mode 2,8
cls 
load png "assets\title_8bit3.png",0,0

RotFix=-1
if mm.info(version)>5.0505 then RotFix=1

const SCREEN_BUFFER = 1
const SCREEN_GROUND_SPRITES_1 = 3
const SCREEN_PLAYER_SPRITES_1 = 4
const SCREEN_UI_ELEMENTS = 5
const SCREEN_EXPLOSIONS=6
const SCREEN_ENEMY_SPRITES=7
const SCREEN_BLUEPRINT=8
const SCREEN_BLAST=9
const SCREEN_HIGHSCORE=10

const GAME_STATE_START_SCREEN = 1
const GAME_STATE_RUNNING = 2
const GAME_STATE_GAME_OVER = 3
const GAME_STATE_PAUSED=4
const GAME_STATE_HIGHSCORE=5

dim float x,y, x2, y2, diffx,diffy
dim float cl,sl ' Sin and Cosine cahce variables
'dim int t ' General looping and temporary variables
dim float FPS_Timer, FPS_Scan_Count ' Used to track the frames per second
'dim int Game_State ' 1 = Title Page, 2= runn
dim float Player_Angle_Degrees = 0 ' Angle in degrees of the players helicopter
dim float Player_Angle_Radians = 0 ' Derived from Player_Angle_Degrees (read only)
dim float Player_X = 150 ' Player X co-ordinate in 300 x 300 world
dim float Player_Y = 150 ' Player Y co-ordinate in 300 x 300 world
dim float Player_Inertia_X=0
dim float Player_Inertia_Y=0
dim float Player_Boost=0
dim float Player_Boost_Charge=0
dim float Player_Armour=100
dim float Player_Ammo=1000
dim float Player_Fuel=100
dim integer Player_Score=0
dim integer Player_Money=0
dim integer Player_Hover_Count=0 ' Used to detect if the player is hovering long enough to refuel
dim integer index
dim integer HighScore(100)
dim integer GameState=1
dim Enemy_X(10)
dim Enemy_Y(10)
dim Enemy_Angle(10)
dim Enemy_DX(10)
dim Enemy_DY(10)
dim Enemy_Health(10)
dim Enemy_Speed(10)
dim Enemy_OnRadar(10)

dim Explosion_Step%(20)
dim Explosion_X(20)
dim Explosion_Y(20)
dim Explosion_Type(20)   ' 0-Missile, Non Zero-Building type (this allows us to change react ammo dumps)
dim Explosion_DX(20,4)
dim Explosion_DY(20,4)

' Used to optimise the number of sprites we need to show on the screen
dim Grid_Min_X%(360)
dim Grid_Max_X%(360)
dim Grid_Min_Y%(360,20)
dim Grid_Max_Y%(360,20)

dim GrndSpriteX(50)
dim GrndSpriteY(50)
dim menuText$(8)
dim float Bullet_X(40)
dim float Bullet_Y(40)
dim float Bullet_DX(40)
dim float Bullet_DY(40)
boomChannel=3
MasterVol=64

for grnd%=1 to 50
  GrndSpriteX(grnd%)=int(grnd% mod 13)
  GrndSpriteY(grnd%)=int(grnd%/13)
next grnd%

page write SCREEN_HIGHSCORE
load bmp "assets\scrHighScore.bmp"

LoadHighScoreTable()
LastHighScore=0
' Build map
dim integer Map_Ground(300,300)
dim float Map_Health(300,300)
page write SCREEN_BLUEPRINT
load png "assets\Blueprint1.png",0,0

' Setup initial enemies
for e=1 to 10
  Enemy_Health(e)=6
  Enemy_X(e)=10+rnd*280
  Enemy_Y(e)=10+rnd*100
  Enemy_Angle(e)=rnd*6
  Enemy_Speed(e)=0.05
next e

page write SCREEN_PLAYER_SPRITES_1
load bmp "assets\scrPlayerSprites.bmp"

page write SCREEN_EXPLOSIONS
cls
load png "assets\explosion.png",0,0
load png "assets\drone2.png",407,7

page write SCREEN_ENEMY_SPRITES
' Now produce all of the rotated sprites
' 640x400 - need 46x46 per sprite - 13 across x 8 down (104 sprites)
' so lets do 5 degree rotations on the enemy sprites. 360/5=72
load bmp "assets\scrEnemySprites.bmp"

page write SCREEN_BLAST
load bmp "assets\scrBlast.bmp"

page write SCREEN_GROUND_SPRITES_1 ' Sprite source screen
' Each sprite has a blank area directly below it reserved for a temporary rotated version
' 32+7+7=46 width for each sprite
' Each 32x32 sprite is written to location 7,7 in the 46x46 area to give it space for rotation
load bmp "assets\scrGroundSprites.bmp"

dim Asset_Rotation%(50)
for t=0 to 50:Asset_Rotation%(t)=-720:Next ' Make sure all rotations are invalid, so they get regenerated
Game_State = GAME_STATE_RUNNING
dim px%(8)=(100,640,640,500,300,200,500,400,450)
dim py%(8)=(0,0,400,300,250,200,100,50,25)

page write SCREEN_UI_ELEMENTS
load bmp "assets\scrUIElements.bmp"

' Explaining Grin_Min/Max_X/Y arrays:
' Originally we displayed the grids that were -6 to +6 each side, and above and below the player. 
' This is enough to keep the screen fully populated. It draws up to 169 sprites to fill the screen
' However if the player rotates 45 degrees, the corners of the screen will show sprites from further
' away (up to 8 squares). So they will appear blank unless we extend the player drawing field to
' -8 to +8 from the player location on the X and the y axis. This increaes the max sprite count to 
' 289. This is 70% more sprites. Killing the frame rate
' Of course, if the player is at 45 degrees, a lot of those outer sprites are going to be off the
' screen. So we use an algorithm to calculate for each of the 360 possible angles what the min and max
' values for the X component are, and then for each of those X lines, what the min and max Y values
' would be for that X line.
' These are stored in Grid_Min_X%(angle), Grid_Max_X%(angle), Grid_Min_Y%(angle,x value) and
' Grid_Max_Y%(angle, x value)
' The values for these arrays are calculated in subroutine CalculateScreenAreaBasedOnAngle()
' It takes a while to run, so once it had finished I saved it to a file and now I just load
' the file from SD card to keep the program load time fast.
' I have left the subroutine intact though in case anyone wants to use it themselves.
' At the time of writing, this algorithm caused an increase in fram rate from 22 fps to 28 fps on
' average. So definitely worth doing.
open "gridarray.dat" for input as #1
for k=0 to 360
  input #1, Grid_Min_X%(k)
  input #1, Grid_Max_X%(k)
  for j=0 to 20
    input #1, Grid_Min_Y%(k,j)
    input #1, Grid_Max_Y%(k,j)
  next j
next k
close #1
'CalculateScreenAreaBasedOnAngle()


dim integer Radar_Line=0
map(32)=RGB(0,0,0)
map(68)=RGB(32,32,32)
Page Write SCREEN_BUFFER
' Main loop
Fire_Toggle=1
Colour_Cycle%=0
Enemy_Step=1
High_Score_Cursor=100
GameState=GAME_STATE_HIGHSCORE
EndOfGameCounter=100
'lt=timer
'framecount=0
LongFlash=0
ResetGameVariables()
play modfile "assets\stranger_-_run.mod",8000

do
  FPS_Timer=timer
  LongFlash=LongFlash+1
  if LongFlash>20 then LongFlash=0
  if GameState=GAME_STATE_GAME_OVER then 
    EndOFGameCounter=EndOfGameCounter+1

    if EndOfGameCounter>=100 then
      LastHighScore=Player_Score
      ResetGameVariables()
      GameState=GAME_STATE_HIGHSCORE
    endif
  endif
  if GameState=GAME_STATE_HIGHSCORE then
    DrawHighScoreScreen()
    goto EndOfGameLoop
  endif
  if GameState=GAME_STATE_PAUSED or GameState=GAME_STATE_START_SCREEN then
    DrawMenuScreen() 
    goto EndOfGameLoop
  endif
  cls rgb(128,128,128)

