解决方法
根据
GraphViz documentation这样的事情应该做布局工作：
- (void) testGraph {
Agraph_t* G;
GVC_t* gvc;
gvc = gvContext();
char* testGraph = "\
digraph G {\
subgraph cluster_c0 {a0 -> a1 -> a2 -> a3;}\
subgraph cluster_c1 {b0 -> b1 -> b2 -> b3;}\
x -> a0;\
x -> b0;\
a1 -> a3;\
a3 -> a0;\
}";
G = agmemread((char*)testGraph);
[self dumpGraph:G];
gvLayout (gvc,G,"dot");
NSLog(@"after layout:");
[self dumpGraph:G];
gvFreeLayout(gvc,G);
gvFreeContext(gvc);
}
- (void) printNode:(Agnode_t*) node {
NSLog(@"Node: %s {{%f,%f},{%f,%f}}",node->name,node->u.coord.x,node->u.coord.y,ND_width(node),ND_height(node));
}
- (void) dumpGraph:(Agraph_t*)graph {
if (!graph)
return;
Agnode_t *n = NULL;
Dict_t *dict = graph->nodes;
for (n= dtfirst(dict); n ; n = dtnext(dict,n)) {
[self printNode:n];
}
}
而不是使用logNode：你应该写一些绘图代码.
日志输出：
GraphTest[32319:303] Node: a0 {{0.000000,0.000000},{0.000000,0.000000}}
GraphTest[32319:303] Node: a1 {{0.000000,0.000000}}
GraphTest[32319:303] Node: a2 {{0.000000,0.000000}}
GraphTest[32319:303] Node: a3 {{0.000000,0.000000}}
GraphTest[32319:303] Node: b0 {{0.000000,0.000000}}
GraphTest[32319:303] Node: b1 {{0.000000,0.000000}}
GraphTest[32319:303] Node: b2 {{0.000000,0.000000}}
GraphTest[32319:303] Node: b3 {{0.000000,0.000000}}
GraphTest[32319:303] Node: x {{0.000000,0.000000}}
GraphTest[32319:303] after layout:
GraphTest[32319:303] Node: a0 {{83.000000,250.000000},{0.750000,0.500000}}
GraphTest[32319:303] Node: a1 {{63.000000,178.000000},0.500000}}
GraphTest[32319:303] Node: a2 {{43.000000,106.000000},0.500000}}
GraphTest[32319:303] Node: a3 {{83.000000,34.000000},0.500000}}
GraphTest[32319:303] Node: b0 {{161.000000,0.500000}}
GraphTest[32319:303] Node: b1 {{161.000000,0.500000}}
GraphTest[32319:303] Node: b2 {{161.000000,0.500000}}
GraphTest[32319:303] Node: b3 {{161.000000,0.500000}}
GraphTest[32319:303] Node: x {{122.000000,322.000000},0.500000}}
