C64_Superchase/superchase.bas

'***********************************************************************
'**                      SUPERCHASE                                   **
'**                         REMIX!                                    **
'**                                                                   **
'**    3 different versions of the same game into one program!        **
'**                                                                   **
'** - Original VIC-20 version by Anthony Godshall - October 1982      **
'** - Atari version by someone @ Compute! Gazette                     **
'** - TI-99 4/A version by Cheryl Regena                              **
'**                                                                   **
'** Written in XC-BASIC 3.0.8 by @JJFlash@mastodon.social - Sep 2022  **
'** XC-BASIC created by Csaba Fekete! - https://xc-basic.net/         **
'**                                                                   **
'**                   WORK IN PROGRESS!!                              **
'***********************************************************************


'--------------INITIAL-SETUP--------------------------------------------
Dim scrAddrCache(25) as WORD @loc_scrAddrCache ' 0 -> 24
loc_scrAddrCache:
DATA AS WORD 1024, 1064, 1104, 1144, 1184, 1224, 1264, 1304, 1344, 1384
DATA AS WORD 1424, 1464, 1504, 1544, 1584, 1624, 1664, 1704, 1744, 1784
DATA AS WORD 1824, 1864, 1904, 1944, 1984

poke 53280, 0 : poke 53281, 0

memcpy @LOC_charset_addr, $3800, 1024
poke $D018, 31 'final character location: $3800
poke 657, 128 'disable upper-lower case change
Dim wStack(128) as WORD @LOC_charset_addr 'recycling the charset data already copied to the final location!
'-----------------------------------------------------------------------

'-------------CONSTANTS-------------------------------------------------
Const TRUE = 255
Const FALSE = 0
Const INIT = 255
Const GO_ON = 0

Const SPACE = 88
Const MARKED_SPACE = 89
Const WALL = 96
Const EX_WALL = 98
Const DOOR_CLOSED = 97
Const DOOR_CLOSED_REVERSED = 101
Const DOOR_OPEN = 99
Const DOOR_OPEN_REVERSED = 103

Const PLAYER = 64
Const PLAYER_LEFT = 66
Const MONSTER = 68
Const MONSTER_ALT = 69
Const TRAIL = 80
Const TREASURES = 112
Const TREASURE_GOLD = 116

Const EAST = 0
Const NORTH = 1
Const WEST = 2
Const SOUTH = 3

Const MASK_WALKABLE = 16           '0001 0000
Const MASK_ALL = 48                '0011 0000
Const MASK_SUBGROUP = 8            '0000 1000
Const MASK_ALL_SUBGROUP = 56       '0011 1000
Const MASK_TILE = 7                '0000 0111

Const GROUP_CREATURES = 0          '0000 0000
Const GROUP_WALKABLE = 16          '0001 0000
'~ Const GROUP_WALLS = 32             '0010 0000
Const GROUP_TREASURE = 48          '0011 0000
Const SUBGROUP_TREASURE = 56       '0011 1000

Const VIC_COLOR_OFFSET = $D400
'-----------------------------------------------------------------------

'--------------GAME-STATE-&-GLOBAL-STUFF--------------------------------
Dim bPeekedTileContent as BYTE

Dim bFrameCounter as BYTE
Dim bAnimFrameCounter as BYTE

Dim iDirections(4) as INT @loc_iDirections
loc_iDirections:
DATA as INT 1, -40, -1, 40 'east, north, west, south

Dim bPlayer_Col as BYTE
Dim bPlayer_Row as BYTE
Dim bPlayer_FacingCharacter as BYTE

Dim bMonsterIsOn as BYTE
Dim bMonster_Col as BYTE
Dim bMonster_Row as BYTE
Dim bMonster_Direction as BYTE
Dim bMonster_Lag as BYTE
Dim bMonster_PreviousTile as BYTE
Dim bMonster_SpeedUpMode as BYTE
Dim bMonster_DelayFrame as BYTE
Dim bMonster_Distance_TurnONSpeedUp as BYTE
Dim bMonster_Distance_TurnOFFSpeedUp as BYTE

