engine: fix assertion failure with overlong walls in rintersect().

git-svn-id: https://svn.eduke32.com/eduke32@3605 1a8010ca-5511-0410-912e-c29ae57300e0
This commit is contained in:
helixhorned 2013-03-24 18:55:40 +00:00
parent 8d2a60ff70
commit a101698dfb

View file

@ -8151,24 +8151,26 @@ static int32_t rintersect(int32_t x1, int32_t y1, int32_t z1,
int32_t *intx, int32_t *inty, int32_t *intz) int32_t *intx, int32_t *inty, int32_t *intz)
{ {
//p1 towards p2 is a ray //p1 towards p2 is a ray
int64_t x34, y34, x31, y31, bot, topt, topu, t; int64_t topt, topu, t;
const int64_t vx=vx_, vy=vy_; const int64_t vx=vx_, vy=vy_;
const int64_t x34=x3-x4, y34=y3-y4;
const int64_t bot = vx*y34 - vy*x34;
if (bot == 0)
return -1;
x34 = x3-x4; y34 = y3-y4;
bot = vx*y34 - vy*x34;
if (bot >= 0) if (bot >= 0)
{ {
if (bot == 0) return -1; int64_t x31=x3-x1, y31 = y3-y1;
x31 = x3-x1; y31 = y3-y1;
topt = x31*y34 - y31*x34; if (topt < 0) return -1; topt = x31*y34 - y31*x34; if (topt < 0) return -1;
topu = vx*y31 - vy*x31; if ((topu < 0) || (topu >= bot)) return -1; topu = vx*y31 - vy*x31; if (topu < 0 || topu >= bot) return -1;
} }
else else
{ {
x31 = x3-x1; y31 = y3-y1; int32_t x31=x3-x1, y31=y3-y1;
topt = x31*y34 - y31*x34; if (topt > 0) return -1; topt = x31*y34 - y31*x34; if (topt > 0) return -1;
topu = vx*y31 - vy*x31; if ((topu > 0) || (topu <= bot)) return -1; topu = vx*y31 - vy*x31; if (topu > 0 || topu <= bot) return -1;
} }
t = (topt<<16)/bot; t = (topt<<16)/bot;
@ -8176,7 +8178,7 @@ static int32_t rintersect(int32_t x1, int32_t y1, int32_t z1,
*inty = y1 + ((vy*t)>>16); *inty = y1 + ((vy*t)>>16);
*intz = z1 + ((vz*t)>>16); *intz = z1 + ((vz*t)>>16);
t = divscale16(topu, bot); t = (topu<<16)/bot;
Bassert((unsigned)t < 65536); Bassert((unsigned)t < 65536);
return t; return t;