On the way to a simplified losight interface.

Added a function
void losight(env_show_grid& sh, const coord_def& center,
             opacity_func opc, bounds_func bounds)
with sensible defaults for opc and bounds.

It's not necessary to abstract away the geometry as I initially
did with los_param.

4 files changed, 65 insertions, 2 deletions

diff --git a/crawl-ref/source/los.cc b/crawl-ref/source/los.cc
index a1723cd72b..896ad452c9 100644
--- a/crawl-ref/source/los.cc
+++ b/crawl-ref/source/los.cc
@@ -859,6 +859,40 @@ void losight(env_show_grid& sh, const los_param& dat)
     sh(o+sh_o) = dat.appearance(o);
 }
 
+struct los_param_funcs : public los_param
+{
+    coord_def center;
+    opacity_func opc;
+    bounds_func bounds;
+
+    los_param_funcs(const coord_def& c,
+                    opacity_func o, bounds_func b)
+        : center(c), opc(o), bounds(b)
+    {
+    }
+
+    bool los_bounds(const coord_def& p) const
+    {
+        return (map_bounds(p + center) && bounds(p));
+    }
+
+    unsigned appearance(const coord_def& p) const
+    {
+        return (grid_appearance(p + center));
+    }
+
+    opacity_type opacity(const coord_def& p) const
+    {
+        return (opc(p + center));
+    }
+};
+
+void losight(env_show_grid& sh, const coord_def& center,
+             opacity_func opc, bounds_func bounds)
+{
+    losight(sh, los_param_funcs(center, opc, bounds));
+}
+
 void losight_permissive(env_show_grid &sh, const coord_def& center)
 {
     for (int x = -ENV_SHOW_OFFSET; x <= ENV_SHOW_OFFSET; ++x)
@@ -875,7 +909,7 @@ void calc_show_los()
     if (!crawl_state.arena && !crawl_state.arena_suspended)
     {
         // Must be done first.
-        losight(env.show, los_param_base(you.pos()));
+        losight(env.show, you.pos());
 
         // What would be visible, if all of the translucent walls were
         // made opaque.
diff --git a/crawl-ref/source/los.h b/crawl-ref/source/los.h
index 045534ac4e..7e70bd7a08 100644
--- a/crawl-ref/source/los.h
+++ b/crawl-ref/source/los.h
@@ -31,7 +31,10 @@ int num_feats_between(const coord_def& source, const coord_def& target,
 bool cell_see_cell(const coord_def& p1, const coord_def& p2);
 
 void clear_rays_on_exit();
-void losight(env_show_grid& sh, const los_param& dat);
+void losight(env_show_grid& sh, const coord_def& center,
+             opacity_func opc = &opc_default,
+             bounds_func bounds = &bounds_los_radius);
+void losight(env_show_grid& sh, const los_param& param);
 void calc_show_los();
 
 bool see_grid( const env_show_grid &show,
diff --git a/crawl-ref/source/losparam.cc b/crawl-ref/source/losparam.cc
index 833ee04003..47c995f5bd 100644
--- a/crawl-ref/source/losparam.cc
+++ b/crawl-ref/source/losparam.cc
@@ -14,6 +14,26 @@ REVISION("$Rev$");
 #include "stuff.h"
 #include "terrain.h"
 
+opacity_type opc_default(const coord_def& p)
+{
+    int m;
+    dungeon_feature_type f = env.grid(p);
+    if (grid_is_opaque(f))
+        return OPC_OPAQUE;
+    else if (is_opaque_cloud(env.cgrid(p)))
+        return OPC_HALF;
+    else if (f == DNGN_TREES)
+        return OPC_HALF;
+    else if ((m = mgrd(p)) != NON_MONSTER && menv[m].type == MONS_BUSH)
+        return OPC_HALF;
+    else
+        return OPC_CLEAR;
+}
+
+bool bounds_los_radius(const coord_def& p)
+{
+    return (p.abs() <= get_los_radius_squared());
+}
 
 /* los_param_trans */
 
diff --git a/crawl-ref/source/losparam.h b/crawl-ref/source/losparam.h
index 6dfac41dde..8953c1883e 100644
--- a/crawl-ref/source/losparam.h
+++ b/crawl-ref/source/losparam.h
@@ -15,6 +15,12 @@ enum opacity_type
     NUM_OPACITIES
 };
 
+typedef opacity_type (*opacity_func)(const coord_def&);
+typedef bool (*bounds_func)(const coord_def&);
+
+opacity_type opc_default(const coord_def&);
+bool bounds_los_radius(const coord_def& p);
+
 // Subclasses of this are passed to losight() to modify the
 // LOS calculation. Implementations will have to translate between
 // relative coordinates (-8,-8)..(8,8) and real coordinates,