Dim bTreasuresToActivateMonster as BYTE

Dim bManhattanDistance as BYTE

Dim wDoorAddress as WORD
Dim wGoldColorAddress as WORD

Dim bSkillLevel as BYTE : bSkillLevel = 1
Dim wScore as WORD
Dim wLastExitScore as WORD : wLastExitScore = 0
Dim bTreasures_Quantity as BYTE
Dim bTreasuresCollected as BYTE
Dim bTreasuresToOpenDoor as BYTE
Dim bGoldNotCollected as BYTE
Dim bPlayerExited as BYTE
Dim bPlayerCaught as BYTE

declare sub generateMaze () STATIC
declare sub placeDoor() STATIC
declare sub playerMovement() STATIC
declare sub initMonster() STATIC
declare sub handleMonster() STATIC
declare sub monsterMovement() STATIC
declare sub drawInfoBox() STATIC
declare sub shakeScreen() STATIC
declare sub mazeShiftAway() STATIC
declare sub openDoorAnimation() STATIC
declare sub goldFlashAnimation(bInitAnim as BYTE) STATIC
declare sub titleScreen() STATIC
'-----------------------------------------------------------------------

'------------------HELPER FUNCTIONS-------------------------------------
function myRandom as BYTE (bMax as BYTE, bMask as BYTE) STATIC
	do
		myRandom = RNDB() AND bMask
	loop while myRandom > bMax
end function

function myByteABS as BYTE (bNumber as BYTE) STATIC
	if (bNumber AND 128) = 128 then bNumber = (NOT bNumber) + 1
	return bNumber
end function


'------------------TITLE SCREEN-----------------------------------------
sys $E544 FAST ' clear screen
call titleScreen()

'------------------LEVEL-START------------------------------------------

'~ Dim lRandomSeed as LONG : lRandomSeed = clong(248) ' <<<<<<<<<<<<<<<------------- RANDOM!!!

sys $E544 FAST ' clear screen
textat 32, 0, "super", 1 'white
textat 33, 1, "chase!", 1 'white
textat 32, 7, "skill", 5 'green
textat 33, 8, "level", 5 'green
textat 32, 13, "score", 3 'cyan
textat 32, 18, "speed", 7 'yellow

Randomize (TI() * (clong(peek( $D012)) + clong(1)))

redraw:
For N as BYTE = 0 to 24
	memset scrAddrCache(N), 31, WALL
	memset VIC_COLOR_OFFSET + scrAddrCache(N), 31, 6 'blue
Next N

'~ lRandomSeed = lRandomSeed + clong(1)
'~ textat 33, 23, str$(lRandomSeed), 14 'light blue
'~ Randomize (lRandomSeed)

For N as BYTE = 1 to 10 : bPeekedTileContent = RNDB() : Next N ' bPeekedTileContent used here as a dummy variable!

call generateMaze()
'~ textat 33, 24, str$(bTreasures_Quantity), 7 'yellow
call placeDoor()

bFrameCounter = 0

bPlayer_Col = 1
bPlayer_Row = 1
bPlayer_FacingCharacter = PLAYER

call initMonster()

wScore = wLastExitScore
bTreasuresCollected = 0
bPlayerExited = FALSE
bPlayerCaught = FALSE

textat 33, 10, str$(bSkillLevel), 1 'white
memset 1657, 5, 32 'erase previous printed score
textat 33, 15, str$(wScore), 10 'light red
textat 33, 20, "1 ", 2 'red

bTreasuresToOpenDoor = shr(bTreasures_Quantity, 1) 
if bSkillLevel < bTreasuresToOpenDoor then
	bTreasuresToOpenDoor = bTreasuresToOpenDoor + bSkillLevel
else
	bTreasuresToOpenDoor = bTreasures_Quantity
end if
'~ textat 36, 24, str$(bTreasuresToOpenDoor), 12 'gray

'-------------------------MAIN LOOP!------------------------------------
do
	on bFrameCounter goto actorMovement, endFrame, animation, endFrame

actorMovement:
	'-------PLAYER MOVEMENT-----------------
	call playerMovement()
	if (bPlayerCaught OR bPlayerExited) then exit do
	'~ textat 33, 22, str$(bTreasuresCollected) + "  ", 15 ' light gray
	
