FotS

invader.zip

This module is part of the original MMBasic library. It is reproduced here with kind permission of Hugh Buckle and Geoff Graham. Be aware it may reference functionality which has changed or is deprecated in the latest versions of MMBasic.

This is a version of the Space Invaders game for the Maximite. It was written by Fabrice Muller (France).

To play, unzip all the files into a directory on your SD card, change into the directory and then run the file INVADERS.BAS.

Space Bar = The fire button Left Arrow = Move your gun to the left Right Arrow = Move your gun to the right CTRL-C = Quit

This must be run using MMBasic 3.0A as it relies on some advanced features of this version to control the invaders.

It looks best if played on a composite PAL monitor but it will also run fine on a VGA monitor.

 'Space Invaders for the Maximite
Option base 1
Clear
 'Initialise variables
Dim FireCoord(2)
Dim OldFireCoord(2)
NbCols = 11
NbInvFire = 5
SprWide = 16
MinX = 0 : MaxX = 120
Dim Invaders(5,NbCols)
Dim InvCols(NbCols)
Dim InvFireCoord(20,2)
Dim InvFireOld(20,2)
Dim InvLine(5)
Dim InvErase(5)
Dim InvLine$(5)
Dim InvChar$(5,2)
Dim InvScore(5)
InvScore(1) = 30
InvScore(2) = 30
InvScore(3) = 20
InvScore(4) = 20
InvScore(5) = 10
InvMiScore = 100
Mistery = 117
Canon = 118
CanonExp1 = 119
CanonExp2 = 120
Dx = -2
InvInterval = 200
InvMiInterval = 200
InvMiSpeed = 20
InvFireTimer = 25
InvFireSpeed = 25
FireSpeed = 5
MisteryOn = 0
Score = 0
Lives = 3
Level = 0
NextLevel = 1
InvaderX = 16
InvaderY = 40
OriginMaxY = 70
InvMaxY = OriginMaxY
MisteryX = 280
OldMisteryX = MisteryX
OldInvaderX = InvaderX
OldInvaderY = InvaderY
CanonX = 100
CanonY = 180
OldCanonX = CanonX
OldCanonY = CanonY
Fire = 0
InvHitB = 0
Cycle = 0
 'Get the Invaders font (16 x 13 pixels)
Font Load "invader.fnt" As #6
 'Get the start Screen font (8 x 8 pixels)
Font Load "invmenu.fnt" As #7
 'Setting the joystick pins
 'PIN 13 = LEFT
SetPin 13,2
 'PIN 14 = RIGHT
SetPin 14,2
 'PIN 15 = Fire Button 1
SetPin 15,2
 'We start here
Cls
GoSub StartScreen
Randomize Timer
Pause 500
Cls
Timer = 0
Counter1 = 0
Counter2 = 0
Counter3 = 0
Counter4 = 0
Counter5 = 0
Counter6 = 0
RedrawInvaders = 1
 'General game loop
Do While 1
 'check if we draw a new level
 If NextLevel = 1 Then GoSub DrawNextLevel
 'check if we have to move the Invaders
 If Counter1 >= InvInterval Then
  Sound 300,50
  Timer = 0
  GoSub MoveInvaders
  RedrawInvaders = 1
  If Cycle = 0 Then Cycle = 1 Else Cycle = 0
 EndIf
 'check if we redraw the Invaders fire
