自定义 GMT 的 Logo

void gmt_timestamp (struct GMT_CTRL *GMT, struct PSL_CTRL *PSL, double x, double y, unsigned int justify, char *U_label)
{
    /* x, y = location of the time stamp box
    * justify indicates the corner of the box that (x,y) refers to, see below
    * U_label = label to be plotted to the right of the box
    *
    *   9        10       11
    *   |------------------|
    *   5         6        7
    *   |------------------|
    *   1         2        3
    */

    time_t right_now;
    char label[GMT_LEN256] = {""}, text[GMT_LEN256] = {""};
    double dim[3] = {0.365, 0.15, 0.032};   /* Predefined dimensions in inches */
    double unset_rgb[4] = {-1.0, -1.0, -1.0, 0.0};

    /* Plot time string in format defined by format_time_stamp */

    right_now = time ((time_t *)0);
    strftime (text, sizeof(text), GMT->current.setting.format_time_stamp, localtime (&right_now));
    sprintf (label,"  %s  ", text);

    PSL_command (PSL,"%% Begin GMT time-stamp\nV\n");
    PSL_setorigin (PSL, x, y, 0.0, PSL_FWD);
    PSL_setlinewidth (PSL, 0.25);
    PSL_setfont (PSL, GMT->current.setting.font_logo.id);
    PSL_defunits (PSL,"PSL_g_w", dim[0]);  /* Size of the black [GMT] box */
    PSL_defunits (PSL,"PSL_g_h", dim[1]);
    PSL_deftextdim (PSL,"PSL_b", 8.0, label);  /* Size of the white [timestamp] box (use only length) */

    /* When justification is not BL (justify == 1), add some PostScript code to move to the
    location where the lower left corner of the time stamp box is to be drawn */

    switch ((justify + 3) % 4) {
        case 1: /* Center */
            PSL_command (PSL,"PSL_g_w PSL_b_w add 2 div neg 0 T\n"); break;
        case 2: /* Right justify */
            PSL_command (PSL,"PSL_g_w PSL_b_w add neg 0 T\n"); break;
    }
    switch (justify / 4) {
        case 1: /* Middle */
            PSL_command (PSL,"0 PSL_g_h 2 div neg T\n"); break;
        case 2: /* Top justify */
            PSL_command (PSL,"0 PSL_g_h neg T\n"); break;
    }

    /* Now draw black box with GMT logo, and white box with time stamp */

    PSL_setfill (PSL, GMT->current.setting.map_default_pen.rgb, true);
    PSL_plotsymbol (PSL, 0.5*dim[0], 0.5*dim[1], dim, PSL_RECT);
    PSL_plotcolorimage (PSL, 0.0, 0.0, dim[0], dim[1], PSL_BL, GMT_glyph, 220, 90, 1);
    PSL_setfill (PSL, GMT->PSL->init.page_rgb, true);
    PSL_command (PSL,"PSL_g_h PSL_b_w PSL_g_w 0 Sb\n");
    PSL_plottext (PSL, dim[0], dim[2], 8.0, label, 0.0, 1, 0);

    /* Optionally, add additional label to the right of the box */

    if (U_label && U_label[0]) {
        sprintf (label,"   %s", U_label);
        PSL_plottext (PSL, 0.0, 0.0, -7.0, label, 0.0, 1, 0);
    }

    PSL_command (PSL,"U\n%% End GMT time-stamp\n");

    /* Reset fill style to empty and no outline and reset linewidth */
    PSL_setfill (PSL, unset_rgb, false);
    PSL->current.linewidth = -1.0;
}

/* Get bitmapped 600 dpi GMT glyph for timestamp.  The glyph is a 90 x 220 pixel 1-bit image
   and it is here represented as ceil (220 / 8) * 90 = 2520 bytes */
unsigned char GMT_glyph[2520]={
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
……
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x0f, 0x00, 0x00, 0x00, 0x00,
};

int PSL_plotcolorimage (struct PSL_CTRL *PSL, double x, double y, double xsize, double ysize, int justify, unsigned char *buffer, int nx, int ny, int nbits);
/* Plots a 24-bit color image in Grayscale, RGB or CMYK mode.
 * When the number of unique colors does not exceed PSL_MAX_COLORS, the routine will index
 * 24-bit RGB images and then attempt to reduce the depth of the indexed image to 1, 2 or 4 bits.
 *
 * x, y     : lower left position of image in plot units
 * xsize, ysize : image size in units (if 0, adjust to keep the original aspect ratio)
 * justify  : indicates what corner x,y refers to (see graphic below)
 * buffer   : contains the bytes for the image
 * nx, ny   : pixel dimension
 * nbits    : number of bits per pixel (1, 2, 4, 8, 24)
 *
 * Special cases:
 * nx <0   : 8- or 24-bit image contains a color mask (first 1 or 3 bytes)
 * nbits <0    :"Hardware" interpolation requested
 *
 *   9       10      11
 *   |----------------|
 *   5    <image>     7
 *   |----------------|
 *   1       2        3
 */