	'-------MONSTER MOVEMENT-----------------
	if bMonsterIsOn then
		call handleMonster()
		if bPlayerCaught then exit do
	else
		if bTreasuresCollected = bTreasuresToActivateMonster then bMonsterIsOn = TRUE
	end if
	
	if NOT bGoldNotCollected then call goldFlashAnimation(GO_ON)
	goto endFrame
	'-------------------------------------------------------------------

animation:
	if bGoldNotCollected then
		poke wGoldColorAddress, peek(wGoldColorAddress) XOR 6 'alternates white, yellow, white, yellow, ...
	else
		call goldFlashAnimation(GO_ON)
	end if
	charat bPlayer_Col, bPlayer_Row, bPlayer_FacingCharacter XOR 1, 13 'light green
	if bMonsterIsOn then
		if bMonster_SpeedUpMode then
			call handleMonster()
		else
			charat bMonster_Col, bMonster_Row, MONSTER_ALT, 2 'red
		end if
	end if
	if bTreasuresCollected = bTreasuresToOpenDoor then call openDoorAnimation()
	'-------------------------------------------------------------------
	
endFrame:
	'~ if (peek ( $DC00) AND 16) = 0 then goto redraw
	wait $d011, 128, 128 : wait $d011, 128 : wait $d011, 128, 128 : wait $d011, 128
	bFrameCounter = (bFrameCounter + 1) AND 3
loop

if bPlayerCaught then
	call shakeScreen()
	call drawInfoBox()
	textat 8, 12, "a tasty morsel", 8 'orange
	textat 12, 13, "indeed!", 8 'orange
	wScore = wLastExitScore
else
	call drawInfoBox()
	textat 8, 12, "congratulations!", 7 'yellow
	textat 6, 13, "onto the next level!", 7 'yellow
	wLastExitScore = wScore
	if bSkillLevel < 255 then bSkillLevel = bSkillLevel + 1
end if

wait $DC00, 16, 16 'wait for fire to be pressed
if bPlayerExited then call mazeShiftAway()
goto redraw

'------------GAME-SUBROUTINES-------------------------------------------
sub generateMaze () STATIC
	Dim bRow as BYTE
	Dim bCol as BYTE
	Dim bRowEnd as BYTE
	Dim bColEnd as BYTE

	memset 1065, 5, EX_WALL
	poke 1105, EX_WALL
	poke 1145, EX_WALL
	poke 1185, EX_WALL
	poke 1225, EX_WALL

	For N as BYTE = 1 to 65
		bCol = shl(myRandom(13, 15), 1) + 1
		bRow = shl(myRandom(11, 15), 1) + 1
		bColEnd = bCol + 6 : if bColEnd > 29 then bColEnd = 29
		memset scrAddrCache(bRow) + bCol, bColEnd - bCol + 1, EX_WALL
	Next N

	For N as BYTE = 1 to 60
		bCol = shl(myRandom(14, 15), 1) + 1
		bRow = shl(myRandom(10, 15), 1) + 1
		bRowEnd = bRow + 4 : if bRowEnd > 23 then bRowEnd = 23
		For K AS BYTE = bRow to bRowEnd
			poke scrAddrCache(K) + bCol, EX_WALL
		Next K
	Next N

	Dim wCalcScreenAddress as WORD
	Dim bStackPointer as BYTE
	Dim wFilledCells as WORD
	Dim wPatchScrAddress as WORD

	bStackPointer = 1 : wFilledCells = 0
	wStack(0) = 1065 'player starting position: Row 1, Column 1
	wPatchScrAddress = 1226 'row 5, column 2
	Const PATCHSCRADDRESS_END = 1253 'row 5, column 29
	
	Dim bTreasures_Color(5) as BYTE @loc_bbTreasures_Color
loc_bbTreasures_Color:
	DATA AS BYTE 12, 9, 10, 8, 7 'gray, brown, light red, orange, yellow

	Dim bTreasures_Sequence(51) as BYTE @loc_bTreasures_Sequence
	'26 treasure 0, 15 treasure 1, 12 treasure 2, 7 treasure 3, 1 treasure 4 (gold!)
loc_bTreasures_Sequence:
	'0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
	'1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1
	'2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2
	'3, 3, 3, 3, 3, 3, 3
	'                     4
	DATA AS BYTE 0, 1, 2, 3, 0, 1, 2, 3, 0, 1, 2, 3, 0, 1, 2, 3, 0, 1, 2, 3, 0, 1, 2, 3, 0, 1, 2, 3, 0, 1, 2, 4
	DATA AS BYTE 0, 1, 2, 0, 1, 2, 0, 1, 2, 0, 1, 2, 0, 1, 0, 1, 0, 1, 0
	
	Dim bTreasures_Index as BYTE : bTreasures_Index = 0
	Dim bTileType as BYTE
	Dim bTileColor as BYTE
	bTreasures_Quantity = 0
	bGoldNotCollected = FALSE 'in the event the Gold treasure doesn't show up...

