about summary refs log tree commit diff
path: root/converter/ppm/ppmtosixel.c
blob: 5f361e454c78363b53a40ad78ecf2b4f9360c696 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
/* ppmtosix.c - read a portable pixmap and produce a color sixel file
**
** Copyright (C) 1991 by Rick Vinci.
**
** Permission to use, copy, modify, and distribute this software and its
** documentation for any purpose and without fee is hereby granted, provided
** that the above copyright notice appear in all copies and that both that
** copyright notice and this permission notice appear in supporting
** documentation.  This software is provided "as is" without express or
** implied warranty.
*/

#include "ppm.h"

static void WriteHeader ARGS((void));
static void WriteColorMap 
  ARGS((colorhist_vector chv, int colors, pixval maxval));
static void WriteRawImage ARGS((colorhash_table cht, int rows, int cols));
static void WritePackedImage ARGS((colorhash_table cht, int rows, int cols));
static void WriteEnd ARGS((void));
#define MAXVAL 100
#define MAXCOLORS 256

#define DCS '\220'   /* Device Control String */
#define ST  '\234'   /* String Terminator */
#define CSI '\233'   /* Control String Introducer */
#define ESC '\033'   /* Escape character */

static pixel** pixels;   /* stored ppm pixmap input */
static colorhash_table cht;
int margin;



int
main( argc, argv )
    int argc;
    char* argv[];
{
    FILE* ifp;
    int argn, rows, cols, colors;
    int raw;
    pixval maxval;
    colorhist_vector chv;
    const char* const usage = "[-raw] [-margin] [ppmfile]";


    ppm_init( &argc, argv );

    argn = 1;
    raw = 0;
    margin = 0;

    /* Parse args. */
    while ( argn < argc && argv[argn][0] == '-' && argv[argn][1] != '\0' )
	{
	if ( pm_keymatch( argv[argn], "-raw", 2 ) )
	    raw = 1;
	else if ( pm_keymatch( argv[argn], "-margin", 2 ) )
	    margin = 1;
	else
	    pm_usage( usage );
	++argn;
	}

    if ( argn < argc )
	{
	ifp = pm_openr( argv[argn] );
	++argn;
	}
    else
	ifp = stdin;

    if ( argn != argc )
	pm_usage( usage );

    /* Read in the whole ppmfile. */
    pixels = ppm_readppm( ifp, &cols, &rows, &maxval );
    pm_close( ifp );

    /* Print a warning if we could lose accuracy when rescaling colors. */
    if ( maxval > MAXVAL )
	pm_message(
	    "maxval is not %d - automatically rescaling colors", MAXVAL );

    /* Figure out the colormap. */
    pm_message( "computing colormap..." );
    chv = ppm_computecolorhist( pixels, cols, rows, MAXCOLORS, &colors );
    if ( chv == (colorhist_vector) 0 )
	pm_error( "too many colors - try doing a 'pnmquant %d'", MAXCOLORS );
    pm_message( "%d colors found", colors );

    /* Make a hash table for fast color lookup. */
    cht = ppm_colorhisttocolorhash( chv, colors );

    WriteHeader();
    WriteColorMap( chv, colors, maxval );
    if ( raw == 1 )
	WriteRawImage( cht, rows, cols );
    else
	WritePackedImage( cht, rows, cols );
    WriteEnd();

    /* If the program failed, it previously aborted with nonzero completion
       code, via various function calls.
    */
    return 0;
}



static void
WriteHeader()
    {
    if ( margin == 1 )
	printf( "%c%d;%ds", CSI, 14, 72 );
    printf( "%c", DCS );  /* start with Device Control String */
    printf( "0;0;8q" );   /* Horizontal Grid Size at 1/90" and graphics On */
    printf( "\"1;1\n" );  /* set aspect ratio 1:1 */
    }



static void
WriteColorMap( colorhist_vector chv, int colors, pixval maxval )
    {
    register int colornum;
    pixel p;

    for ( colornum = 0; colornum < colors ; ++colornum )
	{
	p = chv[colornum].color;
	if ( maxval != MAXVAL )
	    PPM_DEPTH( p, p, maxval, MAXVAL );
	printf( "#%d;2;%d;%d;%d", colornum,
	    (int) PPM_GETR( p ), (int) PPM_GETG( p ), (int) PPM_GETB( p ) );
	}
    printf( "\n" );
    }



static void
WriteRawImage( cht, rows, cols )
    colorhash_table cht;
    int rows, cols;
    {
    int rownum, colnum, b;
    const char* sixel = "@ACGO_";
    register pixel* pP;

    for ( rownum = 0; rownum < rows; ++rownum )
	{
	b = rownum % 6;
	for ( colnum = 0, pP = pixels[rownum]; colnum < cols; ++colnum, ++pP )
	    printf( "#%d%c", ppm_lookupcolor(cht, pP), sixel[b] );
	printf( "$\n" );   /* Carriage Return */
	if ( b == 5 )
	    printf( "-\n" );   /* Line Feed (one sixel height) */
	}
    }



static void
WritePackedImage( cht, rows, cols )
    colorhash_table cht;
    int rows, cols;
    {
    int rownum, colnum, b, repeat, thiscolor, nextcolor;
    const char* sixel = "@ACGO_";
    register pixel* pP;

    for ( rownum = 0; rownum < rows; ++rownum )
	{
	b = rownum % 6;
	repeat = 1;
	for ( colnum = 0, pP = pixels[rownum]; colnum < cols; ++colnum, ++pP )
	    {
	    thiscolor = ppm_lookupcolor(cht, pP);
	    if ( colnum == cols -1 )   /* last pixel in row */
		if ( repeat == 1 )
		    printf( "#%d%c", thiscolor, sixel[b] );
		else
		    printf( "#%d!%d%c", thiscolor, repeat, sixel[b] );
	    else   /* not last pixel in row */
		{
		nextcolor =  ppm_lookupcolor(cht, pP+1);
		if ( thiscolor == nextcolor )
		    ++repeat;
		else
		    if ( repeat == 1 )
			printf( "#%d%c", thiscolor, sixel[b] );
		    else
		    {
		    printf( "#%d!%d%c", thiscolor, repeat, sixel[b] );
		    repeat = 1;
		    }
		}
	    }   /* end column loop */
	printf( "$\n" );   /* Carriage Return */
	if ( b == 5 )
	    printf( "-\n" );   /* Line Feed (one sixel height) */
	}
    }



static void
WriteEnd()
    {
    if ( margin == 1 )
	printf ( "%c%d;%ds", CSI, 1, 80 );
    printf( "%c\n", ST );
    }