(svn r7452) -Fix: GetRandom(Industry|Town) must return a valid industry/town and should not need to loop over the pool for a second time.
--- a/industry.h Sat Dec 09 14:14:51 2006 +0000
+++ b/industry.h Sat Dec 09 14:18:08 2006 +0000
@@ -90,6 +90,11 @@
return industry->xy != 0;
}
+static inline bool IsValidIndustryID(IndustryID index)
+{
+ return index < GetIndustryPoolSize() && IsValidIndustry(GetIndustry(index));
+}
+
VARDEF int _total_industries;
static inline IndustryID GetMaxIndustryIndex(void)
@@ -108,23 +113,23 @@
}
/**
- * Return a random valid town.
+ * Return a random valid industry.
*/
static inline Industry *GetRandomIndustry(void)
{
- uint num = RandomRange(GetNumIndustries());
- uint index = 0;
+ int num = RandomRange(GetNumIndustries());
+ IndustryID index = INVALID_INDUSTRY;
if (GetNumIndustries() == 0) return NULL;
- while (num > 0) {
+ while (num >= 0) {
num--;
-
index++;
+
/* Make sure we have a valid industry */
- while (GetIndustry(index) == NULL) {
+ while (!IsValidIndustryID(index)) {
index++;
- if (index > GetMaxIndustryIndex()) index = 0;
+ assert(index <= GetMaxIndustryIndex());
}
}
--- a/town.h Sat Dec 09 14:14:51 2006 +0000
+++ b/town.h Sat Dec 09 14:18:08 2006 +0000
@@ -6,6 +6,10 @@
#include "oldpool.h"
#include "player.h"
+enum {
+ INVALID_TOWN = 0xFFFF,
+};
+
struct Town {
TileIndex xy;
@@ -162,6 +166,11 @@
return town->xy != 0;
}
+static inline bool IsValidTownID(TownID index)
+{
+ return index < GetTownPoolSize() && IsValidTown(GetTown(index));
+}
+
VARDEF uint _total_towns;
static inline TownID GetMaxTownIndex(void)
@@ -184,28 +193,23 @@
*/
static inline Town *GetRandomTown(void)
{
- uint num = RandomRange(GetNumTowns());
- uint index = 0;
+ int num = RandomRange(GetNumTowns());
+ TownID index = INVALID_TOWN;
- while (num > 0) {
+ while (num >= 0) {
num--;
index++;
/* Make sure we have a valid industry */
- while (GetTown(index) == NULL) {
+ while (!IsValidTownID(index)) {
index++;
- if (index > GetMaxTownIndex()) index = 0;
+ assert(index <= GetMaxTownIndex());
}
}
return GetTown(index);
}
-static inline bool IsValidTownID(uint index)
-{
- return index < GetTownPoolSize() && IsValidTown(GetTown(index));
-}
-
void DestroyTown(Town *t);
static inline void DeleteTown(Town *t)