trunk/rdesktop/bitmap.c

/*
   rdesktop: A Remote Desktop Protocol client.
   Bitmap decompression routines
   Copyright (C) Matthew Chapman 1999-2000
   
   This program 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; either version 2 of the License, or
   (at your option) any later version.
   
   This program 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 this program; if not, write to the Free Software
   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/

#include "rdesktop.h"

#define CVAL(p)   (*(p++))
#define SVAL(p)   ((*((p++) + 1) << 8) | CVAL(p))

#define REPEAT(statement) { while ((count > 0) && (x < width)) { statement; count--; x++; } }
#define MASK_UPDATE() { mixmask <<= 1; if (mixmask == 0) { mask = CVAL(input); mixmask = 1; } }

BOOL
bitmap_decompress(unsigned char *output, int width, int height,
                  unsigned char *input, int size)
{
        unsigned char *end = input + size;
        unsigned char *prevline = NULL, *line = NULL;
        int opcode, count, offset, isfillormix, x = width;
        int lastopcode = -1, insertmix = False, bicolour = False;
        uint8 code, colour1 = 0, colour2 = 0;
        uint8 mixmask, mask = 0, mix = 0xff;

        while (input < end)
        {
                code = CVAL(input);
                opcode = code >> 4;

                /* Handle different opcode forms */
                switch (opcode)
                {
                        case 0xc:
                        case 0xd:
                        case 0xe:
                                opcode -= 6;
                                count = code & 0xf;
                                offset = 16;
                                break;

                        case 0xf:
                                opcode = code & 0xf;
                                count = (opcode < 13) ? SVAL(input) : 1;
                                offset = 0;
                                break;

                        default:
                                opcode >>= 1;
                                count = code & 0x1f;
                                offset = 32;
                                break;
                }

                /* Handle strange cases for counts */
                if (offset != 0)
                {
                        isfillormix = ((opcode == 2) || (opcode == 7));

                        if (count == 0)
                        {
                                if (isfillormix)
                                        count = CVAL(input) + 1;
                                else
                                        count = CVAL(input) + offset;
                        }
                        else if (isfillormix)
                        {
                                count <<= 3;
                        }
                }

                /* Read preliminary data */
                mixmask = 0;
                switch (opcode)
                {
                        case 0: /* Fill */
                                if ((lastopcode == opcode)
                                    && !((x == width) && (prevline == NULL)))
                                        insertmix = True;
                                break;
                        case 8: /* Bicolour */
                                colour1 = CVAL(input);
                        case 3: /* Colour */
                                colour2 = CVAL(input);
                                break;
                        case 6: /* SetMix/Mix */
                        case 7: /* SetMix/FillOrMix */
                                mix = CVAL(input);
                                opcode -= 5;
                                break;
                }
                lastopcode = opcode;

                /* Output body */
                while (count > 0)
                {
                        if (x >= width)
                        {
                                if (height <= 0)
                                        return False;

                                x = 0;
                                height--;

                                prevline = line;
                                line = output + height * width;
                        }

                        switch (opcode)
                        {
                                case 0: /* Fill */
                                        if (insertmix)
                                        {
                                                if (prevline == NULL)
                                                        line[x] = mix;
                                                else
                                                        line[x] =
                                                                prevline[x] ^
                                                                mix;

                                                insertmix = False;
                                                count--;
                                                x++;
                                        }

                                        if (prevline == NULL)
                                        {
                                                REPEAT(line[x] = 0);
                                        }
                                        else
                                        {
                                                REPEAT(line[x] = prevline[x]);
                                        }
                                        break;

                                case 1: /* Mix */
                                        if (prevline == NULL)
                                        {
                                                REPEAT(line[x] = mix);
                                        }
                                        else
                                        {
                                                REPEAT(line[x] =
                                                       prevline[x] ^ mix);
                                        }
                                        break;

