1 /* Copyright (C) 1996, 1999 Aladdin Enterprises. All rights reserved. 2 3 This software is provided AS-IS with no warranty, either express or 4 implied. 5 6 This software is distributed under license and may not be copied, 7 modified or distributed except as expressly authorized under the terms 8 of the license contained in the file LICENSE in this distribution. 9 10 For more information about licensing, please refer to 11 http://www.ghostscript.com/licensing/. For information on 12 commercial licensing, go to http://www.artifex.com/licensing/ or 13 contact Artifex Software, Inc., 101 Lucas Valley Road #110, 14 San Rafael, CA 94903, U.S.A., +1(415)492-9861. 15 */ 16 17 /* $Id: spngpx.h,v 1.4 2002/02/21 22:24:54 giles Exp $ */ 18 /* Definitions for PNGPredictor filters */ 19 /* Requires strimpl.h */ 20 21 #ifndef spngpx_INCLUDED 22 # define spngpx_INCLUDED 23 24 /* PNGPredictorDecode / PNGPredictorEncode */ 25 typedef struct stream_PNGP_state_s { 26 stream_state_common; 27 /* The client sets the following before initialization. */ 28 int Colors; /* # of colors, 1..16 */ 29 int BitsPerComponent; /* 1, 2, 4, 8, 16 */ 30 uint Columns; /* >0 */ 31 int Predictor; /* 10-15, only relevant for Encode */ 32 /* The init procedure computes the following. */ 33 uint row_count; /* # of bytes per row */ 34 byte end_mask; /* mask for left-over bits in last byte */ 35 int bpp; /* bytes per pixel */ 36 byte *prev_row; /* previous row */ 37 int case_index; /* switch index for case dispatch, */ 38 /* set dynamically when decoding */ 39 /* The following are updated dynamically. */ 40 long row_left; /* # of bytes left in row */ 41 byte prev[32]; /* previous samples */ 42 } stream_PNGP_state; 43 44 #define private_st_PNGP_state() /* in sPNGP.c */\ 45 gs_private_st_ptrs1(st_PNGP_state, stream_PNGP_state,\ 46 "PNGPredictorEncode/Decode state", pngp_enum_ptrs, pngp_reloc_ptrs,\ 47 prev_row) 48 #define s_PNGP_set_defaults_inline(ss)\ 49 ((ss)->Colors = 1, (ss)->BitsPerComponent = 8, (ss)->Columns = 1,\ 50 (ss)->Predictor = 15,\ 51 /* Clear pointers */\ 52 (ss)->prev_row = 0) 53 extern const stream_template s_PNGPD_template; 54 extern const stream_template s_PNGPE_template; 55 56 #endif /* spngpx_INCLUDED */ 57