	do
		bStackPointer = bStackPointer - 1
		wCalcScreenAddress = wStack(bStackPointer)
		
		do while peek(wCalcScreenAddress) = EX_WALL
			wCalcScreenAddress = wCalcScreenAddress - cword(1)
		loop
		wCalcScreenAddress = wCalcScreenAddress + cword(1)
		
		do while peek(wCalcScreenAddress) = EX_WALL
			bTileType = SPACE
			if wFilledCells > 5 then
				If myRandom(5, 7) = 5 then
					bTileType = TREASURES + bTreasures_Sequence(bTreasures_Index)
					bTileColor = bTreasures_Color(bTileType AND 7)
					if bTreasures_Index < 50 then bTreasures_Index = bTreasures_Index + 1
					bTreasures_Quantity = bTreasures_Quantity + 1
				end if
			end if
			if bTileType = TREASURE_GOLD then wGoldColorAddress = VIC_COLOR_OFFSET + wCalcScreenAddress : bGoldNotCollected = TRUE
			poke wCalcScreenAddress, bTileType : poke VIC_COLOR_OFFSET + wCalcScreenAddress, bTileColor
			wFilledCells = wFilledCells + 1
			
			wCalcScreenAddress = wCalcScreenAddress - cword(40) 'one row UP
			if peek(wCalcScreenAddress) = EX_WALL then
				wStack(bStackPointer) = wCalcScreenAddress
				bStackPointer = bStackPointer + 1
			end if
			wCalcScreenAddress = wCalcScreenAddress + cword(80) 'back to the original row + one row DOWN
			if peek(wCalcScreenAddress) = EX_WALL then
				wStack(bStackPointer) = wCalcScreenAddress
				bStackPointer = bStackPointer + 1
			end if
			
			wCalcScreenAddress = wCalcScreenAddress - cword(39) 'one row UP + one column RIGHT
		loop
		
		if bStackPointer = 0 then
			if wFilledCells < 280 then
				do until peek(wPatchScrAddress) = WALL
					wPatchScrAddress = wPatchScrAddress + 1
					if wPatchScrAddress > PATCHSCRADDRESS_END then exit sub
				loop
				poke wPatchScrAddress, EX_WALL
				wStack(bStackPointer) = wPatchScrAddress
				bStackPointer = 1
			else
				exit sub
			end if
		end if
	loop
end sub

sub placeDoor() STATIC
	wDoorAddress = $0586 'Col 30, Row 9
	do
		For bRowIncrement AS BYTE = 0 to 22 'row 9 -> 23 + 1 -> 8
			if ((peek(wDoorAddress - cword(1)) AND MASK_WALKABLE) = GROUP_WALKABLE) then
				poke wDoorAddress, DOOR_CLOSED
				poke VIC_COLOR_OFFSET + wDoorAddress, 14 'light blue
				exit sub
			else
				if bRowIncrement = 14 then
					wDoorAddress = wDoorAddress - 880 'up 22 rows
				else
					wDoorAddress = wDoorAddress + cword(40) 'next row
				end if
			end if
		Next bRowIncrement
		
		'back to row 9? Try the previous column...
		wDoorAddress = wDoorAddress - cword(1)
	loop
end sub

sub playerMovement() STATIC
	Dim wScoreTable(5) as WORD @loc_wScoreTable
loc_wScoreTable:
	DATA AS WORD 10, 20, 30, 50, 500

	Dim bJoystick2 as BYTE
	bJoystick2 = peek ( $DC00) XOR 127
	
	if (bJoystick2 AND 1) then
		bJoystick2 = NORTH
	else
		if (bJoystick2 AND 2) then
			bJoystick2 = SOUTH
		else
			if (bJoystick2 AND 4) then
				bJoystick2 = WEST
				bPlayer_FacingCharacter = PLAYER_LEFT
			else
				if (bJoystick2 AND 8) then
					bJoystick2 = EAST
					bPlayer_FacingCharacter = PLAYER
				else
					exit sub
				end if
			end if
		end if
	end if
	
	bPeekedTileContent = peek(scrAddrCache(bPlayer_Row) + bPlayer_Col + iDirections(bJoystick2))
	
	if (bPeekedTileContent AND MASK_ALL) = GROUP_CREATURES then 'Player bumped into Monster!
		charat bPlayer_Col, bPlayer_Row, SPACE, 11 'dark grey
		bPlayerCaught = TRUE : exit sub
	end if
	