 'at new positions
 If Counter2 >= InvFireSpeed Then
  Counter2 = 0
  GoSub InvFireShow
 EndIf
 'Check if one of the invader can fire
 If Counter3 >= InvFireTimer Then
  Counter3 = 0
  GoSub InvNewFire
 EndIf
 'Check if we activate the Mistery Ship
 If (Counter4 >= InvMiInterval) And (MisteryOn = 0) Then
  MisteryOn = 1
 EndIf
 'Check if we show the Mistery Ship
 If (MisteryOn = 1) And (Counter6 >= InvMiSpeed) Then
  Counter6 = 0
  GoSub MoveMistery
 EndIf
 char = Asc(Inkey$)
 'check if we move the Canon to Left
 If (char = 130) Then
  OldCanonX = CanonX
  CanonX = CanonX - 2
  If CanonX < 0 Then CanonX = 0
 EndIf
 'check if we move the Canon to Right
 If (char = 131) Then
  OldCanonX = CanonX
  CanonX = CanonX + 2
  If CanonX > 285 Then CanonX = 285
 EndIf
 'check if we Fire
 If (char = 32) And (Fire = 0) Then
  GoSub CanonFire
 EndIf
 'check if we kill a Invaders
 If (Fire = 1) And (Counter5 >= FireSpeed) Then
  Counter5 = 0
  OldFireCoord(1) = FireCoord(1)
  OldFireCoord(2) = FireCoord(2)
  FireCoord(2) = FireCoord(2) - 5
  If (FireCoord(2) <= ActMaxY) Then GoSub CheckKill
  GoSub CanonHitBunker
  If FireCoord(2) < 0 Then
   Line (OldFireCoord(1) , OldFireCoord(2)) - (OldFireCoord(1) , OldFireCoord(2) - 3),0
   Fire = 0
  EndIf
 EndIf
 'Actualize all Counters
 Counter1 = Timer
 Counter2 = Counter2 + 1
 Counter3 = Counter3 + 1
 Counter4 = Counter4 + 1
 Counter5 = Counter5 + 1
 Counter6 = Counter6 + 1
 GoSub Redraw
Loop
 'Draw a new level and set the variables
DrawNextLevel:
Level = Level + 1
If Level = 10 Then GoTo YouWin
InvInterval = 200 - ((Level - 1) * 10)
If InvInterval < 40 Then InvInterval = 40
InvFireTimer = 20 - ((Level - 1) * 2)
If InvFireTimer < 10 Then InvFireTimer = 10
InvaderX = 16
InvaderY = 21
CanonX = 100
CanonY = 180
Fire = 0
 'Set the Invaders
For a = 1 To 5
 For b = 1 To NbCols
  Invaders(a , b) = 1
 Next b
Next a
For a = 1 To NbInvFire
 InvFireCoord(a,1) = -1
 InvFireCoord(a,2) = -1
Next a
For a = 1 To 5
 InvLine(a) = NbCols
 InvErase(a) = 1
 InvChar$(a , 1) = "c"
 InvChar$(a , 1) = "a"
 InvChar$(a , 1) = "b"
 InvChar$(a , 1) = "e"
 InvChar$(a , 1) = "f"
 InvChar$(a , 2) = "d"
 InvChar$(a , 2) = "b"
 InvChar$(a , 2) = "a"
 InvChar$(a , 2) = "f"
 InvChar$(a , 2) = "e"
Next a
InvMaxY = OriginMaxY
MinX = 0 : MaxX = 120
NbInvFire = 5 + (Level - 1)
InvFireTimer = 25 - ((Level - 1) * 2)
InvFireSpeed = 25 - (Level - 1)
 'Draw the Level
Cls
GoSub ShowBunker
GoSub Redraw
NextLevel = 0
Return
MoveInvaders:
OldInvaderX = InvaderX
