enum {
  KTX_ETC1_RGB8_OES = 0x8D64,
  KTX_COMPRESSED_RGB8_ETC2 = 0x9274,
  KTX_COMPRESSED_RGBA8_ETC2_EAC = 0x9278,
  KTX_RGB_S3TC = 0x83A0,
  KTX_RGB4_S3TC = 0x83A1,
  KTX_COMPRESSED_RGB_S3TC_DXT1_EXT = 0x83F0,
  KTX_COMPRESSED_RGBA_S3TC_DXT1_EXT = 0x83F1,
  KTX_COMPRESSED_SRGB_S3TC_DXT1_EXT = 0x8C4C,
  KTX_COMPRESSED_SRGB_ALPHA_S3TC_DXT1_EXT = 0x8C4D,
  KTX_RGBA_S3TC = 0x83A2,
  KTX_RGBA4_S3TC = 0x83A3,
  KTX_COMPRESSED_RGBA_S3TC_DXT3_EXT = 0x83F2,
  KTX_COMPRESSED_SRGB_ALPHA_S3TC_DXT3_EXT = 0x8C4E,
  KTX_COMPRESSED_RGBA_S3TC_DXT5_EXT = 0x83F3,
  KTX_COMPRESSED_SRGB_ALPHA_S3TC_DXT5_EXT = 0x8C4F,
  KTX_RGBA_DXT5_S3TC = 0x83A4,
  KTX_RGBA4_DXT5_S3TC = 0x83A5,
  KTX_COMPRESSED_RED_RGTC1_EXT = 0x8DBB,
  KTX_COMPRESSED_SIGNED_RED_RGTC1_EXT = 0x8DBC,
  KTX_COMPRESSED_RED_GREEN_RGTC2_EXT = 0x8DBD,
  KTX_COMPRESSED_SIGNED_RED_GREEN_RGTC2_EXT = 0x8DBE,
  KTX_COMPRESSED_LUMINANCE_LATC1_EXT = 0x8C70,
  KTX_COMPRESSED_SIGNED_LUMINANCE_LATC1_EXT = 0x8C71,
  KTX_COMPRESSED_LUMINANCE_ALPHA_LATC2_EXT = 0x8C72,
  KTX_COMPRESSED_SIGNED_LUMINANCE_ALPHA_LATC2_EXT = 0x8C73
};

// Pixel formats (various internal, base, and base internal formats)
enum {
  KTX_R8 = 0x8229,
  KTX_R8UI = 0x8232,
  KTX_RGB8 = 0x8051,
  KTX_SRGB8 = 0x8C41,
  KTX_SRGB = 0x8C40,
  KTX_SRGB_ALPHA = 0x8C42,
  KTX_SRGB8_ALPHA8 = 0x8C43,
  KTX_RGBA8 = 0x8058,
  KTX_STENCIL_INDEX = 0x1901,
  KTX_DEPTH_COMPONENT = 0x1902,
  KTX_DEPTH_STENCIL = 0x84F9,
  KTX_RED = 0x1903,
  KTX_GREEN = 0x1904,
  KTX_BLUE = 0x1905,
  KTX_ALPHA = 0x1906,
  KTX_RG = 0x8227,
  KTX_RGB = 0x1907,
  KTX_RGBA = 0x1908,
  KTX_BGR = 0x80E0,
  KTX_BGRA = 0x80E1,
  KTX_RED_INTEGER = 0x8D94,
  KTX_GREEN_INTEGER = 0x8D95,
  KTX_BLUE_INTEGER = 0x8D96,
  KTX_ALPHA_INTEGER = 0x8D97,
  KTX_RGB_INTEGER = 0x8D98,
  KTX_RGBA_INTEGER = 0x8D99,
  KTX_BGR_INTEGER = 0x8D9A,
  KTX_BGRA_INTEGER = 0x8D9B,
  KTX_LUMINANCE = 0x1909,
  KTX_LUMINANCE_ALPHA = 0x190A,
  KTX_RG_INTEGER = 0x8228,
  KTX_RG8 = 0x822B,
  KTX_ALPHA8 = 0x803C,
  KTX_LUMINANCE8 = 0x8040,
  KTX_LUMINANCE8_ALPHA8 = 0x8045
};