                                case 2: /* Fill or Mix */
                                        if (prevline == NULL)
                                        {
                                                REPEAT(MASK_UPDATE();
                                                       if (mask & mixmask)
                                                       line[x] = mix;
                                                       else
                                                       line[x] = 0;);
                                        }
                                        else
                                        {
                                                REPEAT(MASK_UPDATE();
                                                       if (mask & mixmask)
                                                       line[x] =
                                                       prevline[x] ^ mix;
                                                       else
                                                       line[x] =
                                                       prevline[x];);
                                        }
                                        break;

                                case 3: /* Colour */
                                        REPEAT(line[x] = colour2);
                                        break;

                                case 4: /* Copy */
                                        REPEAT(line[x] = CVAL(input));
                                        break;

                                case 8: /* Bicolour */
                                        REPEAT(if (bicolour)
                                               {
                                               line[x] = colour2;
                                               bicolour = False;}
                                               else
                                               {
                                               line[x] = colour1;
                                               bicolour = True; count++;}
                                        );
                                        break;

                                case 13:        /* White */
                                        REPEAT(line[x] = 0xff);
                                        break;

                                case 14:        /* Black */
                                        REPEAT(line[x] = 0x00);
                                        break;

                                default:
                                        NOTIMP("bitmap opcode 0x%x\n",
                                               opcode);
                                        return False;
                        }
                }
        }

