1 /*
2  * tumble: build a PDF file from image files
3  *
4  * bitblt table generator
5  * Copyright 2003, 2017 Eric Smith <spacewar@gmail.com>
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License version 2 as
9  * published by the Free Software Foundation.  Note that permission is
10  * not granted to redistribute this program under the terms of any
11  * other version of the General Public License.
12  *
13  * This program is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16  * GNU General Public License for more details.
17  *
18  * You should have received a copy of the GNU General Public License
19  * along with this program; if not, write to the Free Software
20  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111 USA
21  */
22 
23 
24 #include <stdbool.h>
25 #include <stdio.h>
26 #include <stdlib.h>
27 #include <string.h>
28 
29 
gen_bit_reverse_table(bool header)30 void gen_bit_reverse_table (bool header)
31 {
32   int i, j;
33 
34   if (header)
35     printf ("extern ");
36   printf ("const uint8_t bit_reverse_byte [0x100]");
37   if (header)
38     {
39       printf (";\n");
40       return;
41     }
42   printf (" =\n");
43   printf ("{\n");
44   for (i = 0; i < 0x100; i++)
45     {
46       if ((i & 7) == 0)
47 	printf ("  ");
48       j = (((i & 0x01) << 7) |
49 	   ((i & 0x02) << 5) |
50 	   ((i & 0x04) << 3) |
51 	   ((i & 0x08) << 1) |
52 	   ((i & 0x10) >> 1) |
53 	   ((i & 0x20) >> 3) |
54 	   ((i & 0x40) >> 5) |
55 	   ((i & 0x80) >> 7));
56       printf ("0x%02x", j);
57       if (i != 0xff)
58 	printf (",");
59       if ((i & 7) == 7)
60 	printf ("\n");
61       else
62 	printf (" ");
63     }
64   printf ("};\n");
65 }
66 
67 
count_run(int byte,int start_bit,int desired_val)68 int count_run (int byte, int start_bit, int desired_val)
69 {
70   int count = 0;
71   int i;
72 
73 #ifdef WORDS_BIGENDIAN
74   for (i = 7 - start_bit; i >= 0; i--)
75     {
76       int bit = (byte >> i) & 1;
77       if (bit == desired_val)
78 	count++;
79       else
80 	break;
81     }
82 #else
83   for (i = start_bit; i < 8; i++)
84     {
85       int bit = (byte >> i) & 1;
86       if (bit == desired_val)
87 	count++;
88       else
89 	break;
90     }
91 #endif
92 
93   return (count);
94 }
95 
96 
gen_run_length_table(bool header,int val,char * name)97 void gen_run_length_table (bool header, int val, char *name)
98 {
99   int i, j;
100 
101   if (header)
102     printf ("extern ");
103   printf ("const uint8_t %s [8][256]", name);
104   if (header)
105     {
106       printf (";\n");
107       return;
108     }
109   printf (" =\n");
110   printf ("{\n");
111   for (i = 0; i < 8; i++)
112     {
113       printf ("  {\n");
114       for (j = 0; j < 256; j++)
115 	{
116 	  if ((j & 15) == 0)
117 	    printf ("  ");
118 	  printf ("%d", count_run (j, i, val));
119 	  if (j != 0xff)
120 	    printf (",");
121 	  if ((j & 15) == 15)
122 	    printf ("\n");
123 	  else
124 	    printf (" ");
125 	}
126       printf ("  }");
127       if (i != 7)
128 	printf (",");
129       printf ("\n");
130     }
131   printf ("};\n");
132 }
133 
134 
main(int argc,char * argv[])135 int main (int argc, char *argv[])
136 {
137   bool header;
138 
139   if (argc != 2)
140     {
141       fprintf (stderr, "wrong arg count\n");
142       exit (2);
143     }
144   if (strcmp (argv [1], "-h") == 0)
145     header = 1;
146   else if (strcmp (argv [1], "-c") == 0)
147     header = 0;
148   else
149     {
150       fprintf (stderr, "wrong args\n");
151       exit (2);
152     }
153 
154   printf ("/* This file is automatically generated; do not edit */\n");
155   printf ("\n");
156 
157   if (! header)
158     {
159       printf ("#include <stdint.h>\n");
160       printf ("#include \"bitblt_tables.h\"\n");
161       printf ("\n");
162     }
163 
164   gen_bit_reverse_table (header);
165   printf ("\n");
166 
167   gen_run_length_table (header, 0, "rle_tab");
168   printf ("\n");
169 
170   return (0);
171 }
172