new builder functions

map_gen/shared/builders.lua

@@ -1,5 +1,4 @@
 -- helpers
-
 tau = 2 * math.pi
 deg_to_rad = tau / 360
 function degrees(angle)
@@ -7,7 +6,6 @@ function degrees(angle)
 end
 
 -- shape builders
-
 function empty_builder(x, y)
     return false
 end
@@ -170,7 +168,6 @@ function picture_builder(pic)
 end
 
 -- transforms and shape helpers
-
 function translate(builder, x_offset, y_offset)
     return function(x, y, world_x, world_y, surface)
         return builder(x - x_offset, y - y_offset, world_x, world_y, surface)
@@ -312,6 +309,17 @@ function choose(condition, true_shape, false_shape)
     end
 end
 
+function shape_or_else(shape, else_shape)
+    return function(local_x, local_y, world_x, world_y, surface)
+        local tile, entity = shape(local_x, local_y, world_x, world_y, surface)
+        if (tile) then
+            return tile, entity
+        else
+            return else_shape(local_x, local_y, world_x, world_y, surface)
+        end
+    end
+end
+
 function linear_grow(shape, size)
     local half_size = size / 2
     return function(local_x, local_y, world_x, world_y, surface)
@@ -431,7 +439,6 @@ function project_overlap(shape, size, r)
 end
 
 -- ore generation.
-
 -- builder is the shape of the ore patch.
 function resource_module_builder(builder, resource_type, amount_function)
     amount_function = amount_function or function(a, b)
@@ -463,7 +470,6 @@ function builder_with_resource(land_builder, resource_module)
 end
 
 -- pattern builders.
-
 function single_pattern_builder(shape, width, height)
     shape = shape or empty_builder
     local half_width = width / 2
@@ -545,6 +551,49 @@ function grid_pattern_builder(pattern, columns, rows, width, height)
     end
 end
 
+function grid_pattern_overlap_builder(pattern, columns, rows, width, height)
+    local half_width = width / 2
+    local half_height = height / 2
+    
+    return function(local_x, local_y, world_x, world_y, surface)
+        local local_y2 = ((local_y + half_height) % height) - half_height
+        local row_pos = math.floor(local_y / height + 0.5)
+        local row_i = row_pos % rows + 1
+        local row = pattern[row_i] or {}
+        
+        local local_x2 = ((local_x + half_width) % width) - half_width
+        local col_pos = math.floor(local_x / width + 0.5)
+        local col_i = col_pos % columns + 1
+        
+        local shape = row[col_i] or empty_builder
+        
+        local tile, entity = shape(local_x2, local_y2, world_x, world_y, surface)
+        if tile then return tile, entity end
+        
+        local col_i_left = (col_pos - 1) % columns + 1
+        shape = row[col_i_left] or empty_builder
+        tile, entity = shape(local_x2 + width, local_y2, world_x, world_y, surface)
+        if tile then return tile, entity end
+        
+        local col_i_right = (col_pos + 1) % columns + 1
+        shape = row[col_i_right] or empty_builder
+        tile, entity = shape(local_x2 - width, local_y2, world_x, world_y, surface)
+        if tile then return tile, entity end
+        
+        local row_i_up = (row_pos - 1) % rows + 1
+        local row_up = pattern[row_i_up] or {}
+        shape = row_up[col_i]
+        tile, entity = shape(local_x2, local_y2 + height, world_x, world_y, surface)
+        if tile then return tile, entity end
+        
+        local row_i_down = (row_pos + 1) % rows + 1
+        local row_down = pattern[row_i_down] or {}
+        shape = row_down[col_i]
+        tile, entity = shape(local_x2, local_y2 - height, world_x, world_y, surface)
+        if tile then return tile, entity end
+    end
+end
+
 function segment_pattern_builder(pattern)
     local count = #pattern
     
@@ -557,7 +606,6 @@ function segment_pattern_builder(pattern)
 end
 
 -- tile converters
-
 function change_tile(builder, old_tile, new_tile)
     return function(local_x, local_y, world_x, world_y, surface)
         local tile, entity = builder(local_x, local_y, world_x, world_y, surface)
@@ -624,6 +672,16 @@ function spawn_fish(builder, spawn_rate)
     end
 end
 
+function spawn_entity(builder, name)
+    return function(local_x, local_y, world_x, world_y, surface)
+        if builder(local_x, local_y, world_x, world_y, surface) then
+            return {name = name, position = {world_x, world_y}}
+        else
+            return nil
+        end
+    end
+end
+
 function apply_effect(builder, func)
     return function(local_x, local_y, world_x, world_y, surface)
         local tile, entity = builder(local_x, local_y, world_x, world_y, surface)