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* grid.c: allocate face/edge/dot arrays incrementally.Simon Tatham2023-07-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Previously, the 'faces', 'edges' and 'dots' arrays in a grid structure were arrays of actual grid_face, grid_edge and grid_dot structures, physically containing all the data about the grid. But they also referred to each other by pointers, which meant that they were hard to realloc larger (you'd have to go through and rewrite all the pointers whenever the base of an array moved). And _that_ meant that every grid type had to figure out a reasonably good upper bound on the number of all those things it was going to need, so that it could allocate those arrays the right size to begin with, and not have to grow them painfully later. For some grid types - particularly the new aperiodic ones - that was actually a painful part of the job. So I think enough is enough: counting up how much memory you're going to need before using it is a mug's game, and we should instead realloc on the fly. So now g->faces, g->edges and g->dots have an extra level of indirection. Instead of being arrays of actual structs, they're arrays of pointers, and each struct in them is individually allocated. Once a grid_face has been allocated, it never moves again, even if the array of pointers changes size. The old code had a common idiom of recovering the array index of a particular element by subtracting it from the array base, e.g. writing 'f - g->faces' or 'e - g->edges'. To make that lookup remain possible, I've added an 'index' field to each sub-structure, which is initialised at the point where we decide what array index it will live at. This should involve no functional change, but the code that previously had to figure out max_faces and max_dots up front for each grid type is now completely gone, and nobody has to solve those problems in advance any more.
* Fall back to <math.h> if <tgmath.h> doesn't work.Simon Tatham2023-04-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This fixes a build failure introduced by commit 2e48ce132e011e8 yesterday. When I saw that commit I expected the most likely problem would be in the NestedVM build, which is currently the thing with the most most out-of-date C implementation. And indeed the NestedVM toolchain doesn't have <tgmath.h> - but much more surprisingly, our _Windows_ builds failed too, with a compile error inside <tgmath.h> itself! I haven't looked closely into the problem yet. Our Windows builds are done with clang, which comes with its own <tgmath.h> superseding the standard Windows one. So you'd _hope_ that clang could make sense of its own header! But perhaps the problem is that this is an unusual compile mode and hasn't been tested. My fix is to simply add a cmake check for <tgmath.h> - which doesn't just check the file's existence, it actually tries compiling a file that #includes it, so it will detect 'file exists but is mysteriously broken' just as easily as 'not there at all'. So this makes the builds start working again, precisely on Ben's theory of opportunistically using <tgmath.h> where possible and falling back to <math.h> otherwise. It looks ugly, though! I'm half tempted to make a new header file whose job is to include a standard set of system headers, just so that that nasty #ifdef doesn't have to sit at the top of almost all the source files. But for the moment this at least gets the build working again.
* Replace <math.h> with <tgmath.h> throughoutBen Harris2023-04-04
| | | | | | | | | | | | | | | C89 provided only double-precision mathematical functions (sin() etc), and so despite using single-precision elsewhere, those are what Puzzles has traditionally used. C99 introduced single-precision equivalents (sinf() etc), and I hope it's been long enough that we can safely use them. Maybe they'll even be faster. Rather than directly use the single-precision functions, though, we use the magic macros from <tgmath.h> that automatically choose the precision of mathematical functions based on their arguments. This has the advantage that we only need to change which header we include, and thus that we can switch back again if some platform has trouble with the new header.
* Use C99 bool within source modules.Simon Tatham2018-11-13
| | | | | | | | | | 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.
* Replace TRUE/FALSE with C99 true/false throughout.Simon Tatham2018-11-13
| | | | | | 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.
* New puzzle! Or rather, new-ish, because this one has been lying aroundSimon Tatham2012-01-22
in the 'unfinished' directory for a while, and has now been finished up thanks to James Harvey putting in some effort and galvanising me to put in the rest. This is 'Pearl', an implementation of Nikoli's 'Masyu'. The code in Loopy that generates a random loop along grid edges to use as the puzzle solution has been abstracted out into loopgen.[ch] so that Pearl can use it for its puzzle solutions too. I've also introduced a new utility module called 'tdq' (for 'to-do queue'). [originally from svn r9379]