Tracks allowed moves in execute_move() that shouldn't have been allowed,
like changing the state of the edges of the board. This moves couldn't
be generated by interpret_move(), but could be loaded from a save file.
Now execute_move() uses the same ui_can_flip_*() functions as
interpret_move() to decide whether a particular move is allowed. This
should prevent some assertion failures when loading corrupted save
files.
Simon points out that if you have an ambiguous puzzle then it might
need different flash data for different solutions, so if you solve it
one way, than manually unsolve it and solve it another way, the old
flash data in the game state need to be cleared out when the new flash
data are written.
Tested by solving the hugely ambiguous "5x5:CwC,5,5,5,5,S5,S5,5,5,5,5".
COL_GRID used to be mid-way between the usual COL_BACKGROUND and
COL_TRACK_BACKGROUND. But then I changed mkhighlight() so that it
didn't make COL_BACKGROUND so dark and that made the grid lines
indistinguishable from the track background.
Now COL_GRID is generated from COL_BACKGROUND and COL_TRACK_BACKGROUND
so as long as those are sufficiently distinct from each other, COL_GRID
will be distinct from both of them.
Normally, Tracks puts error marks on row and column clues only when one
of the existing track or no-track marks will have to be removed to
satisfy the clue. This could lead to a situation where the player had
built a track from A to B and got neither a win nor a highlighted error
because the only error was in a row or column having too few track
segments.
This commit re-arranges the completion checking so that if there's a
complete track from A to B and no spurious track then the game will
highlight any clue that isn't matched by the actually laid track. This
should mean that any solution with a track from A to B will either be a
win or have a highlighted error.
This should fix Android issue #266.
This means that Range, Singles, and Tracks can now use the default
background colour even if it's close to white. In the case of Singles
I've left a dummy entry in the colour list so as not to renumber the
rest and break everyone's environment variables. If Singles ever needs
a new colour it can re-use that slot.
This provides a way for the front end to ask how a particular key should
be labelled right now (specifically, for a given game_state and
game_ui). This is useful on feature phones where it's conventional to
put a small caption above each soft key indicating what it currently
does.
The function currently provides labels only for CURSOR_SELECT and
CURSOR_SELECT2. This is because these are the only keys that need
labelling on KaiOS.
The concept of labelling keys also turns up in the request_keys() call,
but there are quite a few differences. The labels returned by
current_key_label() are dynamic and likely to vary with each move, while
the labels provided by request_keys() are constant for a given
game_params. Also, the keys returned by request_keys() don't generally
include CURSOR_SELECT and CURSOR_SELECT2, because those aren't necessary
on platforms with pointing devices. It might be possible to provide a
unified API covering both of this, but I think it would be quite
difficult to work with.
Where a key is to be unlabelled, current_key_label() is expected to
return an empty string. This leaves open the possibility of NULL
indicating a fallback to button2label or the label specified by
request_keys() in the future.
It's tempting to try to implement current_key_label() by calling
interpret_move() and parsing its output. This doesn't work for two
reasons. One is that interpret_move() is entitled to modify the
game_ui, and there isn't really a practical way to back those changes
out. The other is that the information returned by interpret_move()
isn't sufficient to generate a label. For instance, in many puzzles it
generates moves that toggle the state of a square, but we want the label
to reflect which state the square will be toggled to. The result is
that I've generally ended up pulling bits of code from interpret_move()
and execute_move() together to implement current_key_label().
Alongside the back-end function, there's a midend_current_key_label()
that's a thin wrapper around the back-end function. It just adds an
assertion about which key's being requested and a default null
implementation so that back-ends can avoid defining the function if it
will do nothing useful.
The basic tile size in Tracks is required to be a multiple of 6, which
means that for small tile sizes the steps are rather large. With the
standard border widths, this means that the default 8-by-8 puzzle can be
246 pixels wide (tilesize == 24) or 184 pixels wide (tilesize == 18).
This is particularly annoying if you happen to have a 240-pixel-wide
screen.