// Pixel data types
enum {
  KTX_UNSIGNED_BYTE = 0x1401,
  KTX_BYTE = 0x1400,
  KTX_UNSIGNED_SHORT = 0x1403,
  KTX_SHORT = 0x1402,
  KTX_UNSIGNED_INT = 0x1405,
  KTX_INT = 0x1404,
  KTX_HALF_FLOAT = 0x140B,
  KTX_FLOAT = 0x1406,
  KTX_UNSIGNED_BYTE_3_3_2 = 0x8032,
  KTX_UNSIGNED_BYTE_2_3_3_REV = 0x8362,
  KTX_UNSIGNED_SHORT_5_6_5 = 0x8363,
  KTX_UNSIGNED_SHORT_5_6_5_REV = 0x8364,
  KTX_UNSIGNED_SHORT_4_4_4_4 = 0x8033,
  KTX_UNSIGNED_SHORT_4_4_4_4_REV = 0x8365,
  KTX_UNSIGNED_SHORT_5_5_5_1 = 0x8034,
  KTX_UNSIGNED_SHORT_1_5_5_5_REV = 0x8366,
  KTX_UNSIGNED_INT_8_8_8_8 = 0x8035,
  KTX_UNSIGNED_INT_8_8_8_8_REV = 0x8367,
  KTX_UNSIGNED_INT_10_10_10_2 = 0x8036,
  KTX_UNSIGNED_INT_2_10_10_10_REV = 0x8368,
  KTX_UNSIGNED_INT_24_8 = 0x84FA,
  KTX_UNSIGNED_INT_10F_11F_11F_REV = 0x8C3B,
  KTX_UNSIGNED_INT_5_9_9_9_REV = 0x8C3E,
  KTX_FLOAT_32_UNSIGNED_INT_24_8_REV = 0x8DAD
};

bool is_packed_pixel_ogl_type(uint32 ogl_type);
uint get_ogl_type_size(uint32 ogl_type);
bool get_ogl_fmt_desc(uint32 ogl_fmt, uint32 ogl_type, uint& block_dim, uint& bytes_per_block);
uint get_ogl_type_size(uint32 ogl_type);
uint32 get_ogl_base_internal_fmt(uint32 ogl_fmt);

class ktx_texture {
 public:
  ktx_texture() {
    clear();
  }

  ktx_texture(const ktx_texture& other) {
    *this = other;
  }

  ktx_texture& operator=(const ktx_texture& rhs) {
    if (this == &rhs)
      return *this;

    clear();

    m_header = rhs.m_header;
    m_key_values = rhs.m_key_values;
    m_image_data = rhs.m_image_data;
    m_block_dim = rhs.m_block_dim;
    m_bytes_per_block = rhs.m_bytes_per_block;
    m_opposite_endianness = rhs.m_opposite_endianness;

    return *this;
  }

  void clear() {
    m_header.clear();
    m_key_values.clear();
    m_image_data.clear();

    m_block_dim = 0;
    m_bytes_per_block = 0;

    m_opposite_endianness = false;
  }

  // High level methods
  bool read_from_stream(data_stream_serializer& serializer);
  bool write_to_stream(data_stream_serializer& serializer, bool no_keyvalue_data = false);

  bool init_2D(uint width, uint height, uint num_mips, uint32 ogl_internal_fmt, uint32 ogl_fmt, uint32 ogl_type);
  bool init_2D_array(uint width, uint height, uint num_mips, uint array_size, uint32 ogl_internal_fmt, uint32 ogl_fmt, uint32 ogl_type);
  bool init_3D(uint width, uint height, uint depth, uint num_mips, uint32 ogl_internal_fmt, uint32 ogl_fmt, uint32 ogl_type);
  bool init_cubemap(uint dim, uint num_mips, uint32 ogl_internal_fmt, uint32 ogl_fmt, uint32 ogl_type);

  bool check_header() const;
  bool consistency_check() const;