  ' Colours are 3 bytes for Red, 3 Bytes for Green, 2 bytes for blue.
  ' So 001 011 00 is RGB(32,96,0) because the colours jump up in 32s
  ' i.e. 001*32, 3*32, 0*32
  Map(4)=RGB(0,0,0): Map(8)=RGB(0,0,0): Map(12)=RGB(0,0,0): Map(16)=RGB(0,0,0)
  Map(36)=RGB(0,0,0): Map(40)=RGB(0,0,0): Map(44)=RGB(0,0,0):Map(48)=RGB(0,0,0)
  Colour_Cycle%=Colour_Cycle%+1
  if Colour_Cycle%>7 then Colour_Cycle%=0  
  if Colour_Cycle%=0 then Map(4)=RGB(0,148,255)
  if Colour_Cycle%=1 then Map(8)=RGB(0,148,255)
  if Colour_Cycle%=2 then Map(12)=RGB(0,148,255)
  if Colour_Cycle%=3 then Map(16)=RGB(0,148,255)
  if Colour_Cycle%=4 then Map(36)=RGB(0,148,255)
  if Colour_Cycle%=5 then Map(40)=RGB(0,148,255)
  if Colour_Cycle%=6 then Map(44)=RGB(0,148,255)
  if Colour_Cycle%=7 then Map(48)=RGB(0,148,255)
  Map Set


  Fire_Toggle=Fire_Toggle*-1
  ' Check and see if the player is hovering (i.e. no key press)
  if keydown(0)=0 then
    Player_Hover_Count=Player_Hover_Count+1
  else
    Player_Hover_Count=0
  endif

  player_base_sprite=0
'  speed=0.2
  Player_Boost_Charge=Player_Boost_Charge+0.1   '+0.1 ' Slow recharge
  if Player_Boost_Charge>100 then Player_Boost_Charge=100
  Player_Fire=0
  Player_Slide_Left=0
  Player_Slide_Right=0

  'Process key strokes
  ScanKeyboard()

  if GameState=GAME_STATE_RUNNING then 
    if kbd_left then Player_Angle_Degrees=Player_Angle_Degrees-4: player_base_sprite=4
    if kbd_right then Player_Angle_Degrees=Player_Angle_Degrees+4: player_base_sprite=8    
    if kbd_up then Player_Inertia_Y1=-cl*Player_Speed:Player_Inertia_X1=sl*Player_Speed   ' Up cursor
    if kbd_down then Player_Inertia_Y1=cl*Player_Speed:Player_Inertia_X1=-sl*Player_Speed   ' Down cursor
    if Fire_Toggle=1 and kbd_w then Player_Fire=Player_Gun_Count  'W = Fire
    if Player_Boost_Charge> 3 and kbd_s then Player_Boost=Player_Boost+1:Player_Boost_Charge=Player_Boost_Charge-1
    if kbd_a then Player_Slide_Left=1     ' A - Strafe left
    if kbd_d then Player_Slide_Right=1   ' D - Strafe right
    if kbd_f1 then GameState=GAME_STATE_PAUSED
  endif
  ' There are 3 possible source of inertia on the chopper
  ' 1 is from the up/down (Forward-back) cursor keys
  ' 2 is from strafing left or right (A/D keys)
  ' 3 is from the boost (S key)

  if Player_Slide_Right=1 then 
    Player_Inertia_Y2=sl*Player_Speed
    Player_Inertia_X2=cl*Player_Speed
    if Player_Base_Sprite=0 then Player_Base_Sprite=8   ' Use the right leaning sprite
  endif    
  if Player_Slide_Left=1 then
    Player_Inertia_Y2=-sl*Player_Speed
    Player_Inertia_X2=-cl*Player_Speed
    if Player_Base_Sprite=0 then Player_Base_Sprite=4   ' Use the left leaning sprite
  end if

  Player_Inertia_X3=0    ' Boost inertia
  Player_Inertia_Y3=0

  if Player_Boost_Charge<=0 then Player_Boost_Charge=0
  if Player_Boost>=0 then 
    if Player_Boost>20 then Player_Boost=20 ' Max Boost
    Player_Inertia_Y3=-cl*Player_Boost/20
    Player_Inertia_X3=sl*Player_Boost/20
    Player_Boost=Player_Boost-0.5
  else
    Player_Boost=0
  endif
  Player_X=Player_X+Player_Inertia_X1+Player_Inertia_X2+Player_Inertia_X3
  Player_Y=Player_Y+Player_Inertia_Y1+Player_Inertia_Y2+Player_Inertia_Y3

  ' Reduce the inertia's to slow the chopper down  
  ' Note: The boost inertia will naturally fade away   
  if abs(Player_Inertia_X1)>0.01 then 
    Player_Inertia_X1=Player_Inertia_X1-(Player_Inertia_X1*0.1)
  else
    Player_Inertia_X1=0
  endif
  if abs(Player_Inertia_Y1)>0.01 then 
    Player_Inertia_Y1=Player_Inertia_Y1-(Player_Inertia_Y1*0.1)
  else
    Player_Inertia_Y1=0
  endif
 
  if abs(Player_Inertia_X2)>0.01 then 
    Player_Inertia_X2=Player_Inertia_X2-(Player_Inertia_X2*0.1)    ' Left right straff inertia
  else
    Player_Inertia_X2=0
  endif
  if abs(Player_Inertia_Y2)>0.01 then 
    Player_Inertia_Y2=Player_Inertia_Y2-(Player_Inertia_Y2*0.1)    ' Left right straff inertia
  else
    Player_Inertia_Y2=0
  endif
  Player_Fuel=Player_Fuel-0.01

  ' Make sure player doesn't fly off the edge of the map
  if Player_X<10 then Player_X=10
  if Player_X>290 then Player_X=290
  if Player_Y<10 then Player_Y=10
  if Player_Y>290 then Player_Y=290

  ' See if the player has been hovering long enough near a fuel or ammo dump to resupply
  if Player_Hover_count>Player_Hover_Limit then
    Refuel_Count=0
    Rearm_Count=0
    for refx=Player_X-1 to Player_X+1
      for refy=Player_Y-1 to Player_Y+1
        if Map_Ground(refx,refy)=6 then Rearm_Count=Rearm_Count+1
        if Map_Ground(refx,refy)=3 then Refuel_Count=Refuel_Count+1
      next refy
    next refx
    Player_Ammo=Player_Ammo+Rearm_Count*4
    if Player_Ammo>Player_Max_Ammo then Player_Ammo=Player_Max_Ammo
    Player_Fuel=Player_Fuel+Refuel_Count/10
    if Player_Fuel>Player_Max_Fuel then Player_Fuel=Player_Max_Fuel
  endif
   
  if Player_Angle_Degrees >= 360 then Player_Angle_Degrees = Player_Angle_Degrees - 360
  if Player_Angle_Degrees <0 then Player_Angle_Degrees = Player_Angle_Degrees + 360
  Player_Angle_Radians = (Player_Angle_Degrees/180) * 3.1415

  blade_rotation=blade_rotation+1
  if blade_rotation>=4 then blade_rotation=0
  player_spriteX=Player_Base_Sprite+blade_rotation   

  blitFlag = &B100
    
  cl =cos(Player_Angle_Radians)
  sl =sin(Player_Angle_Radians)

