Quickfort blueprints can't place bridges over stairs

[nickthetinker]

Although the game allows it, Quickfort forbids bridge construction on tiles with existing stairs.
Up, Down, or otherwise.
Steps to reproduce: attempt the following two blueprints:

(start dig_bridge_test.csv)
#dig ,#,#,#,#,#,#,#,#,#
d,d,d,d,d,d,d,d,d,#
j,d,d,d,d,d,d,d,d,#
j,d,j,j,d,d,j,j,d,#
j,d,j,j,d,d,j,j,d,#
j,d,d,d,d,d,d,d,d,#
j,d,d,d,d,d,d,d,d,#
j,d,j,j,d,d,j,j,d,#
j,d,j,j,d,d,j,j,d,#
j,d,d,d,d,d,d,d,d,#
d,d,d,d,d,d,d,d,d,#
#>,#,#,#,#,#,#,#,#,#
d,d,d,d,d,d,d,d,d,#
i,d,d,d,d,d,d,d,d,#
i,d,i,i,d,d,i,i,d,#
i,d,i,i,d,d,i,i,d,#
i,d,d,d,d,d,d,d,d,#
i,d,d,d,d,d,d,d,d,#
i,d,i,i,d,d,i,i,d,#
i,d,i,i,d,d,i,i,d,#
i,d,d,d,d,d,d,d,d,#
d,d,d,d,d,d,d,d,d,#
#> ,#,#,#,#,#,#,#,#,#
d,d,d,d,d,d,d,d,d,#
u,d,d,d,d,d,d,d,d,#
u,d,u,u,d,d,u,u,d,#
u,d,u,u,d,d,u,u,d,#
u,d,d,d,d,d,d,d,d,#
u,d,d,d,d,d,d,d,d,#
u,d,u,u,d,d,u,u,d,#
u,d,u,u,d,d,u,u,d,#
u,d,d,d,d,d,d,d,d,#
d,d,d,d,d,d,d,d,d,#
#,#,#,#,#,#,#,#,#,#
(end dig_bridge_test.csv)

(start build_bridge_test.csv)
#build,#,#,#,#,#,#,#,#,#
,,,,,,,,,#
,,,,,,,,,#
,,g(2x2),,,ga(3x2),,,,#
,,,,,,,,,#
,,,,,,,,,#
,,,,,,gw(2x3),,,#
,gd(3x2),,,,,,,,#
,,,,,,,,,#
,,,,,,,,,#
,,,,,,,,,#
#>,#,#,#,#,#,#,#,#,#
,,,,,,,,,#
,,,,,,,,,#
,,g(2x2),,,ga(3x2),,,,#
,,,,,,,,,#
,,,,,,,,,#
,,,,,,gw(2x3),,,#
,gd(3x2),,,,,,,,#
,,,,,,,,,#
,,,,,,,,,#
,,,,,,,,,#
#> ,#,#,#,#,#,#,#,#,#
,,,,,,,,,#
,,,,,,,,,#
,,g(2x2),,,ga(3x2),,,,#
,,,,,,,,,#
,,,,,,,,,#
,,,,,,gw(2x3),,,#
,gd(3x2),,,,,,,,#
,,,,,,,,,#
,,,,,,,,,#
,,,,,,,,,#
#,#,#,#,#,#,#,#,#,#
(end build_bridge_test.csv)

[nickthetinker]

This issue should be under /DFHack/scripts/
Closing this and opening one there ...

[nickthetinker]

it helps to click the "close with comment button."

[nickthetinker]

issues are not enabled on /DFHack/scripts
so I reopened.