  // General info

  bool is_valid() const { return (m_header.m_pixelWidth > 0) && (m_image_data.size() > 0); }

  uint get_width() const { return m_header.m_pixelWidth; }
  uint get_height() const { return CRNLIB_MAX(m_header.m_pixelHeight, 1); }
  uint get_depth() const { return CRNLIB_MAX(m_header.m_pixelDepth, 1); }
  uint get_num_mips() const { return CRNLIB_MAX(m_header.m_numberOfMipmapLevels, 1); }
  uint get_array_size() const { return CRNLIB_MAX(m_header.m_numberOfArrayElements, 1); }
  uint get_num_faces() const { return m_header.m_numberOfFaces; }

  uint32 get_ogl_type() const { return m_header.m_glType; }
  uint32 get_ogl_fmt() const { return m_header.m_glFormat; }
  uint32 get_ogl_base_fmt() const { return m_header.m_glBaseInternalFormat; }
  uint32 get_ogl_internal_fmt() const { return m_header.m_glInternalFormat; }

  uint get_total_images() const { return get_num_mips() * (get_depth() * get_num_faces() * get_array_size()); }

  bool is_compressed() const { return m_block_dim > 1; }
  bool is_uncompressed() const { return !is_compressed(); }

  bool get_opposite_endianness() const { return m_opposite_endianness; }
  void set_opposite_endianness(bool flag) { m_opposite_endianness = flag; }

  uint32 get_block_dim() const { return m_block_dim; }
  uint32 get_bytes_per_block() const { return m_bytes_per_block; }

  const ktx_header& get_header() const { return m_header; }

  // Key values
  const ktx_key_value_vec& get_key_value_vec() const { return m_key_values; }
  ktx_key_value_vec& get_key_value_vec() { return m_key_values; }

  const uint8_vec* find_key(const char* pKey) const;
  bool get_key_value_as_string(const char* pKey, dynamic_string& str) const;

  uint add_key_value(const char* pKey, const void* pVal, uint val_size);
  uint add_key_value(const char* pKey, const char* pVal) { return add_key_value(pKey, pVal, static_cast<uint>(strlen(pVal)) + 1); }

  // Image data
  uint get_num_images() const { return m_image_data.size(); }

  const uint8_vec& get_image_data(uint image_index) const { return m_image_data[image_index]; }
  uint8_vec& get_image_data(uint image_index) { return m_image_data[image_index]; }

  const uint8_vec& get_image_data(uint mip_index, uint array_index, uint face_index, uint zslice_index) const { return get_image_data(get_image_index(mip_index, array_index, face_index, zslice_index)); }
  uint8_vec& get_image_data(uint mip_index, uint array_index, uint face_index, uint zslice_index) { return get_image_data(get_image_index(mip_index, array_index, face_index, zslice_index)); }

  const ktx_image_data_vec& get_image_data_vec() const { return m_image_data; }
  ktx_image_data_vec& get_image_data_vec() { return m_image_data; }

  void add_image(uint face_index, uint mip_index, const void* pImage, uint image_size) {
    const uint image_index = get_image_index(mip_index, 0, face_index, 0);
    if (image_index >= m_image_data.size())
      m_image_data.resize(image_index + 1);
    if (image_size) {
      uint8_vec& v = m_image_data[image_index];
      v.resize(image_size);
      memcpy(&v[0], pImage, image_size);
    }
  }

  uint get_image_index(uint mip_index, uint array_index, uint face_index, uint zslice_index) const {
    CRNLIB_ASSERT((mip_index < get_num_mips()) && (array_index < get_array_size()) && (face_index < get_num_faces()) && (zslice_index < get_depth()));
    return zslice_index + (face_index * get_depth()) + (array_index * (get_depth() * get_num_faces())) + (mip_index * (get_depth() * get_num_faces() * get_array_size()));
  }

  void get_mip_dim(uint mip_index, uint& mip_width, uint& mip_height) const {
    CRNLIB_ASSERT(mip_index < get_num_mips());
    mip_width = CRNLIB_MAX(get_width() >> mip_index, 1);
    mip_height = CRNLIB_MAX(get_height() >> mip_index, 1);
  }

  void get_mip_dim(uint mip_index, uint& mip_width, uint& mip_height, uint& mip_depth) const {
    CRNLIB_ASSERT(mip_index < get_num_mips());
    mip_width = CRNLIB_MAX(get_width() >> mip_index, 1);
    mip_height = CRNLIB_MAX(get_height() >> mip_index, 1);
    mip_depth = CRNLIB_MAX(get_depth() >> mip_index, 1);
  }

 private:
  ktx_header m_header;

  ktx_key_value_vec m_key_values;
  ktx_image_data_vec m_image_data;

  uint32 m_block_dim;
  uint32 m_bytes_per_block;

  bool m_opposite_endianness;

  bool compute_pixel_info();
};

}  // namespace crnlib

#endif  // #ifndef _KTX_TEXTURE_H_