rpng2-x.c

openmeetings组件之GS openmeetings组件之GS openmeetings组件之GS

        fgets(tmpline, 80, infile);
        fclose(infile);
        sgi_gamma = atof(tmpline);
        if (sgi_gamma > 0.0)
            LUT_exponent = 1.0 / sgi_gamma;
    }
#elif defined(Macintosh)
    LUT_exponent = 1.8 / 2.61;
    /*
    if (some_mac_function_that_returns_gamma(&mac_gamma))
        LUT_exponent = mac_gamma / 2.61;
     */
#else
    LUT_exponent = 1.0;   /* assume no LUT:  most PCs */
#endif

    /* the defaults above give 1.0, 1.3, 1.5 and 2.2, respectively: */
    default_display_exponent = LUT_exponent * CRT_exponent;


    /* If the user has set the SCREEN_GAMMA environment variable as suggested
     * (somewhat imprecisely) in the libpng documentation, use that; otherwise
     * use the default value we just calculated.  Either way, the user may
     * override this via a command-line option. */

    if ((p = getenv("SCREEN_GAMMA")) != NULL)
        rpng2_info.display_exponent = atof(p);
    else
        rpng2_info.display_exponent = default_display_exponent;


    /* Now parse the command line for options and the PNG filename. */

    while (*++argv && !error) {
        if (!strncmp(*argv, "-display", 2)) {
            if (!*++argv)
                ++error;
            else
                displayname = *argv;
        } else if (!strncmp(*argv, "-gamma", 2)) {
            if (!*++argv)
                ++error;
            else {
                rpng2_info.display_exponent = atof(*argv);
                if (rpng2_info.display_exponent <= 0.0)
                    ++error;
            }
        } else if (!strncmp(*argv, "-bgcolor", 4)) {
            if (!*++argv)
                ++error;
            else {
                bgstr = *argv;
                if (strlen(bgstr) != 7 || bgstr[0] != '#')
                    ++error;
                else {
                    have_bg = TRUE;
                    bg_image = FALSE;
                }
            }
        } else if (!strncmp(*argv, "-bgpat", 4)) {
            if (!*++argv)
                ++error;
            else {
                pat = atoi(*argv);
                if (pat >= 0 && pat < num_bgpat) {
                    bg_image = TRUE;
                    have_bg = FALSE;
                } else
                    ++error;
            }
        } else if (!strncmp(*argv, "-usleep", 2)) {
            if (!*++argv)
                ++error;
            else {
                usleep_duration = (ulg)atol(*argv);
                demo_timing = TRUE;
            }
        } else if (!strncmp(*argv, "-pause", 2)) {
            pause_after_pass = TRUE;
        } else if (!strncmp(*argv, "-timing", 2)) {
            timing = TRUE;
#ifdef FEATURE_LOOP
        } else if (!strncmp(*argv, "-loop", 2)) {
            loop = TRUE;
            if (!argv[1] || !is_number(argv[1]))
                loop_interval = 2;
            else {
                ++argv;
                loop_interval = atol(*argv);
                if (loop_interval < 0)
                    loop_interval = 2;
                else if (loop_interval > 100000)   /* bit more than one day */
                    loop_interval = 100000;
            }
#endif
#if (defined(__i386__) || defined(_M_IX86) || defined(__x86_64__))
        } else if (!strncmp(*argv, "-nommxfilters", 7)) {
            rpng2_info.nommxfilters = TRUE;
        } else if (!strncmp(*argv, "-nommxcombine", 7)) {
            rpng2_info.nommxcombine = TRUE;
        } else if (!strncmp(*argv, "-nommxinterlace", 7)) {
            rpng2_info.nommxinterlace = TRUE;
        } else if (!strcmp(*argv, "-nommx")) {
            rpng2_info.nommxfilters = TRUE;
            rpng2_info.nommxcombine = TRUE;
            rpng2_info.nommxinterlace = TRUE;
#endif
        } else {
            if (**argv != '-') {
                filename = *argv;
                if (argv[1])   /* shouldn't be any more args after filename */
                    ++error;
            } else
                ++error;   /* not expecting any other options */
        }
    }