        return True;
}
1	matty	3	/*
2			rdesktop: A Remote Desktop Protocol client.
3			Bitmap decompression routines
4			Copyright (C) Matthew Chapman 1999-2000
5
6			This program is free software; you can redistribute it and/or modify
7			it under the terms of the GNU General Public License as published by
8			the Free Software Foundation; either version 2 of the License, or
9			(at your option) any later version.
10
11			This program is distributed in the hope that it will be useful,
12			but WITHOUT ANY WARRANTY; without even the implied warranty of
13			MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14			GNU General Public License for more details.
15
16			You should have received a copy of the GNU General Public License
17			along with this program; if not, write to the Free Software
18			Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
19			*/
20
21	matty	10	#include "rdesktop.h"
22	matty	3
23	matty	7	#define CVAL(p) (*(p++))
24			#define SVAL(p) ((*((p++) + 1) << 8) \| CVAL(p))
25	matty	3
26	matty	7	#define REPEAT(statement) { while ((count > 0) && (x < width)) { statement; count--; x++; } }
27	matty	9	#define MASK_UPDATE() { mixmask <<= 1; if (mixmask == 0) { mask = CVAL(input); mixmask = 1; } }
28	matty	3
29	matty	25	BOOL
30			bitmap_decompress(unsigned char *output, int width, int height,
31			unsigned char *input, int size)
32	matty	3	{
33			unsigned char *end = input + size;
34	matty	10	unsigned char prevline = NULL, line = NULL;
35	matty	7	int opcode, count, offset, isfillormix, x = width;
36	matty	19	int lastopcode = -1, insertmix = False, bicolour = False;
37	matty	10	uint8 code, colour1 = 0, colour2 = 0;
38			uint8 mixmask, mask = 0, mix = 0xff;
39	matty	3
40			while (input < end)
41			{
42	matty	7	code = CVAL(input);
43			opcode = code >> 4;
44
45			/* Handle different opcode forms */
46			switch (opcode)
47	matty	3	{
48	matty	7	case 0xc:
49			case 0xd:
50			case 0xe:
51			opcode -= 6;
52			count = code & 0xf;
53			offset = 16;
54			break;
55	matty	3
56	matty	7	case 0xf:
57			opcode = code & 0xf;
58			count = (opcode < 13) ? SVAL(input) : 1;
59			offset = 0;
60			break;
61
62			default:
63			opcode >>= 1;
64			count = code & 0x1f;
65			offset = 32;
66			break;
67			}
68
69			/* Handle strange cases for counts */
70			if (offset != 0)
71			{
72			isfillormix = ((opcode == 2) \|\| (opcode == 7));
73
74			if (count == 0)
75	matty	3	{
76	matty	7	if (isfillormix)
77			count = CVAL(input) + 1;
78			else
79			count = CVAL(input) + offset;
80	matty	3	}
81	matty	7	else if (isfillormix)
82			{
83			count <<= 3;
84			}
85			}
86	matty	3
87	matty	7	/* Read preliminary data */
88	matty	9	mixmask = 0;
89	matty	7	switch (opcode)
90			{
91	matty	24	case 0: /* Fill */
92	matty	18	if ((lastopcode == opcode)
93			&& !((x == width) && (prevline == NULL)))
94	matty	9	insertmix = True;
95	matty	3	break;
96	matty	24	case 8: /* Bicolour */
97	matty	9	colour1 = CVAL(input);
98	matty	24	case 3: /* Colour */
99	matty	9	colour2 = CVAL(input);
100			break;
101	matty	24	case 6: /* SetMix/Mix */
102			case 7: /* SetMix/FillOrMix */
103	matty	7	mix = CVAL(input);
104			opcode -= 5;
105	matty	3	break;
106	matty	7	}
107	matty	9	lastopcode = opcode;
108	matty	3
109	matty	7	/* Output body */
110			while (count > 0)
111			{
112			if (x >= width)
113			{
114			if (height <= 0)
115	matty	9	return False;
116	matty	7
117			x = 0;
118			height--;
119
120			prevline = line;
121			line = output + height * width;
122			}
123
124			switch (opcode)
125			{
126	matty	24	case 0: /* Fill */
127	matty	9	if (insertmix)
128			{
129			if (prevline == NULL)
130			line[x] = mix;
131			else
132	matty	24	line[x] =
133			prevline[x] ^
134			mix;
135	matty	9
136			insertmix = False;
137			count--;
138			x++;
139			}
140
141	matty	7	if (prevline == NULL)
142	matty	24	{
143			REPEAT(line[x] = 0);
144			}
145	matty	7	else
146	matty	24	{
147			REPEAT(line[x] = prevline[x]);
148			}
149	matty	3	break;
150	matty	7
151	matty	24	case 1: /* Mix */
152	matty	7	if (prevline == NULL)
153	matty	24	{
154			REPEAT(line[x] = mix);
155			}
156	matty	7	else
157	matty	24	{
158			REPEAT(line[x] =
159			prevline[x] ^ mix);
160			}
161	matty	3	break;
162	matty	7
163	matty	24	case 2: /* Fill or Mix */
164	matty	7	if (prevline == NULL)
165	matty	24	{
166			REPEAT(MASK_UPDATE();
167			if (mask & mixmask)
168			line[x] = mix;
169			else
170			line[x] = 0;);
171			}
172	matty	7	else
173	matty	24	{
174			REPEAT(MASK_UPDATE();
175			if (mask & mixmask)
176			line[x] =
177			prevline[x] ^ mix;
178			else
179			line[x] =
180			prevline[x];);
181			}
182	matty	7	break;
183	matty	3
184	matty	24	case 3: /* Colour */
185			REPEAT(line[x] = colour2);
186	matty	7	break;
187	matty	3
188	matty	24	case 4: /* Copy */
189			REPEAT(line[x] = CVAL(input));
190	matty	7	break;
191	matty	3
192	matty	24	case 8: /* Bicolour */
193			REPEAT(if (bicolour)
194			{
195			line[x] = colour2;
196			bicolour = False;}
197			else
198			{
199			line[x] = colour1;
200			bicolour = True; count++;}
201			);
202	matty	7	break;
203	matty	3
204	matty	24	case 13: /* White */
205			REPEAT(line[x] = 0xff);
206	matty	7	break;
207	matty	3
208	matty	24	case 14: /* Black */
209			REPEAT(line[x] = 0x00);
210	matty	7	break;
211	matty	3
212	matty	7	default:
213	matty	24	NOTIMP("bitmap opcode 0x%x\n",
214			opcode);
215	matty	7	return False;
216			}
217			}
218	matty	3	}
219
220	matty	7	return True;
221	matty	3	}