I have located the source of the issue in DFHack\scripts\internal\quickfort\build.lua

function is_valid_tile_bridge() calls is_valid_tile_has_space_or_is_ramp() which returns false for stair tiles:

tracing the logic for is_valid_tile_bridge over a stair tile my comments ***:

***first we look what kind of bridge and test the 'b' anchor points and the rest of the bridge
-- ramps are ok everywhere except under the anchor point of directional bridges
local function is_valid_tile_bridge(pos, db_entry, b)
local dir = db_entry.direction
local T_direction = df.building_bridgest.T_direction
if (dir == T_direction.Up and pos.y == b.pos.y) or
(dir == T_direction.Down and pos.y == b.pos.y+b.height-1) or
(dir == T_direction.Left and pos.x == b.pos.x) or
(dir == T_direction.Right and pos.x == b.pos.x+b.width-1) then
return is_valid_tile_has_space(pos)
end
return is_valid_tile_has_space_or_is_ramp(pos)
end

*** is_valid_tile_has_space_or_is_ramp() calls is_valid_tile_has_space() and jsut also allows ramps

local function is_valid_tile_has_space_or_is_ramp(pos)
local shape = df.tiletype.attrs[dfhack.maps.getTileType(pos)].shape
return is_valid_tile_has_space(pos) or shape == df.tiletype_shape.RAMP
end

*** it looks like the test just left out df.tiletype_shape.STAIR_UP and STAIR_UPDOWN and STAIR_DOWN)

-- essentially, anywhere you could build a construction, plus constructed floors
local function is_valid_tile_has_space(pos)
if not is_valid_tile_base(pos) then return false end
local shape = df.tiletype.attrs[dfhack.maps.getTileType(pos)].shape
return shape == df.tiletype_shape.EMPTY or
shape == df.tiletype_shape.FLOOR or
shape == df.tiletype_shape.BOULDER or
shape == df.tiletype_shape.PEBBLES or
shape == df.tiletype_shape.RAMP_TOP or
shape == df.tiletype_shape.BROOK_TOP or
shape == df.tiletype_shape.TWIG or
shape == df.tiletype_shape.SAPLING or
shape == df.tiletype_shape.SHRUB
end

*** is_valid_tile_base seems to just check for occupancy and flooding

I'm going to do some in game testing for legal placement, try and hack my changes into my local copy of "C:\Program Files (x86)\Steam\steamapps\common\Dwarf Fortress\hack\scripts\internal\quickfort\build.lua", test that out, and then make a recommendation.

[nickthetinker]

testing changes in bold italic...

local function is_valid_tile_bridge(pos, db_entry, b)
local dir = db_entry.direction
local T_direction = df.building_bridgest.T_direction
if (dir == T_direction.Up and pos.y == b.pos.y) or
(dir == T_direction.Down and pos.y == b.pos.y+b.height-1) or
(dir == T_direction.Left and pos.x == b.pos.x) or
(dir == T_direction.Right and pos.x == b.pos.x+b.width-1) then
return is_valid_tile_has_space(pos)
end
return is_valid_tile_has_space_or_is_ramp(pos)
return is_valid_tile_machine(pos)
end

[nickthetinker]

Preliminary test looks good.
I'm under a tornado warning so I'll test it thoroughly later

[nickthetinker]

Testing the above I encountered another limitation for hatches, grates, bars.
These constructions & furniture do not require an orthagonal floor, just a place to stand and an orthagonal supporting structure, like a stair or wall.
My change for that code is below.
I intend to do some more testing before submitting a pull req.

-- for floor hatches, grates, and bars
local function is_tile_coverable(pos)
local shape = df.tiletype.attrs[dfhack.maps.getTileType(pos)].shape
if not is_valid_tile_base(pos) or
(shape ~= df.tiletype_shape.FLOOR and
shape ~= df.tiletype_shape.EMPTY and
shape ~= df.tiletype_shape.RAMP_TOP and
shape ~= df.tiletype_shape.STAIR_UP and
shape ~= df.tiletype_shape.STAIR_UPDOWN and
shape ~= df.tiletype_shape.STAIR_DOWN) then
return false
end
return is_tile_floor_adjacent(pos)
return true
end

[nickthetinker]

changes made to my fork https://github.com/nickthetinker/scripts/blob/master/internal/quickfort/build.lua

[nickthetinker]

Pull request posted.
Update build.lua #1332