  'Rotate the sprites required for this screen  
  'Then draw them
  DrawRotatedMapSprites()

  'Do Enemy AI - Just do one enemy AI per turn (as deifned by Enemy_Step)
  if Enemy_Health(Enemy_Step)>0 then
    ' work out desired heading
    diffx=Enemy_X(Enemy_Step)-Player_X
    diffy=Enemy_Y(Enemy_Step)-Player_Y
    newangle=atan2(diffy,diffx)-1.57
    if newangle<0 then newangle=newangle+6.283
    newangledeg=(newangle*180)/3.1415
    diffangle=Enemy_Angle(Enemy_Step)-newangle+rnd*0.3-0.15
    ' Do we turn left or right
    if diffangle<-3.1415 then diffangle=diffangle+6.283
    if diffangle>3.1415 then diffangle=diffangle-6.283
    ' Note angles are in radians. Where 180 degrees = pi
    if Enemy_Speed(Enemy_Step)>0.2 then
      Fast_Turn=0.25
      Slow_Turn=0.1
    else
      Fast_Turn=Enemy_Step/10   ' Give each missile a different speed when homing in on the player
      Slow_Turn=0.25
    endif

    if abs(diffangle)<1 then 'small turn
      Enemy_Angle(Enemy_Step)=Enemy_Angle(Enemy_Step)-sgn(diffangle)*Slow_Turn
    else
      Enemy_Angle(Enemy_Step)=Enemy_Angle(Enemy_Step)-sgn(diffangle)*Fast_Turn
    endif      
    if Enemy_Angle(Enemy_Step)<0 then Enemy_Angle(Enemy_Step)=Enemy_Angle(Enemy_Step)+6.283
    if Enemy_Angle(Enemy_Step)>6.283 then Enemy_Angle(Enemy_Step)=Enemy_Angle(Enemy_Step)-6.283

    Enemy_DX(Enemy_Step)=sin(Enemy_Angle(Enemy_Step))
    Enemy_DY(Enemy_Step)=-cos(Enemy_Angle(Enemy_Step))

    ' Speed is fast if far away
    dist=sqr(diffx*diffx+diffy*diffy)
    if dist>12 then 
      Enemy_Speed(Enemy_Step)=0.5
      Enemy_OnRadar(Enemy_Step)=0
    else
      Enemy_OnRadar(Enemy_Step)=1
      Enemy_Speed(Enemy_Step)=(Enemy_Step/100) +0.1 ' A bit of randomness to stop them all bunching up
    end if
    if dist<1 then ' hit
      Player_Armour=Player_Armour-10
      if Player_Armour<0 then Player_Armour=0
      StartExplosion(Enemy_X(Enemy_Step),Enemy_Y(Enemy_Step))
      Enemy_X(Enemy_Step)=10+rnd*230
      Enemy_Y(Enemy_Step)=10+rnd*230
      Enemy_Angle(Enemy_Step)=rnd*6
      Enemy_Health(Enemy_Step)=6
    endif
  end if  
  Enemy_Step=Enemy_Step+1
  if Enemy_Step=11 then Enemy_Step=1

  UpdateAndDrawEnemies()

  RunExplosions()

  UpdatePlayerBullets()

  ' Move the player up the rankings
  if High_Score_Cursor>1 then
    if Player_Score>HighScore(High_Score_Cursor-1) then High_Score_Cursor=High_Score_Cursor-1
  endif
  
  DrawUserInterface()

  'draw player
  x=player_spritex*64
  y=0
  if x>639 then x=x-640:y=80
  if GameState = GAME_STATE_RUNNING then blit x,y,168,163,64,74,SCREEN_PLAYER_SPRITES_1,&B100
  if GameState = GAME_STATE_RUNNING and (Player_Armour<=0 or Player_Fuel<=0) then
    GameState=GAME_STATE_GAME_OVER
    EndOfGameCounter=0
    UpdateHighScoreTable(Player_Score)
    for j=1 to 20
      StartExplosion(Player_X+(rnd)-0.5,player_Y+(rnd)-0.5,-1)
    next j     
  endif   
  if Player_Fuel<25 then
    if LongFlash>10 then 
      text 200,310,"LOW FUEL",CM,2,1,rgb(red)
    endif
    if Player_Fuel<20 then
      text 200,330,"HOVER OVER A FUEL DUMP TO REFUEL",CM,1,1,rgb(red)
    endif
    if Player_Fuel<0.5 then
      text 200,310,"OUT OF FUEL",CM,2,1,rgb(red)    
    endif
  endif

  if GameState = GAME_STATE_RUNNING and Player_Ammo<100 then
    if LongFlash>10 then 
      text 200,350,"LOW AMMO",CM,2,1,rgb(red)
    endif
    if Player_Ammo<20 then
      text 200,370,"HOVER OVER AN AMMO DUMP TO REFUEL",CM,1,1,rgb(red)
    endif
  endif
  FPS_Actual = (1000/(timer-FPS_Timer))*0.1 + (FPS_Actual)*0.9 ' weight the FPS to average it out
  Text 585,2, "FPS:" + str$(int(FPS_Actual)),,,,RGB(white),RGB(64,32,0)

'  print @(410,220,1) str$(int(FPS_Actual))
'  print "  " + str$(Count_of_Active_Explosions)
'  frameCount=frameCount+1
'  longFPS=frameCount/((timer-lt)/1000)
'  print @(0,0,1) "Long FPS:" + str$(longFPS)
EndOfGameLoop:
  page copy SCREEN_BUFFER, 0, B
'  page copy 3, 0, B
loop
end

sub ScanKeyboard()
  kbd_up=0
  kbd_down=0
  kbd_left=0
  kbd_right=0
  kbd_a=0
  kbd_d=0
  kbd_s=0
  kbd_w=0
  kbd_f1=0
  kbd_space=0
  kd=keydown(0)
  for key=1 to kd
    if keydown(key)=130 then kbd_left=1
    if keydown(key)=131 then kbd_right=1    
    if keydown(key)=128 then kbd_up=1
    if keydown(key)=129 then kbd_down=1
    if keydown(key)=119 or keydown(key)=87 then kbd_w=1
    if keydown(key)=115 or keydown(key)=83 then kbd_s=1
    if keydown(key)=65 or keydown(key)=97 then kbd_a=1
    if keydown(key)=100 or keydown(key)=68 then kbd_d=1
    if keydown(key)=32 then kbd_space=1
    if keydown(key)=145 then kbd_f1=1
    if keyDown(key)=146 and MasterVol>=2 then MasterVol=MasterVol-2
    if keyDown(key)=147 and MasterVol<=62 then MasterVol=MasterVol+2
  next key
end sub



sub DrawRotatedMapSprites()
  pad%=int(Player_Angle_Degrees)
  cc%=0
  page write SCREEN_BUFFER
  ' Get reference from center of screen
  PopulateLXandLY(0,0)
  x1=lx
  y1=ly
  ' Get reference one square away on x
  PopulateLxandLY(1,0)
  lx2=lx
  ly2=ly
  ' Get reference one square away on y
  PopulateLXandLY(0,1)
  lx3=lx
  ly3=ly

