/* $Id$ */ /** @file grf.cpp */ #include "../stdafx.h" #include "../gfx.h" #include "../fileio.h" #include "../debug.h" #include "grf.hpp" bool SpriteLoaderGrf::LoadSprite(SpriteLoader::Sprite *sprite, const char *filename, uint32 file_pos) { /* Open the right file and go to the correct position */ FioSeekToFile(file_pos); /* Read the size and type */ int num = FioReadWord(); byte type = FioReadByte(); /* Type 0xFF indicates either a colormap 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; /* XXX -- We should use a pre-located memory segment for this, malloc/free is pretty expensive */ byte *dest_orig = MallocT<byte>(num); byte *dest = dest_orig; /* 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; for (; size > 0; size--) { *dest = FioReadByte(); dest++; } } else { /* Copy bytes from earlier in the sprite */ const uint data_offset = ((code & 7) << 8) | FioReadByte(); int size = -(code >> 3); num -= size; for (; size > 0; size--) { *dest = *(dest - data_offset); dest++; } } } assert(num == 0); sprite->data = CallocT<SpriteLoader::CommonPixel>(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 { 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]; for (int x = 0; x < length; x++) { data->m = *dest; dest++; data++; } } while (!last_item); } } else { dest = dest_orig; for (int i = 0; i < sprite->width * sprite->height; i++) sprite->data[i].m = 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; free(dest_orig); return true; }