116 lines
3.1 KiB
Lua
116 lines
3.1 KiB
Lua
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local function check_condition(key, value, mapblock_pos, building_def)
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local condition = building_lib.conditions[key]
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if condition and type(condition.can_build) == "function" then
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return condition.can_build(mapblock_pos, building_def, value)
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end
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return true
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end
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local function check_map(mode, map, mapblock_pos, building_def)
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local placement_allowed = false
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local error_msg
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for key, value in pairs(map) do
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local success, msg = check_condition(key, value, mapblock_pos, building_def)
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if success then
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-- success
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placement_allowed = true
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elseif mode == "and" then
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-- failure and in AND mode, return immediately
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return false, msg or "condition failed: '" .. key .. "'"
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else
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error_msg = msg or "condition failed: '" .. key .. "'"
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end
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end
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return placement_allowed, error_msg
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end
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function building_lib.check_conditions(mapblock_pos, conditions, building_def)
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-- go through conditions
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if conditions then
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-- array-like AND/OR def support
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if conditions[1] then
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-- OR'ed array
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local placement_allowed = false
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local error_msg
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for _, entry in ipairs(conditions) do
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local success, msg = check_map("and", entry, mapblock_pos, building_def)
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if success then
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placement_allowed = true
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break
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else
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error_msg = msg
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end
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end
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if not placement_allowed then
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return false, error_msg or "<unknown>"
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end
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else
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-- map
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local success, error_msg = check_map("or", conditions, mapblock_pos, building_def)
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if not success then
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return false, error_msg or "<unknown>"
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end
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end
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end
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return true
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end
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local function check_free(mapblock_pos)
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if building_lib.get_building_at_pos(mapblock_pos) then
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return false
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else
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return true
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end
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end
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function building_lib.can_build(mapblock_pos, building_def)
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-- check placement definition
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local placement = building_lib.placements[building_def.placement]
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local success, message = placement.check(placement, mapblock_pos, building_def)
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if not success then
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return false, message or "placement check '" .. building_def.placement .. "' failed"
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end
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-- check the conditions on every mapblock the building would occupy
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local size
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size, message = placement.get_size(placement, mapblock_pos, building_def)
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if not size then
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return false, message or "size check '" .. building_def.placement .. "' failed"
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end
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for x=mapblock_pos.x, mapblock_pos.x+size.x-1 do
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for z=mapblock_pos.z, mapblock_pos.z+size.z-1 do
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for y=mapblock_pos.y, mapblock_pos.y+size.y-1 do
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local offset_mapblock_pos = {x=x, y=y, z=z}
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local is_free = check_free(offset_mapblock_pos)
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if not is_free then
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return false, "Space already occupied at " .. minetest.pos_to_string(offset_mapblock_pos)
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end
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if y == mapblock_pos.y then
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-- check ground conditions
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success, message = building_lib.check_conditions(offset_mapblock_pos, building_def.ground_conditions, building_def)
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if not success then
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return false, message
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end
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end
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success, message = building_lib.check_conditions(offset_mapblock_pos, building_def.conditions, building_def)
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if not success then
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return false, message
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end
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end
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end
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end
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-- all checks ok
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return true
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end
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