Graphviz

Makefile

@@ -2,9 +2,9 @@ MODULES=$(shell sed -n -E 's/^- (.*\.pl)$$/\1/p' toc.org)
 # load_test_files/1 should make this useless, but I cannot find how to use it
 TEST_MODULES=$(wildcard $(MODULES:.pl=.plt))
 
-all: biocham biocham_debug tests doc
+all: biocham biocham_debug test doc
 
-.PHONY: tests doc clean
+.PHONY: test doc clean
 
 biocham: $(MODULES) toc.org Makefile
 	@echo $(MODULES)
@@ -13,7 +13,7 @@ biocham: $(MODULES) toc.org Makefile
 biocham_debug: $(MODULES) $(TEST_MODULES) toc.org Makefile
 	swipl -o biocham_debug --goal=initialize -c $(MODULES) $(TEST_MODULES)
 
-tests: biocham_tests
+test: biocham_tests
 	./biocham_tests
 
 doc: biocham

modules/graphviz/Makefile

+CC=swipl-ld
+LDFLAGS=-shared
+
+all: graphviz_swiprolog test
+
+.PHONY: clean test
+
+clean:
+	rm -f graphviz_swiprolog graphviz_swiprolog.so graphviz_swiprolog.o
+
+graphviz_swiprolog: graphviz_swiprolog.o
+	swipl-ld -shared -o graphviz_swiprolog graphviz_swiprolog.o
+	mv graphviz_swiprolog.so graphviz_swiprolog
+
+graphviz_swiprolog.o: graphviz_swiprolog.c
+
+test:
+	swipl -g "\
+	  call_cleanup((['graphviz.plt'], run_tests, halt(0)), halt(1))\
+	"

modules/graphviz/graphviz.pl

+:- module(
+  graphviz,
+  [
+    agclose/1,
+    agread/2,
+    gvFreeLayout/1,
+    gvLayout/2,
+    gvRender/3
+  ]
+).
+
+
+:- use_foreign_library(foreign(graphviz_swiprolog)).

modules/graphviz/graphviz.plt

+:- use_module(library(plunit)).
+
+:- use_module(graphviz).
+
+:- begin_tests(graphviz).
+
+test(say_hello) :-
+  say_hello('Hello world.').
+
+:- end_tests(graphviz).

modules/graphviz/graphviz_swiprolog.c

+#include <stdio.h>
 #include <SWI-Prolog.h>
+#include <gvc.h>
+
+GVC_t *gvc;
+
+static foreign_t
+pl_agclose(term_t graph_term) {
+    Agraph_t *graph;
+    if (!PL_get_pointer(graph_term, &graph)) {
+        PL_fail;
+    }
+    agclose(graph);
+    PL_succeed;
+}
+
+static foreign_t
+pl_agread(term_t filename_term, term_t graph_term) {
+    char *filename;
+    FILE *file;
+    Agraph_t *graph;
+    if (!PL_get_atom_chars(filename_term, &filename)) {
+        PL_fail;
+    }
+    file = fopen(filename, "r");
+    graph = agread(file);
+    fclose(file);
+    if (!PL_put_pointer(graph_term, graph)) {
+        agclose(graph);
+        PL_fail;
+    }
+    PL_succeed;
+}
 
 static foreign_t
-pl_say_hello(term_t to) {
-    char *a;
+pl_gvFreeLayout(term_t graph_term) {
+    Agraph_t *graph;
+    if (!PL_get_pointer(graph_term, &graph)) {
+        PL_fail;
+    }
+    gvFreeLayout(gvc, graph);
+    PL_succeed;
+}
 
-    if (PL_get_atom_chars(to, &a)) {
-        PL_succeed;
+static foreign_t
+pl_gvLayout(term_t graph_term, term_t engine_term) {
+    Agraph_t *graph;
+    char *engine;
+    if (!PL_get_pointer(graph_term, &graph)) {
+        PL_fail;
     }
+    if (!PL_get_atom_chars(engine_term, &engine)) {
+        PL_fail;
+    }
+    gvLayout(gvc, graph, engine);
+    PL_succeed;
+}
 
-    PL_fail;
+static foreign_t
+pl_gvRender(term_t graph_term, term_t format_term, term_t filename) {
+    Agraph_t *graph;
+    char *format;
+    FILE *file;
+    if (!PL_get_pointer(graph_term, &graph)) {
+        PL_fail;
+    }
+    if (!PL_get_atom_chars(format_term, &format)) {
+        PL_fail;
+    }
+    if (!PL_get_atom_chars(filename_term, &filename)) {
+        PL_fail;
+    }
+    file = fopen(filename, "w");
+    gvRender(gvc, graph, format, file);
+    PL_succeed;
 }
 
 install_t
-install_mylib() {
-    PL_register_foreign("say_hello", 1, pl_say_hello, 0);
+install_graphviz_swiprolog() {
+    gvc = gvContext();
+
+    PL_register_foreign("agclose", 1, pl_agclose, 0);
+    PL_register_foreign("agread", 2, pl_agread, 0);
+    PL_register_foreign("gvFreeLayout", 1, pl_gvFreeLayout, 0);
+    PL_register_foreign("gvLayout", 2, pl_gvLayout, 0);
+    PL_register_foreign("gvRender", 3, pl_gvRender, 0);
 }