	if ((bPeekedTileContent AND MASK_WALKABLE) = GROUP_WALKABLE) OR (bPeekedTileContent = DOOR_OPEN) then
		charat bPlayer_Col, bPlayer_Row, TRAIL, 11 'dark grey

		if (bJoystick2 AND 1) then 'odd number, vertical direction
			bPlayer_Row = bPlayer_Row + cbyte(SGN(iDirections(bJoystick2)))
		else 'even number, horizontal direction
			bPlayer_Col = bPlayer_Col + cbyte(iDirections(bJoystick2))
		end if
		charat bPlayer_Col, bPlayer_Row, bPlayer_FacingCharacter, 13 'light green
		
		if (bPeekedTileContent AND MASK_ALL) = GROUP_TREASURE Then
			'~ poke 53280, (bPeekedTileContent AND MASK_TILE) + 1
			'~ wait $d011, 128, 128 : wait $d011, 128 : wait $d011, 128, 128 : wait $d011, 128
			'~ poke 53280, 0
			bTreasuresCollected = bTreasuresCollected + 1
			if (bPeekedTileContent AND 247) = TREASURE_GOLD then call goldFlashAnimation(INIT) 'both non-marked and marked!
			wScore = wScore + wScoreTable ( (bPeekedTileContent AND MASK_TILE) )
			textat 33, 15, str$(wScore), 10 'light red
		else
			if bPeekedTileContent = DOOR_OPEN then bPlayerExited = TRUE
		end if

	end if
end sub

sub initMonster() STATIC
	bMonsterIsOn = FALSE
	if bSkillLevel < 8 then
		bTreasuresToActivateMonster = 8 - bSkillLevel
	else
		bTreasuresToActivateMonster = 1
	end if

	bMonster_Col = 1
	bMonster_Row = 1
	bMonster_Direction = EAST
	bMonster_Lag = 10
	bMonster_PreviousTile = SPACE
	bMonster_SpeedUpMode = FALSE	
	if bSkillLevel < 14 then
		bMonster_Distance_TurnONSpeedUp = 20 - bSkillLevel
		bMonster_Distance_TurnOFFSpeedUp = 12 - shr(bSkillLevel, 1)
	else
		bMonster_Distance_TurnONSpeedUp = 7
		bMonster_Distance_TurnOFFSpeedUp = 5
	end if
	
	bMonster_DelayFrame = 9 '= Lag - 1
	
	'~ textat 33, 3, "   "
	'~ textat 33, 4, "   "
	'~ textat 33, 21, "   "
end sub

sub handleMonster() STATIC
	Dim bMoveFrame as BYTE
	
	bManhattanDistance = myByteABS(bPlayer_Row - bMonster_Row) + myByteABS(bPlayer_Col - bMonster_Col)
	'~ textat 33, 21, str$(bManhattanDistance) + " ", 11 'dark gray
	if bManhattanDistance > bMonster_Distance_TurnONSpeedUp then
		bMonster_SpeedUpMode = TRUE
	else
		if bManhattanDistance < bMonster_Distance_TurnOFFSpeedUp then
			if bMonster_SpeedUpMode then
				if bMonster_Lag > 1 then
					bMonster_Lag = bMonster_Lag - 1
					textat 33, 20, str$(11 - bMonster_Lag), 2 'red
				end if
				bMonster_SpeedUpMode = FALSE
			end if
		end if
	end if
	if bMonster_SpeedUpMode then call monsterMovement() : exit sub

	if bMonster_DelayFrame = 0 then
		call monsterMovement()
		if bMoveFrame > 0 then bMoveFrame = bMoveFrame - 1
		if bMoveFrame = 0 then bMonster_DelayFrame = bMonster_Lag - 1
	else
		bMonster_DelayFrame = bMonster_DelayFrame - 1
		if bMonster_DelayFrame = 0 then bMoveFrame = bSkillLevel
	end if
	
	'~ textat 33, 3, str$(bMonster_DelayFrame), 10 'light red
	'~ textat 33, 4, str$(bMoveFrame) + " ", 13 'light green
end sub

sub monsterMovement() STATIC
	Const MINUS_ONE = 255
	Dim wPeekingLocation as WORD
	Dim bMonster_PreviousColour as BYTE

