annotate.c

/*
 * IPv4 Heatmap
 * (C) 2007 The Measurement Factory, Inc
 * Licensed under the GPL, version 2
 * http://maps.measurement-factory.com/
 */

/*
 * Place annotations (text) on the image.
 */

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <err.h>

#include <gd.h>
#include "ipv4-heatmap.h"
#include "bbox.h"
#include "text.h"

/*
 * FONT_ALPHA sets the transparency for the annotations. in libgd, 0 means 100%
 * transparent, and 127 means 100% opaque.
 */
#define FONT_ALPHA 75

int annotateColor = -1;


/*
 * Calculate the bounding box, draw an outline of the box, then render the
 * text.
 */
static void
annotate_cidr(gdImagePtr image, const char *cidr, const char *label, const char *sublabel)
{
    bbox box = bbox_from_cidr(cidr);
    if (box.xmin < 0) {
	fprintf(stderr, "Warning: annotation %s is out of range for this image\n", cidr);
	return;
    }
    bbox_draw_outline(box, image, annotateColor);
    text_in_bbox(image, label, box, annotateColor, 128.0);
    if (sublabel) {
	bbox box2 = box;
	box2.ymin = (box.ymin + box.ymax) / 2 + (int)(_text_last_sz / 2) + 6;
	box2.ymax = box2.ymin + 24;
	if (0 == strcmp(sublabel, "prefix"))
	    sublabel = cidr;
	text_in_bbox(image, sublabel, box2, annotateColor, 12.0);
    }
}

/*
 * Input is a text file with TAB-separated fields First field is a CIDR address
 * Second field is a text label
 */
void
annotate_file(gdImagePtr image, const char *fn)
{
    char buf[512];
    FILE *fp = fopen(fn, "r");
    if (NULL == fp)
	err(1, "%s", fn);
    if (annotateColor < 0) {
	if (reverse_flag)
	    annotateColor = gdImageColorAllocateAlpha(image, 0, 0, 0, FONT_ALPHA);
	else 
	    annotateColor = gdImageColorAllocateAlpha(image, 255, 255, 255, FONT_ALPHA);
    }
    if (!gdFTUseFontConfig(1))
	warnx("fontconfig not available");
    while (NULL != fgets(buf, 512, fp)) {
	char *cidr;
	char *label;
	char *sublabel = NULL;
	cidr = strtok(buf, "\t");
	if (NULL == cidr)
	    continue;
	label = strtok(NULL, "\t\r\n");
	if (NULL == label)
	    continue;
	sublabel = strtok(NULL, "\t\r\n");
	annotate_cidr(image, cidr, label, sublabel);
    }
    fclose(fp);
}