| /* -*- Mode: C; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ |
| /* ***** BEGIN LICENSE BLOCK ***** |
| * Version: MPL 1.1/GPL 2.0/LGPL 2.1 |
| * |
| * The contents of this file are subject to the Mozilla Public License Version |
| * 1.1 (the "License"); you may not use this file except in compliance with |
| * the License. You may obtain a copy of the License at |
| * http://www.mozilla.org/MPL/ |
| * |
| * Software distributed under the License is distributed on an "AS IS" basis, |
| * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License |
| * for the specific language governing rights and limitations under the |
| * License. |
| * |
| * The Original Code is Mozilla Communicator client code. |
| * |
| * The Initial Developer of the Original Code is |
| * Netscape Communications Corporation. |
| * Portions created by the Initial Developer are Copyright (C) 1998 |
| * the Initial Developer. All Rights Reserved. |
| * |
| * Contributor(s): |
| * |
| * Alternatively, the contents of this file may be used under the terms of |
| * either the GNU General Public License Version 2 or later (the "GPL"), or |
| * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"), |
| * in which case the provisions of the GPL or the LGPL are applicable instead |
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| * the provisions above, a recipient may use your version of this file under |
| * the terms of any one of the MPL, the GPL or the LGPL. |
| * |
| * ***** END LICENSE BLOCK ***** */ |
| |
| #ifndef _GIF_H_ |
| #define _GIF_H_ |
| |
| // Define ourselves as the clientPtr. Mozilla just hacked their C++ callback class into this old C decoder, |
| // so we will too. |
| #include "GIFImageDecoder.h" |
| |
| #define MAX_LZW_BITS 12 |
| #define MAX_BITS 4097 /* 2^MAX_LZW_BITS+1 */ |
| #define MAX_COLORS 256 |
| #define MAX_HOLD_SIZE 256 |
| |
| /* gif2.h |
| The interface for the GIF87/89a decoder. |
| */ |
| // List of possible parsing states |
| typedef enum { |
| gif_type, |
| gif_global_header, |
| gif_global_colormap, |
| gif_image_start, |
| gif_image_header, |
| gif_image_colormap, |
| gif_image_body, |
| gif_lzw_start, |
| gif_lzw, |
| gif_sub_block, |
| gif_extension, |
| gif_control_extension, |
| gif_consume_block, |
| gif_skip_block, |
| gif_done, |
| gif_oom, |
| gif_error, |
| gif_comment_extension, |
| gif_application_extension, |
| gif_netscape_extension_block, |
| gif_consume_netscape_extension, |
| gif_consume_comment |
| } gstate; |
| |
| struct GIFFrameReader { |
| /* LZW decoder state machine */ |
| unsigned char *stackp; /* Current stack pointer */ |
| int datasize; |
| int codesize; |
| int codemask; |
| int clear_code; /* Codeword used to trigger dictionary reset */ |
| int avail; /* Index of next available slot in dictionary */ |
| int oldcode; |
| unsigned char firstchar; |
| int bits; /* Number of unread bits in "datum" */ |
| int datum; /* 32-bit input buffer */ |
| |
| /* Output state machine */ |
| int ipass; /* Interlace pass; Ranges 1-4 if interlaced. */ |
| unsigned int rows_remaining; /* Rows remaining to be output */ |
| unsigned int irow; /* Current output row, starting at zero */ |
| unsigned char *rowbuf; /* Single scanline temporary buffer */ |
| unsigned char *rowend; /* Pointer to end of rowbuf */ |
| unsigned char *rowp; /* Current output pointer */ |
| |
| /* Parameters for image frame currently being decoded */ |
| unsigned int x_offset, y_offset; /* With respect to "screen" origin */ |
| unsigned int height, width; |
| int tpixel; /* Index of transparent pixel */ |