OldInvaderY = InvaderY
InvaderX = InvaderX + Dx
If InvaderX < MinX Then
 InvaderX = MinX
 OldInvaderY = InvaderY
 InvaderY = InvaderY + 5
 InvInterval = InvInterval - 10
 If InvInterval < 40 Then InvInterval = 40
 Dx = Abs(Dx)
EndIf
If InvaderX > MaxX Then
 InvaderX = MaxX
 OldInvaderY = InvaderY
 InvaderY = InvaderY + 5
 InvInterval = InvInterval - 10
 If InvInterval < 40 Then InvInterval = 40
 Dx = -Dx
EndIf
If InvaderY >= InvMaxY Then
 GoTo GameOver
EndIf
Return
MoveMistery:
OldMisteryX = MisteryX
MisteryX = MisteryX - 3
If MisteryX < 0 Then
 Line (OldMisteryX , 0) - (OldMisteryX + 16, 20) , 0,BF
 MisteryOn = 0
 Counter4 = 0
 MisteryX = 280
EndIf
Return
Redraw:
 'Draw the Invaders
Font #6
If RedrawInvaders = 1 Then
 For a = 1 To 5
  InvLine$(a) = ""
 Next a
 If Cycle = 0 Then
  For a = 1 To 5
   For b = 1 To NbCols
    If Invaders(a , b) <> 121 Then
     InvLine$(a) = InvLine$(a) + InvChar$(a , 1)
    Else
     InvLine$(a) = InvLine$(a) + Chr$(121)
    EndIf
   Next b
  Next a
 Else
  For a = 1 To 5
   For b = 1 To NbCols
    If Invaders(a , b) <> 121 Then
     InvLine$(a) = InvLine$(a) + InvChar$(a , 2)
    Else
     InvLine$(a) = InvLine$(a) + Chr$(121)
    EndIf
   Next b
  Next a
 EndIf
 For a = 1 To 5
  If InvLine(a) <> 0 Then
   oy1 = OldInvaderY + ((a - 1) * 20)
   oy2 = OldInvaderY + ((a - 1) * 20) + 13
   oy3 = InvaderY + ((a - 1) * 20)
   Line (OldInvaderX , oy1) - (OldInvaderX + (16 * NbCols) , oy2),0,BF
   Print @(InvaderX , oy3) InvLine$(a)
   ActMaxY = oy2
  EndIf
 Next a
 RedrawInvaders = 0
EndIf
 'Draw the Canon
Line (OldCanonX , OldCanonY) - (OldCanonX + 16, OldCanonY + 13) , 0,BF
Print @(CanonX , CanonY) Chr$(Canon)
 'Draw the Mistery Ship
If MisteryOn = 1 Then
 Line (OldMisteryX , 0) - (OldMisteryX + 16, 20) , 0,BF
 Print @(MisteryX , 0) Chr$(Mistery)
EndIf
 'Draw the Canon Fire
If Fire = 1 Then
  Line (OldFireCoord(1) , OldFireCoord(2)) - (OldFireCoord(1) , OldFireCoord(2) - 3),0
  Line (FireCoord(1) , FireCoord(2)) - (FireCoord(1) , FireCoord(2) - 3),1
EndIf
 'Draw Lives , Score and Level
Font #1
Print @(1,200) "Lives = "; Lives
Print @(100,200) "Score = "; Score
Print @(200,200) "Level = "; Level
Return
InvNewFire:
a = 1
ValidFire = 0
Do While a <= NbInvFire
 If InvFireCoord(a,1) = -1 And InvFireCoord(a,2) = -1 Then
  x = Int(Rnd * 10) + 1
  y = Int(Rnd * 4) + 1
  If Invaders(y , x) <> 121 Then ValidFire = 1
  If ValidFire = 1 Then
   InvFireCoord(a,1) = InvaderX + ((x - 1) * 16) + 8
   InvFireCoord(a,2) = InvaderY + (y * 20)
   InvFireOld(a,1) = InvFireCoord(a,1)
