[MIRROR] Better Viro (#9421)

Co-authored-by: Guti <32563288+TheCaramelion@users.noreply.github.com>
Co-authored-by: Kashargul <144968721+Kashargul@users.noreply.github.com>

code/__defines/diseases.dm

@@ -0,0 +1,30 @@
+#define VIRUS_SYMPTOM_LIMIT	6
+
+//Visibility Flags
+#define HIDDEN_SCANNER	(1<<0)
+#define HIDDEN_PANDEMIC	(1<<1)
+
+//Disease Flags
+#define CURABLE		(1<<0)
+#define CAN_CARRY	(1<<1)
+#define CAN_RESIST	(1<<2)
+
+//Spread Flags
+#define SPECIAL			(1<<0)
+#define NON_CONTAGIOUS	(1<<1)
+#define BLOOD			(1<<2)
+#define CONTACT_FEET	(1<<3)
+#define CONTACT_HANDS	(1<<4)
+#define CONTACT_GENERAL	(1<<5)
+#define AIRBORNE		(1<<6)
+
+
+//Severity Defines
+#define NONTHREAT	"No threat"
+#define MINOR		"Minor"
+#define MEDIUM		"Medium"
+#define HARMFUL		"Harmful"
+#define DANGEROUS 	"Dangerous!"
+#define BIOHAZARD	"BIOHAZARD THREAT!"
+
+#define SYMPTOM_ACTIVATION_PROB 3

code/__defines/math.dm

@@ -222,3 +222,9 @@
 #define ROUNDUPTOPOWEROFTWO(x) (2 ** -round(-log(2,x)))
 
 #define DEFAULT(a, b) (a? a : b)
+
+// sqrt, but if you give it a negative number, you get 0 instead of a runtime
+/proc/sqrtor0(num)
+	if(num < 0)
+		return 0
+	return sqrt(num)