Some constants in wild_encounter.c, document Feebas spot generation

1 files changed, 80 insertions, 57 deletions

diff --git a/src/wild_encounter.c b/src/wild_encounter.c
index 32316c119..5d7425762 100644
--- a/src/wild_encounter.c
+++ b/src/wild_encounter.c
@@ -25,9 +25,27 @@
 
 extern const u8 EventScript_RepelWoreOff[];
 
-#define NUM_FEEBAS_SPOTS    6
+#define MAX_ENCOUNTER_RATE 2880
+
+#define NUM_FEEBAS_SPOTS 6
+
+// Number of accessible fishing spots in each section of Route 119
+// Each section is an area of the route between the y coordinates in sRoute119WaterTileData
+#define NUM_FISHING_SPOTS_1 131
+#define NUM_FISHING_SPOTS_2 167
+#define NUM_FISHING_SPOTS_3 149
+#define NUM_FISHING_SPOTS (NUM_FISHING_SPOTS_1 + NUM_FISHING_SPOTS_2 + NUM_FISHING_SPOTS_3)
+
+enum {
+    WILD_AREA_LAND,
+    WILD_AREA_WATER,
+    WILD_AREA_ROCKS,
+    WILD_AREA_FISHING,
+};
+
+#define WILD_CHECK_REPEL    (1 << 0)
+#define WILD_CHECK_KEEN_EYE (1 << 1)
 
-// this file's functions
 static u16 FeebasRandom(void);
 static void FeebasSeedRng(u16 seed);
 static bool8 IsWildLevelAllowedByRepel(u8 level);
@@ -36,60 +54,64 @@ static void ApplyCleanseTagEncounterRateMod(u32 *encRate);
 static bool8 TryGetAbilityInfluencedWildMonIndex(const struct WildPokemon *wildMon, u8 type, u8 ability, u8 *monIndex);
 static bool8 IsAbilityAllowingEncounter(u8 level);
 
-// EWRAM vars
 EWRAM_DATA static u8 sWildEncountersDisabled = 0;
 EWRAM_DATA static u32 sFeebasRngValue = 0;
 
 #include "data/wild_encounters.h"
 
-//Special Feebas-related data.
-const struct WildPokemon gWildFeebasRoute119Data = {20, 25, SPECIES_FEEBAS};
+static const struct WildPokemon sWildFeebas = {20, 25, SPECIES_FEEBAS};
 
-const u16 gRoute119WaterTileData[] =
+static const u16 sRoute119WaterTileData[] =
 {
-    0, 0x2D, 0,
-    0x2E, 0x5B, 0x83,
-    0x5C, 0x8B, 0x12A,
+//yMin, yMax, numSpots in previous sections 
+     0,  45,  0,
+    46,  91,  NUM_FISHING_SPOTS_1,
+    92, 139,  NUM_FISHING_SPOTS_1 + NUM_FISHING_SPOTS_2,
 };
 
-// code
 void DisableWildEncounters(bool8 disabled)
 {
     sWildEncountersDisabled = disabled;
 }
 
-static u16 GetRoute119WaterTileNum(s16 x, s16 y, u8 section)
+// Each fishing spot on Route 119 is given a number between 1 and NUM_FISHING_SPOTS inclusive.
+// The number is determined by counting the valid fishing spots left to right top to bottom.
+// The map is divided into three sections, with each section having a pre-counted number of
+// fishing spots to start from to avoid counting a large number of spots at the bottom of the map.
+// Note that a spot is considered valid if it is surfable and not a waterfall. To exclude all
+// of the inaccessible water metatiles (so that they can't be selected as a Feebas spot) they
+// use a different metatile that isn't actually surfable because it has MB_NORMAL instead.
+// This function is given the coordinates and section of a fishing spot and returns which number it is.
+static u16 GetFeebasFishingSpotId(s16 targetX, s16 targetY, u8 section)
 {
-    u16 xCur;
-    u16 yCur;
-    u16 yMin = gRoute119WaterTileData[section * 3 + 0];
-    u16 yMax = gRoute119WaterTileData[section * 3 + 1];
-    u16 tileNum = gRoute119WaterTileData[section * 3 + 2];
+    u16 x, y;
+    u16 yMin = sRoute119WaterTileData[section * 3 + 0];
+    u16 yMax = sRoute119WaterTileData[section * 3 + 1];
+    u16 spotId = sRoute119WaterTileData[section * 3 + 2];
 