    if (!filename) {
        ++error;
    } else if (!(infile = fopen(filename, "rb"))) {
        fprintf(stderr, PROGNAME ":  can't open PNG file [%s]\n", filename);
        ++error;
    } else {
        incount = fread(inbuf, 1, INBUFSIZE, infile);
        if (incount < 8 || !readpng2_check_sig(inbuf, 8)) {
            fprintf(stderr, PROGNAME
              ":  [%s] is not a PNG file: incorrect signature\n",
              filename);
            ++error;
        } else if ((rc = readpng2_init(&rpng2_info)) != 0) {
            switch (rc) {
                case 2:
                    fprintf(stderr, PROGNAME
                      ":  [%s] has bad IHDR (libpng longjmp)\n",
                      filename);
                    break;
                case 4:
                    fprintf(stderr, PROGNAME ":  insufficient memory\n");
                    break;
                default:
                    fprintf(stderr, PROGNAME
                      ":  unknown readpng2_init() error\n");
                    break;
            }
            ++error;
        } else {
            display = XOpenDisplay(displayname);
            if (!display) {
                readpng2_cleanup(&rpng2_info);
                fprintf(stderr, PROGNAME ":  can't open X display [%s]\n",
                  displayname? displayname : "default");
                ++error;
            }
        }
        if (error)
            fclose(infile);
    }


    /* usage screen */

    if (error) {
        fprintf(stderr, "\n%s %s:  %s\n\n", PROGNAME, VERSION, appname);
        readpng2_version_info();
        fprintf(stderr, "\n"
          "Usage:  %s [-display xdpy] [-gamma exp] [-bgcolor bg | -bgpat pat]\n"
#if (defined(__i386__) || defined(_M_IX86) || defined(__x86_64__))
          "        %*s [[-nommxfilters] [-nommxcombine] [-nommxinterlace] | -nommx]\n"
#endif
#ifdef FEATURE_LOOP
          "        %*s [-usleep dur | -timing] [-pause] [-loop [sec]] file.png\n\n"
#else
          "        %*s [-usleep dur | -timing] [-pause] file.png\n\n"
#endif
          "    xdpy\tname of the target X display (e.g., ``hostname:0'')\n"
          "    exp \ttransfer-function exponent (``gamma'') of the display\n"
          "\t\t  system in floating-point format (e.g., ``%.1f''); equal\n"
          "\t\t  to the product of the lookup-table exponent (varies)\n"
          "\t\t  and the CRT exponent (usually 2.2); must be positive\n"
          "    bg  \tdesired background color in 7-character hex RGB format\n"
          "\t\t  (e.g., ``#ff7700'' for orange:  same as HTML colors);\n"
          "\t\t  used with transparent images; overrides -bgpat\n"
          "    pat \tdesired background pattern number (0-%d); used with\n"
          "\t\t  transparent images; overrides -bgcolor\n"
#ifdef FEATURE_LOOP
          "    -loop\tloops through background images after initial display\n"
          "\t\t  is complete (depends on -bgpat)\n"
          "    sec \tseconds to display each background image (default = 2)\n"
#endif
#if (defined(__i386__) || defined(_M_IX86) || defined(__x86_64__))
          "    -nommx*\tdisable optimized MMX routines for decoding row filters,\n"
          "\t\t  combining rows, and expanding interlacing, respectively\n"
#endif
          "    dur \tduration in microseconds to wait after displaying each\n"
          "\t\t  row (for demo purposes)\n"
          "    -timing\tenables delay for every block read, to simulate modem\n"
          "\t\t  download of image (~36 Kbps)\n"
          "    -pause\tpauses after displaying each pass until key pressed\n"
          "\nPress Q, Esc or mouse button 1 (within image window, after image\n"
          "is displayed) to quit.\n"
          "\n", PROGNAME,
#if (defined(__i386__) || defined(_M_IX86) || defined(__x86_64__))
          (int)strlen(PROGNAME), " ",
#endif
          (int)strlen(PROGNAME), " ", default_display_exponent, num_bgpat-1);
        exit(1);
    }


    /* set the title-bar string, but make sure buffer doesn't overflow */

    alen = strlen(appname);
    flen = strlen(filename);
    if (alen + flen + 3 > 1023)
        sprintf(titlebar, "%s:  ...%s", appname, filename+(alen+flen+6-1023));
    else
        sprintf(titlebar, "%s:  %s", appname, filename);


