about summary refs log tree commit diff
path: root/other/ppmsvgalib.c
blob: 67cc2b1a7f2d43086b90e7c5c5eaa8a8fea85632 (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
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
/******************************************************************************
                               ppmsvgalib
*******************************************************************************
   Display a PPM image on a Linux console using Svgalib.

   By Bryan Henderson, San Jose CA 2002.01.06.

   Contributed to the public domain.
   
******************************************************************************/

#define _XOPEN_SOURCE    /* Make sure modern signal stuff is in signal.h */
#include <stdio.h>
#include <vga.h>
#include <string.h>
#include <errno.h>
#include <signal.h>
#include <unistd.h>
#include "ppm.h"
#include "shhopt.h"

struct cmdlineInfo {
    /* All the information the user supplied in the command line,
       in a form easy for the program to use.
    */
    const char *inputFilespec;  /* Filespec of input file */
    unsigned int mode;
    unsigned int verbose;
};



static void
parseCommandLine (int argc, char ** argv,
                  struct cmdlineInfo *cmdlineP) {
/*----------------------------------------------------------------------------
   parse program command line described in Unix standard form by argc
   and argv.  Return the information in the options as *cmdlineP.  

   If command line is internally inconsistent (invalid options, etc.),
   issue error message to stderr and abort program.

   Note that the strings we return are stored in the storage that
   was passed to us as the argv array.  We also trash *argv.
-----------------------------------------------------------------------------*/
    optEntry *option_def = malloc( 100*sizeof( optEntry ) );
        /* Instructions to optParseOptions3 on how to parse our options.
         */
    optStruct3 opt;

    unsigned int option_def_index;

    unsigned int modeSpec;

    option_def_index = 0;   /* incremented by OPTENT3 */
    OPTENT3(0,   "mode",         OPT_UINT,
            &cmdlineP->mode,   &modeSpec, 0);
    OPTENT3(0,   "verbose",      OPT_FLAG,
            NULL,   &cmdlineP->verbose,   0);

    opt.opt_table = option_def;
    opt.short_allowed = FALSE;  /* We have no short (old-fashioned) options */
    opt.allowNegNum = FALSE;  /* We have no parms that are negative numbers */

    optParseOptions3( &argc, argv, opt, sizeof(opt), 0 );
        /* Uses and sets argc, argv, and some of *cmdline_p and others. */

    if (!modeSpec)
        pm_error("You must specify the -mode option.");

    if (argc-1 > 1)
        pm_error("Program takes at most one argument: the input file "
                 "specification.  "
                 "You specified %d arguments.", argc-1);
    if (argc-1 < 1)
        cmdlineP->inputFilespec = "-";
    else
        cmdlineP->inputFilespec = argv[1];
}



static void
displayImage(FILE * const ifP, 
             int    const cols, 
             int    const rows,
             pixval const maxval, 
             int    const format,
             int    const originCol,
             int    const originRow) {
/*----------------------------------------------------------------------------
   Draw the PPM image which is in file 'ifP', which is positioned after the
   PPM header on the screen with its upper left corner (originCol, originRow).

   The image is 'cols' x 'rows' with maxval 'maxval' and PNM format 'format'.

   Svgalib is initialized and the mode selected.

   The image fits on the screen.
-----------------------------------------------------------------------------*/
    unsigned int svgalibMaxval = 255;
        /* This is the maxval for intensity values passed to Svgalib */
    unsigned int row;
    pixel * pixelrow;

    pixelrow = ppm_allocrow(cols);

    /* Implementation note:  It might be faster to use 
       vga_drawscansegment() instead of vga_drawpixel()
    */

    for (row = 0; row < rows; ++row) {
        unsigned int col;
        ppm_readppmrow(ifP, pixelrow, cols, maxval, format);
        for (col = 0; col < cols; ++col) {
            pixel const p = pixelrow[col];
            int const red = PPM_GETR(p) * svgalibMaxval / maxval;
            int const grn = PPM_GETG(p) * svgalibMaxval / maxval;
            int const blu = PPM_GETB(p) * svgalibMaxval / maxval;

            vga_setrgbcolor(red, grn, blu);
            vga_drawpixel(originCol + col, originRow + row);
        }
    }
    ppm_freerow(pixelrow);
}



static void
sigintHandler(int const signal) {
/*----------------------------------------------------------------------------
   This is a signal handler for the SIGINT signal (Control-C).