-    for (yCur = yMin; yCur <= yMax; yCur++)
+    for (y = yMin; y <= yMax; y++)
     {
-        for (xCur = 0; xCur < gMapHeader.mapLayout->width; xCur++)
+        for (x = 0; x < gMapHeader.mapLayout->width; x++)
         {
-            u8 tileBehaviorId = MapGridGetMetatileBehaviorAt(xCur + MAP_OFFSET, yCur + MAP_OFFSET);
-            if (MetatileBehavior_IsSurfableAndNotWaterfall(tileBehaviorId) == TRUE)
+            u8 behavior = MapGridGetMetatileBehaviorAt(x + MAP_OFFSET, y + MAP_OFFSET);
+            if (MetatileBehavior_IsSurfableAndNotWaterfall(behavior) == TRUE)
             {
-                tileNum++;
-                if (x == xCur && y == yCur)
-                    return tileNum;
+                spotId++;
+                if (targetX == x && targetY == y)
+                    return spotId;
             }
         }
     }
-    return tileNum + 1;
+    return spotId + 1;
 }
 
 static bool8 CheckFeebas(void)
 {
     u8 i;
     u16 feebasSpots[NUM_FEEBAS_SPOTS];
-    s16 x;
-    s16 y;
+    s16 x, y;
     u8 route119Section = 0;
-    u16 waterTileNum;
+    u16 spotId;
 
     if (gSaveBlock1Ptr->location.mapGroup == MAP_GROUP(ROUTE119)
      && gSaveBlock1Ptr->location.mapNum == MAP_NUM(ROUTE119))
@@ -98,29 +120,42 @@ static bool8 CheckFeebas(void)
         x -= MAP_OFFSET;
         y -= MAP_OFFSET;
 
-        if (y >= gRoute119WaterTileData[3 * 0 + 0] && y <= gRoute119WaterTileData[3 * 0 + 1])
+        // Get which third of the map the player is in
+        if (y >= sRoute119WaterTileData[3 * 0 + 0] && y <= sRoute119WaterTileData[3 * 0 + 1])
             route119Section = 0;
-        if (y >= gRoute119WaterTileData[3 * 1 + 0] && y <= gRoute119WaterTileData[3 * 1 + 1])
+        if (y >= sRoute119WaterTileData[3 * 1 + 0] && y <= sRoute119WaterTileData[3 * 1 + 1])
             route119Section = 1;
-        if (y >= gRoute119WaterTileData[3 * 2 + 0] && y <= gRoute119WaterTileData[3 * 2 + 1])
+        if (y >= sRoute119WaterTileData[3 * 2 + 0] && y <= sRoute119WaterTileData[3 * 2 + 1])
             route119Section = 2;
 
-        if (Random() % 100 > 49) // 50% chance of encountering Feebas
+        // 50% chance of encountering Feebas (assuming this is a Feebas spot)
+        if (Random() % 100 > 49)
             return FALSE;
 
         FeebasSeedRng(gSaveBlock1Ptr->dewfordTrends[0].rand);
+
+        // Assign each Feebas spot to a random fishing spot.
+        // Randomness is fixed depending on the seed above.
         for (i = 0; i != NUM_FEEBAS_SPOTS;)
         {
-            feebasSpots[i] = FeebasRandom() % 447;
+            feebasSpots[i] = FeebasRandom() % NUM_FISHING_SPOTS;
             if (feebasSpots[i] == 0)
-                feebasSpots[i] = 447;
+                feebasSpots[i] = NUM_FISHING_SPOTS;
+            
+            // < 1 below is a pointless check, it will never be TRUE.
+            // >= 4 to skip fishing spots 1-3, because these are inaccessible
+            // spots at the top of the map, at (9,7), (7,13), and (15,16).
+            // The first accessible fishing spot is spot 4 at (18,18).
             if (feebasSpots[i] < 1 || feebasSpots[i] >= 4)
                 i++;
         }
-        waterTileNum = GetRoute119WaterTileNum(x, y, route119Section);
+
+        // Check which fishing spot the player is at, and see if
+        // it matches any of the Feebas spots.
+        spotId = GetFeebasFishingSpotId(x, y, route119Section);
         for (i = 0; i < NUM_FEEBAS_SPOTS; i++)
         {
-            if (waterTileNum == feebasSpots[i])
+            if (spotId == feebasSpots[i])
                 return TRUE;
         }
     }
@@ -256,7 +291,6 @@ static u8 ChooseWildMonLevel(const struct WildPokemon *wildPokemon)
                 rand--;
         }
     }
-
     return min + rand;
 }
 