	Dim bTravelingDirection as BYTE

	Dim bThisTileDistance as BYTE
	Dim bClosestDistance as BYTE
	Dim bThisTileRow as BYTE
	Dim bThisTileCol as BYTE
	Dim bClosestTileDirection as BYTE
	Dim bPeekedDirection as BYTE

	Dim bWalkableDirections(4) as BYTE '0...3
	Dim bWalkableDirections_Count as BYTE
	Dim bTrailDirections(4) as BYTE '0...3
	Dim bTrailDirections_Count as BYTE	
	'------------------------------------------------
	wPeekingLocation = scrAddrCache(bMonster_Row) + bMonster_Col
	
	bTravelingDirection = bMonster_Direction

	bWalkableDirections_Count = MINUS_ONE
	bTrailDirections_Count = MINUS_ONE

	bClosestDistance = 255
	
	bMonster_Direction = (bMonster_Direction - 1) AND 3 'starting from the Monster's right (going clockwise)
	For bPeekedDirection = 1 to 4
		bPeekedTileContent = peek(wPeekingLocation + iDirections(bMonster_Direction))
		
		if (bPeekedTileContent AND MASK_ALL) = GROUP_CREATURES then bPlayerCaught = TRUE : exit for 'Gotcha, Player!!
		
		if (bPeekedTileContent AND MASK_WALKABLE) = GROUP_WALKABLE then
			'~ if (bPeekedTileContent AND MASK_ALL_SUBGROUP) = GROUP_TRAIL then
			if bPeekedTileContent = TRAIL then
				bWalkableDirections_Count = bWalkableDirections_Count + 1
				'~ bWalkableDirections(bWalkableDirections_Count) = bMonster_Direction
				bTrailDirections_Count = bTrailDirections_Count + 1
				bTrailDirections(bTrailDirections_Count) = bMonster_Direction
			else
				if ((bPeekedTileContent AND MASK_ALL_SUBGROUP) <> SUBGROUP_TREASURE) AND (bPeekedTileContent <> MARKED_SPACE) and bPeekedDirection < 4 then 'ignoring the opposite direction travelled!
					bWalkableDirections_Count = bWalkableDirections_Count + 1
					bWalkableDirections(bWalkableDirections_Count) = bMonster_Direction
					'ALSO, find the closest tile to the player...
					bThisTileRow = bMonster_Row : bThisTileCol = bMonster_Col
					if (bMonster_Direction AND 1) then 'odd number, vertical direction
						bThisTileRow = bMonster_Row + cbyte(SGN(iDirections(bMonster_Direction)))
					else 'even number, horizontal direction
						bThisTileCol = bMonster_Col + cbyte(iDirections(bMonster_Direction))
					end if
					bThisTileDistance = myByteABS(bPlayer_Row - bThisTileRow) + myByteABS(bPlayer_Col - bThisTileCol)
					if bThisTileDistance < bClosestDistance then
						bClosestDistance = bThisTileDistance
						bClosestTileDirection = bMonster_Direction
					end if
				end if
			end if
		end if
		
		bMonster_Direction = (bMonster_Direction + 1) AND 3 'now going counter-clockwise
	next bPeekedDirection
	
	if bPlayerCaught = FALSE then
		if bTrailDirections_Count <> MINUS_ONE then
			bMonster_Direction = bTrailDirections(myRandom(bTrailDirections_Count, 3))
		else
			if bWalkableDirections_Count = MINUS_ONE then
				bMonster_Direction = (bTravelingDirection + 2) AND 3 'opposite direction
			else
				bWalkableDirections_Count = bWalkableDirections_Count + 1
				bWalkableDirections(bWalkableDirections_Count) = bClosestTileDirection
				bMonster_Direction = bWalkableDirections(myRandom(bWalkableDirections_Count, 3))
			end if
		end if	
	end if

'------------------------DRAW-------------------------------------------

	'~ for bMonsterDebug as BYTE = 0 to 3
		'~ textat 33, 2 + bMonsterDebug, "   "
	'~ next bMonsterDebug
	