   It does nothing; The handler exists only to replace the default action,
   which is to terminate the process.  Though the handler does nothing,
   the signal still causes the wait() system call, assuming it's in progress,
   to terminate so that this program can terminate.
-----------------------------------------------------------------------------*/
}



static void 
waitforSigint(void) {

    struct sigaction oldsigaction;
    struct sigaction newsigaction;
    int rc;
    
    newsigaction.sa_handler = &sigintHandler;
    sigemptyset(&newsigaction.sa_mask);
    newsigaction.sa_flags = 0;
    rc = sigaction(SIGINT, &newsigaction, &oldsigaction);
    if (rc != 0)
        pm_error("Unable to set up SIGINTR signal handler.  Errno=%d (%s)",
                 errno, strerror(errno));

    pause();  /* Wait for a signal, e.g. control-C */

    sigaction(SIGINT, &oldsigaction, NULL);
}



static void
display(FILE * const ifP, 
        int    const cols, 
        int    const rows, 
        pixval const maxval, 
        int    const format, 
        int    const videoMode, 
        bool   const verbose) {

    int xmax, ymax;
    vga_modeinfo *modeinfo;

    modeinfo = vga_getmodeinfo(videoMode);
    
    if (verbose) {
        pm_message("Screen Width: %d  Height: %d  Colors: %d",
                   modeinfo->width,
                   modeinfo->height,
                   modeinfo->colors);
        pm_message("DisplayStartRange: %xh  Maxpixels: %d  Blit: %s",
                   modeinfo->startaddressrange,
                   modeinfo->maxpixels,
                   modeinfo->haveblit ? "YES" : "NO");
    }

    if (modeinfo->colors <= 256)
        pm_error("This video mode has %d or fewer colors, which means "
                 "it is colormapped (aka paletted, aka pseudocolor).  "
                 "This program cannot drive colormapped modes.", 
                 modeinfo->colors);

    if (cols > modeinfo->width)
        pm_error("Image is too wide (%d columns) for screen (%d columns).  "
                 "Use Pamcut to select part to display.", 
                 cols, modeinfo->width);
    if (rows > modeinfo->height)
        pm_error("Image is too tall (%d rows) for screen (%d rows).  "
                 "Use Pamcut to select part to display.",
                 rows, modeinfo->height);
    
    /* The program must not terminate after we set the video mode and before
       we reset it to text mode.  Note that vga_setmode() sets up handlers
       for signals such as SIGINT that attempt to restore modes and then exit
       the program.
    */

    vga_setmode(videoMode);

    vga_screenoff();

    xmax = vga_getxdim() - 1;
    ymax = vga_getydim() - 1;

    /* Draw white border */

    vga_setcolor(vga_white());
    vga_drawline(0, 0, xmax, 0);
    vga_drawline(xmax, 0, xmax, ymax);
    vga_drawline(xmax, ymax, 0, ymax);
    vga_drawline(0, ymax, 0, 0);

    vga_screenon();

    {
        int const originCol = (modeinfo->width - cols) / 2;
        int const originRow = (modeinfo->height - rows) / 2;
        displayImage(ifP, cols, rows, maxval, format, originCol, originRow);
    }

    waitforSigint();

    vga_setmode(TEXT);
}



int 
main(int argc, char *argv[]) {

    FILE * ifP;
    struct cmdlineInfo cmdline;
    int cols, rows;
    pixval maxval;
    int format;
    int rc;

    ppm_init( &argc, argv );

    rc = vga_init();         /* Initialize. */
    if (rc < 0)
        pm_error("Svgalib unable to allocate a virtual console.");

    parseCommandLine(argc, argv, &cmdline);

    ifP = pm_openr(cmdline.inputFilespec);

    ppm_readppminit(ifP, &cols, &rows, &maxval, &format);

    {
        enum pm_check_code checkResult;
        ppm_check(ifP, PM_CHECK_BASIC, format, cols, rows, maxval, 
                  &checkResult);
    }

    if (vga_hasmode(cmdline.mode))
        display(ifP, cols, rows, maxval, format, 
                cmdline.mode, cmdline.verbose);
    else {
        pm_error("Svgalib video mode #%d not available.  Either the "
                 "video controller isn't capable of that mode or the "
                 "Svgalib video driver doesn't know how to use it.",
                 cmdline.mode);
    }

    pm_close(ifP);

    return 0;
}