AppTitle "Celestial Rift - Version 1.0 (C)2001 Myke P" ;what this program will be called in MICROSOFT WINDOWS.
;This makes two CONSTants. These are values which will NOT change at any point in the program, so we set their values now.
Const SCREEN_WIDTH = 800
Const SCREEN_HEIGHT = 600
;This is the code which tells Blitz what Display Resolution to use on the Graphics Card. The "GRAPHICS" command should always be placed before you do
;*anything* image-related in your program
Graphics SCREEN_WIDTH,SCREEN_HEIGHT,0,1 ;start the graphics mode at SCREEN_WIDTH by SCREEN_HEIGHT, let Blitz choose the depth (,0) and run full screen (,1)
;more program CONSTants..
Const GAME_AREA_X = 50000 ;these two set the size of the map. You *should* keep them the same, 'cos the radar is square
Const GAME_AREA_Y = 50000 ;but technically, you can change the values to anything you like! ;)
;the following constants are keyboard "SCAN" codes. Every key on the keyboard has a number. You can get the full list in your Blitz manual.
Const KEY_CLOCKWISE = 25 ;(p)
Const KEY_ANTICWISE = 24 ;(o)
Const KEY_SPEEDUP = 16 ;(q)
Const KEY_SPEEDDOWN = 30 ;(a)
Const KEY_FIRE = 57 ;(Space)
Const KEY_HYPER = 2 ;(1)
Const KEY_BOOST = 50 ;(m)
Const KEY_CLOAK = 46 ;(c)
Const KEY_QUIT = 1 ;(Escape)
Const KEY_PAUSE = 7 ;(Number 6 on the main keyboard)
Const KEY_DEBUG = 59 ;(F1)
Const KEY_SAVESCREEN = 88 ;(F12)
;the following constants affect the way the game plays. Feel free to mess with the values..
Const INCR_ROTATE# = 5 ;.. but DON'T touch this, otherwise the game will crash (I only drew the animation frames for 5 degree intervals!)
Const INCR_SPEED# = 0.5
Const INCR_SLOW# = 0.125
Const INCR_BOOSTERS_UP# = 0.025
Const INCR_BOOSTERS_DOWN# = .75
Const INCR_CLOAK_UP#= 0.0125
Const INCR_CLOAK_DOWN# = .25
Const SPEED_MAX = 25
Const SPEED_MIN = -5
Const ENEMY_MAX_DIST = 5000
Const ENEMY_MIN_DIST = 50
Const DAMAGE_ENEMY_BASH = 2
Const DAMAGE_ENEMY_IS_SHOT = 35
Const DAMAGE_PLAYER_BASH = 2
Const DAMAGE_PLAYER_IS_SHOT = 5
Const SCORE_ENEMYCOLLIDE = 50
Const SCORE_ICONCOLLECT = 200
Const SCORE_ENEMY_IS_SHOT = 400
Const SCORE_ENEMY_IS_DESTROYED = 1500
Const BONUS_BOOSTERS = 48
Const BONUS_SHIELD = 48
Const BONUS_CLOAK = 48
;set up changable variables for game/menu (with initial values, if you like - i.e.: you could just as soon as set them later!)
Global FLAG_GAMEON
Global FLAG_MENUON
Global FLAG_PAUSE
Global FLAG_SAVESCREEN = 0
Global FLAG_DEBUG = 0
Global FLAG_GAMESTARTER
Global PLAYER_SHIELD#
Global PLAYER_BOOSTERS#
Global PLAYER_CLOAK#
Global PLAYER_JUMPS
Global PLAYER_SPEED#
Global PLAYER_ANGLE#
Global PLAYER_X#
Global PLAYER_Y#
Global PLAYER_SCORE
Global PLAYER_SCORE_STR$
Global HI_SCORE
Global HI_SCORE_STR$
Global LAST_SCORE
Global LAST_SCORE_STR$
Global SCORE_FILE
Global timer
Global frames
Global starson
Global menu_frame
Global menu_accept_quit
Global game_pause_frame
Global game_accept_pause
Global game_pause_stat
Global gameovercounter
Global gameoverstat
Global whichway
Global hypercount# ;a "#" symbol after the variable name means it can hold a FLOATING POINT number, i.e.: 190.1234
Global pausecount ;without the "#" symbol, the variable is, by default, an INTEGER (Whole) number, i.e.: 190
Global cloakon# ;use the symbols when you are *sure* that you want it to hold specific types of data:
Global frame1 ;# - floating point
Global frame2 ;% - integer (whole number)
Global frame3 ;$ - string (text, i.e.: "MYKE 12345"
Global frame4 ;
Global frame5
Global frame6
Global frame7
Global frame8
Global tempstr$
timer = CreateTimer(50) ;create a timer set at 50ms (game speed) - play with this to see how you can increase or decrease the speed of the game.