@@ -365,24 +399,13 @@ static void CreateWildMon(u16 species, u8 level)
         else
             gender = MON_FEMALE;
 
-        CreateMonWithGenderNatureLetter(&gEnemyParty[0], species, level, 32, gender, PickWildMonNature(), 0);
+        CreateMonWithGenderNatureLetter(&gEnemyParty[0], species, level, USE_RANDOM_IVS, gender, PickWildMonNature(), 0);
         return;
     }
 
-    CreateMonWithNature(&gEnemyParty[0], species, level, 32, PickWildMonNature());
+    CreateMonWithNature(&gEnemyParty[0], species, level, USE_RANDOM_IVS, PickWildMonNature());
 }
 
-enum
-{
-    WILD_AREA_LAND,
-    WILD_AREA_WATER,
-    WILD_AREA_ROCKS,
-    WILD_AREA_FISHING,
-};
-
-#define WILD_CHECK_REPEL    0x1
-#define WILD_CHECK_KEEN_EYE 0x2
-
 static bool8 TryGenerateWildMon(const struct WildPokemonInfo *wildMonInfo, u8 area, u8 flags)
 {
     u8 wildMonIndex = 0;
@@ -436,7 +459,7 @@ static bool8 SetUpMassOutbreakEncounter(u8 flags)
         return FALSE;
 
     CreateWildMon(gSaveBlock1Ptr->outbreakPokemonSpecies, gSaveBlock1Ptr->outbreakPokemonLevel);
-    for (i = 0; i < 4; i++)
+    for (i = 0; i < MAX_MON_MOVES; i++)
         SetMonMoveSlot(&gEnemyParty[0], gSaveBlock1Ptr->outbreakPokemonMoves[i], i);
 
     return TRUE;
@@ -444,7 +467,7 @@ static bool8 SetUpMassOutbreakEncounter(u8 flags)
 
 static bool8 DoMassOutbreakEncounterTest(void)
 {
-    if (gSaveBlock1Ptr->outbreakPokemonSpecies != 0
+    if (gSaveBlock1Ptr->outbreakPokemonSpecies != SPECIES_NONE
      && gSaveBlock1Ptr->location.mapNum == gSaveBlock1Ptr->outbreakLocationMapNum
      && gSaveBlock1Ptr->location.mapGroup == gSaveBlock1Ptr->outbreakLocationMapGroup)
     {
@@ -456,7 +479,7 @@ static bool8 DoMassOutbreakEncounterTest(void)
 
 static bool8 DoWildEncounterRateDiceRoll(u16 encounterRate)
 {
-    if (Random() % 2880 < encounterRate)
+    if (Random() % MAX_ENCOUNTER_RATE < encounterRate)
         return TRUE;
     else
         return FALSE;
@@ -486,8 +509,8 @@ static bool8 DoWildEncounterRateTest(u32 encounterRate, bool8 ignoreAbility)
         else if (ability == ABILITY_SAND_VEIL && gSaveBlock1Ptr->weather == WEATHER_SANDSTORM)
             encounterRate /= 2;
     }
-    if (encounterRate > 2880)
-        encounterRate = 2880;
+    if (encounterRate > MAX_ENCOUNTER_RATE)
+        encounterRate = MAX_ENCOUNTER_RATE;
     return DoWildEncounterRateDiceRoll(encounterRate);
 }
 
@@ -639,7 +662,7 @@ void RockSmashWildEncounter(void)
             gSpecialVar_Result = FALSE;
         }
         else if (DoWildEncounterRateTest(wildPokemonInfo->encounterRate, 1) == TRUE
-         && TryGenerateWildMon(wildPokemonInfo, 2, WILD_CHECK_REPEL | WILD_CHECK_KEEN_EYE) == TRUE)
+         && TryGenerateWildMon(wildPokemonInfo, WILD_AREA_ROCKS, WILD_CHECK_REPEL | WILD_CHECK_KEEN_EYE) == TRUE)
         {
             BattleSetup_StartWildBattle();
             gSpecialVar_Result = TRUE;
@@ -744,9 +767,9 @@ void FishingWildEncounter(u8 rod)
 
     if (CheckFeebas() == TRUE)
     {
-        u8 level = ChooseWildMonLevel(&gWildFeebasRoute119Data);
+        u8 level = ChooseWildMonLevel(&sWildFeebas);
 
-        species = gWildFeebasRoute119Data.species;
+        species = sWildFeebas.species;
         CreateWildMon(species, level);
     }
     else