Replace at least some shuffle algorithms with Shuffle (#3801)

Most of these are the poor-quality and slow "naive shuffle", but some might be better.
In any case, Shuffle is known good.

src/apprentice.c

@@ -207,14 +207,7 @@ static void ShuffleApprenticeSpecies(void)
  for (i = 0; i < ARRAY_COUNT(species); i++)
  species[i] = i;
 
- // Shuffle the possible species an arbitrary 50 times
- for (i = 0; i < 50; i++)
- {
- u8 temp;
- u8 rand1 = Random() % ARRAY_COUNT(species);
- u8 rand2 = Random() % ARRAY_COUNT(species);
- SWAP(species[rand1], species[rand2], temp);
- }
+ Shuffle(species, APPRENTICE_SPECIES_COUNT, sizeof(species[0]));
 
  for (i = 0; i < MULTI_PARTY_SIZE; i++)
  PLAYER_APPRENTICE.speciesIds[i] = ((species[i * 2] & 0xF) << 4) | ((species[i * 2 + 1]) & 0xF);
@@ -254,33 +247,19 @@ static void SetRandomQuestionData(void)
  u8 questionOrder[APPRENTICE_MAX_QUESTIONS + 1];
  u8 partyOrder[MULTI_PARTY_SIZE];
  u8 partySlot;
+ u8 rand;
  u8 i, j;
- u8 rand1, rand2;
  u8 id;
 
  for (i = 0; i < ARRAY_COUNT(partyOrder); i++)
  partyOrder[i] = i;
 
- // Shuffle the party an arbitrary 10 times
- for (i = 0; i < 10; i++)
- {
- u8 temp;
- rand1 = Random() % ARRAY_COUNT(partyOrder);
- rand2 = Random() % ARRAY_COUNT(partyOrder);
- SWAP(partyOrder[rand1], partyOrder[rand2], temp);
- }
+ Shuffle(partyOrder, MULTI_PARTY_SIZE, sizeof(partyOrder[0]));
 
  for (i = 0; i < ARRAY_COUNT(questionOrder); i++)
  questionOrder[i] = sQuestionPossibilities[i];
 
- // Shuffle the questions an arbitrary 50 times
- for (i = 0; i < 50; i++)
- {
- u8 temp;
- rand1 = Random() % ARRAY_COUNT(questionOrder);
- rand2 = Random() % ARRAY_COUNT(questionOrder);
- SWAP(questionOrder[rand1], questionOrder[rand2], temp);
- }
+ Shuffle(questionOrder, APPRENTICE_MAX_QUESTIONS + 1, sizeof(questionOrder[0]));
 
  gApprenticePartyMovesData = AllocZeroed(sizeof(*gApprenticePartyMovesData));
  gApprenticePartyMovesData->moveCounter = 0;
@@ -302,16 +281,16 @@ static void SetRandomQuestionData(void)
  {
  do
  {
- rand1 = Random() % MAX_MON_MOVES;
+ rand = Random() % MAX_MON_MOVES;
  for (j = 0; j < gApprenticePartyMovesData->moveCounter + 1; j++)
  {
- if (gApprenticePartyMovesData->moveSlots[id][j] == rand1)
+ if (gApprenticePartyMovesData->moveSlots[id][j] == rand)
  break;
  }
  } while (j != gApprenticePartyMovesData->moveCounter + 1);
 
- gApprenticePartyMovesData->moveSlots[id][gApprenticePartyMovesData->moveCounter] = rand1;
- PLAYER_APPRENTICE.questions[i].moveSlot = rand1;
+ gApprenticePartyMovesData->moveSlots[id][gApprenticePartyMovesData->moveCounter] = rand;
+ PLAYER_APPRENTICE.questions[i].moveSlot = rand;
  PLAYER_APPRENTICE.questions[i].data = GetRandomAlternateMove(PLAYER_APPRENTICE.questions[i].monId);
  }
  }

src/battle_pike.c

@@ -886,14 +886,8 @@ static bool8 TryInflictRandomStatus(void)
 
  for (i = 0; i < FRONTIER_PARTY_SIZE; i++)
  indices[i] = i;
- for (j = 0; j < 10; j++)
- {
- u8 temp, id;
 
- i = Random() % FRONTIER_PARTY_SIZE;
- id = Random() % FRONTIER_PARTY_SIZE;
- SWAP(indices[i], indices[id], temp);
- }
+ Shuffle(indices, FRONTIER_PARTY_SIZE, sizeof(indices[0]));
 
  if (gSaveBlock2Ptr->frontier.curChallengeBattleNum <= 4)
  count = 1;
@@ -1265,7 +1259,7 @@ static void Task_DoStatusInflictionScreenFlash(u8 taskId)
 
 static void TryHealMons(u8 healCount)
 {
- u8 j, i, k;
+ u8 j, i;
  u8 indices[FRONTIER_PARTY_SIZE];
 
  if (healCount == 0)
@@ -1276,15 +1270,7 @@ static void TryHealMons(u8 healCount)
 
  // Only 'healCount' number of pokemon will be healed.
  // The order in which they're (attempted to be) healed is random,
- // and determined by performing 10 random swaps to this index array.
- for (k = 0; k < 10; k++)
- {
- u8 temp;
-
- i = Random() % FRONTIER_PARTY_SIZE;
- j = Random() % FRONTIER_PARTY_SIZE;
- SWAP(indices[i], indices[j], temp);
- }
+ Shuffle(indices, FRONTIER_PARTY_SIZE, sizeof(indices[0]));
 
  for (i = 0; i < FRONTIER_PARTY_SIZE; i++)
  {

src/mauville_old_man.c

@@ -320,11 +320,7 @@ static void InitGiddyTaleList(void)
  // Shuffle question list
  for (i = 0; i < GIDDY_MAX_QUESTIONS; i++)
  giddy->questionList[i] = i;
- for (i = 0; i < GIDDY_MAX_QUESTIONS; i++)
- {
- var = Random() % (i + 1);
- SWAP(giddy->questionList[i], giddy->questionList[var], temp);
- }
+ Shuffle(giddy->questionList, GIDDY_MAX_QUESTIONS, sizeof(giddy->questionList[0]));
 