This commit allows the puzzle to reduce or remove the borders at small
tile sizes, on the grounds that a slightly narrower border is acceptable
if it avoids needing to use a smaller tile size. It encodes the border
width in (tilesize % 6), and is thus enabled when the default border
width is 5 or less. Above that size (which is a tilesize of 48), I
assume the steps in tile size aren't big enough to be a serious problem.
The former grey was almost indistinguishable from its background colours
even on a good screen. I've separated the cursor colour from the grid
colour and made it a lot darker. This gives a contrast ratio over 3.0
even against a darkened tile.
The cursor is still hard to see against trackwork, so maybe something
that isn't grey would be even better.
I don't know how I've never thought of this before! Pretty much every
game in this collection has to have a mechanism for noticing when
game_redraw is called for the first time on a new drawstate, and if
so, start by covering the whole window with a filled rectangle of the
background colour. This is a pain for implementers, and also awkward
because the drawstate often has to _work out_ its own pixel size (or
else remember it from when its size method was called).
The backends all do that so that the frontends don't have to guarantee
anything about the initial window contents. But that's a silly
tradeoff to begin with (there are way more backends than frontends, so
this _adds_ work rather than saving it), and also, in this code base
there's a standard way to handle things you don't want to have to do
in every backend _or_ every frontend: do them just once in the midend!
So now that rectangle-drawing operation happens in midend_redraw, and
I've been able to remove it from almost every puzzle. (A couple of
puzzles have other approaches: Slant didn't have a rectangle-draw
because it handles even the game borders using its per-tile redraw
function, and Untangle clears the whole window on every redraw
_anyway_ because it would just be too confusing not to.)
In some cases I've also been able to remove the 'started' flag from
the drawstate. But in many cases that has to stay because it also
triggers drawing of static display furniture other than the
background.
The Rockbox frontend allows games to be displayed in a "zoomed-in"
state targets with small displays. Currently we use a modal interface
-- a "viewing" mode in which the cursor keys are used to pan around
the rendered bitmap; and an "interaction" mode that actually sends
keys to the game.
This commit adds a midend_get_cursor_location() function to allow the
frontend to retrieve the backend's cursor location or other "region of
interest" -- such as the player location in Cube or Inertia.
With this information, the Rockbox frontend can now intelligently
follow the cursor around in the zoomed-in state, eliminating the need
for a modal interface.
This is the contrapositive of the deduction introduced in the previous
commit. Previously I said: a square A can have some edges blocked in
such a way that you know it can't be filled without a particular one
of its neighbours B also being filled. And then, if you know the row
containing A and B only has one filled square left to find, then it
can't be A.
This commit adds the obvious followup: if you know the row only has
one _empty_ square left, then for the same reason, it can't be B!
I'm putting this in at the new Hard difficulty, mostly out of
guesswork rather than rigorous play-testing, because I don't remember
ever having _observed_ myself making this deduction in the past. I'm
open to changing the settings if someone has a good argument for it.
This is another deduction I've known about in principle for ages but
the game didn't implement.
In the simplest case, it's obvious: if you can draw a line across the
grid that separates the track endpoints from each other, and the track
doesn't yet cross that line at all, then it's going to have to cross
it at _some_ point. So when you've narrowed down to only one possible
crossing place, you can fill it in as definite.
IF the track already crosses your line and goes back again, the same
rule still applies: _some_ part of your track is on one side of the
line, and needs to get to the other. A more sensible way of expressing
this is to say that the track must cross the boundary an _odd_ number
of times if the two endpoints are on opposite sides of it.
And conversely, if you've drawn a line across the grid that both
endpoints are on the _same_ side of, then the track must cross it an
_even_ number of times - every time it goes to the 'wrong' side (where
the endpoints aren't), it will have to come back again eventually.
But this doesn't just apply to a _line_ across the grid. You can pick
any subset you like of the squares of the grid, and imagine the closed
loop bounding that subset as your 'line'. (Or the _set_ of closed
loops, in the most general case, because your subset doesn't _have_ to
be simply connected - or even connected at all - to make this argument
valid.) If your boundary is a closed loop, then both endpoints are
always on the same side of that boundary - namely, the outside - and
so the track has to cross the boundary an even number of times. So any
time you can identify such a subset in which all but one boundary edge
is already filled in, you can fill in the last one by parity.
