R_FogFactor segfault fixed

JACoders/OpenJK@efc56dd

Author: ouned

src/game/q_shared.h

@@ -703,6 +703,8 @@ signed short ClampShort( int i );
 
 float q3powf ( float x, int y );
 
+qboolean Q_isnan(float f);
+
 // this isn't a real cheap function to call!
 int DirToByte( vec3_t dir );
 void ByteToDir( int b, vec3_t dir );

src/qcommon/q_math.cpp

@@ -2,6 +2,7 @@
 //
 // q_math.c -- stateless support routines that are included in each code module
 #include "../game/q_shared.h"
+#include <float.h>
 
 
 vec3_t	vec3_origin = {0,0,0};
@@ -546,11 +547,7 @@ float Q_rsqrt( float number )
 	y  = y * ( threehalfs - ( x2 * y * y ) );   // 1st iteration
 //	y  = y * ( threehalfs - ( x2 * y * y ) );   // 2nd iteration, this can be removed
 
-#ifndef Q3_VM
-#ifdef __linux__
-	assert( !isnan(y) ); // bk010122 - FPE?
-#endif
-#endif
+	assert(!Q_isnan(y));
 	return y;
 }
 
@@ -1036,3 +1033,11 @@ float q3powf ( float x, int y )
 		r = r * r;
 	return r;
 }
+
+qboolean Q_isnan(float f) {
+#ifdef _WIN32
+	return (qboolean)(_isnan(f) != 0);
+#else
+	return (qboolean)(isnan(f) != 0);
+#endif
+}

src/renderer/tr_shade_calc.cpp

@@ -904,8 +904,8 @@ void RB_CalcFogTexCoords( float *st ) {
 			}
 		}
 
-		st[0] = s;
-		st[1] = t;
+		st[0] = Q_isnan(s) ? 0.0f : s;
+		st[1] = Q_isnan(s) ? 0.0f : t;
 		st += 2;
 	}
 }