/* $Id$ */ /* * 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 <http://www.gnu.org/licenses/>. */ /** @file grf.cpp Reading graphics data from (New)GRF files. */ #include "../stdafx.h" #include "../gfx_func.h" #include "../fileio_func.h" #include "../debug.h" #include "../core/alloc_func.hpp" #include "../strings_func.h" #include "table/strings.h" #include "../gui.h" #include "grf.hpp" /** * We found a corrupted sprite. This means that the sprite itself * contains invalid data or is too small for the given dimensions. * @param file_slot the file the errored sprite is in * @param file_pos the location in the file of the errored sprite * @param line the line where the error occurs. * @return always false (to tell loading the sprite failed) */ static bool WarnCorruptSprite(uint8 file_slot, size_t file_pos, int line) { static byte warning_level = 0; if (warning_level == 0) { SetDParamStr(0, FioGetFilename(file_slot)); ShowErrorMessage(INVALID_STRING_ID, STR_NEWGRF_ERROR_CORRUPT_SPRITE, 0, 0); } DEBUG(sprite, warning_level, "[%i] Loading corrupted sprite from %s at position %i", line, FioGetFilename(file_slot), (int)file_pos); warning_level = 6; return false; } bool SpriteLoaderGrf::LoadSprite(SpriteLoader::Sprite *sprite, uint8 file_slot, size_t file_pos, SpriteType sprite_type) { /* Open the right file and go to the correct position */ FioSeekToFile(file_slot, file_pos); /* Read the size and type */ int num = FioReadWord(); byte type = FioReadByte(); /* Type 0xFF indicates either a colourmap or some other non-sprite info; we do not handle them here */ if (type == 0xFF) return false; sprite->height = FioReadByte(); sprite->width = FioReadWord(); sprite->x_offs = FioReadWord(); sprite->y_offs = FioReadWord(); /* 0x02 indicates it is a compressed sprite, so we can't rely on 'num' to be valid. * In case it is uncompressed, the size is 'num' - 8 (header-size). */ num = (type & 0x02) ? sprite->width * sprite->height : num - 8; byte *dest_orig = AllocaM(byte, num); byte *dest = dest_orig; const int dest_size = num; /* Read the file, which has some kind of compression */ while (num > 0) { int8 code = FioReadByte(); if (code >= 0) { /* Plain bytes to read */ int size = (code == 0) ? 0x80 : code; num -= size; if (num < 0) return WarnCorruptSprite(file_slot, file_pos, __LINE__); for (; size > 0; size--) { *dest = FioReadByte(); dest++; } } else { /* Copy bytes from earlier in the sprite */ const uint data_offset = ((code & 7) << 8) | FioReadByte(); if (dest - data_offset < dest_orig) return WarnCorruptSprite(file_slot, file_pos, __LINE__); int size = -(code >> 3); num -= size; if (num < 0) return WarnCorruptSprite(file_slot, file_pos, __LINE__); for (; size > 0; size--) { *dest = *(dest - data_offset); dest++; } } } if (num != 0) return WarnCorruptSprite(file_slot, file_pos, __LINE__); sprite->AllocateData(sprite->width * sprite->height); /* When there are transparency pixels, this format has an other trick.. decode it */ if (type & 0x08) { for (int y = 0; y < sprite->height; y++) { bool last_item = false; /* Look up in the header-table where the real data is stored for this row */ int offset = (dest_orig[y * 2 + 1] << 8) | dest_orig[y * 2]; /* Go to that row */ dest = dest_orig + offset; do { if (dest + 2 > dest_orig + dest_size) { free(sprite->data); return WarnCorruptSprite(file_slot, file_pos, __LINE__); } SpriteLoader::CommonPixel *data; /* Read the header: * 0 .. 14 - length * 15 - last_item * 16 .. 31 - transparency bytes */ last_item = ((*dest) & 0x80) != 0; int length = (*dest++) & 0x7F; int skip = *dest++; data = &sprite->data[y * sprite->width + skip]; if (skip + length > sprite->width || dest + length > dest_orig + dest_size) { free(sprite->data); return WarnCorruptSprite(file_slot, file_pos, __LINE__); } for (int x = 0; x < length; x++) { data->m = ((sprite_type == ST_NORMAL && _palette_remap_grf[file_slot]) ? _palette_remap[*dest] : *dest); dest++; data++; } } while (!last_item); } } else { if (dest_size < sprite->width * sprite->height) { free(sprite->data); return WarnCorruptSprite(file_slot, file_pos, __LINE__); } if (dest_size > sprite->width * sprite->height) { static byte warning_level = 0; DEBUG(sprite, warning_level, "Ignoring %i unused extra bytes from the sprite from %s at position %i", dest_size - sprite->width * sprite->height, FioGetFilename(file_slot), (int)file_pos); warning_level = 6; } dest = dest_orig; for (int i = 0; i < sprite->width * sprite->height; i++) { sprite->data[i].m = ((sprite_type == ST_NORMAL && _palette_remap_grf[file_slot]) ? _palette_remap[dest[i]] : dest[i]); } } /* Make sure to mark all transparent pixels transparent on the alpha channel too */ for (int i = 0; i < sprite->width * sprite->height; i++) if (sprite->data[i].m != 0) sprite->data[i].a = 0xFF; return true; }