(This most general boundary-based system takes in all the previous
cases as special cases. In the original case where it looks as if you
need odd parity for a line across the grid separating the endpoints,
what you're really doing is drawing a closed loop around one half of
the grid, and considering the actual endpoint itself to be the place
where the track leaves that region again - so, looked at that way, the
parity is back to even.)
The tricky part of implementing this is to avoid having to iterate
over all subsets of the grid looking for one whose boundary has the
right property. Luckily, we don't have to: a nice way to look at it is
to define a graph whose vertices are grid squares, with neighbouring
squares joined by a _graph_ edge if the _grid_ edge between those
squares is not yet in a known state. Then we're looking for an edge of
that graph which if removed would break it up into more separate
components than it's already in. That is, we want a _bridge_ in the
graph - which we can find all of in linear time using Tarjan's
bridge-finding algorithm, conveniently implemented already in this
collection in findloop.c.
Having found a bridge edge of that graph, you imagine removing it, and
find one of the two connected components it's just broken its previous
component up into. That's your subset of grid squares, and now you can
count track crossings around the boundary and fill in the bridge edge
by parity.
When I actually came to implement this, it turned out that the very
first puzzle it generated was actually hard for me to solve, because
as it turns out, this general analysis is much better at identifying
opportunities to use this deduction than I am. A straight line right
across the grid is often obvious: a few squares tucked into a
complicated half-solved piece of the worldl, not so much. So I'm
introducing a new Hard difficulty level, and putting this solution
technique in there.
This is a deduction I've been using in my own head for years: if you
only have one remaining filled square to put in a row, then it can't
be any square that has two adjacent edges blocked, because if that
square contains anything at all then it would have to be a corner
piece, and a corner piece forces the square next to it to be filled as
well.
I ran across a puzzle today that this implementation couldn't solve,
but I solved it fine by hand and found the deduction I was using that
wasn't implemented here. Now it is.
Having one of these makes it much easier to debug what's going on when
the solver can't solve something. Also, now the solver can grade the
difficulty of a puzzle, it's useful to expose that feature in a
command-line tool.
This should speed up game generation, because now we don't have to run
the solver _twice_ whenever we want to check that the grid has exactly
the intended difficulty. Instead, we can just run it once and check
the max_diff output.
Another thing I spotted while trawling the whole source base was that
a couple of games had omitted 'static' on a lot of their internal
functions. Checking with nm, there turned out to be quite a few more
than I'd spotted by eye, so this should fix them all.
Also added one missing 'const', on the lookup table nbits[] in Tracks.
This is the main bulk of this boolification work, but although it's
making the largest actual change, it should also be the least
disruptive to anyone interacting with this code base downstream of me,
because it doesn't modify any interface between modules: all the
inter-module APIs were updated one by one in the previous commits.
This just cleans up the code within each individual source file to use
bool in place of int where I think that makes things clearer.
This commit removes the old #defines of TRUE and FALSE from puzzles.h,
and does a mechanical search-and-replace throughout the code to
replace them with the C99 standard lowercase spellings.
encode_params, validate_params and new_desc now take a bool parameter;
fetch_preset, can_format_as_text_now and timing_state all return bool;
and the data fields is_timed, wants_statusbar and can_* are all bool.
All of those were previously typed as int, but semantically boolean.
This commit changes the API declarations in puzzles.h, updates all the
games to match (including the unfinisheds), and updates the developer
docs as well.
This function gives the front end a way to find out what keys the back
end requires; and as such it is mostly useful for ports without a
keyboard. It is based on changes originally found in Chris Boyle's
Android port, though some modifications were needed to make it more
flexible.
This allows me to use different types for the mutable, dynamically
allocated string value in a C_STRING control and the fixed constant
list of option names in a C_CHOICES.
Now midend.c directly tests the returned pointer for equality to this
value, instead of checking whether it's the empty string.