| WebCore::RGBA32Buffer::FrameDisposalMethod disposal_method; /* Restore to background, leave in place, etc.*/ |
| unsigned char *local_colormap; /* Per-image colormap */ |
| int local_colormap_size; /* Size of local colormap array. */ |
| |
| bool is_local_colormap_defined : 1; |
| bool progressive_display : 1; /* If TRUE, do Haeberli interlace hack */ |
| bool interlaced : 1; /* TRUE, if scanlines arrive interlaced order */ |
| bool is_transparent : 1; /* TRUE, if tpixel is valid */ |
| |
| unsigned delay_time; /* Display time, in milliseconds, |
| for this image in a multi-image GIF */ |
| |
| |
| unsigned short* prefix; /* LZW decoding tables */ |
| unsigned char* suffix; /* LZW decoding tables */ |
| unsigned char* stack; /* Base of LZW decoder stack */ |
| |
| |
| GIFFrameReader() { |
| stackp = 0; |
| datasize = codesize = codemask = clear_code = avail = oldcode = 0; |
| firstchar = 0; |
| bits = datum = 0; |
| ipass = 0; |
| rows_remaining = irow = 0; |
| rowbuf = rowend = rowp = 0; |
| |
| x_offset = y_offset = width = height = 0; |
| tpixel = 0; |
| disposal_method = WebCore::RGBA32Buffer::DisposeNotSpecified; |
| |
| local_colormap = 0; |
| local_colormap_size = 0; |
| is_local_colormap_defined = progressive_display = is_transparent = interlaced = false; |
| |
| delay_time = 0; |
| |
| prefix = 0; |
| suffix = stack = 0; |
| } |
| |
| ~GIFFrameReader() { |
| delete []rowbuf; |
| delete []local_colormap; |
| delete []prefix; |
| delete []suffix; |
| delete []stack; |
| } |
| }; |
| |
| struct GIFImageReader { |
| WebCore::GIFImageDecoder* clientptr; |
| /* Parsing state machine */ |
| gstate state; /* Current decoder master state */ |
| unsigned bytes_to_consume; /* Number of bytes to accumulate */ |
| unsigned bytes_in_hold; /* bytes accumulated so far*/ |
| unsigned char hold[MAX_HOLD_SIZE]; /* Accumulation buffer */ |
| unsigned char* global_colormap; /* (3* MAX_COLORS in size) Default colormap if local not supplied, 3 bytes for each color */ |
| |
| /* Global (multi-image) state */ |
| int screen_bgcolor; /* Logical screen background color */ |
| int version; /* Either 89 for GIF89 or 87 for GIF87 */ |
| unsigned screen_width; /* Logical screen width & height */ |
| unsigned screen_height; |
| int global_colormap_size; /* Size of global colormap array. */ |
| int images_decoded; /* Counts completed frames for animated GIFs */ |
| int images_count; /* Counted all frames seen so far (including incomplete frames) */ |
| int loop_count; /* Netscape specific extension block to control |
| the number of animation loops a GIF renders. */ |
| |
| // Not really global, but convenient to locate here. |
| int count; /* Remaining # bytes in sub-block */ |
| |
| GIFFrameReader* frame_reader; |
| |
| GIFImageReader(WebCore::GIFImageDecoder* client = 0) { |
| clientptr = client; |
| state = gif_type; |
| bytes_to_consume = 6; |
| bytes_in_hold = 0; |
| frame_reader = 0; |
| global_colormap = 0; |
| |
| screen_bgcolor = version = 0; |
| screen_width = screen_height = 0; |
| global_colormap_size = images_decoded = images_count = 0; |
| loop_count = -1; |
| count = 0; |
| } |
| |
| ~GIFImageReader() { |
| close(); |
| } |
| |
| void close() { |
| delete []global_colormap; |
| global_colormap = 0; |
| delete frame_reader; |
| frame_reader = 0; |
| } |
| |
| bool read(const unsigned char * buf, unsigned int numbytes, |
| WebCore::GIFImageDecoder::GIFQuery query = WebCore::GIFImageDecoder::GIFFullQuery, unsigned haltAtFrame = -1); |
| |
| private: |
| void output_row(); |
| int do_lzw(const unsigned char *q); |
| }; |
| |
| #endif |
| |