  dxx=lx2-x1
  dxy=ly2-y1
  dyx=lx3-x1
  dyy=ly3-y1
  for j=Grid_Min_X%(pad%) to Grid_Max_X%(pad%)
    x=int(Player_X)+j
    dxxj=x1+dxx*j
    dxyj=y1+dxy*j
    for s=Grid_Min_Y%(pad%,j+10) to Grid_Max_Y%(pad%,j+10)
      y=int(Player_Y)+s
      if Map_Ground(x,y)>0 then
        x2=dxxj+dyx*s
        y2=dxyj+dyy*s
        grnd%=Map_Ground(x,y)
        Rotation_Error%=abs(Asset_Rotation%(grnd%)-pad%)
        ' Try to limit only doing 8 rotations per cycle, unless the cached image is
        ' more than 5 degrees out (then do the one with the big error as well)
        xindex=GrndSpriteX(grnd%)
        yindex=GrndSpriteY(grnd%)
        if (Rotation_Error%>3 and cc%<8) or Rotation_Error%>5 then
          page write SCREEN_GROUND_SPRITES_1
          image rotate_fast xindex*46,yindex*92,45,45,xindex*46,yindex*92+46,-pad%,3
          Asset_Rotation%(grnd%)=pad%
          page write SCREEN_BUFFER
          cc%=cc%+1
        end if
        blit xindex*46,yindex*92+46, x2+180,y2+184,45,45,3,blitFlag
      end if
    next s
  next j
end sub

sub PopulateLXandLY(tx, ty)
  x=Player_X+tx
  diffx = (int(x)-Player_X)*32+16
  diffxcl = diffx*cl
  diffxsl=diffx*sl
  y=Player_Y+ty
  diffy = (int(y)-Player_Y)*32+16
  lx = diffxcl+diffy*sl
  ly = diffy*cl-diffxsl
end sub


sub UpdateAndDrawEnemies()
  for e=1 to 10
    ' Update enemy position
    Enemy_X(e)=Enemy_X(e)+Enemy_DX(e)*Enemy_Speed(e)
    Enemy_Y(e)=Enemy_Y(e)+Enemy_DY(e)*Enemy_Speed(e)
    if Enemy_OnRadar(e)=1 then
      diffx=Enemy_X(e)-Player_X
      diffy=Enemy_Y(e)-Player_Y
      if abs(diffx)<8 and abs(diffy)<8 then ' They might be on screen
        tx=(diffx)*32
        ty=(diffy)*32
        tx2 = tx*cl+ty*sl
        ty2 = ty*cl-tx*sl
        diffangle=Enemy_Angle(e)-Player_Angle_Radians
        if diffangle<0 then diffangle=diffangle+6.283
        if diffangle>6.283 then diffangle-diffangle-6.283
        index=int(diffangle*11.459) 'Change radians into 0 to 72 i.e. 5 deg steps (360/6.283)/5=11.459
        x=(index mod 13)*46
        y=int(index/13)*46   
        blit x,y, tx2+177,ty2+177,46,46,SCREEN_ENEMY_SPRITES,&B100      
      end if 
    endif 
  next e
end sub

sub StartExplosion(ex, ey, explosionType)
  if GameState=GAME_STATE_RUNNING THEN
    PlaySound(3)  'Boom
    if ExplosionType=0 then Player_Score=Player_Score+100   ' Missile
    if ExplosionType>0 then Player_Score=Player_Score+50   ' Building
    if ExplosionType=2 then Player_Money=Player_Money+10   ' Yellow house
    if ExplosionType=33 then Player_Money=Player_Money+100   ' Yellow pyramid
    if ExplosionType=3 then Player_Money=Player_Money+5  ' Yellow fuel dump
  endif
  for expNum=1 to 20
    if Explosion_Step%(expNum)=0 then
      Explosion_Step%(expNum)=1
      Explosion_X(expNum)=ex
      Explosion_Y(expNum)=ey
      Explosion_Type(expNum)=explosionType
      if ExplosionType<>0 then ' Non missile
        for expJ=1 to 4
          Explosion_DX(expNum,expJ)=rnd*20-10
          Explosion_DY(expNum,expJ)=rnd*20-10
        next expJ
      else
        for expJ=1 to 4
          Explosion_DX(expNum,expJ)=0
          Explosion_DY(expNum,expJ)=0
        next expJ 
      endif
      if expNum>Count_Of_Active_Explosions then Count_Of_Active_Explosions = expNum
      exit sub
    end if
  next expNum 
end sub

sub RunExplosions
'  if Count_Of_Active_Explosions>19 then Count_Of_Active_Explosions=20
  loopCount = Count_Of_Active_Explosions ' C_Of_A_E can be updated within the loop
  for et=1 to loopCount
    if Explosion_Step%(et) <> 0 then
      ' Draw sprite
      diffx = (Explosion_X(et)-Player_X)*32+16
      diffxcl = diffx*cl
      diffxsl=diffx*sl
      diffy = (Explosion_Y(et)-Player_Y)*32+16
'    x2 = diffx*cos(Player_Angle_Radians)+diffy*sin(Player_Angle_Radians)
'    y2 = diffy*cos(Player_Angle_Radians)-diffx*sin(Player_Angle_Radians)
      x2 = diffxcl+diffy*sl
      if x2>-232 and x2<200 then
        y2 = diffy*cl-diffxsl
        if y2>-232 and y2<200 then 
          ey=int(Explosion_Step%(et) / 8)
          ex=int(Explosion_Step%(et) mod 8)
          blit ex*32,ey*32,x2+180,y2+184,32,32,SCREEN_EXPLOSIONS,blitFlag
          ' If fuel or ammo dump, do shock wave
          if (Explosion_Type(et)=3 or Explosion_Type(et)=6) and Explosion_Step%(et)<7 then
            index=6-Explosion_Step%(et)
            size=(5-index)*20
            if size<10 then size=10
            blit index*100,0,x2+196-size/2,y2+200-size/2,size,size,SCREEN_BLAST,blitFlag
          endif
        endif
      endif

      xbase=x2+180+16
      ybase=y2+184+16
      for expJ=1 to 4
       
        x1= xbase+Explosion_DX(et,expJ)*Explosion_Step%(et)
        y1= ybase+Explosion_DY(et,expJ)*Explosion_Step%(et)
        x2= xbase+Explosion_DX(et,expJ)*(Explosion_Step%(et)+1)
        y2= ybase+Explosion_DY(et,expJ)*(Explosion_Step%(et)+1)
        line x1,y1,x2,y2,,rgb(red)
      next expJ

      Explosion_Step%(et)=Explosion_Step%(et)+1
      if Explosion_Step%(et)=15 then ' Fuel tank
        if Explosion_Type(et)=3 or Explosion_Type(et)=6 then ' Fuel or ammo dump - chain reaction
          for expX=Explosion_X(et)-1 to Explosion_X(et)+1
            for expY=Explosion_Y(et)-1 to Explosion_Y(et)+1
              if Map_Health(expX, expY)>0 then
                StartExplosion(expX,expY,Map_Ground(expX,expY))
                Map_Health(expX,expY)=0
                Map_Ground(expX,expY)=0
              endif
            next expY
          next expX
        endif
      endif
      if Explosion_Step%(et)=38 then 
        Explosion_Step%(et)=0
        'Update the Count of explosions, so we don't waste time each loop looking for them
        Count_Of_Active_Explosions=0
        for st=1 to 20
          if Explosion_Step%(st)>0 and st>Count_Of_Active_Explosions then Count_Of_Active_Explosions=st
        next st
      end if
    end if
  next et
end sub