A minor effect of this is that games may now return a dynamically
allocated empty string from interpret_move() and treat it as just
another legal move description. But I don't expect anyone to be
perverse enough to actually do that! The main purpose is that it
avoids returning a string literal from a function whose return type is
a pointer to _non-const_ char, i.e. we are now one step closer to
being able to make this code base clean under -Wwrite-strings.
This makes it much easier to see the commonality in these formulaic
lines.
Whitespace change only.
Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>
Since these lines are always orthogonal, it's easier to draw them
using draw_rect than draw_thick_line.
Previously, the grid lines were drawn just inside the top and left
edges of the region redrawn by draw_square(), so only the bottom and
right edges of the whole grid were not covered by any draw_square
call. To avoid having to shift the logical grid centre, I'm now
drawing parts of the grid outline on all four sides of the
draw_square() region, so that half the thickened grid edge protrudes
on every side of the grid as a whole.
In the process of splitting up the grid line width into the part on
the top and left edges and the part on the bottom and right, I've
renamed the confusingly named BORDER_WIDTH define (which wasn't used
anyway) to a set of things that make it clear that they're referring
to the grid lines as opposed to the border of the whole puzzle.
The default of 1/30 is rather thin, and probably wasn't chosen
deliberately (since it was just inherited from the default 1-pixel
line width, and the preferred tile size).
Thicker crosses stand out more and make play easier.
Use 1/16 since it's a rounder number than 1/15 :-).
Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>
Simply replace the calls to draw_line with calls to draw_thick_line.
We need to choose a thickness parameter. The preferred tile size is
30, and the "draw_line" function draws a 1-pixel line, so the
thickness right now is 1/30 the tile size, at the preferred size.
Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>
To do this, I've completely replaced the API between mid-end and front
end, so any downstream front end maintainers will have to do some
rewriting of their own (sorry). I've done the necessary work in all
five of the front ends I keep in-tree here - Windows, GTK, OS X,
Javascript/Emscripten, and Java/NestedVM - and I've done it in various
different styles (as each front end found most convenient), so that
should provide a variety of sample code to show downstreams how, if
they should need it.
I've left in the old puzzle back-end API function to return a flat
list of presets, so for the moment, all the puzzle backends are
unchanged apart from an extra null pointer appearing in their
top-level game structure. In a future commit I'll actually use the new
feature in a puzzle; perhaps in the further future it might make sense
to migrate all the puzzles to the new API and stop providing back ends
with two alternative ways of doing things, but this seemed like enough
upheaval for one day.
Fix errors pointed out by clang
error: logical not is only applied to the left hand side of this bitwise operator [-Werror,-Wlogical-not-parentheses]
| if (only_immutable && !copy->flags[i] & FLAG_IMMUTABLE) continue;
| ^
Signed-off-by: Khem Raj <raj.khem@gmail.com>
A user pointed out that Tracks could sometimes flash for completion
when there wasn't even a full path from A to B! And it looks as if
that wasn't even a mistake I introduced with the loop-checking revamp
this week.
Now I _think_ it's complete: we set ret=FALSE in check_completion
wherever we also produce an error highlight, and also whenever there
is no path connecting A with B. And if there is a path connecting A
with B, then any square not on the path becomes an error highlight.
If you had a single connected path linking the source to the
destination but _also_ had a spurious edge elsewhere in the grid, then
the spurious edge would be highlighted as an error, but it wouldn't
inhibit declaring the game complete and showing the victory flash.
Tracks's previous loop detector was very basic, and only bothered to
highlight one loop, even if the player managed to create more than one
at a time. Now we highlight all of them.
Commit 44e2690ab loosened check_completion's idea of what made a
square count as 'having track in it' for purposes of checking
violations of the row/column counts. Unfortunately, that loosened
notion also applied to the check for the game being complete - so the
game would announce a win as soon as you had every square shaded, even
if you hadn't actually laid all the exact track positions down.
Now we separately count up the number of track-ish squares and the
number of fully completed ones, and use the former for error checking
and the latter for completion checking.
- Count any square as having a track either if the square is marked
as such (rendered as a different background), or if at least one
adjacent edge is marked as containing a segment of train track
(rendered as train tracks if they're placed, else as an '=').
- Do the same counting in rows and columns.
