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;
        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))
                                        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(line[x] = colour1; line[++x] = colour2)
                                        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	9	int lastopcode = -1, insertmix = 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	9	case 0: /* Fill */
91			if ((lastopcode == opcode) && (x != width))
92			insertmix = True;
93	matty	3	break;
94	matty	9	case 8: /* Bicolour */
95			colour1 = CVAL(input);
96			case 3: /* Colour */
97			colour2 = CVAL(input);
98			break;
99	matty	7	case 6: /* SetMix/Mix */
100			case 7: /* SetMix/FillOrMix */
101			mix = CVAL(input);
102			opcode -= 5;
103	matty	3	break;
104	matty	7	}
105	matty	9	lastopcode = opcode;
106	matty	3
107	matty	7	/* Output body */
108			while (count > 0)
109			{
110			if (x >= width)
111			{
112			if (height <= 0)
113	matty	9	return False;
114	matty	7
115			x = 0;
116			height--;
117
118			prevline = line;
119			line = output + height * width;
120			}
121
122			switch (opcode)
123			{
124			case 0: /* Fill */
125	matty	9	if (insertmix)
126			{
127			if (prevline == NULL)
128			line[x] = mix;
129			else
130			line[x] = prevline[x] ^ mix;
131
132			insertmix = False;
133			count--;
134			x++;
135			}
136
137	matty	7	if (prevline == NULL)
138			REPEAT(line[x] = 0)
139			else
140			REPEAT(line[x] = prevline[x])
141	matty	3	break;
142	matty	7
143			case 1: /* Mix */
144			if (prevline == NULL)
145			REPEAT(line[x] = mix)
146			else
147			REPEAT(line[x] = prevline[x] ^ mix)
148	matty	3	break;
149	matty	7
150			case 2: /* Fill or Mix */
151			if (prevline == NULL)
152			REPEAT(
153			MASK_UPDATE();
154	matty	3
155	matty	9	if (mask & mixmask)
156	matty	7	line[x] = mix;
157			else
158			line[x] = 0;
159			)
160			else
161			REPEAT(
162			MASK_UPDATE();
163	matty	3
164	matty	9	if (mask & mixmask)
165	matty	7	line[x] = prevline[x] ^ mix;
166			else
167			line[x] = prevline[x];
168			)
169			break;
170	matty	3
171	matty	7	case 3: /* Colour */
172	matty	9	REPEAT(line[x] = colour2)
173	matty	7	break;
174	matty	3
175	matty	7	case 4: /* Copy */
176			REPEAT(line[x] = CVAL(input))
177			break;
178	matty	3
179	matty	9	case 8: /* Bicolour */
180			REPEAT(line[x] = colour1; line[++x] = colour2)
181	matty	7	break;
182	matty	3
183	matty	7	case 13: /* White */
184			REPEAT(line[x] = 0xff)
185			break;
186	matty	3
187	matty	7	case 14: /* Black */
188			REPEAT(line[x] = 0x00)
189			break;
190	matty	3
191	matty	7	default:
192	matty	9	NOTIMP("bitmap opcode 0x%x\n", opcode);
193	matty	7	return False;
194			}
195			}
196	matty	3	}
197
198	matty	7	return True;
199	matty	3	}