From d4f2d24921614003359ef9d6e1c877e618d766fd Mon Sep 17 00:00:00 2001 From: Monster Iestyn Date: Sat, 10 Oct 2015 21:21:16 +0100 Subject: [PATCH] Fix up lib_finetangent so tan() returns values starting from "0" in Lua (finetangent itself hasn't been touched) Also fixed how the function went out of the array's bounds for ANGLE_180 and above (or negative angles) --- src/lua_mathlib.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/src/lua_mathlib.c b/src/lua_mathlib.c index 8ca2e17af..f4b5ca5fe 100644 --- a/src/lua_mathlib.c +++ b/src/lua_mathlib.c @@ -77,7 +77,9 @@ static int lib_finecosine(lua_State *L) static int lib_finetangent(lua_State *L) { - lua_pushfixed(L, FINETANGENT((luaL_checkangle(L, 1)>>ANGLETOFINESHIFT) & FINEMASK)); + // HACK: add ANGLE_90 to make tan() in Lua start at 0 like it should + // use & 4095 instead of & FINEMASK (8191), so it doesn't go out of the array's bounds + lua_pushfixed(L, FINETANGENT(((luaL_checkangle(L, 1)+ANGLE_90)>>ANGLETOFINESHIFT) & 4095)); return 1; }