MaxBullets=1
sub UpdatePlayerBullets()
  BulletCountChanged=0
  'Update and draw bullets
   if Player_Fire>0 and Player_Ammo>0 then MaxBullets=MaxBullets+4 ' create pace for 4 new bullets
   if MaxBullets>40 then MaxBullets=40

  for b=1 to MaxBullets   '40
    if Bullet_X(b)<>-1000 then ' It is active
      tx=(Bullet_X(b)-Player_X)*32
      ty=(Bullet_Y(b)-Player_Y)*32
      tx2 = tx*cl+ty*sl
      ty2 = ty*cl-tx*sl
      ' Update bullet position 
      Bullet_X(b)=Bullet_X(b)+Bullet_DX(b)
      Bullet_Y(b)=Bullet_Y(b)+Bullet_DY(b)
      ' And rotate based on player rotation
      bx=(Bullet_X(b)-Player_X)*32
      by=(Bullet_Y(b)-Player_Y)*32
      bx2 = bx*cl+by*sl
      by2 = by*cl-bx*sl
      if bx2>-232 and bx2<200 and by2>-232 and by2<200 then
        line tx2+200,ty2+200,bx2+200,by2+200,1,rgb(yellow)
        pixel bx2+200,by2+200,rgb(red)
        'Check if it hit something
        bbx=int(Bullet_X(b))
        bby=int(Bullet_Y(b))
        ' Check for ground targets
        if Map_Health(bbx,bby)>0 then
          PlaySound(2)
          Map_Health(bbx,bby) = Map_Health(bbx, bby)-Player_Damage
          if Map_Health(bbx, bby)<=0 then ' Target destroyed
            StartExplosion(bbx,bby,Map_Ground(bbx,bby))
            Map_Ground(bbx,bby)=0   ' Remove this ground item from the world
          endif
          Bullet_X(b)=-1000   ' destroy bullet
          BulletCountChanged=1
        else ' Check for air targets
          for e=1 to 10
            if Enemy_OnRadar(e) then            
              diffx=abs(Enemy_X(e)-Bullet_X(b))
              if diffx<1 then
                diffy=abs(Enemy_Y(e)-Bullet_Y(b))
                if diffy<1 then
                  Enemy_Health(e)=Enemy_Health(e)-Player_Damage
                  if Enemy_Health(e)<1 then
                    StartExplosion(Enemy_X(e),Enemy_Y(e),0)
                    'Respawn enemy
                    Enemy_X(e)=10+rnd*230
                    Enemy_Y(e)=10+rnd*230
                    Enemy_Angle(e)=rnd*6
                    Enemy_Health(e)=6
                  end if
                  Bullet_X(b)=-1000
                  BulletCountChanged=1
                end if
              end if
            end if
          next e
        end if
      else
        'Remove this bullet from active service
        Bullet_X(b)=-1000
        BulletCountChanged=1
      end if
    end if

    'Now check and see if we need to respawn a new bullet
    if Player_Fire>0 and Bullet_X(b)=-1000 and Player_Ammo>0 then
      PlaySound(1) ' Gunfire
      BulletCountChanged=1
      ' Create new bullet
      if Player_Fire=1 then
        Bullet_X(b)=Player_X+cl*0.2
        Bullet_Y(b)=Player_Y+sl*0.2
      end if
      if Player_Fire=2 then
        Bullet_X(b)=Player_X+cl*-0.2
        Bullet_Y(b)=Player_Y+sl*-0.2
      endif
      if Player_Fire=3 then
        Bullet_X(b)=Player_X+cl*0.4 
        Bullet_Y(b)=Player_Y+sl*0.4
      end if
      if Player_Fire=4 then
        Bullet_X(b)=Player_X+cl*-0.4 
        Bullet_Y(b)=Player_Y+sl*-0.4
      endif
      ' Set direction as straight up from player
      Bullet_DX(b)=sl*1 
      Bullet_DY(b)=-cl*1
      Player_Fire=Player_Fire-1
      Player_Ammo=Player_Ammo-1
    end if  
  next b

  'Compact the bullet arrays
  MaxBullets=0
  for t=1 to 40
    if Bullet_X(t)<>-1000 then
      MaxBullets=MaxBullets+1
      Bullet_X(MaxBullets)=Bullet_X(t)
      Bullet_Y(MaxBullets)=Bullet_Y(t)
      Bullet_DX(MaxBullets)=Bullet_DX(t)
      Bullet_DY(MaxBullets)=Bullet_DY(t)
      if t>maxBullets then Bullet_X(t)=-1000
    endif
  next t
end sub

sub DrawUserInterface()
  ' Draw User Interace
  box 380,0,260,400,1,rgb(255,255,255),rgb(64,32,0)     ' Right hand panel
  box 0,380,380,20,1,rgb(255,255,255),rgb(64,32,0)     ' bottom panel

  ' Update satelite radar
  page write SCREEN_UI_ELEMENTS
  Radar_Step=Radar_Step+1
  if Radar_Step=10 then 
    Radar_Step=0
    line 20,5+Radar_Line/2,170,5+Radar_Line/2,1, RGB(50,200,50) ' Blank out this line ready for pixels 
  end if
  y = Radar_Line
  startx=Radar_Step*30
  for t=startx to startx+29 step 2
    tempa=Map_Health(t,y)+ Map_Health(t+1,y)+Map_Health(t,y+1)+Map_Health(t+1,y+1)
    tempb=Map_Health(t,y+2)+ Map_Health(t+1,y+2)+Map_Health(t,y+3)+Map_Health(t+1,y+3)
    if Map_Health(t,y)+ Map_Health(t+1,y)+Map_Health(t,y+1)+Map_Health(t+1,y+1)>0 then 
      pixel 20+t/2,5+Radar_Line/2,rgb(red)
    endif
  next t
  if Radar_Step=9 then
    ' Move to next line
    Radar_Line = Radar_Line+4
    if Radar_Line=300 then Radar_line=0
    if Radar_Line<294 then line 20,5+Radar_Line/2+2,170,5+Radar_Line/2+2,1, RGB(200,200,250)  ' Draw a white line scanning down 
  endif

  page write SCREEN_BUFFER
  blit 0,0,410,25,210,370,SCREEN_UI_ELEMENTS,&B000
  box 430+Player_X/2-4, 30+Player_Y/2-4, 9,9,1, RGB(yellow)  ' Draw box in satelite radar
  
  'Draw local Radar
  for e=1 to 10
    if Enemy_OnRadar(e)=1 then
      diffx=(Enemy_X(e)-Player_X)*3
      diffy=(Enemy_Y(e)-Player_Y)*3
      newx=diffx*cl+diffy*sl
      newy=diffy*cl-diffx*sl
      if newy<35 then pixel 457+newx, 270+newy, rgb(yellow) ' If in boost mode items might shoot off bottomo radar
    endif
  next e  
  pixel 457,270, rgb(white)
  Text 427,10, "Live Satellite Feed",,,,RGB(yellow),RGB(64,32,0)

