newgrf_act14.cpp

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/*
 * This file is part of OpenTTD.
 * 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.
 * 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.
 * 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 <https://www.gnu.org/licenses/old-licenses/gpl-2.0>.
 */

 
#include "../stdafx.h"
#include "../debug.h"
#include "../newgrf_text.h"
#include "newgrf_bytereader.h"
#include "newgrf_internal.h"
 
#include "../safeguards.h"

static bool ChangeGRFName(uint8_t langid, std::string_view str)
{
  AddGRFTextToList(_cur_gps.grfconfig->name, langid, _cur_gps.grfconfig->ident.grfid, false, str);
  return true;
}

static bool ChangeGRFDescription(uint8_t langid, std::string_view str)
{
  AddGRFTextToList(_cur_gps.grfconfig->info, langid, _cur_gps.grfconfig->ident.grfid, true, str);
  return true;
}

static bool ChangeGRFURL(uint8_t langid, std::string_view str)
{
  AddGRFTextToList(_cur_gps.grfconfig->url, langid, _cur_gps.grfconfig->ident.grfid, false, str);
  return true;
}

static bool ChangeGRFNumUsedParams(size_t len, ByteReader &buf)
{
  if (len != 1) {
    GrfMsg(2, "StaticGRFInfo: expected only 1 byte for 'INFO'->'NPAR' but got {}, ignoring this field", len);
    buf.Skip(len);
  } else {
    _cur_gps.grfconfig->num_valid_params = std::min(buf.ReadByte(), GRFConfig::MAX_NUM_PARAMS);
  }
  return true;
}

static bool ChangeGRFPalette(size_t len, ByteReader &buf)
{
  if (len != 1) {
    GrfMsg(2, "StaticGRFInfo: expected only 1 byte for 'INFO'->'PALS' but got {}, ignoring this field", len);
    buf.Skip(len);
  } else {
    char data = buf.ReadByte();
    GRFPalette pal = GRFP_GRF_UNSET;
    switch (data) {
      case '*':
      case 'A': pal = GRFP_GRF_ANY;     break;
      case 'W': pal = GRFP_GRF_WINDOWS; break;
      case 'D': pal = GRFP_GRF_DOS;     break;
      default:
        GrfMsg(2, "StaticGRFInfo: unexpected value '{:02X}' for 'INFO'->'PALS', ignoring this field", data);
        break;
    }
    if (pal != GRFP_GRF_UNSET) {
      _cur_gps.grfconfig->palette &= ~GRFP_GRF_MASK;
      _cur_gps.grfconfig->palette |= pal;
    }
  }
  return true;
}

static bool ChangeGRFBlitter(size_t len, ByteReader &buf)
{
  if (len != 1) {
    GrfMsg(2, "StaticGRFInfo: expected only 1 byte for 'INFO'->'BLTR' but got {}, ignoring this field", len);
    buf.Skip(len);
  } else {
    char data = buf.ReadByte();
    GRFPalette pal = GRFP_BLT_UNSET;
    switch (data) {
      case '8': pal = GRFP_BLT_UNSET; break;
      case '3': pal = GRFP_BLT_32BPP;  break;
      default:
        GrfMsg(2, "StaticGRFInfo: unexpected value '{:02X}' for 'INFO'->'BLTR', ignoring this field", data);
        return true;
    }
    _cur_gps.grfconfig->palette &= ~GRFP_BLT_MASK;
    _cur_gps.grfconfig->palette |= pal;
  }
  return true;
}

static bool ChangeGRFVersion(size_t len, ByteReader &buf)
{
  if (len != 4) {
    GrfMsg(2, "StaticGRFInfo: expected 4 bytes for 'INFO'->'VRSN' but got {}, ignoring this field", len);
    buf.Skip(len);
  } else {
    /* Set min_loadable_version as well (default to minimal compatibility) */
    _cur_gps.grfconfig->version = _cur_gps.grfconfig->min_loadable_version = buf.ReadDWord();
  }
  return true;
}

