aseprite/src/docio/detect_format.cpp

141 lines
3.4 KiB
C++

// Aseprite Document IO Library
// Copyright (c) 2016 David Capello
//
// This file is released under the terms of the MIT license.
// Read LICENSE.txt for more information.
#include "docio/detect_format.h"
#include "base/file_handle.h"
#include "base/path.h"
#include "base/string.h"
#include "flic/flic_details.h"
#include <cstring>
#define ASE_MAGIC_NUMBER 0xA5E0
#define BMP_MAGIC_NUMBER 0x4D42 // "BM"
#define JPG_MAGIC_NUMBER 0xD8FF
#define GIF_87_STAMP "GIF87a"
#define GIF_89_STAMP "GIF89a"
#define PNG_MAGIC_DWORD1 0x474E5089
#define PNG_MAGIC_DWORD2 0x0A1A0A0D
namespace docio {
FileFormat detect_format(const std::string& filename)
{
FileFormat ff = detect_format_by_file_content(filename);
if (ff == FileFormat::UNKNOWN)
ff = detect_format_by_file_extension(filename);
return ff;
}
FileFormat detect_format_by_file_content(const std::string& filename)
{
#define IS_MAGIC_WORD(offset, word) \
((buf[offset+0] == (word & 0xff)) && \
(buf[offset+1] == ((word & 0xff00) >> 8)))
#define IS_MAGIC_DWORD(offset, dword) \
((buf[offset+0] == (dword & 0xff)) && \
(buf[offset+1] == ((dword & 0xff00) >> 8)) && \
(buf[offset+2] == ((dword & 0xff0000) >> 16)) && \
(buf[offset+3] == ((dword & 0xff000000) >> 24)))
base::FileHandle handle(base::open_file(filename.c_str(), "rb"));
if (!handle)
return FileFormat::ERROR;
FILE* f = handle.get();
unsigned char buf[8];
int count = fread(buf, 1, 8, f);
if (count >= 2) {
if (IS_MAGIC_WORD(0, BMP_MAGIC_NUMBER))
return FileFormat::BMP_IMAGE;
if (IS_MAGIC_WORD(0, JPG_MAGIC_NUMBER))
return FileFormat::JPEG_IMAGE;
if (count >= 6) {
if (std::strncmp((const char*)buf, GIF_87_STAMP, 6) == 0 ||
std::strncmp((const char*)buf, GIF_89_STAMP, 6) == 0)
return FileFormat::GIF_ANIMATION;
if (IS_MAGIC_WORD(4, ASE_MAGIC_NUMBER))
return FileFormat::ASE_ANIMATION;
if (IS_MAGIC_WORD(4, FLI_MAGIC_NUMBER) ||
IS_MAGIC_WORD(4, FLC_MAGIC_NUMBER))
return FileFormat::FLIC_ANIMATION;
if (count >= 8) {
if (IS_MAGIC_DWORD(0, PNG_MAGIC_DWORD1) &&
IS_MAGIC_DWORD(4, PNG_MAGIC_DWORD2))
return FileFormat::PNG_IMAGE;
}
}
}
return FileFormat::UNKNOWN;
}
FileFormat detect_format_by_file_extension(const std::string& filename)
{
// By extension
const std::string ext = base::string_to_lower(base::get_file_extension(filename));
if (ext == "ase" ||
ext == "aseprite")
return FileFormat::ASE_ANIMATION;
if (ext == "bmp")
return FileFormat::BMP_IMAGE;
if (ext == "col")
return FileFormat::COL_PALETTE;
if (ext == "flc" ||
ext == "fli")
return FileFormat::FLIC_ANIMATION;
if (ext == "gif")
return FileFormat::GIF_ANIMATION;
if (ext == "gpl")
return FileFormat::GPL_PALETTE;
if (ext == "hex")
return FileFormat::HEX_PALETTE;
if (ext == "ico")
return FileFormat::ICO_IMAGES;
if (ext == "jpg" ||
ext == "jpeg")
return FileFormat::JPEG_IMAGE;
if (ext == "pal")
return FileFormat::PAL_PALETTE;
if (ext == "pcx")
return FileFormat::PCX_IMAGE;
if (ext == "anim")
return FileFormat::PIXLY_ANIMATION;
if (ext == "png")
return FileFormat::PNG_IMAGE;
if (ext == "tga")
return FileFormat::TARGA_IMAGE;
if (ext == "webp")
return FileFormat::WEBP_ANIMATION;
return FileFormat::UNKNOWN;
}
} // namespace docio