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Misa b8fdbe53b9 Fix loading plain font.png Unicode indexing out of bounds 
This code was introduced by Dav999 in
abf12632bb (PR #1077), but it contains a
memory error. I spotted this with Valgrind.

The problem comes from the fact that `max_codepoint` is calculated from
the width and height of the surface (which will have the same width and
height as the source `font.png` from the filesystem). Let's work through
an example using a typical 128 by 128 `font.png` and an 8 by 8 glyph.

`chars_per_line` is calculated by dividing the width of the image
(`temp_surface->w`, or 128) by `f->glyph_w` (8), yielding 16.
`max_codepoint` is calculated by first calculating the height of the
image divided by the height of the glyph - which here just happens to be
the same as `chars_per_line` (16) since we have a square `font.png` -
and then multiplying the result by `chars_per_line`. 16 times 16 is 256.

Now it is important to recognize here that this is the _amount_ of
glyphs in `font.png`. It is _not_ the last codepoint in the image. To
see why, consider the fact that codepoint 0 is contained in the image.
If we have codepoint 0, then we can't have codepoint 256, because that
would imply that we have 257 codepoints, but clearly, we don't. If we
try to read codepoint 256, then after working through the calculations
to read the glyphs, we would be trying to read from pixel columns 0
through 7 and pixel rows 128 through 135... in a 128 by 128 image...
which is clearly incorrect.

Therefore, it's incorrect to write the upper bound of the for-loop
iterating over every codepoint as `codepoint <= max_codepoint` instead
of `codepoint < max_codepoint`.
2023-12-29 11:55:09 -08:00
.github Use Android SDL2 via Maven 2023-11-14 17:18:08 -08:00
desktop_version Fix loading plain font.png Unicode indexing out of bounds 2023-12-29 11:55:09 -08:00
mobile_version add missing files to mobile_version data folder 2023-10-07 18:48:36 +01:00
third_party Update c-hashmap submodule [2023-08-02] 2023-08-12 15:52:58 -07:00
tools Adding original mapping tools for the sake of completeness 2020-01-12 19:49:24 +01:00
.gitattributes fix actionscript misclassified as angelscript 2020-01-12 15:18:45 -05:00
.gitmodules Remove utfcpp submodule 2023-02-27 23:00:41 -08:00
License exceptions.md Update my GitHub username and Ved repo link 2023-10-28 19:04:44 -07:00
LICENSE.md Updated link to Make and Play edition 2020-01-13 19:37:50 +01:00
README.md Update link to FamilyJules' 2023-09-10 11:44:53 +01:00

README.md

This is the source code to VVVVVV, version 2.0+. For more context about this release, see the announcement on Terry's blog!

License

VVVVVV's source code is made available under a custom license. See LICENSE.md for more details.

In general, if you're interested in creating something that falls outside the license terms, get in touch with Terry and we'll talk about it!

Authors

Versions

There are two versions of the VVVVVV source code available - the desktop version (based on the C++ port, and currently live on Steam), and the mobile version (based on a fork of the original flash source code, and currently live on iOS and Android).