  'Draw compass arrow
  tempcl=cos(Player_Angle_Radians-0.785) ' -0.785 = Minus 45 degrees (but in radians)
  tempsl=sin(Player_Angle_Radians-0.785)
  tempcl2=cos(Player_Angle_Radians-2.356)
  tempsl2=sin(Player_Angle_Radians-2.356)
  'front point
  p0x=550+(15*tempcl+15*tempsl)
  p0y=270+(15*tempsl-15*tempcl)

  p1x=550+(-15*tempcl-15*tempsl)
  p1y=270+(-15*tempsl+15*tempcl)

  p2x=p1x+(5*tempcl2+5*tempsl2)
  p2y=p1y+(5*tempsl2-5*tempcl2)

  p3x=p1x+(-5*tempcl2-5*tempsl2)
  p3y=p1y+(-5*tempsl2+5*tempcl2)

  triangle p0x,p0y,p1x,p1y,p2x,p2y,rgb(white), rgb(100,100,100)
  triangle p0x,p0y,p1x,p1y,p3x,p3y,rgb(white), rgb(100,100,100)

  colour RGB(black)
  print @(230, 190,1) "Ammo: " + str$(Player_Ammo)
  print @(230,215,1) "Fuel: " + str$(Player_Fuel)
  print @(230,240,1) "Armour: " + str$(Player_Armour)  
  print @(230,265,1) "Boost"
  box 220,205,100,5,1,rgb(green),rgb(black)  
  box 220,205,100*(Player_Ammo/Player_Max_Ammo),5,1,rgb(black), rgb(green)  

  box 220,230,100,5,1,rgb(green),rgb(black)  
  box 220,230,100*(Player_Fuel/Player_Max_Fuel),5,1,rgb(black), rgb(green)  

  box 220,255,100,5,1,rgb(green),rgb(black)  
  box 220,255,100*(Player_Armour/100),5,1,rgb(black), rgb(green)  

  box 220,280,100,5,1,rgb(green),rgb(black)
  box 220,280,100*(Player_Boost_Charge/100),5,1,rgb(black), rgb(green)
  
  colour RGB(green)

  print @(10,385,1) "Score: " +str$(Player_Score);
  if High_Score_Cursor=1 then 
    print @(110,385,1) "HIGH SCORE !!!";
  else
    print @(110,385,1) "Rank " + str$(High_Score_Cursor) + " Next @ " +str$(HighScore(High_Score_Cursor-1));
  end if
  print @(280,385,1) "Cash $" + str$(Player_Money);

end sub

sub LoadHighScoreTable()
  on error skip
  open "highscore.dat" for input as #1
  if MM.ERRNO=0 then
    for i=1 to 100
      input #1, HighScore(i)
    next i
    close #1
  else
    ' Create new file
    for i=1 to 100
      HighScore(i)=(101-i)*500
    next i  
    WriteHighScoreTable()
  endif 
end sub

sub WriteHighScoreTable()
  open "highscore.dat" for output as #1
  for i=1 to 100
    print #1, HighScore(i)
  next i  
  close #1  
end sub

sub UpdateHighScoreTable(score)
  for i=1 to 100
    if score >HighScore(i) then
      ' This is the spot to insert
      'Move everything down one
      for j=99 to i step -1
        HighScore(j+1)=HighScore(j)
      next j
      HighScore(i)=score
      exit for
    endif
  next i
  WriteHighScoreTable()
end sub

sub ResetGameVariables
  Player_Angle_Degrees = 0 ' Angle in degrees of the players helicopter
  Player_Angle_Radians = 0 ' Derived from Player_Angle_Degrees (read only)
  Player_X = 150 ' Player X co-ordinate in 300 x 300 world
  Player_Y = 150 ' Player Y co-ordinate in 300 x 300 world
  Player_Inertia_X=0
  Player_Inertia_Y=0
  Player_Boost=0
  Player_Boost_Charge=0
  Player_Armour=100
  Player_Ammo=1000
  Player_Max_Ammo=1000
  Player_Fuel=100
  Player_Max_Fuel=100
  Player_Damage=1
  Player_Score=0
  Player_Money=2000
  Player_Hover_Count=0 ' Used to detect if the player is hovering long enough to refuel
  Player_Hover_Limit=50
  Player_Gun_Count=2
  Player_Speed=0.25
  High_Score_Cursor=100
  menuCursor=0
  menuTextCursor=1
  menuTextLine=1
  HighScoreBillBoard=1
'  LastHighScore=40000
end sub

sub DrawHighScoreScreen()
  page write 1
  blit 0,0,0,0,640,400,SCREEN_HIGHSCORE
  Colour_Cycle%=Colour_Cycle%+1
  if Colour_Cycle%>20 then Colour_Cycle%=1
  map(255)=rgb(0,0,255)
  for t=1 to 20
    map(t)=rgb(0,0,0)
    if t=Colour_Cycle% then map(t)=rgb(0,0,255)
  next t
  map set
  font 3
  for t=0 to 9
    colour rgb(yellow)
    font 3
    if HighScore(HighScoreBillBoard+t)=LastHighScore then 
      colour rgb(green)
      font 5
      print @(340,60+t*30,1) "Last Score"
      box 98,58+t*30,500,30,1,rgb(green)
    endif
    print @(100,60+t*30,1) str$(HighScoreBillBoard+t)
    print @(170,60+t*30,1) str$(HighScore(HighScoreBillBoard+t))  
  next t
  color rgb(red)
  font 5
  print @(200,5,1) "HIGH SCORERS"
  font 3
  print @(80,30,1) "Rank  Score"
  font 7
  colour rgb(yellow)
  print @(200,380,1) "Press 'space' to continue"
  font 1
  print @(290,290,1) "CREDITS"
  print @(290,305,1) "Game Design and Programming by Pete Cotton"
  print @(290,320,1) "(Poorly drawn) graphics by Pete Cotton"
  print @(290,335,1) "Music by 'stranger' on ModArchive.com"
  print @(290,350,1) "Title page generated by photofunia.com"
  font 7  

  if LastHighScore <>0 and HighScoreBillboard<91 and HighScore(HighScoreBillBoard+5)>LastHighScore then
    HighScoreBillboard=HighScoreBillBoard+1
  endif
  
  ScanKeyboard()
  if kbd_space then 
    GameState = GAME_STATE_START_SCREEN
    debounce=1 ' stop the space being registered straight away on the next screen
    map reset
    map(32)=RGB(0,0,0) ' Remap my 'black'
    map(68)=RGB(32,32,32)
    map set
  endif  
end sub

sub DrawMenuScreen()
  blit 0,0,0,0,640,400,SCREEN_BLUEPRINT
  colour RGB(green)
  font 4
  print @(0,0,1) "Mission Briefing"
  font 7
  menuText$(1)= "The International Terrorist Organisation Red Dawn are planning an attack"
  menuText$(2)= "on the World Leaders Summit in Kirzmekistan. Their base of operations has"
  menuText$(3)= "been located, but it is too remote for friendly forces to reach it in time"
  menuText$(4)= "to stop the attack. You have been authorised to take the prototype Helix"
  menuText$(5)= "HX-9000 attack helicopter and cause as much damage to the base as possible."
  menuText$(6)= "The base is heavily defended with surface to air missiles. However, you"
  menuText$(7)= "will be able to re-arm and refuel by hovering over arms and fuel dumps."
  menuText$(8)= "                                               Good luck pilot!"

  menuTextCursor=menuTextCursor+1
  for txt=1 to 8
    if menuTextLine>txt then
      print @(2,6+12*txt,1) menuText$(txt)
    endif
    if menuTextLine=txt then
      print @(2,6+12*txt,1) mid$(menuText$(txt),1,menuTextCursor)
      if menuTextCursor=len(menuText$(txt)) then menuTextCursor=1:menuTextLine=menuTextLine+1 
    endif
  next txt

