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	7	BOOL bitmap_decompress(unsigned char *output, int width, int height,
30			unsigned char *input, int size)
31	matty	3	{
32			unsigned char *end = input + size;
33	matty	10	unsigned char prevline = NULL, line = NULL;
34	matty	7	int opcode, count, offset, isfillormix, x = width;
35	matty	19	int lastopcode = -1, insertmix = False, bicolour = False;
36	matty	10	uint8 code, colour1 = 0, colour2 = 0;
37			uint8 mixmask, mask = 0, mix = 0xff;
38	matty	3
39			while (input < end)
40			{
41	matty	7	code = CVAL(input);
42			opcode = code >> 4;
43
44			/* Handle different opcode forms */
45			switch (opcode)
46	matty	3	{
47	matty	7	case 0xc:
48			case 0xd:
49			case 0xe:
50			opcode -= 6;
51			count = code & 0xf;
52			offset = 16;
53			break;
54	matty	3
55	matty	7	case 0xf:
56			opcode = code & 0xf;
57			count = (opcode < 13) ? SVAL(input) : 1;
58			offset = 0;
59			break;
60
61			default:
62			opcode >>= 1;
63			count = code & 0x1f;
64			offset = 32;
65			break;
66			}
67
68			/* Handle strange cases for counts */
69			if (offset != 0)
70			{
71			isfillormix = ((opcode == 2) \|\| (opcode == 7));
72
73			if (count == 0)
74	matty	3	{
75	matty	7	if (isfillormix)
76			count = CVAL(input) + 1;
77			else
78			count = CVAL(input) + offset;
79	matty	3	}
80	matty	7	else if (isfillormix)
81			{
82			count <<= 3;
83			}
84			}
85	matty	3
86	matty	7	/* Read preliminary data */
87	matty	9	mixmask = 0;
88	matty	7	switch (opcode)
89			{
90	matty	24	case 0: /* Fill */
91	matty	18	if ((lastopcode == opcode)
92			&& !((x == width) && (prevline == NULL)))
93	matty	9	insertmix = True;
94	matty	3	break;
95	matty	24	case 8: /* Bicolour */
96	matty	9	colour1 = CVAL(input);
97	matty	24	case 3: /* Colour */
98	matty	9	colour2 = CVAL(input);
99			break;
100	matty	24	case 6: /* SetMix/Mix */
101			case 7: /* SetMix/FillOrMix */
102	matty	7	mix = CVAL(input);
103			opcode -= 5;
104	matty	3	break;
105	matty	7	}
106	matty	9	lastopcode = opcode;
107	matty	3
108	matty	7	/* Output body */
109			while (count > 0)
110			{
111			if (x >= width)
112			{
113			if (height <= 0)
114	matty	9	return False;
115	matty	7
116			x = 0;
117			height--;
118
119			prevline = line;
120			line = output + height * width;
121			}
122
123			switch (opcode)
124			{
125	matty	24	case 0: /* Fill */
126	matty	9	if (insertmix)
127			{
128			if (prevline == NULL)
129			line[x] = mix;
130			else
131	matty	24	line[x] =
132			prevline[x] ^
133			mix;
134	matty	9
135			insertmix = False;
136			count--;
137			x++;
138			}
139
140	matty	7	if (prevline == NULL)
141	matty	24	{
142			REPEAT(line[x] = 0);
143			}
144	matty	7	else
145	matty	24	{
146			REPEAT(line[x] = prevline[x]);
147			}
148	matty	3	break;
149	matty	7
150	matty	24	case 1: /* Mix */
151	matty	7	if (prevline == NULL)
152	matty	24	{
153			REPEAT(line[x] = mix);
154			}
155	matty	7	else
156	matty	24	{
157			REPEAT(line[x] =
158			prevline[x] ^ mix);
159			}
160	matty	3	break;
161	matty	7
162	matty	24	case 2: /* Fill or Mix */
163	matty	7	if (prevline == NULL)
164	matty	24	{
165			REPEAT(MASK_UPDATE();
166			if (mask & mixmask)
167			line[x] = mix;
168			else
169			line[x] = 0;);
170			}
171	matty	7	else
172	matty	24	{
173			REPEAT(MASK_UPDATE();
174			if (mask & mixmask)
175			line[x] =
176			prevline[x] ^ mix;
177			else
178			line[x] =
179			prevline[x];);
180			}
181	matty	7	break;
182	matty	3
183	matty	24	case 3: /* Colour */
184			REPEAT(line[x] = colour2);
185	matty	7	break;
186	matty	3
187	matty	24	case 4: /* Copy */
188			REPEAT(line[x] = CVAL(input));
189	matty	7	break;
190	matty	3
191	matty	24	case 8: /* Bicolour */
192			REPEAT(if (bicolour)
193			{
194			line[x] = colour2;
195			bicolour = False;}
196			else
197			{
198			line[x] = colour1;
199			bicolour = True; count++;}
200			);
201	matty	7	break;
202	matty	3
203	matty	24	case 13: /* White */
204			REPEAT(line[x] = 0xff);
205	matty	7	break;
206	matty	3
207	matty	24	case 14: /* Black */
208			REPEAT(line[x] = 0x00);
209	matty	7	break;
210	matty	3
211	matty	7	default:
212	matty	24	NOTIMP("bitmap opcode 0x%x\n",
213			opcode);
214	matty	7	return False;
215			}
216			}
217	matty	3	}
218
219	matty	7	return True;
220	matty	3	}