static bool ChangeGRFMinVersion(size_t len, ByteReader &buf)
{
  if (len != 4) {
    GrfMsg(2, "StaticGRFInfo: expected 4 bytes for 'INFO'->'MINV' but got {}, ignoring this field", len);
    buf.Skip(len);
  } else {
    _cur_gps.grfconfig->min_loadable_version = buf.ReadDWord();
    if (_cur_gps.grfconfig->version == 0) {
      GrfMsg(2, "StaticGRFInfo: 'MINV' defined before 'VRSN' or 'VRSN' set to 0, ignoring this field");
      _cur_gps.grfconfig->min_loadable_version = 0;
    }
    if (_cur_gps.grfconfig->version < _cur_gps.grfconfig->min_loadable_version) {
      GrfMsg(2, "StaticGRFInfo: 'MINV' defined as {}, limiting it to 'VRSN'", _cur_gps.grfconfig->min_loadable_version);
      _cur_gps.grfconfig->min_loadable_version = _cur_gps.grfconfig->version;
    }
  }
  return true;
}
 
static GRFParameterInfo *_cur_parameter; 

static bool ChangeGRFParamName(uint8_t langid, std::string_view str)
{
  AddGRFTextToList(_cur_parameter->name, langid, _cur_gps.grfconfig->ident.grfid, false, str);
  return true;
}

static bool ChangeGRFParamDescription(uint8_t langid, std::string_view str)
{
  AddGRFTextToList(_cur_parameter->desc, langid, _cur_gps.grfconfig->ident.grfid, true, str);
  return true;
}

static bool ChangeGRFParamType(size_t len, ByteReader &buf)
{
  if (len != 1) {
    GrfMsg(2, "StaticGRFInfo: expected 1 byte for 'INFO'->'PARA'->'TYPE' but got {}, ignoring this field", len);
    buf.Skip(len);
  } else {
    GRFParameterType type = (GRFParameterType)buf.ReadByte();
    if (type < PTYPE_END) {
      _cur_parameter->type = type;
    } else {
      GrfMsg(3, "StaticGRFInfo: unknown parameter type {}, ignoring this field", type);
    }
  }
  return true;
}

static bool ChangeGRFParamLimits(size_t len, ByteReader &buf)
{
  if (_cur_parameter->type != PTYPE_UINT_ENUM) {
    GrfMsg(2, "StaticGRFInfo: 'INFO'->'PARA'->'LIMI' is only valid for parameters with type uint/enum, ignoring this field");
    buf.Skip(len);
  } else if (len != 8) {
    GrfMsg(2, "StaticGRFInfo: expected 8 bytes for 'INFO'->'PARA'->'LIMI' but got {}, ignoring this field", len);
    buf.Skip(len);
  } else {
    uint32_t min_value = buf.ReadDWord();
    uint32_t max_value = buf.ReadDWord();
    if (min_value <= max_value) {
      _cur_parameter->min_value = min_value;
      _cur_parameter->max_value = max_value;
    } else {
      GrfMsg(2, "StaticGRFInfo: 'INFO'->'PARA'->'LIMI' values are incoherent, ignoring this field");
    }
  }
  return true;
}

static bool ChangeGRFParamMask(size_t len, ByteReader &buf)
{
  if (len < 1 || len > 3) {
    GrfMsg(2, "StaticGRFInfo: expected 1 to 3 bytes for 'INFO'->'PARA'->'MASK' but got {}, ignoring this field", len);
    buf.Skip(len);
  } else {
    uint8_t param_nr = buf.ReadByte();
    if (param_nr >= GRFConfig::MAX_NUM_PARAMS) {
      GrfMsg(2, "StaticGRFInfo: invalid parameter number in 'INFO'->'PARA'->'MASK', param {}, ignoring this field", param_nr);
      buf.Skip(len - 1);
    } else {
      _cur_parameter->param_nr = param_nr;
      if (len >= 2) _cur_parameter->first_bit = std::min<uint8_t>(buf.ReadByte(), 31);
      if (len >= 3) _cur_parameter->num_bit = std::min<uint8_t>(buf.ReadByte(), 32 - _cur_parameter->first_bit);
    }
  }
 