  ScanKeyboard()
  Colour RGB(yellow)
  font 1
  print @(10,115,1) "You have $" + str$(Player_Money) + " to spend"
  print @(10,130,1) "Use cursor keys to navigate, and 'space' to buy"
  'font 7


  if Player_Max_Ammo<4000 then 
    Colour RGB(white)
    ammo_cost=1000 * (2^(Player_Max_Ammo/1000))
    if Player_Money<ammo_Cost then Colour RGB(black)
    print @(10,150,1) "Increase Ammo Capacity to " + str$(Player_Max_Ammo+1000)   
    print @(360,150,1) "$" + str$(ammo_cost)
  else
    Colour(RGB(black))
    print @(10,150,1) "Max Ammo Capacity reached"  
  endif 

  if Player_Max_Fuel<400 then
    colour RGB(white)
    fuel_cost=1000 * (2^((Player_Max_Fuel-50)/50))
    if Player_Money<fuel_Cost then Colour RGB(black)
    print @(10,170,1) "Increase Fuel Capacity to " + str$(Player_Max_Fuel+50) 
    print @(360,170,1) "$" + str$(fuel_cost)
  else
    Colour(RGB(black))
    print @(10,170,1) "Max Fuel Capacity reached" 
  endif

  if Player_Damage<4 then
    colour RGB(white)
    damage_cost=1000 * (2^((Player_Damage-1)*2))
    if Player_Money<damage_Cost then Colour RGB(black)
    print @(10,190,1) "Increase Damage to " + str$((Player_damage+0.5)*100) + "%" 
    print @(360,190,1) "$" + str$(damage_cost)
  else
    Colour(RGB(black))
    print @(10,190,1) "Max Damage reached" 
  endif

  if Player_Hover_Limit>0 then
    colour RGB(white)
    hover_cost=1000*(2^((60-Player_Hover_Limit)/10))
    if Player_Money<hover_Cost then Colour RGB(black)
    print @(10,210,1) "Decrease Hover Time for Resupply to " + str$((Player_Hover_Limit-10)*2) + "%" 
    print @(360,210,1) "$" + str$(hover_cost)
  else
    Colour(RGB(black))
    print @(10,210,1) "Min Hover Time for Resupply reached" 
  endif
 
  if Player_Gun_Count=2 then
    colour RGB(white)
    if Player_Money<2000 then Colour RGB(black)
    print @(10,230,1) "Upgrade to quad cannons"
    print @(360,230,1) "$2000"
  else
    Colour(RGB(black))
    print @(10,230,1) "Quad cannons purchased"
  endif

  if Player_Speed<0.4 then
    colour RGB(white)
    speed_cost=1000*(2^((Player_Speed-0.25)*20))
    if Player_Money<speed_Cost then Colour RGB(black)
    print @(10,250,1) "Increase Speed to " + str$((Player_Speed+0.05)*1000) + "km/h" 
    print @(360,250,1) "$" + str$(speed_cost)
  else
    Colour(RGB(black))
    print @(10,250,1) "Max Speed reached" 
  endif

  colour RGB(white)     

  if GameState=GAME_STATE_GAME_OVER then
    print @(10,270,1) "Start New Game"
  else
    print @(10,270,1) "Continue Game"  
  endif

  print @(10,310,1) "INSTRUCTIONS"
  font 7
  print @(10,325,1) "Use cursor keys to fly"
  print @(10,340,1) "A and D to straff, W to fire and S for turbo boost"
  print @(10,355,1) "Hover over fuel and ammor dumps to resupply"
  print @(10,370,1) "Shoot yellow buildings to earn money"
  print @(10,385,1) "Hovering requires no key presses for 3 seconds";
  box 0,147+menuCursor*20,410,17,,rgb(white)

  if debounce=0 then
    if kbd_down and menuCursor < 6 then menuCursor=menuCursor+1
    if kbd_up and menuCursor>0 then menuCursor=menuCursor-1 
    if kbd_space then ' try and purchase
      if menuCursor=0 and Player_Money>= ammo_Cost then Player_Money=Player_Money-ammo_Cost:Player_max_Ammo=Player_Max_Ammo+1000
      if menuCursor=1 and Player_Money>= fuel_Cost then Player_Money=Player_Money-fuel_Cost:Player_max_Fuel=Player_Max_Fuel+50
      if menuCursor=2 and Player_Money>= damage_Cost then Player_Money=Player_Money-damage_Cost:Player_Damage=Player_Damage+0.5
      if menuCursor=3 and Player_Money>= hover_Cost then Player_Money=Player_Money-hover_Cost:Player_Hover_Limit=Player_Hover_Limit-10
      if menuCursor=4 and Player_Money>= 2000 then Player_Money=Player_Money-2000:Player_Gun_Count=4
      if menuCursor=5 and Player_Money>= speed_Cost then Player_Money=Player_Money-speed_Cost:Player_Speed=Player_Speed+0.05
      if menuCursor=6 then
        if GameState=GAME_STATE_START_SCREEN then
          GameState=GAME_STATE_RUNNING
          GenerateWorld()
        else
          GameState=GAME_STATE_RUNNING
        endif
      endif
    endif
  endif
  if menuCursor<0 then menuCursor=0
  'Debounce keyboard
  if kd=0 then
    debounce=0
  else
    debounce=1
  end if    
end sub

sub PlaySound(snd)
  if snd=1 then play modsample 6,1,MasterVol/2
  if snd=2 then play modsample 7,2,MasterVol
  if snd=3 then
    play modsample 8,boomChannel,MasterVol
    boomChannel=boomChannel+1
    if boomChannel=5 then boomChannel=3
  endif
end sub


sub GenerateWorld()
  page write 0
  cls
  load png "assets\title_8bit3.png",0,0

  print "Please wait while we randomly generate the world."
  print "================================================="
  print
  print "Clearing out squatters..."
  for x=1 to 300
    for y=1 to 300
      Map_Ground(x,y)=0
      Map_Health(x,y)=0
    next y
  next x
  print "Paving roads..."

  'Draw the roads
  'Outer edge
  for x=11 to 289
    Map_Ground(x,11)=27
    Map_Ground(x,189)=27
    Map_Ground(11,x)=12
    Map_Ground(189,x)=12
  next x
  'In between buildings
  for x=11 to 289 step 28
    for y=11 to 289
      Map_Ground(x,y)=12
      Map_Ground(y,x-1)=9
      Map_Ground(y,x)=27
    next y
  next x
  print "Populating world...."
  ' Do random 6 line vertical and horizontal rows
  for a=1 to 2000
    x1=12+rnd*270
    y1=12+rnd*276
    x2=12+rnd*276
    y2=12+rnd*270
    t1=int(rnd*7)
    type1=2 ' Yellow house
    if t1=1 then type1=13 ' small horizontal power
    if t1=2 then type1=10 ' oval power thingy
    if t1=3 then type1=11 ' Hatch
    if t1=4 then type1=6   'Ammo
    if t1=5 then type1=3  'Fuel
    if t1=6 then type1=29 'k30 yellow strip
    type2=type1
    if type1=29 then type2=30 ' vertical yellow stripe
    count=int(rnd*4)+1
    for j=0 to count
      if Map_Ground(x1+j,y1)=0 then Map_Ground(x1+j,y1)=type1    
      if Map_Ground(x1+j,y1+1)=0 then Map_Ground(x1+j,y1+1)=type1    
      if Map_Ground(x2,y2+j)=0 then Map_Ground(x2,y2+j)=type2
      if Map_Ground(x2+1,y2+j)=0 then Map_Ground(x2+1,y2+j)=type2
    next j   

  next a
  print "Flaunting bylaws...."

