Experiments with simplication of ways

diff --git a/Makefile b/Makefile
index 1fe49f8a6dd5a2ca491264ad9d9f5569fe05f58c..bf458e8a8d20a130e283ea93937ec5e354538832 100644 (file)
--- a/Makefile
+++ b/Makefile
@@ -16,7 +16,7 @@ include $(BUILDSYS)/Maketop
 PROGS+=$(o)/leo
 CFLAGS+=$(LIBUCW_CFLAGS)
 
-LEO_MODULES=leo xml osm svg svg-icon css-parse css-lex style css dict sym sym-point sym-line sym-text map shp fixed graph
+LEO_MODULES=leo xml osm svg svg-icon css-parse css-lex style css dict sym sym-point sym-line sym-text map shp fixed graph simplify
 LEO_OBJECTS=$(addprefix $(o)/, $(addsuffix .o, $(LEO_MODULES)))
 $(o)/leo: $(LEO_OBJECTS)
 

diff --git a/leo.c b/leo.c
index 5c25ff6205bafa6b9aeddfe4720fd97189b2f769..b62d21b8d7acfa93f29eb7b37333d4d525d03a03 100644 (file)
--- a/leo.c
+++ b/leo.c
@@ -18,6 +18,7 @@
 #include "sym.h"
 #include "map.h"
 #include "graph.h"
+#include "simplify.h"
 
 uns debug_dump_source, debug_dump_after_proj, debug_dump_after_scaling;
 uns debug_dump_multipolygons, debug_dump_css, debug_dump_styling, debug_dump_symbols;
@@ -46,6 +47,7 @@ static const struct opt_section options = {
   }
 };
 
+#if 0
 // FIXME: Make generic
 static void draw_scale(struct svg *svg)
 {
@@ -110,6 +112,7 @@ static void draw_scale(struct svg *svg)
   scale_text(svg, width, 5, osm_val_encode("1 km"));
   svg_pop(svg);
 }
+#endif
 
 int main(int argc UNUSED, char **argv)
 {
@@ -121,6 +124,7 @@ int main(int argc UNUSED, char **argv)
   styles_init();
   map_load_styles();
   map_load_sources();
+  simplify();
   graph_build();
   map_set_scale();
   map_generalize();

diff --git a/simplify.c b/simplify.c
new file mode 100644 (file)
index 0000000..a621027
--- /dev/null
+++ b/simplify.c
@@ -0,0 +1,124 @@
+/*
+ *     Hic Est Leo -- Map Simplification
+ *
+ *     (c) 2022 Martin Mares <mj@ucw.cz>
+ */
+
+#include "leo.h"
+
+#include <ucw/lib.h>
+#include <ucw/clists.h>
+#include <ucw/mempool.h>
+
+#include <stdio.h>
+#include <math.h>
+
+#include "osm.h"
+#include "map.h"
+#include "simplify.h"
+
+static struct mempool *simp_pool;
+
+struct coords {
+  double x, y;
+};
+
+struct simp_node_ref {
+  cnode n;
+  struct osm_node *to;
+};
+
+struct simp_way_ref {
+  cnode n;
+  struct osm_way *to;
+  bool is_end;
+};
+
+struct simp_node {
+  union {
+    struct coords c;
+    byte raw_coords[sizeof(struct coords)];
+  };
+  clist node_refs;
+  clist way_refs;
+  byte can_be_merged;
+};
+
+static void simp_hash_init_data(struct simp_node *s)
+{
+  clist_init(&s->node_refs);
+  clist_init(&s->way_refs);
+  s->can_be_merged = false;
+}
+
+#define HASH_NODE struct simp_node
+#define HASH_PREFIX(x) simp_hash_##x
+#define HASH_KEY_MEMORY raw_coords
+#define HASH_KEY_SIZE sizeof(struct coords)
+#define HASH_WANT_LOOKUP
+#define HASH_GIVE_INIT_DATA
+#define HASH_USE_POOL simp_pool
+#define HASH_TABLE_ALLOC
+#include <ucw/hashtable.h>
+
+static bool simp_can_be_merged(struct simp_node *s)
+{
+  uint num_nodes = clist_size(&s->node_refs);
+  uint num_ways = clist_size(&s->way_refs);
+
+  ASSERT(num_nodes);
+  if (num_nodes > 1)
+    {
+      msg(L_WARN, "Simplify: Multiple (%u) nodes at [%f, %f]", num_nodes, s->c.x, s->c.y);
+      return false;
+    }
+
+  if (num_ways > 2)
+    return false;
+
+  return false;
+}
+
+static void simplify_source(struct data_source *ds)
+{
+  msg(L_INFO, "Simplifying source %s", ds->file);
+  simp_pool = mp_new(65536);
+  simp_hash_init();
+  osm_this = ds->osm;
+
+  CLIST_FOR_EACH(struct osm_way *, w, osm_this->obj_list[OSM_TYPE_WAY])
+    {
+      struct osm_node *n_first = (struct osm_node *) osm_ref_head(&w->nodes);
+      struct osm_node *n_last = (struct osm_node *) osm_ref_tail(&w->nodes);
+
+      OSM_FOR_EACH_BEGIN(struct osm_node *, n, w->nodes)
+       {
+         struct coords c = { .x = n->x, .y = n->y };
+         struct simp_node *s = simp_hash_lookup((byte *) &c);
+
+         struct simp_node_ref *nref = mp_alloc(simp_pool, sizeof(*nref));
+         nref->to = n;
+         clist_add_tail(&s->node_refs, &nref->n);
+
+         struct simp_way_ref *wref = mp_alloc(simp_pool, sizeof(*wref));
+         wref->to = w;
+         wref->is_end = (n == n_first || n == n_last);
+         clist_add_tail(&s->way_refs, &wref->n);
+       }
+      OSM_FOR_EACH_END;
+    }
+
+  HASH_FOR_ALL(simp_hash, s)
+    {
+      s->can_be_merged = simp_can_be_merged(s);
+    }
+  HASH_END_FOR;
+
+  mp_delete(simp_pool);
+}
+
+void simplify(void)
+{
+  CLIST_FOR_EACH(struct data_source *, ds, map_sources)
+    simplify_source(ds);
+}

diff --git a/simplify.h b/simplify.h
new file mode 100644 (file)
index 0000000..423b879
--- /dev/null
+++ b/simplify.h
@@ -0,0 +1,12 @@
+/*
+ *     Hic Est Leo -- Map Simplification
+ *
+ *     (c) 2022 Martin Mares <mj@ucw.cz>
+ */
+
+#ifndef _LEO_SIMPLIFY_H
+#define _LEO_SIMPLIFY_H
+
+void simplify(void);
+
+#endif