;this should be set at a speed which will look near enough the same on *every* PC it will be played on.
;My PC (a 733MHz PIII with an nVidia GeForce card) will handle upwards of 150 frames per second, quite happily
;but 'lesser' machines will not. 50, therefore, is quite sensible For a game of this nature, who's minimum system spec
;will be something like a PII 300MHz machine (i.e.: Blitz Basic's minimum spec!)
;NOTE: there's no need to organise your variable declarations, as I have here, into sections. They can appear in any order you like, before the main program begins.
;I just do this, 'cos it looks right professional! :))))
;picture/animation (and related) variables
Dim game_stars(5) ;these 3 are ARRAYS. An array is automatically Global, but requires the Keyword (Yellow bit) DIM instead. This means "Dimension".
Dim game_icons(4) ;the arrays have single dimensions (imagine one straight line of boxes, each that can contain a single variable) 0 to.. (the number in brackets)
Dim game_jumps_level(5) ;in the case of "game_jumps_level", it has *SIX* containers: 0, 1, 2, 3, 4, 5 and 6.
Global game_background
Global game_radar
Global game_shields
Global game_jumps
Global game_boosters
Global game_cloak
Global game_shields_level
Global game_boosters_level
Global game_cloak_level
Global game_levels
Global game_score
Global game_hiscore
Global game_icon_dot
Global game_player
Global game_player_frame
Global game_player_dot
Global game_enemy1
Global game_enemy1_dot
Global game_scorefont
Global game_bullet_player
Global game_bullet_enemy1
Global game_explosion
Global player_explosion_frame#
Global game_gameover
Global game_paused
Global menu_hiscore
Global menu_lastscore
Global menu_scorefont
Global menu_start
Global menu_start_stat
Global menu_logo
Global menu_credit
Global menu_guildhall
Global menu_thanks
Global menu_quit
Global menu_ship1
Global menu_ship2
Global menu_ship_hor
Global menu_ship_ver#
Global menu_ship_type
;sounds (and related) variables
Global sound_explosion1
Global sound_explosion2
Global sound_explosion_channel
Global sound_icon
Global sound_icon_channel
Global sound_boosters
Global sound_boosters_channel
Global sound_enemy_laser
Global sound_enemy_laser_channel
Global sound_player_laser
Global sound_player_laser_channel
Global sound_hyperjump
Global sound_hyperjump_channel
Global sound_collision
Global sound_collision_channel
Global sound_cloak
Global sound_cloak_channel
Global sound_bullethit1
Global sound_bullethit2
Global sound_bullethit_channel
Global music_menu
Global music_menu_level#
Global music_game
Global music_game_level#
;Types are like Structures in C. You have a "Type" called whatever. Then you can make multiple versions of the type. Each version of the Type has the same properties, i.e.:
;a FISH (the Type) has EYES, MOUTH, SCALES And FINS (it's properties) - ALL FISH have these properties.
;a DOG (the Type) has EYES, MOUTH, FUR and TAIL (it's properties) - ALL DOGS have these properties (look like this.)
Type stars ;create "Type" for parallex stars
Field depth,x#,y# ;each star has a depth, x and y position and a picture
End Type
Type enemies ;same for enemies
Field x#,y#,energy,angle,speed#,style,maxspeed,dest_angle,dist_travelled,dist_to_go,dest_opp#,dest_hyp#,dest_adj#,rotate_angle,status,bulletlimiter,exp_frame#,gen
End Type
;notice the "enemies" Type has a "style"?
;originally, I planned to have different styles of enemy space-ships, but never got around to drawing the graphics!
