Implement rltiles %weight command and skewed dngn tile probabilities.

In dc-dngn.txt you can now use the %weight command to specify the
probability of a given tile whenever a variant is chosen randomly
from a set of variant tiles.

Example:
%weight 5
floor/floor_sand_stone0 FLOOR_SAND_STONE
floor/floor_sand_stone1
floor/floor_sand_stone2
floor/floor_sand_stone3
%weight 2
floor/floor_sand_stone4
floor/floor_sand_stone5
floor/floor_sand_stone7
%weight 1
floor/floor_sand_stone6

... will make plain sand more likely than the rocky versions and the
big rock rarer than the smaller ones.

This is not visible from the dngn.png but you can check the (cumulative)
weights in tiledef-dngn.cc.

Aside from the above, this is also used for the brick wall in all its
colorations. (The repeat command also repeats the weight settings.)

5 files changed, 57 insertions, 3 deletions

diff --git a/crawl-ref/source/rltiles/dc-dngn.txt b/crawl-ref/source/rltiles/dc-dngn.txt
index ef8e062e57..ed69c900b6 100644
--- a/crawl-ref/source/rltiles/dc-dngn.txt
+++ b/crawl-ref/source/rltiles/dc-dngn.txt
@@ -9,13 +9,16 @@ dngn_unseen DNGN_UNSEEN
 # Multiple tile definitions are STATIC, that is they may change between
 # saves but are otherwise fixed.
 
+%weight 5
 wall/brick_brown0 WALL_NORMAL WALL_BRICK WALL_BRICK_BROWN
 wall/brick_brown1
 wall/brick_brown2
-wall/brick_brown3
 wall/brick_brown4
 wall/brick_brown5
+%weight 2
+wall/brick_brown3
 wall/brick_brown6
+%weight 1
 wall/brick_brown7
 
 %variation WALL_BRICK blue
@@ -604,14 +607,17 @@ floor/rough_red3
 %repeat FLOOR_ROUGH FLOOR_ROUGH_WHITE
 %resetcol
 
+%weight 5
 floor/floor_sand_stone0 FLOOR_SAND_STONE
 floor/floor_sand_stone1
 floor/floor_sand_stone2
 floor/floor_sand_stone3
+%weight 2
 floor/floor_sand_stone4
 floor/floor_sand_stone5
-floor/floor_sand_stone6
 floor/floor_sand_stone7
+%weight 1
+floor/floor_sand_stone6
 
 wall/wall_yellow_rock0 WALL_YELLOW_ROCK
 wall/wall_yellow_rock1
diff --git a/crawl-ref/source/rltiles/tool/tile_list_processor.cc b/crawl-ref/source/rltiles/tool/tile_list_processor.cc
index 9a21af3c19..7138ab5408 100644
--- a/crawl-ref/source/rltiles/tool/tile_list_processor.cc
+++ b/crawl-ref/source/rltiles/tool/tile_list_processor.cc
@@ -19,7 +19,8 @@ tile_list_processor::tile_list_processor() :
     m_prefix("TILE"),
     m_start_value("0"),
     m_variation_idx(-1),
-    m_variation_col(-1)
+    m_variation_col(-1),
+    m_weight(1)
 {
 }
 
@@ -455,6 +456,20 @@ bool tile_list_processor::process_line(char *read_line, const char *list_file,
             CHECK_ARG(1);
             m_sdir = m_args[1];
         }
+        else if (strcmp(arg, "weight") == 0)
+        {
+            CHECK_ARG(1);
+            int tmp = atoi(m_args[1]);
+
+            if (tmp <= 0)
+            {
+                fprintf(stderr, "Error (%s:%d): weight must be >= 1.\n",
+                        list_file, line);
+                return (false);
+            }
+
+            m_weight = tmp;
+        }
         else if (strcmp(arg, "shrink") == 0)
         {
             CHECK_ARG(1);
@@ -592,11 +607,14 @@ bool tile_list_processor::process_line(char *read_line, const char *list_file,
 
             int cnt = m_page.m_counts[idx];
 
+            int old_w = 0;
             for (int i = 0; i < cnt; ++i)
             {
                 tile img;
                 img.copy(*m_page.m_tiles[idx + i]);
                 recolour(img);
+                m_weight = m_page.m_probs[idx + i] - old_w;
+                old_w    = m_page.m_probs[idx + i];
                 add_image(img, (i == 0 && m_args[2]) ? m_args[2] : NULL);
             }
 
