diff options
Diffstat (limited to 'Build/source/libs/freetype2/freetype-2.5.1/src/lzw/ftzopen.c')
-rw-r--r-- | Build/source/libs/freetype2/freetype-2.5.1/src/lzw/ftzopen.c | 415 |
1 files changed, 415 insertions, 0 deletions
diff --git a/Build/source/libs/freetype2/freetype-2.5.1/src/lzw/ftzopen.c b/Build/source/libs/freetype2/freetype-2.5.1/src/lzw/ftzopen.c new file mode 100644 index 00000000000..d7a64576bad --- /dev/null +++ b/Build/source/libs/freetype2/freetype-2.5.1/src/lzw/ftzopen.c @@ -0,0 +1,415 @@ +/***************************************************************************/ +/* */ +/* ftzopen.c */ +/* */ +/* FreeType support for .Z compressed files. */ +/* */ +/* This optional component relies on NetBSD's zopen(). It should mainly */ +/* be used to parse compressed PCF fonts, as found with many X11 server */ +/* distributions. */ +/* */ +/* Copyright 2005-2007, 2009, 2011 by David Turner. */ +/* */ +/* This file is part of the FreeType project, and may only be used, */ +/* modified, and distributed under the terms of the FreeType project */ +/* license, LICENSE.TXT. By continuing to use, modify, or distribute */ +/* this file you indicate that you have read the license and */ +/* understand and accept it fully. */ +/* */ +/***************************************************************************/ + +#include "ftzopen.h" +#include FT_INTERNAL_MEMORY_H +#include FT_INTERNAL_STREAM_H +#include FT_INTERNAL_DEBUG_H + + + static int + ft_lzwstate_refill( FT_LzwState state ) + { + FT_ULong count; + + + if ( state->in_eof ) + return -1; + + count = FT_Stream_TryRead( state->source, + state->buf_tab, + state->num_bits ); /* WHY? */ + + state->buf_size = (FT_UInt)count; + state->buf_total += count; + state->in_eof = FT_BOOL( count < state->num_bits ); + state->buf_offset = 0; + state->buf_size = ( state->buf_size << 3 ) - ( state->num_bits - 1 ); + + if ( count == 0 ) /* end of file */ + return -1; + + return 0; + } + + + static FT_Int32 + ft_lzwstate_get_code( FT_LzwState state ) + { + FT_UInt num_bits = state->num_bits; + FT_Int offset = state->buf_offset; + FT_Byte* p; + FT_Int result; + + + if ( state->buf_clear || + offset >= state->buf_size || + state->free_ent >= state->free_bits ) + { + if ( state->free_ent >= state->free_bits ) + { + state->num_bits = ++num_bits; + state->free_bits = state->num_bits < state->max_bits + ? (FT_UInt)( ( 1UL << num_bits ) - 256 ) + : state->max_free + 1; + } + + if ( state->buf_clear ) + { + state->num_bits = num_bits = LZW_INIT_BITS; + state->free_bits = (FT_UInt)( ( 1UL << num_bits ) - 256 ); + state->buf_clear = 0; + } + + if ( ft_lzwstate_refill( state ) < 0 ) + return -1; + + offset = 0; + } + + state->buf_offset = offset + num_bits; + + p = &state->buf_tab[offset >> 3]; + offset &= 7; + result = *p++ >> offset; + offset = 8 - offset; + num_bits -= offset; + + if ( num_bits >= 8 ) + { + result |= *p++ << offset; + offset += 8; + num_bits -= 8; + } + if ( num_bits > 0 ) + result |= ( *p & LZW_MASK( num_bits ) ) << offset; + + return result; + } + + + /* grow the character stack */ + static int + ft_lzwstate_stack_grow( FT_LzwState state ) + { + if ( state->stack_top >= state->stack_size ) + { + FT_Memory memory = state->memory; + FT_Error error; + FT_Offset old_size = state->stack_size; + FT_Offset new_size = old_size; + + new_size = new_size + ( new_size >> 1 ) + 4; + + if ( state->stack == state->stack_0 ) + { + state->stack = NULL; + old_size = 0; + } + + /* requirement of the character stack larger than 1<<LZW_MAX_BITS */ + /* implies bug in the decompression code */ + if ( new_size > ( 1 << LZW_MAX_BITS ) ) + { + new_size = 1 << LZW_MAX_BITS; + if ( new_size == old_size ) + return -1; + } + + if ( FT_RENEW_ARRAY( state->stack, old_size, new_size ) ) + return -1; + + state->stack_size = new_size; + } + return 0; + } + + + /* grow the prefix/suffix arrays */ + static int + ft_lzwstate_prefix_grow( FT_LzwState state ) + { + FT_UInt old_size = state->prefix_size; + FT_UInt new_size = old_size; + FT_Memory memory = state->memory; + FT_Error error; + + + if ( new_size == 0 ) /* first allocation -> 9 bits */ + new_size = 512; + else + new_size += new_size >> 2; /* don't grow too fast */ + + /* + * Note that the `suffix' array is located in the same memory block + * pointed to by `prefix'. + * + * I know that sizeof(FT_Byte) == 1 by definition, but it is clearer + * to write it literally. + * + */ + if ( FT_REALLOC_MULT( state->prefix, old_size, new_size, + sizeof ( FT_UShort ) + sizeof ( FT_Byte ) ) ) + return -1; + + /* now adjust `suffix' and move the data accordingly */ + state->suffix = (FT_Byte*)( state->prefix + new_size ); + + FT_MEM_MOVE( state->suffix, + state->prefix + old_size, + old_size * sizeof ( FT_Byte ) ); + + state->prefix_size = new_size; + return 0; + } + + + FT_LOCAL_DEF( void ) + ft_lzwstate_reset( FT_LzwState state ) + { + state->in_eof = 0; + state->buf_offset = 0; + state->buf_size = 0; + state->buf_clear = 0; + state->buf_total = 0; + state->stack_top = 0; + state->num_bits = LZW_INIT_BITS; + state->phase = FT_LZW_PHASE_START; + } + + + FT_LOCAL_DEF( void ) + ft_lzwstate_init( FT_LzwState state, + FT_Stream source ) + { + FT_ZERO( state ); + + state->source = source; + state->memory = source->memory; + + state->prefix = NULL; + state->suffix = NULL; + state->prefix_size = 0; + + state->stack = state->stack_0; + state->stack_size = sizeof ( state->stack_0 ); + + ft_lzwstate_reset( state ); + } + + + FT_LOCAL_DEF( void ) + ft_lzwstate_done( FT_LzwState state ) + { + FT_Memory memory = state->memory; + + + ft_lzwstate_reset( state ); + + if ( state->stack != state->stack_0 ) + FT_FREE( state->stack ); + + FT_FREE( state->prefix ); + state->suffix = NULL; + + FT_ZERO( state ); + } + + +#define FTLZW_STACK_PUSH( c ) \ + FT_BEGIN_STMNT \ + if ( state->stack_top >= state->stack_size && \ + ft_lzwstate_stack_grow( state ) < 0 ) \ + goto Eof; \ + \ + state->stack[state->stack_top++] = (FT_Byte)(c); \ + FT_END_STMNT + + + FT_LOCAL_DEF( FT_ULong ) + ft_lzwstate_io( FT_LzwState state, + FT_Byte* buffer, + FT_ULong out_size ) + { + FT_ULong result = 0; + + FT_UInt old_char = state->old_char; + FT_UInt old_code = state->old_code; + FT_UInt in_code = state->in_code; + + + if ( out_size == 0 ) + goto Exit; + + switch ( state->phase ) + { + case FT_LZW_PHASE_START: + { + FT_Byte max_bits; + FT_Int32 c; + + + /* skip magic bytes, and read max_bits + block_flag */ + if ( FT_Stream_Seek( state->source, 2 ) != 0 || + FT_Stream_TryRead( state->source, &max_bits, 1 ) != 1 ) + goto Eof; + + state->max_bits = max_bits & LZW_BIT_MASK; + state->block_mode = max_bits & LZW_BLOCK_MASK; + state->max_free = (FT_UInt)( ( 1UL << state->max_bits ) - 256 ); + + if ( state->max_bits > LZW_MAX_BITS ) + goto Eof; + + state->num_bits = LZW_INIT_BITS; + state->free_ent = ( state->block_mode ? LZW_FIRST + : LZW_CLEAR ) - 256; + in_code = 0; + + state->free_bits = state->num_bits < state->max_bits + ? (FT_UInt)( ( 1UL << state->num_bits ) - 256 ) + : state->max_free + 1; + + c = ft_lzwstate_get_code( state ); + if ( c < 0 || c > 255 ) + goto Eof; + + old_code = old_char = (FT_UInt)c; + + if ( buffer ) + buffer[result] = (FT_Byte)old_char; + + if ( ++result >= out_size ) + goto Exit; + + state->phase = FT_LZW_PHASE_CODE; + } + /* fall-through */ + + case FT_LZW_PHASE_CODE: + { + FT_Int32 c; + FT_UInt code; + + + NextCode: + c = ft_lzwstate_get_code( state ); + if ( c < 0 ) + goto Eof; + + code = (FT_UInt)c; + + if ( code == LZW_CLEAR && state->block_mode ) + { + /* why not LZW_FIRST-256 ? */ + state->free_ent = ( LZW_FIRST - 1 ) - 256; + state->buf_clear = 1; + + /* not quite right, but at least more predictable */ + old_code = 0; + old_char = 0; + + goto NextCode; + } + + in_code = code; /* save code for later */ + + if ( code >= 256U ) + { + /* special case for KwKwKwK */ + if ( code - 256U >= state->free_ent ) + { + /* corrupted LZW stream */ + if ( code - 256U > state->free_ent ) + goto Eof; + + FTLZW_STACK_PUSH( old_char ); + code = old_code; + } + + while ( code >= 256U ) + { + if ( !state->prefix ) + goto Eof; + + FTLZW_STACK_PUSH( state->suffix[code - 256] ); + code = state->prefix[code - 256]; + } + } + + old_char = code; + FTLZW_STACK_PUSH( old_char ); + + state->phase = FT_LZW_PHASE_STACK; + } + /* fall-through */ + + case FT_LZW_PHASE_STACK: + { + while ( state->stack_top > 0 ) + { + --state->stack_top; + + if ( buffer ) + buffer[result] = state->stack[state->stack_top]; + + if ( ++result == out_size ) + goto Exit; + } + + /* now create new entry */ + if ( state->free_ent < state->max_free ) + { + if ( state->free_ent >= state->prefix_size && + ft_lzwstate_prefix_grow( state ) < 0 ) + goto Eof; + + FT_ASSERT( state->free_ent < state->prefix_size ); + + state->prefix[state->free_ent] = (FT_UShort)old_code; + state->suffix[state->free_ent] = (FT_Byte) old_char; + + state->free_ent += 1; + } + + old_code = in_code; + + state->phase = FT_LZW_PHASE_CODE; + goto NextCode; + } + + default: /* state == EOF */ + ; + } + + Exit: + state->old_code = old_code; + state->old_char = old_char; + state->in_code = in_code; + + return result; + + Eof: + state->phase = FT_LZW_PHASE_EOF; + goto Exit; + } + + +/* END */ |