Descent 2, but not Descent 1, had a useless test in render_side:
type == QUAD ? 0 :
type == TRI_13 ? 1 :
0
This is useless since, if type is not QUAD, the second expression will
apply. If type is QUAD, then the type is not TRI_13, so the second
expression would choose the same result as the first. The extra
comparison does not save any work, so it is useless. Remove it.
Previously, valptridx used PREFIX for allow-invalid+mutable, c#PREFIX
for allow-invalid+const, v#PREFIX for require-valid+mutable, vc#PREFIX
for require-valid+const. Convert the types, factories, and all usage
sites to specify a qualifier for all four combinations:
im#PREFIX -> allow-invalid+mutable
ic#PREFIX -> allow-invalid+const
vm#PREFIX -> require-valid+mutable
vc#PREFIX -> require-valid+const
Changes to common/include/valptridx.h and common/include/fwd-valptridx.h
are manual. All other changes are generated by:
git grep -lz -e '\(obj\|seg\|clwall\|wall\|actdoor\|trg\)\(ptridx\|ptr\|idx\)\(_t\)\?\>' | xargs -0 sed -i -e 's/\<\(v\?\)\(\(obj\|seg\|clwall\|wall\|actdoor\|trg\)\(ptridx\|ptr\|idx\)\(_t\)\?\)\>/\1m\2/g'
for the 'm' prefix and:
git grep -lz -e '\(obj\|seg\|clwall\|wall\|actdoor\|trg\)\(ptridx\|ptr\|idx\)\(_t\)\?\>' | xargs -0 sed -i -e 's/\<\([cm]\(obj\|seg\|clwall\|wall\|actdoor\|trg\)\(ptridx\|ptr\|idx\)\(_t\)\?\)\>/i&/g'
for the 'i' prefix.
clang becomes confused trying to determine which vm_distance_squared
constructor to use for a literal input of 0x7fffffffffffffff, even
though the size of the input requires it to be `long` and only one
constructor can take a `long`. Switch from an explicit
0x7fffffffffffffff to the symbolic constant INT64_MAX, which has the
same value, but a platform-appropriate suffix to force the compiler to
pick the right type.
For general clarity, switch some other instances of integer maximum
literals to symbolic constants of the same value.
This commit has no effect on the generated code (except for changes to
line numbers).
Reported-by: kreatordxx <https://github.com/dxx-rebirth/dxx-rebirth/pull/324>
Fixes: 17208cca79 ("Disallow int for vm_distance_squared")
GCC 6 `std::sort` sometimes compares an element to itself. For a normal
implementation of comparison, this is useless, but not harmful. The
render comparison predicate relies on accessing A[B[a][b]] when
comparing `a` and `b`. Array `B` has `-1` in positions where `a == b`,
which causes an access to `A[-1]`, which is undefined behavior. This
crashes when using _GLIBCXX_DEBUG:
Error: attempt to subscript container with out-of-bounds index -1, but
container only holds 8 elements.
Objects involved in the operation:
sequence "this" @ 0x0x335adf0 {
type = std::__debug::array<int, 8ul>::_Array_check_subscript<8ul>;
}
Since this is undefined behavior, non-debug builds might also misbehave.
Current data layouts make it likely that the failure would not have
externally observable consequences.
Prevent the invalid access by short-circuiting the result if `a == b`.