	'~ if bWalkableDirections_Count <> MINUS_ONE then
		'~ for bMonsterDebug as BYTE = 0 to bWalkableDirections_Count
			'~ if bWalkableDirections(bMonsterDebug) = bMonster_Direction then
				'~ textat 33, 2 + bMonsterDebug, str$(bWalkableDirections(bMonsterDebug)), 1 'white
			'~ else
				'~ textat 33, 2 + bMonsterDebug, str$(bWalkableDirections(bMonsterDebug)), 11 'gray
			'~ end if
		'~ next bMonsterDebug
	'~ end if
	
	if (bMonster_PreviousTile AND MASK_ALL) = GROUP_TREASURE then
		if bWalkableDirections_Count = MINUS_ONE then
			bMonster_PreviousTile = bMonster_PreviousTile OR MASK_SUBGROUP
		end if
	else
		if bWalkableDirections_Count = MINUS_ONE then
			bMonster_PreviousTile = MARKED_SPACE
		else
			bMonster_PreviousTile = SPACE
		end if
	end if
	
	if (bMonster_PreviousColour AND 15) = 0 then bMonster_PreviousColour = 14
	charat bMonster_Col, bMonster_Row, bMonster_PreviousTile, bMonster_PreviousColour
	
	bMonster_PreviousTile = peek(wPeekingLocation + iDirections(bMonster_Direction))
	bMonster_PreviousColour = peek(VIC_COLOR_OFFSET + wPeekingLocation + iDirections(bMonster_Direction))

	if (bMonster_Direction AND 1) = 1 then 'odd number, vertical direction
		bMonster_Row = bMonster_Row + cbyte(SGN(iDirections(bMonster_Direction)))
	else 'even number, horizontal direction
		bMonster_Col = bMonster_Col + cbyte(iDirections(bMonster_Direction))
	end if
	charat bMonster_Col, bMonster_Row, MONSTER, 2 'red
	
	if bWalkableDirections_Count = MINUS_ONE then bMonster_Direction = bTravelingDirection
end sub

sub drawInfoBox() STATIC
	'~ textat 4, 11, "{168}{171}{171}{171}{171}{171}{171}{171}{171}{171}{171}{171}{171}{171}{171}{171}{171}{171}{171}{171}{171}{171}{173}", 6 'blu
	'~ textat 4, 12, "{169}                     {174}", 6 'blu
	'~ textat 4, 13, "{169}                     {174}", 6 'blu
	'~ textat 4, 14, "{170}{172}{172}{172}{172}{172}{172}{172}{172}{172}{172}{172}{172}{172}{172}{172}{172}{172}{172}{172}{172}{172}{175}", 6 'blu
	poke 1468, 104 'col 4, row 11
	memset 1469, 21, 107 'col 5-25, row 11
	poke 1490, 109 'col 26, row 11
	
	poke 1508, 105 'col 4, row 12
	memset 1509, 21, 32 'col 5-25, row 12
	poke 1530, 110 'col 26, row 12
	
	poke 1548, 105 'col 4, row 13
	memset 1549, 21, 32 'col 5-25, row 13
	poke 1570, 110 'col 26, row 13

	poke 1588, 106 'col 4, row 13
	memset 1589, 21, 108 'col 5-25, row 13
	poke 1610, 111 'col 26, row 13
	
	memset VIC_COLOR_OFFSET + 1468, 23, 6 'blu
	memset VIC_COLOR_OFFSET + 1508, 23, 6 'blu
	memset VIC_COLOR_OFFSET + 1548, 23, 6 'blu
	memset VIC_COLOR_OFFSET + 1588, 23, 6 'blu
	
end sub

sub shakeScreen() STATIC
	Dim bVariance as BYTE : bVariance = 7
	bAnimFrameCounter = 0

	do
		poke $D011, %10011000 OR ((3 + myRandom(bVariance, 7)) AND 7)
		poke $D016, %00001000 OR myRandom(bVariance, 7)
		wait $d011, 128, 128 : wait $d011, 128
		
		bAnimFrameCounter = (bAnimFrameCounter + 1) AND 3
		if bAnimFrameCounter = 0 then bVariance = bVariance - 1
	loop until bVariance = 255
end sub

sub mazeShiftAway() STATIC
	dim wLineAddress as WORD : dim wColorLineAddress as WORD
	wait $d011, 128, 128 : wait $d011, 128
	
	for nShiftColumn as BYTE = 0 to 30
		for nShiftLine as BYTE = 0 to 24
			wLineAddress = scrAddrCache(nShiftLine)
			wColorLineAddress = VIC_COLOR_OFFSET + wLineAddress
			memcpy wLineAddress + 1, wLineAddress, 31
			memcpy wColorLineAddress + 1, wColorLineAddress, 31
		next nShiftLine
		wait $d011, 128, 128 : wait $d011, 128
	next nShiftColumn
end sub

