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| author | Jonathan G Rennison <j.g.rennison@gmail.com> | 2018-01-17 02:34:03 +0000 |
|---|---|---|
| committer | PeterN <peter@fuzzle.org> | 2019-01-24 11:12:06 +0000 |
| commit | 0240e90169570f2ad2343c3cbbeade7886e599e9 (patch) | |
| tree | fc0e6670f6898e3adf50145eb0374ad61bfe9934 | |
| parent | db924a4681f019a6372f5192693af5aede36d080 (diff) | |
| download | openttd-0240e90169570f2ad2343c3cbbeade7886e599e9.tar.xz | |
Fix: [Blitter] Avoid signed overflow when drawing long lines
| -rw-r--r-- | src/blitter/common.hpp | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/src/blitter/common.hpp b/src/blitter/common.hpp index 0e255ca9a..9019dd359 100644 --- a/src/blitter/common.hpp +++ b/src/blitter/common.hpp @@ -50,11 +50,11 @@ void Blitter::DrawLineGeneric(int x, int y, int x2, int y2, int screen_width, in /* compute frac_diff = width * sqrt(dx*dx + dy*dy) * Start interval: * max(dx, dy) <= sqrt(dx*dx + dy*dy) <= sqrt(2) * max(dx, dy) <= 3/2 * max(dx, dy) */ - int frac_sq = width * width * (dx * dx + dy * dy); + int64 frac_sq = ((int64) width) * ((int64) width) * (((int64) dx) * ((int64) dx) + ((int64) dy) * ((int64) dy)); int frac_max = 3 * frac_diff / 2; while (frac_diff < frac_max) { int frac_test = (frac_diff + frac_max) / 2; - if (frac_test * frac_test < frac_sq) { + if (((int64) frac_test) * ((int64) frac_test) < frac_sq) { frac_diff = frac_test + 1; } else { frac_max = frac_test - 1; |