  'Random indivdiual squares
  for a=1 to 1000
    x1=12+rnd*276
    y1=12+rnd*276
    if Map_Ground(x1,y1)=0 then Map_Ground(x1,y1)=33
  next a

  print "Flooding poor areas...."
  for y=0 to 300
    for x=0 to 300
      if x<10 or x>290 or Y<10 or Y>290 then ' sea
        Map_Ground(x,y)=22
      else if x=10 then 
        Map_Ground(x,y)=20
      else if x=290 then 
        Map_Ground(x,y)=16
      else if y=10 then 
        Map_Ground(x,y)=14
      else if y=290 then 
        Map_Ground(x,y)=18  
      else if y=149 or y=150 or y=151 then
        Map_Ground(x,y)=9
      endif
'    else if rnd<0.5 and Map_Ground(x,y)=0 then 
 '     Map_Ground(x,y)=int(rnd*13)+1
    
    next x
  next y
  Map_Ground(10,10)=21
  Map_Ground(290,10)=15
  Map_Ground(10,290)=19
  Map_Ground(290,290)=17
  Map_Ground(150,150)=10
  Map_Ground(151,150)=10
  Map_Ground(152,150)=10
  Map_Ground(153,150)=10
  Map_Ground(154,150)=10
  Map_Ground(155,150)=10

  print "Having a coffee break"
' Now do raised section
' split 280x280 grid into 10x10. Each one has a raised section 
  for y=1 to 10
    for x=1 to 10
      tlx=10+(x-1)*28
      tly=10+(y-1)*28
      'large square
      for k=2 to 24
        SetGround(tlx+k,tly+2,14)
        SetGround(tlx+k, tly+24,18)
        SetGround(tlx+2,tly+k,20)
        SetGround(tlx+24,tly+k,16)
      next k
      'corners
      SetGround(tlx+2,tly+2,21)
      SetGround(tlx+24,tly+2,15)
      SetGround(tlx+2,tly+24,19)
      SetGround(tlx+24,tly+24,17)

      tlx2=tlx+int(rnd*6)+3
      tly2=tly+int(rnd*6)+3
      width=int(rnd*10)+2
      height=int(rnd*5)+2
      'First small grid and duplicate below it
      for k=tlx2 to tlx2+width
        SetGround(k,tly2,14)
        SetGround(k,tly2+height,18)      
      next k
      for k =tly2 to tly2+height
        SetGround(tlx2, k,20)
        SetGround(tlx2+width,k,16)
      next k
      SetGround(tlx2,tly2,21)
      SetGround(tlx2+width,tly2,15)
      SetGround(tlx2,tly2+height,19)
      SetGround(tlx2+width,tly2+height,17)
      'Duplicate grid below it
      tly3=tly2+height+5
      height2=int(rnd*4)+2
      for k=tlx2 to tlx2+width
        SetGround(k,tly3,14)
        SetGround(k,tly3+height2,18)      
      next k
      for k =tly3 to tly3+height2
        SetGround(tlx2, k,20)
        SetGround(tlx2+width,k,16)
      next k
      SetGround(tlx2,tly3,21)
      SetGround(tlx2+width,tly3,15)
      SetGround(tlx2,tly3+height2,19)
      SetGround(tlx2+width,tly3+height2,17)
    
      'bridge between the two
      bw=rnd*width+1
      if bw+3<width then ' there is enough space
        for k=tly2+height to tly3
          SetGround(tlx2+bw,k,20)
          SetGround(tlx2+bw+2,k,16)
          SetGround(tlx2+bw+1,k,31)
        next k 
        SetGround(tlx2+bw,tly2+height,26)
        SetGround(tlx2+bw+2,tly2+height,25)
        SetGround(tlx2+bw+2,tly3,24)
        SetGround(tlx2+bw,tly3,23)
        SetGround(tlx2+bw+1,tly2+height,31)
        SetGround(tlx2+bw+1,tly3,31)
      end if     
    
      '3rd inner grid to right of other two
      tlx4=tlx2+width+2
      width4=(tlx+23)-tlx4
      height4=height+height2
      tly4=tly+3    
      if width4>3 then
        for k=tlx4 to tlx4+width4
          SetGround(k,tly4,14)
          SetGround(k,tly4+height4,18)      
        next k
        for k =tly4 to tly4+height4
          SetGround(tlx4, k,20)
          SetGround(tlx4+width4,k,16)
        next k
        SetGround(tlx4,tly4,21)
        SetGround(tlx4+width4,tly4,15)
        SetGround(tlx4,tly4+height4,19)
        SetGround(tlx4+width4,tly4+height4,17)

      end if
    next x
  next y
  
  print "Counting costs...."
  CountOfBuildings=0
  for x=0 to 300
    for y=0 to 300
      a=Map_Ground(x,y)
      if a=13 or a=2 then
        Map_Health(x,y)=10
        CountOfBuildings=CountOfBuildings+1
      endif
      if a=6 or a=3 then
        Map_Health(x,y)=5
        CountOfBuildings=CountOfBuildings+1
      endif
      if a=10 then
        Map_Health(x,y)=1
        CountOfBuildings=CountOfBuildings+1
      endif
      if a=33 then
        Map_Health(x,y)=30
        CountOfBuildings=CountOfBuildings+1
      endif
    next y
  next x
  lt=timer
  frameCount=0
end sub

sub SetGround(x%,y%,v%)
  Map_Ground(x%,y%)=v%
  Map_Health(x%,y%)=0
end sub

sub CalculateScreenAreaBasedOnAngle()
  ' For each 5 degree angle increment, work out what the min and max values
  ' for the x and y offsets are to fit everything on the screen
  ' I used to just do -9 to +9 for both, but this causes a lot of wasted
  ' processing time.
  page write 0
  for k = 0 to 360  ' *4 for angle
    angleRad= (k/180) * 3.1415
    
    cl5 =cos(angleRad)
    sl5 =sin(angleRad)
    minx=0
    maxx=0 
    for j=-9 to 9   ' xaxis
      miny=0 
      maxy=0
      diffx5 = j*32
      diffxcl5 = diffx5*cl5
      diffxsl5 = diffx5*sl5
      for s=-9 to 9     ' yaxis
        diffy5 = s*32   '+16
  '    x2 = diffx*cos(Player_Angle_Radians)+diffy*sin(Player_Angle_Radians)
  '    y2 = diffy*cos(Player_Angle_Radians)-diffx*sin(Player_Angle_Radians)
        x5 = diffxcl5+diffy5*sl5
        y5 = diffy5*cl5-diffxsl5
        if x5>-232 and x5<200 and y5>-232 and y5<200 then ' This grid is visible at this angle
          if j<minx then minx=j
          if j>maxx then maxx=j
          if s<miny then miny=s
          if s>maxy then maxy=s
        endif
      next s
      Grid_Min_Y%(k,j+10)=miny
      Grid_Max_Y%(k,j+10)=maxy
    '  print str$(Grid_Min_X%(k)) + " " + str$(Grid_Max_X%(k)) + " " +str$(Grid_Min_Y%(k,j+10)) + " " + str$(Grid_Max_Y%(k,j+10))
    '  for grog=1 to 10000: next grog
    next j
    ' At this stage minx,maxx, miny,maxy should hold the optimal sizes for this angle
    Grid_Min_X%(k)=minx
    Grid_Max_X%(k)=maxx
     ' print str$(Grid_Min_X%(k)) + " " + str$(Grid_Max_X%(k)) + " " +str$(Grid_Min_Y%(k,j+10)) + " " + str$(Grid_Max_Y%(k,j+10))
    '  for grog=1 to 10000: next grog
    next j
    ' At this stage minx,maxx, miny,maxy should hold the optimal sizes for this angle
    Grid_Min_X%(k)=minx
    Grid_Max_X%(k)=maxx
     ' print str$(Grid_Min_X%(k)) + " " + str$(Grid_Max_X%(k)) + " " +str$(Grid_Min_Y%(k,j+10)) + " " + str$(Grid_Max_Y%(k,j+10))
      'for grog=1 to 1000000: next grog
  next k    
  open "gridarray.dat" for output as #1
  for k=0 to 360
    print #1, Grid_Min_X%(k)
    print #1, Grid_Max_X%(k)
    for j=0 to 20
      print #1, Grid_Min_Y%(k,j)
      print #1, Grid_Max_Y%(k,j)
    next j
  next k
  close #1
end sub