  return true;
}

static bool ChangeGRFParamDefault(size_t len, ByteReader &buf)
{
  if (len != 4) {
    GrfMsg(2, "StaticGRFInfo: expected 4 bytes for 'INFO'->'PARA'->'DEFA' but got {}, ignoring this field", len);
    buf.Skip(len);
  } else {
    _cur_parameter->def_value = buf.ReadDWord();
  }
  _cur_gps.grfconfig->has_param_defaults = true;
  return true;
}
 
typedef bool (*DataHandler)(size_t, ByteReader &);  
typedef bool (*TextHandler)(uint8_t, std::string_view str); 
typedef bool (*BranchHandler)(ByteReader &);        

struct AllowedSubtags {
  using Span = std::pair<const AllowedSubtags *, const AllowedSubtags *>;
 
  uint32_t id; 
  std::variant<DataHandler, TextHandler, BranchHandler, Span> handler; 
};
 
static bool SkipUnknownInfo(ByteReader &buf, uint8_t type);
static bool HandleNodes(ByteReader &buf, std::span<const AllowedSubtags> tags);

static bool ChangeGRFParamValueNames(ByteReader &buf)
{
  uint8_t type = buf.ReadByte();
  while (type != 0) {
    uint32_t id = buf.ReadDWord();
    if (type != 'T' || id > _cur_parameter->max_value) {
      GrfMsg(2, "StaticGRFInfo: all child nodes of 'INFO'->'PARA'->param_num->'VALU' should have type 't' and the value/bit number as id");
      if (!SkipUnknownInfo(buf, type)) return false;
      type = buf.ReadByte();
      continue;
    }
 
    uint8_t langid = buf.ReadByte();
    std::string_view name_string = buf.ReadString();
 
    auto it = std::ranges::lower_bound(_cur_parameter->value_names, id, std::less{}, &GRFParameterInfo::ValueName::first);
    if (it == std::end(_cur_parameter->value_names) || it->first != id) {
      it = _cur_parameter->value_names.emplace(it, id, GRFTextList{});
    }
    AddGRFTextToList(it->second, langid, _cur_gps.grfconfig->ident.grfid, false, name_string);
 
    type = buf.ReadByte();
  }
  return true;
}

static constexpr AllowedSubtags _tags_parameters[] = {
  AllowedSubtags{'NAME', ChangeGRFParamName},
  AllowedSubtags{'DESC', ChangeGRFParamDescription},
  AllowedSubtags{'TYPE', ChangeGRFParamType},
  AllowedSubtags{'LIMI', ChangeGRFParamLimits},
  AllowedSubtags{'MASK', ChangeGRFParamMask},
  AllowedSubtags{'VALU', ChangeGRFParamValueNames},
  AllowedSubtags{'DFLT', ChangeGRFParamDefault},
};

static bool HandleParameterInfo(ByteReader &buf)
{
  uint8_t type = buf.ReadByte();
  while (type != 0) {
    uint32_t id = buf.ReadDWord();
    if (type != 'C' || id >= _cur_gps.grfconfig->num_valid_params) {
      GrfMsg(2, "StaticGRFInfo: all child nodes of 'INFO'->'PARA' should have type 'C' and their parameter number as id");
      if (!SkipUnknownInfo(buf, type)) return false;
      type = buf.ReadByte();
      continue;
    }
 
    if (id >= _cur_gps.grfconfig->param_info.size()) {
      _cur_gps.grfconfig->param_info.resize(id + 1);
    }
    if (!_cur_gps.grfconfig->param_info[id].has_value()) {
      _cur_gps.grfconfig->param_info[id] = GRFParameterInfo(id);
    }
    _cur_parameter = &_cur_gps.grfconfig->param_info[id].value();
    /* Read all parameter-data and process each node. */
    if (!HandleNodes(buf, _tags_parameters)) return false;
    type = buf.ReadByte();
  }
  return true;
}