;the "style" is used in the subsequent code, and the Type property remains, so *technically* adding new enemy styles to the game should be pretty easy! :)
Type icons ;same for icons
Field x#,y#,style,frame#
End Type
;this is for the bullets. I've used an array, rather than a type (which would have been just as good in this case) to show you how MULTIDIMENSIONAL arrays can work.
Const bulletnum = 500
Global bulletlimiter
Global nextbullet = 0
Dim bullets(bulletnum-1,7) ;create an array for 'bulletnum' (0 to bulletnum -1) on-screen bullets with 8 values per bullet:
SoundPitch sound_hyperjump,32000 ;Mark's sample lasted a bit too long in it's original format (22000 Hz), so increasing the Pitch to 32000 Hz makes the sample play faster (and audibly higher too)
;This peice of code reads a file called "rift.dat" for the HI_SCORE and LAST_SCORE values from the last session
SCORE_FILE = ReadFile("rift.dat") ;use the variable SCORE_FILE (similar to image numbers before) as a reference to the file
;open a file for READING ("ReadFile"). The file is called "Rift.dat"
If SCORE_FILE = 0 Then ;if the file wasn't found, then the reference "SCORE_FILE" will have been set to 0
HI_SCORE = 0
LAST_SCORE = 0
Else ;if the file wasn't found, then the reference "SCORE_FILE" will have been set to something *other* than 0.
HI_SCORE = Int(ReadLine(SCORE_FILE)) ;read in one line from the file, then make it equal a number, rather than the ASCII string it is stored as. The first line becomes the HI_SCORE
LAST_SCORE = Int(ReadLine(SCORE_FILE)) ;read in another line from the file. This is the LAST_SCORE.
End If
CloseFile(SCORE_FILE) ;we've finished with the file, so CLOSE it (tells Blitz to disregard the reference number) - we won't be READing from it anymore!
;This section turns the Integer HI_SCORE and LAST_SCORE values into strings with leading 0's
;i.e.: 1000 becomes "0001000". You will see this exact same peice of code later on, so - professionally - it *should* have been done in a FUNCTION.
;I've kept it separate to show that you *can* just as well use copied code and not see a difference in the final program.
If HI_SCORE < 10 Then ;If the value of HI_SCORE is less than 10, then..
HI_SCORE_STR = "000000"+Str(HI_SCORE) ;make the string "HI_SCORE_STR" = "000000" and put the value of HI_SCORE on the end as a string
;such that, for example, HI_SCORE_STR now holds the text: "0000003"
ElseIf HI_SCORE >=10 And HI_SCORE < 100 Then ;If the value of HI_SCORE is 10 or more, AND the value of HI_SCORE is less than 100, then..
HI_SCORE_STR = "00000"+Str(HI_SCORE) ;.. and so on.. the use of "AND" here means that both 'arguements' (the HI_SCORE >= 10 type bits)
;must be true, or the resulting operation (the HI_SCORE_STR = ... type bit) won't happen.
;In this case, for example, 104 *is* "10 or more" but it *is not* less than 100, so ignore this "If statement"
;The "ElseIf" keyword means that if the first "IF" didn't fire, then "try this one"..
ElseIf HI_SCORE >=100 And HI_SCORE < 1000 Then
HI_SCORE_STR = "0000"+Str(HI_SCORE)
ElseIf HI_SCORE >=1000 And HI_SCORE < 10000 Then
HI_SCORE_STR = "000"+Str(HI_SCORE)
ElseIf HI_SCORE >=10000 And HI_SCORE < 100000 Then
HI_SCORE_STR = "00"+Str(HI_SCORE)
ElseIf HI_SCORE >=100000 And HI_SCORE < 1000000 Then
HI_SCORE_STR = "0"+Str(HI_SCORE)
ElseIf HI_SCORE >=100000 And HI_SCORE < 10000000 Then
HI_SCORE_STR = Str(HI_SCORE)
Else ;The "Else" keyword means that if NONE of the other IF statements fired, then do this next bit, as a last resort!
;The "Else" statement always comes last in an "IF.. ELSEIF.. ENDIF" peice of code
HI_SCORE_STR = "9999999"
End If ;The "EndIf" keyword means that's the end of this set of checks.
If LAST_SCORE < 10 Then ;Starting a new "IF.. ELSEIF.. ENDIF" peice of code, rather than using more "ElseIf"s means that this
LAST_SCORE_STR = "000000"+Str(LAST_SCORE) ;set of decisions is not affected by the previous set.