  // Count total number of words in above word groups
  totalWords = 0;
@@ -1265,27 +1261,12 @@ static void StorytellerRecordNewStat(u32 player, u32 stat)
  sStorytellerPtr->language[player] = gGameLanguage;
 }
 
-static void ScrambleStatList(u8 *arr, s32 count)
-{
- s32 i;
-
- for (i = 0; i < count; i++)
- arr[i] = i;
- for (i = 0; i < count; i++)
- {
- u32 a = Random() % count;
- u32 b = Random() % count;
- u8 temp;
- SWAP(arr[a], arr[b], temp);
- }
-}
-
 static bool8 StorytellerInitializeRandomStat(void)
 {
  u8 storyIds[sNumStories];
  s32 i, j;
 
- ScrambleStatList(storyIds, sNumStories);
+ Shuffle(storyIds, sNumStories, sizeof(storyIds[0]));
  for (i = 0; i < sNumStories; i++)
  {
  u8 stat = sStorytellerStories[storyIds[i]].stat;
@@ -1427,4 +1408,3 @@ bool8 Script_StorytellerInitializeRandomStat(void)
  sStorytellerPtr = &gSaveBlock1Ptr->oldMan.storyteller;
  return StorytellerInitializeRandomStat();
 }
-

src/mirage_tower.c

@@ -598,13 +598,9 @@ static void DoMirageTowerDisintegration(u8 taskId)
  sFallingTower[index].disintegrateRand[i] = i;
 
  // Randomize disintegration pattern
- for (i = 0; i <= (INNER_BUFFER_LENGTH - 1); i++)
- {
- u16 rand1, rand2, temp;
- rand1 = Random() % INNER_BUFFER_LENGTH;
- rand2 = Random() % INNER_BUFFER_LENGTH;
- SWAP(sFallingTower[index].disintegrateRand[rand2], sFallingTower[index].disintegrateRand[rand1], temp);
- }
+ Shuffle(sFallingTower[index].disintegrateRand, INNER_BUFFER_LENGTH,
+ sizeof(sFallingTower[index].disintegrateRand[0]));
+
  if (gTasks[taskId].data[3] <= (OUTER_BUFFER_LENGTH - 1))
  gTasks[taskId].data[3]++;
  gTasks[taskId].data[1] = 0;
@@ -702,13 +698,8 @@ static void Task_FossilFallAndSink(u8 taskId)
  break;
  case 6:
  // Randomize disintegration pattern
- for (i = 0; i < FOSSIL_DISINTEGRATE_LENGTH * sizeof(u16); i++)
- {
- u16 rand1, rand2, temp;
- rand1 = Random() % FOSSIL_DISINTEGRATE_LENGTH;
- rand2 = Random() % FOSSIL_DISINTEGRATE_LENGTH;
- SWAP(sFallingFossil->disintegrateRand[rand2], sFallingFossil->disintegrateRand[rand1], temp);
- }
+ Shuffle(sFallingFossil->disintegrateRand, FOSSIL_DISINTEGRATE_LENGTH,
+ sizeof(sFallingFossil->disintegrateRand[0]));
  gSprites[sFallingFossil->spriteId].callback = SpriteCB_FallingFossil;
  break;
  case 7:

src/tv.c

@@ -1956,7 +1956,6 @@ void AlertTVThatPlayerPlayedRoulette(u16 nCoinsSpent)
 static void SecretBaseVisit_CalculateDecorationData(TVShow *show)
 {
  u8 i, j;
- u16 k;
  u8 n;
  u8 decoration;
 
@@ -2002,12 +2001,7 @@ static void SecretBaseVisit_CalculateDecorationData(TVShow *show)
  break;
  default:
  // More than 1 decoration, randomize the full list
- for (k = 0; k < n * n; k++)
- {
- decoration = Random() % n;
- j = Random() % n;
- SWAP(sTV_DecorationsBuffer[decoration], sTV_DecorationsBuffer[j], i);
- }
+ Shuffle(sTV_DecorationsBuffer, n, sizeof(sTV_DecorationsBuffer[0]));
 
  // Pick the first decorations in the randomized list to talk about on the show
  for (i = 0; i < show->secretBaseVisit.numDecorations; i++)

src/wild_encounter.c

@@ -385,7 +385,6 @@ static u16 GetCurrentMapWildMonHeaderId(void)
 u8 PickWildMonNature(void)
 {
  u8 i;
- u8 j;
  struct Pokeblock *safariPokeblock;
  u8 natures[NUM_NATURES];
 
@@ -396,17 +395,7 @@ u8 PickWildMonNature(void)
  {
  for (i = 0; i < NUM_NATURES; i++)
  natures[i] = i;
- for (i = 0; i < NUM_NATURES - 1; i++)
- {
- for (j = i + 1; j < NUM_NATURES; j++)
- {
- if (Random() & 1)
- {
- u8 temp;
- SWAP(natures[i], natures[j], temp);
- }
- }
- }
+ Shuffle(natures, NUM_NATURES, sizeof(natures[0]));
  for (i = 0; i < NUM_NATURES; i++)
  {
  if (PokeblockGetGain(natures[i], safariPokeblock) > 0)