@@ -690,10 +708,15 @@ void tile_list_processor::add_image(tile &img, const char *enumname)
     m_page.m_tiles.push_back(new_img);
     m_page.m_counts.push_back(1);
 
+    int weight = m_weight;
     if (enumname)
         m_last_enum = m_page.m_counts.size() - 1;
     else if (m_last_enum < m_page.m_counts.size())
+    {
         m_page.m_counts[m_last_enum]++;
+        weight += m_page.m_probs[m_page.m_probs.size() - 1];
+    }
+    m_page.m_probs.push_back(weight);
 
     if (m_categories.size() > 0)
         m_ctg_counts[m_categories.size()-1]++;
@@ -833,6 +856,11 @@ bool tile_list_processor::write_data()
         fprintf(fp, "    %s_%s_MAX\n};\n\n", m_prefix.c_str(), ucname.c_str());
 
         fprintf(fp, "int tile_%s_count(unsigned int idx);\n", lcname.c_str());
+        if (strcmp(m_name.c_str(), "dngn") == 0)
+        {
+            fprintf(fp, "int tile_%s_probs(unsigned int idx);\n",
+                    lcname.c_str());
+        }
         fprintf(fp, "const char *tile_%s_name(unsigned int idx);\n",
             lcname.c_str());
         fprintf(fp, "tile_info &tile_%s_info(unsigned int idx);\n",
@@ -898,6 +926,23 @@ bool tile_list_processor::write_data()
                 lcname.c_str(), m_start_value.c_str());
         fprintf(fp, "}\n\n");
 
+        if (strcmp(m_name.c_str(), "dngn") == 0)
+        {
+            fprintf(fp, "int _tile_%s_probs[%s - %s] =\n{\n",
+                    lcname.c_str(), max.c_str(), m_start_value.c_str());
+            for (unsigned int i = 0; i < m_page.m_probs.size(); i++)
+                fprintf(fp, "    %d,\n", m_page.m_probs[i]);
+            fprintf(fp, "};\n\n");
+
+            fprintf(fp, "int tile_%s_probs(unsigned int idx)\n{\n",
+                        lcname.c_str());
+            fprintf(fp, "    assert(idx >= %s && idx < %s);\n",
+                    m_start_value.c_str(), max.c_str());
+            fprintf(fp, "    return _tile_%s_probs[idx - %s];\n",
+                    lcname.c_str(), m_start_value.c_str());
+            fprintf(fp, "}\n\n");
+        }
+
         fprintf(fp, "const char *_tile_%s_name[%s - %s] =\n{\n",
                 lcname.c_str(), max.c_str(), m_start_value.c_str());
         for (unsigned int i = 0; i < m_page.m_tiles.size(); i++)
diff --git a/crawl-ref/source/rltiles/tool/tile_list_processor.h b/crawl-ref/source/rltiles/tool/tile_list_processor.h
index 5e95d1815b..6135d044cd 100644
--- a/crawl-ref/source/rltiles/tool/tile_list_processor.h
+++ b/crawl-ref/source/rltiles/tool/tile_list_processor.h
@@ -41,6 +41,7 @@ protected:
     tile m_compose;
     int m_variation_idx;
     int m_variation_col;
+    int m_weight;
 
     typedef std::pair<tile_colour, tile_colour> palette_entry;
     typedef std::vector<palette_entry> palette_list;
diff --git a/crawl-ref/source/rltiles/tool/tile_page.cc b/crawl-ref/source/rltiles/tool/tile_page.cc
index 3c90dcfce8..c155e16097 100644
--- a/crawl-ref/source/rltiles/tool/tile_page.cc
+++ b/crawl-ref/source/rltiles/tool/tile_page.cc
@@ -16,6 +16,7 @@ tile_page::~tile_page()
 
     m_tiles.clear();
     m_counts.clear();
+    m_probs.clear();
 }
 
 bool tile_page::place_images()
diff --git a/crawl-ref/source/rltiles/tool/tile_page.h b/crawl-ref/source/rltiles/tool/tile_page.h
index c63ae43a5a..4556281558 100644
--- a/crawl-ref/source/rltiles/tool/tile_page.h
+++ b/crawl-ref/source/rltiles/tool/tile_page.h
@@ -23,6 +23,7 @@ public:
     std::vector<unsigned int> m_counts;
     std::vector<int> m_texcoords;
     std::vector<int> m_offsets;
+    std::vector<unsigned int> m_probs;
 
 protected:
     int m_width;