sub openDoorAnimation() STATIC
	For bAnimFrameCounter = 1 to 5
		poke wDoorAddress, DOOR_CLOSED_REVERSED
		poke VIC_COLOR_OFFSET + wDoorAddress, 13 'light green
		wait $d011, 128, 128 : wait $d011, 128 : wait $d011, 128, 128 : wait $d011, 128
		poke wDoorAddress, DOOR_CLOSED
		poke VIC_COLOR_OFFSET + wDoorAddress, 14 'light blue
		wait $d011, 128, 128 : wait $d011, 128 : wait $d011, 128, 128 : wait $d011, 128
	Next bAnimFrameCounter
	For bAnimFrameCounter = 1 to 5
		poke wDoorAddress, DOOR_OPEN_REVERSED
		poke VIC_COLOR_OFFSET + wDoorAddress, 7 'yellow
		wait $d011, 128, 128 : wait $d011, 128 : wait $d011, 128, 128 : wait $d011, 128
		poke wDoorAddress, DOOR_OPEN
		poke VIC_COLOR_OFFSET + wDoorAddress, 14 'light blue
		wait $d011, 128, 128 : wait $d011, 128 : wait $d011, 128, 128 : wait $d011, 128
	Next bAnimFrameCounter
	
	bTreasuresToOpenDoor = 0
end sub

sub goldFlashAnimation (bInitAnim as BYTE) STATIC
	Dim bFlashTimer as BYTE
	
	if bInitAnim then
		bGoldNotCollected = FALSE
		bFlashTimer = 8
	else
		if bFlashTimer = 0 then exit sub
	end if
	
	bFlashTimer = bFlashTimer - 1
	if (bFlashTimer AND 1) then
		poke 53281, 8 'orange
	else
		poke 53281, 0 'black
	end if
end sub

sub titleScreen() STATIC
	Const PLAYER_LOCATION = 1354
	Const MONSTER_LOCATION = 1434
	
	Dim bJoystick2 as BYTE
	
	'treasure frame for title
	memset 1036, 16, TREASURE_GOLD
	memset 1236, 16, TREASURE_GOLD
	memset 55308, 216, 7 'yellow
	poke 1076, TREASURE_GOLD
	poke 1116, TREASURE_GOLD
	poke 1156, TREASURE_GOLD
	poke 1196, TREASURE_GOLD
	poke 1091, TREASURE_GOLD
	poke 1131, TREASURE_GOLD
	poke 1171, TREASURE_GOLD
	poke 1211, TREASURE_GOLD
	
	textat 15, 2, "superchase", 1 'white
	textat 17, 3, "remix!", 1 'white
	textat 13, 8, "treasure hunter", 3 'cyan
	textat 13, 10, "monster of dungeons!", 7 'yellow
	
	textat 12, 15, "choose skill level", 5 'green
	charat 18, 17, 60, 10 'left arrow, light red
	charat 22, 17, 62, 10 'right arrow, light red
	
	poke PLAYER_LOCATION, PLAYER : poke 55626, 13 'light green
	poke MONSTER_LOCATION, MONSTER : poke 55706, 2 'red
	
	do
		charat 20, 17, 48 + bSkillLevel, 1 'white
		
		poke 55994, 10 'color for left arrow, light red
		poke 55998, 10 'color for right arrow, light red
		
		bJoystick2 = peek( $DC00) XOR 127
		
		if (bJoystick2 AND 4) then 'color for left arrow, left
			poke 55994, 1 'white
			if bSkillLevel > 1 then bSkillLevel = bSkillLevel - 1
		else
			if (bJoystick2 AND 8) then 'right
				poke 55998, 1 'color for right arrow, white
				if bSkillLevel < 9 then bSkillLevel = bSkillLevel + 1
			else
				if (bJoystick2 AND 16) then 'fire
					exit do
				end if
			end if
		end if
		
		poke PLAYER_LOCATION, peek(PLAYER_LOCATION) XOR 1
		poke MONSTER_LOCATION, peek(MONSTER_LOCATION) XOR 1
		
		wait $D011, 128, 128 : wait $D011, 128 : wait $D011, 128, 128 : wait $D011, 128
		wait $D011, 128, 128 : wait $D011, 128 : wait $D011, 128, 128 : wait $D011, 128
		wait $D011, 128, 128 : wait $D011, 128 : wait $D011, 128, 128 : wait $D011, 128
	loop
end sub

'-----------------------------------------------------------------------
LOC_charset_addr:
incbin "charset_superchase.chr"