graphviz drawing

draw.c

#include <graphviz/cgraph.h>
#include <graphviz/gvc.h>
#include <stdio.h>
#include <stdlib.h>
#include "main.h"

#define P_LEN 15
#define max(a,b) \
   ({ __typeof__ (a) _a = (a); \
       __typeof__ (b) _b = (b); \
     _a > _b ? _a : _b; })

void add_node(node *n, Agnode_t **agn, Agraph_t *g);
void draw_list(Agraph_t *g, Agnode_t **agn, node *n, int k);

void draw_graph(TREE *tree) {
	Agraph_t *g;
	GVC_t* gvc;
	gvc = gvContext();

	g = agopen("G", Agstrictundirected, NULL);
	Agsym_t *atr;
	atr = agattr(g, AGNODE, "shape", "circle");
	
	Agnode_t *agn[3];
	if (tree->root == NULL) {
		printf("Tree is empty\n");
		return;
	}
	if (tree->root->left != NULL) {
		char s[P_LEN];
		sprintf(s, "x=%d", tree->root->boundary);
		agn[0] = agnode(g, s, TRUE);
	}
	else {
		draw_list(g, agn, tree->root, 0);
	}
	add_node(tree->root, agn, g);

	gvLayout(gvc, g, "dot");
	gvRenderFilename(gvc, g, "png", "out.png");
	gvFreeLayout(gvc, g);

	agclose(g);
}

void add_node(node *n, Agnode_t **agn, Agraph_t *g) {
	if (n->left == NULL) {
		return;
	}
	char s[P_LEN];
	if (n->left->left != NULL) {
		if (n->axis == 0) {
			sprintf(s, "y=%d", n->left->boundary);
		}
		else {
			sprintf(s, "x=%d", n->left->boundary);
		}
		agn[1] = agnode(g, s, TRUE);
	}
	else {
		draw_list(g, agn, n->left, 1);
	}
	if (n->right->left != NULL) {
		if (n->axis == 0) {
		sprintf(s, "y=%d", n->right->boundary);
		}
		else {
			sprintf(s, "x=%d", n->right->boundary);
		}
		agn[2] = agnode(g, s, TRUE);
	}
	else {
		draw_list(g, agn, n->right, 2);
	}
	
	Agedge_t *e;
	e = agedge(g, agn[0], agn[1], NULL, TRUE);
	e = agedge(g, agn[0], agn[2], NULL, TRUE);

	Agnode_t *right = agn[2];
	agn[0] = agn[1];
	add_node(n->left, agn, g);
	agn[0] = right;
	add_node(n->right, agn, g);
}

void draw_list(Agraph_t *g, Agnode_t **agn, node *n, int k) {
	char *s;
	int len = 0;
	con_list *elem;
	elem = n->content;
	while (elem != NULL) {
		elem = elem->next;
		len++;
	}
	agn[k] = agnode(g, NULL, TRUE);
	if (len != 0) {
		//create node name
		char f[P_LEN];
		s = (char *)malloc(sizeof(char) * P_LEN * len);
		memset(s, 0x00, 1);
		elem = n->content;
		sprintf(f, "{ (%d,%d)", elem->data->key[0], elem->data->key[1]);
		strcat(s, f);
		for (int i = 1; i < len; i++) {
			elem = elem->next;
			sprintf(f, "| (%d,%d)", elem->data->key[0], elem->data->key[1]);
			strcat(s, f);
		}
		strcpy(f, "}");
		strcat(s, f);

		agset(agn[k], "label", s);
		free(s);
	}
	agset(agn[k], "shape", "Mrecord");
}