   InvFireOld(a,2) = InvFireCoord(a,2)
   a = NbInvFire + 1
  EndIf
 EndIf
 a = a + 1
Loop
Return
InvFireShow:
a = 1
Do While a <= NbInvFire
 Dead = 0
 InvHitB = 0
 If InvFireCoord(a,1) <> -1 And InvFireCoord(a,2) <> -1 Then
  InvFireOld(a,1) = InvFireCoord(a,1)
  InvFireOld(a,2) = InvFireCoord(a,2)
  InvFireCoord(a,2) = InvFireCoord(a,2) + 5
  x = InvFireCoord(a,1) : y = InvFireCoord(a,2)
  Line (InvFireOld(a,1) , InvFireOld(a,2)) - (InvFireOld(a,1) , InvFireOld(a,2) + 3),0
  Line (InvFireCoord(a,1) , InvFireCoord(a,2)) - (InvFireCoord(a,1) , InvFireCoord(a,2) + 3),1
  GoSub CheckDead
  If Dead = 1 Then
   Line (InvFireCoord(a,1) , InvFireCoord(a,2)) - (InvFireCoord(a,1) , InvFireCoord(a,2) + 3),0
   InvFireCoord(a,1) = -1
   InvFireCoord(a,2) = -1
   Dead = 0
  EndIf
  GoSub InvHitBunker
  If y > (CanonY + 3) Then
   Line (InvFireCoord(a,1) , InvFireCoord(a,2)) - (InvFireCoord(a,1) , InvFireCoord(a,2) + 3),0
   InvFireCoord(a,1) = -1
   InvFireCoord(a,2) = -1
  EndIf
 EndIf
 a = a + 1
Loop
Return
CanonFire:
Fire = 1
FireCoord(1) = CanonX + 8
FireCoord(2) = CanonY
OldFireCoord(1) = FireCoord(1)
OldFireCoord(2) = FireCoord(2)
GoSub beepFire
Return
CheckKill:
If (FireCoord(1) >= InvaderX) And (FireCoord(1) <= (InvaderX + 175)) Then
 FireColumn = Int((FireCoord(1) - InvaderX) / 16) + 1
 If ((FireCoord(2) - 3) >= InvaderY) And ((FireCoord(2) - 3) <= (InvaderY + 93)) Then
  FireLine = Int((FireCoord(2) - 3 - InvaderY) / 20) + 1
  If Invaders(FireLine , FireColumn) <> 121 Then
   Invaders(FireLine , FireColumn) = 121
   Score = Score + InvScore(FireLine)
   Line (OldFireCoord(1) , OldFireCoord(2)) - (OldFireCoord(1) , OldFireCoord(2) - 3),0
   Fire = 0
   GoSub beepKillInv
   GoSub CheckLevel
  EndIf
 EndIf
EndIf
If MisteryOn = 1 Then
 x1 = MisteryX
 x2 = MisteryX + 16
 y1 = 0
 y2 = 13
 If FireCoord(1) >= x1 And FireCoord(1) <= x2 And FireCoord(2) >= y1 And FireCoord(2) <= y2 Then
  Score = Score + InvMiScore + Int(Rnd * 100) + 100
  Line (OldFireCoord(1) , OldFireCoord(2)) - (OldFireCoord(1) , OldFireCoord(2) - 3),0
  Line (OldMisteryX , 0) - (OldMisteryX + 16, 20) , 0,BF
  Fire = 0
  MisteryOn = 0
  Counter4 = 0
  MisteryX = 280
  GoSub beepKillMis
 EndIf
EndIf
Return
CheckDead:
If (x >= CanonX) And (x <= (CanonX + 16)) And (y >= CanonY) And (y <= (CanonY + 13)) Then
 Font #6
 'We loose one Canon
 Locate CanonX , CanonY : Print Chr$(119)
 Sound 800,200
 Pause 300
 Sound 600,200
 Pause 300
 Locate CanonX , CanonY : Print Chr$(120)
 Sound 300,200
 Pause 500
