OpenTTD Source: src/spriteloader/sprite_file.cpp Source File

OpenTTD Source 15.0-beta1

sprite_file.cpp
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1/*
2 * This file is part of OpenTTD.
3 * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
4 * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
5 * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
6 */
7
10#include "../stdafx.h"
11#include "sprite_file_type.hpp"
12
14extern const uint8_t _grf_cont_v2_sig[8] = {'G', 'R', 'F', 0x82, 0x0D, 0x0A, 0x1A, 0x0A};
15
20 static uint8_t GetGRFContainerVersion(SpriteFile &file)
21{
22 size_t pos = file.GetPos();
23
24 if (file.ReadWord() == 0) {
25 /* Check for GRF container version 2, which is identified by the bytes
26 * '47 52 46 82 0D 0A 1A 0A' at the start of the file. */
27 for (const auto &expected_sig_byte : _grf_cont_v2_sig) {
28 if (file.ReadByte() != expected_sig_byte) return 0; // Invalid format
29 }
30
31 return 2;
32 }
33
34 /* Container version 1 has no header, rewind to start. */
35 file.SeekTo(pos, SEEK_SET);
36 return 1;
37}
38
45SpriteFile::SpriteFile(const std::string &filename, Subdirectory subdir, bool palette_remap)
46 : RandomAccessFile(filename, subdir), palette_remap(palette_remap)
47{
48 this->container_version = GetGRFContainerVersion(*this);
49 this->content_begin = this->GetPos();
50}
RandomAccessFile
A file from which bytes, words and double words are read in (potentially) a random order.
Definition random_access_file_type.h:22
RandomAccessFile::GetPos
size_t GetPos() const
Get position in the file.
Definition random_access_file.cpp:71
RandomAccessFile::SeekTo
void SeekTo(size_t pos, int mode)
Seek in the current file.
Definition random_access_file.cpp:90
RandomAccessFile::ReadByte
uint8_t ReadByte()
Read a byte from the file.
Definition random_access_file.cpp:107
RandomAccessFile::ReadWord
uint16_t ReadWord()
Read a word (16 bits) from the file (in low endian format).
Definition random_access_file.cpp:124
SpriteFile
RandomAccessFile with some extra information specific for sprite files.
Definition sprite_file_type.hpp:19
SpriteFile::SpriteFile
SpriteFile(const std::string &filename, Subdirectory subdir, bool palette_remap)
Create the SpriteFile.
Definition sprite_file.cpp:45
SpriteFile::container_version
uint8_t container_version
Container format of the sprite file.
Definition sprite_file_type.hpp:21
SpriteFile::content_begin
size_t content_begin
The begin of the content of the sprite file, i.e. after the container metadata.
Definition sprite_file_type.hpp:22
Subdirectory
Subdirectory
The different kinds of subdirectories OpenTTD uses.
Definition fileio_type.h:115
GetGRFContainerVersion
static uint8_t GetGRFContainerVersion(SpriteFile &file)
Get the container version of the currently opened GRF file.
Definition sprite_file.cpp:20
_grf_cont_v2_sig
const uint8_t _grf_cont_v2_sig[8]
Signature of a container version 2 GRF.
sprite_file_type.hpp
Random Access File specialised for accessing sprites.