    /* set some final rpng2_info variables before entering main data loop */

    if (have_bg) {
        unsigned r, g, b;   /* this approach quiets compiler warnings */

        sscanf(bgstr+1, "%2x%2x%2x", &r, &g, &b);
        rpng2_info.bg_red   = (uch)r;
        rpng2_info.bg_green = (uch)g;
        rpng2_info.bg_blue  = (uch)b;
    } else
        rpng2_info.need_bgcolor = TRUE;

    rpng2_info.done = FALSE;
    rpng2_info.mainprog_init = rpng2_x_init;
    rpng2_info.mainprog_display_row = rpng2_x_display_row;
    rpng2_info.mainprog_finish_display = rpng2_x_finish_display;


    /* OK, this is the fun part:  call readpng2_decode_data() at the start of
     * the loop to deal with our first buffer of data (read in above to verify
     * that the file is a PNG image), then loop through the file and continue
     * calling the same routine to handle each chunk of data.  It in turn
     * passes the data to libpng, which will invoke one or more of our call-
     * backs as decoded data become available.  We optionally call sleep() for
     * one second per iteration to simulate downloading the image via an analog
     * modem. */

    for (;;) {
        Trace((stderr, "about to call readpng2_decode_data()\n"))
        if (readpng2_decode_data(&rpng2_info, inbuf, incount))
            ++error;
        Trace((stderr, "done with readpng2_decode_data()\n"))
        if (error || feof(infile) || rpng2_info.done)
            break;
        if (timing)
            sleep(1);
        incount = fread(inbuf, 1, INBUFSIZE, infile);
    }


    /* clean up PNG stuff and report any decoding errors */

    fclose(infile);
    Trace((stderr, "about to call readpng2_cleanup()\n"))
    readpng2_cleanup(&rpng2_info);

    if (error) {
        fprintf(stderr, PROGNAME ":  libpng error while decoding PNG image\n");
        exit(3);
    }


#ifdef FEATURE_LOOP

    if (loop && bg_image) {
        for (;;) {
            int i, use_sleep;
            struct timeval now, then;

            /* get current time and add loop_interval to get target time */
            if (gettimeofday(&then, NULL) == 0) {
                then.tv_sec += loop_interval;
                use_sleep = FALSE;
            } else
                use_sleep = TRUE;

            /* do quick check for a quit event but don't wait for it */
            /* GRR BUG:  should also check for Expose events and redraw... */
            if (XCheckMaskEvent(display, KeyPressMask | ButtonPressMask, &e))
                if (QUIT(e,k))
                    break;

            /* generate next background image */
            if (++pat >= num_bgpat)
                pat = 0;
            rpng2_x_reload_bg_image();

            /* wait for timeout, using whatever means are available */
            if (use_sleep || gettimeofday(&now, NULL) != 0) {
                for (i = loop_interval;  i > 0;  --i) {
                    sleep(1);
                    /* GRR BUG:  also need to check for Expose (and redraw!) */
                    if (XCheckMaskEvent(display, KeyPressMask | ButtonPressMask,
                        &e) && QUIT(e,k))
                        break;
                }
            } else {
                /* Y2038 BUG! */
                if (now.tv_sec < then.tv_sec ||
                    (now.tv_sec == then.tv_sec && now.tv_usec < then.tv_usec))
                {
                    int quit = FALSE;
                    long seconds_to_go = then.tv_sec - now.tv_sec;
                    long usleep_usec;

                    /* basically chew up most of remaining loop-interval with
                     *  calls to sleep(1) interleaved with checks for quit
                     *  events, but also recalc time-to-go periodically; when
                     *  done, clean up any remaining time with usleep() call
                     *  (could also use SIGALRM, but signals are a pain...) */
                    while (seconds_to_go-- > 1) {
                        int seconds_done = 0;

                        for (i = seconds_to_go;  i > 0 && !quit;  --i) {
                            sleep(1);
                            /* GRR BUG:  need to check for Expose and redraw */
                            if (XCheckMaskEvent(display, KeyPressMask |
                                ButtonPressMask, &e) && QUIT(e,k))
                                quit = TRUE;
                            if (++seconds_done > 1000)
                                break;   /* time to redo seconds_to_go meas. */
                        }
                        if (quit)
                            break;

                        /* OK, more than 1000 seconds since last check:
                         *  correct the time-to-go measurement for drift */
                        if (gettimeofday(&now, NULL) == 0) {
                            if (now.tv_sec >= then.tv_sec)