 Lives = Lives - 1
 Sound 500,200
 Pause 200
 Locate CanonX , CanonY : Print Chr$(121)
 Dead = 1
 'Check if we loose the game
 If Lives = 0 Then GoTo GameOver
Else
 Dead = 0
EndIf
Return
CanonHitBunker:
If (FireCoord(2) >= 160) And (FireCoord(2) <= 179) Then
 ax = FireCoord(1) : ay = FireCoord(2)
 If Pixel(ax , ay + 1) <> 0 Then
  Sound 1200,50
  For b = 1 To 10
   x = FireCoord(1) + ( Int(Rnd * 10) - 5)
   y = FireCoord(2) + ( Int(Rnd * 10) - 5)
   Pixel(x , y) = 0
  Next b
  Line (ax - 2 , ay - 2) - (ax + 2 , ay + 2) , 0 , BF
  Line (OldFireCoord(1) , OldFireCoord(2)) - (OldFireCoord(1) , OldFireCoord(2) - 3),0
  Fire = 0
 EndIf
EndIf
Return
InvHitBunker:
 'Check if Invaders hit the bunkers
If (y >= 160) And (y <= 179) Then
 If Pixel(x , y - 1) <> 0 Then
  'Invaders hit the bunkers
   Sound 1200,50
   For b = 1 To 10
    x1 = x + ( Int(Rnd * 10) - 5)
    y1 = y + ( Int(Rnd * 10) - 5)
    Pixel(x1 , y1) = 0
   Next b
   Line (x - 2 , y - 2) - (x + 2 , y + 2) , 0 , BF
   Line (InvFireCoord(a,1) , InvFireCoord(a,2)) - (InvFireCoord(a,1) , InvFireCoord(a,2) + 3),0
   InvFireCoord(a,1) = -1
   InvFireCoord(a,2) = -1
 EndIf
EndIf
Return
ShowBunker:
 'Show the 4 bunkers
For a = 1 To 4
 Line (a * 60 , 160) - (a * 60 + 30 , 179) , 1 , BF
 Line (a * 60 + 10, 175) - (a * 60 + 20 , 180) , 0 , BF
Next a
Return
beepKillInv:
Sound 1200,50
Return
beepKillMis:
Sound 1100,50
Pause 50
Sound 1300,50
Pause 50
Sound 1200,50
Pause 50
Sound 1400,50
Return
beepFire:
Sound 1000,50
Return
CheckLevel:
 'Here we look if we killed all Invaders
For l = 1 To 5
 InvLine(l) = 0
Next l
For l = 1 To NbCols
 InvCols(l) = 0
Next l
For l = 1 To 5
 For m = 1 To NbCols
  If Invaders (l , m) <> 121 Then
   InvLine(l) = InvLine(l) + 1
   InvCols(m) = InvCols(m) + 1
  EndIf
 Next m
Next l
If InvLine(1) = 0 And InvLine(2) = 0 And InvLine(3) = 0 And InvLine(4) = 0 And InvLine(5) = 0 Then
 'We finish the Level
 NextLevel = 1
EndIf
For l = 1 To 5
 If (InvLine(l) = 0) And (InvErase(l) <> 0) Then
  InvErase(l) = 0
  Line (OldInvaderX , OldInvaderY + (( l - 1) * 20)) - (OldInvaderX + (16 * NbCols) , OldInvaderY + (( l - 1) * 20) + 13),0,BF
 EndIf
Next l
If InvLine(5) = 0 Then InvMaxY = OriginMaxY + 20
If (InvLine(4) = 0) And (InvLine(5) = 0) Then InvMaxY = OriginMaxY + 40
If (InvLine(3) = 0) And (InvLine(4) = 0) Then InvMaxY = OriginMaxY + 60
If (InvLine(2) = 0) And (InvLine(3) = 0) Then InvMaxY = OriginMaxY + 80
For l = 1 To NbCols
 If InvCols(l) = 0 Then
  MinX = 0 - (SprWide * l)
 Else
  l = NbCols + 1
 EndIf