static constexpr AllowedSubtags _tags_info[] = {
  AllowedSubtags{'NAME', ChangeGRFName},
  AllowedSubtags{'DESC', ChangeGRFDescription},
  AllowedSubtags{'URL_', ChangeGRFURL},
  AllowedSubtags{'NPAR', ChangeGRFNumUsedParams},
  AllowedSubtags{'PALS', ChangeGRFPalette},
  AllowedSubtags{'BLTR', ChangeGRFBlitter},
  AllowedSubtags{'VRSN', ChangeGRFVersion},
  AllowedSubtags{'MINV', ChangeGRFMinVersion},
  AllowedSubtags{'PARA', HandleParameterInfo},
};

static constexpr AllowedSubtags _tags_root[] = {
  AllowedSubtags{'INFO', std::make_pair(std::begin(_tags_info), std::end(_tags_info))},
};
 

static bool SkipUnknownInfo(ByteReader &buf, uint8_t type)
{
  /* type and id are already read */
  switch (type) {
    case 'C': {
      uint8_t new_type = buf.ReadByte();
      while (new_type != 0) {
        buf.ReadDWord(); // skip the id
        if (!SkipUnknownInfo(buf, new_type)) return false;
        new_type = buf.ReadByte();
      }
      break;
    }
 
    case 'T':
      buf.ReadByte(); // lang
      buf.ReadString(); // actual text
      break;
 
    case 'B': {
      uint16_t size = buf.ReadWord();
      buf.Skip(size);
      break;
    }
 
    default:
      return false;
  }
 
  return true;
}

static bool HandleNode(uint8_t type, uint32_t id, ByteReader &buf, std::span<const AllowedSubtags> subtags)
{
  /* Visitor to get a subtag handler's type. */
  struct type_visitor {
    char operator()(const DataHandler &) { return 'B'; }
    char operator()(const TextHandler &) { return 'T'; }
    char operator()(const BranchHandler &) { return 'C'; }
    char operator()(const AllowedSubtags::Span &) { return 'C'; }
  };
 
  /* Visitor to evaluate a subtag handler. */
  struct evaluate_visitor {
    ByteReader &buf;
 
    bool operator()(const DataHandler &handler)
    {
      size_t len = buf.ReadWord();
      if (buf.Remaining() < len) return false;
      return handler(len, buf);
    }
 
    bool operator()(const TextHandler &handler)
    {
      uint8_t langid = buf.ReadByte();
      return handler(langid, buf.ReadString());
    }
 
    bool operator()(const BranchHandler &handler)
    {
      return handler(buf);
    }
 
    bool operator()(const AllowedSubtags::Span &subtags)
    {
      return HandleNodes(buf, {subtags.first, subtags.second});
    }
  };
 
  for (const auto &tag : subtags) {
    if (tag.id != std::byteswap(id) || std::visit(type_visitor{}, tag.handler) != type) continue;
    return std::visit(evaluate_visitor{buf}, tag.handler);
  }
 
  GrfMsg(2, "StaticGRFInfo: unknown type/id combination found, type={:c}, id={:x}", type, id);
  return SkipUnknownInfo(buf, type);
}

static bool HandleNodes(ByteReader &buf, std::span<const AllowedSubtags> subtags)
{
  uint8_t type = buf.ReadByte();
  while (type != 0) {
    uint32_t id = buf.ReadDWord();
    if (!HandleNode(type, id, buf, subtags)) return false;
    type = buf.ReadByte();
  }
  return true;
}

static void StaticGRFInfo(ByteReader &buf)
{
  /* <14> <type> <id> <text/data...> */
  HandleNodes(buf, _tags_root);
}
 
template <> void GrfActionHandler<0x14>::FileScan(ByteReader &buf) { StaticGRFInfo(buf); }
template <> void GrfActionHandler<0x14>::SafetyScan(ByteReader &) { }
template <> void GrfActionHandler<0x14>::LabelScan(ByteReader &) { }
template <> void GrfActionHandler<0x14>::Init(ByteReader &) { }
template <> void GrfActionHandler<0x14>::Reserve(ByteReader &) { }
template <> void GrfActionHandler<0x14>::Activation(ByteReader &) { }