Next l
For l = NbCols To 1 Step - 1
 If InvCols(l) = 0 Then
  MaxX = 120 + (SprWide * (NbCols - l))
 Else
  l = 0
 EndIf
Next l
Return
 'You loose the game
GameOver:
Font #1
Cls
Print @(120,100) "G A M E - O V E R"
Pause 5000
Run
 'You win the game at Level 10
YouWin:
Font #1
Cls
Print @(120,100) "Y O U - W I N"
Pause 5000
Run
 'Start Screen
StartScreen:
Cls
Font #1
Print @(140,50) "PLA"
Font #7
Print @(159,50) "Y"
Font #1
Print @(120,70) "SPACE  INVADERS"
Print @(100,90) "*SCORE ADVANCE TABLE*"
Font #6
Print @(115,105) Chr$(117)
Font #1
Print @(132,108) "=?  MYSTERY"
Font #6
Print @(115,125) "c"
Font #1
Print @(132,128) "=30  POINTS"
Font #6
Print @(115,145) "a"
Font #1
Print @(132,148) "=20  POINTS"
Font #6
Print @(115,165) "e"
Font #1
Print @(132,168) "=10  POINTS"
Print @(110,200) "PRESS FIRE TO START"
Cnt = 0
Animate = 0
AnimX = 290
OldAnimX = AnimX
Spr = 90
Do While (Inkey$ = "")
 Cnt = Cnt + 1
 If (Cnt > 3000) And (Animate = 0) Then
  Animate = 1
  Font #7
 EndIf
 If Animate = 1 Then
  'Go to the reversed 'Y'
  If Spr = 90 Then Spr = 91 Else Spr = 90
  px1 = OldAnimX - 1 : px2 = OldAnimX + 12
  Line (px1 , 50) - (px2 , 61) , 0 , BF
  Pause 5
  Print @(AnimX , 50) Chr$(Spr);
  Pause 5
  OldAnimX = AnimX
  AnimX = AnimX - 1
  If AnimX <= 167 Then
   Animate = 2
   OldAnimX = OldAnimX - 8
   AnimX = AnimX - 8
  EndIf
 EndIf
 If Animate = 2 Then
  'Take the reversed 'Y' away
  If Spr = 90 Then Spr = 91 Else Spr = 90
  Font #7
  px1 = OldAnimX - 1 : px2 = OldAnimX + 22
  Line (px1 , 50) - (px2 , 61) , 0 , BF
  Pause 5
  Locate AnimX , 50 : Print "Y"; Chr$(Spr);
  Pause 5
  OldAnimX = AnimX
  AnimX = AnimX + 1
  If AnimX >= 282 Then Animate = 3
 EndIf
 If Animate = 3 Then
  'Put the good 'Y' in place
  If Spr = 90 Then Spr = 91 Else Spr = 90
  px1 = OldAnimX - 1 : px2 = OldAnimX + 22
  Line (px1 , 50) - (px2 , 61) , 0 , BF
  Pause 5
  Font #1
  Print @(AnimX , 50) "Y";
  Font #7
  Print @(AnimX + 8 , 50) Chr$(Spr);
  Pause 5
  OldAnimX = AnimX
  AnimX = AnimX - 1
  If AnimX <= 158 Then
   Animate = 4
   OldAnimX = OldAnimX + 8
   AnimX = AnimX + 8
  EndIf
 EndIf
 If Animate = 4 Then
  'Invader go away alone
  If Spr = 90 Then Spr = 91 Else Spr = 90
  px1 = OldAnimX - 1 : px2 = OldAnimX + 12
  Line (px1 , 50) - (px2 , 61) , 0 , BF
  Pause 5
  Print @(AnimX , 50) Chr$(Spr);
  Pause 5
  OldAnimX = AnimX
  AnimX = AnimX + 1
  If AnimX >= 290 Then
   Animate = 5
   Line (AnimX - 1 , 50) - (AnimX + 12, 61) , 0 , BF
  EndIf
 EndIf
 If Cnt > 4000 Then Cnt = 0
Loop
Return