ElseIf LAST_SCORE >=10 And LAST_SCORE < 100 Then
LAST_SCORE_STR = "00000"+Str(LAST_SCORE)
ElseIf LAST_SCORE >=100 And LAST_SCORE < 1000 Then
LAST_SCORE_STR = "0000"+Str(LAST_SCORE)
ElseIf LAST_SCORE >=1000 And LAST_SCORE < 10000 Then
LAST_SCORE_STR = "000"+Str(LAST_SCORE)
ElseIf LAST_SCORE >=10000 And LAST_SCORE < 100000 Then
LAST_SCORE_STR = "00"+Str(LAST_SCORE)
ElseIf LAST_SCORE >=100000 And LAST_SCORE < 1000000 Then
LAST_SCORE_STR = "0"+Str(LAST_SCORE)
ElseIf LAST_SCORE >=100000 And LAST_SCORE < 10000000 Then
LAST_SCORE_STR = Str(LAST_SCORE)
Else
LAST_SCORE_STR = "9999999"
End If
;this code makes 4 'objects' in a "Type" called "ICONS".
For i = 1 To 4 ;do this 1, 2, 3, 4 times
icon.icons = New icons ;create a new icon
icon\style = i ;the icon style for each new icon is equal to the increment of i (i.e.: 1, 2, 3 or 4!)
icon\frame = Int(Rnd(0,5)) ;create a random frame number between 0 and 5 for each new icon
Next
menustars = SCREEN_HEIGHT/3 ;generate a number of stars, so that they look dense enough on all test resolutions
starson = 1 ;tells the program to show the stars (see later)
For i=0 To menustars ;create <menustars> number of stars in the STARS type
star.stars=New stars ;add a new star for each increment of i
Next
For i = 1 To 10
enemy.enemies = New enemies ;make 10 enemies (we'll set their variables later)
Next
;this code loads the image numbers into an array called "game_ stars", which we DIMmed earlier. It has 6 containers (0,1,2,3,4,5) but I'm only using 1 to 5!
;an "image number" is what Blitz uses to reference graphics held in the Video Memory, i.e.:
;1. Image number 12 is a picture of a flower.
;2. Make a variable called "flower_pic" = 12
;3. Wherever Blitz is told to draw "flower_pic", reference image number 12 in the Video Memory.
game_stars(1) = LoadImage("GfxRes/backg-star-1.bmp") ;container (1) in "game_stars" holds the image number for this picture ("GfxRes/backg-star-1.bmp")
MaskImage game_stars(i),255,0,255 ;mask the images for each star, so that MAGENTA (255,0,255) is the transparent colour
Next
;similarly, this code loads the image numbers into an array called "game_icons"
;however, these are images that contain the frames of an Animation, so a different Load command is used.
game_icons(1) = LoadAnimImage("GfxRes/icon-boost.bmp",32,32,0,6) ;LoadAnimImage has the same structure as LoadImage, with additional numbers after the picture filename
game_icons(3) = LoadAnimImage("GfxRes/icon-cloak.bmp",32,32,0,6) ;and the Number of Frames in the Image (as *you* would count them (in this case 6)
game_icons(4) = LoadAnimImage("GfxRes/icon-jump.bmp",32,32,0,6) ;have a look at the file "icon-boost" in Paint Shop Pro and see for yourself the 6 frames of animation.
For i = 1 To 4
MaskImage game_icons(i),255,0,255 ;mask the images for each icon, so that MAGENTA (255,0,255) is the transparent colour
MaskImage menu_ship1,255,0,255 ;mask all the images.
MaskImage menu_ship2,255,0,255 ;notice that it doesn't matter what order you do the masks in!
MaskImage menu_credit,255,0,255
MaskImage menu_guildhall,255,0,255 ;by the way, if when testing your program, you get the error message "IMAGE DOES NOT EXIST" at this point
MaskImage menu_thanks,255,0,255 ;in the program, it's because the LOADIMAGE command above didn't find the file properly.
MaskImage menu_start,255,0,255 ;This is usually either because; 1 - You've typed the wrong filename in the LOADIMAGE bit, or
MaskImage menu_quit,255,0,255 ;2 - You've got the variable name wrong in the MASKIMAGE bit.
MaskImage menu_hiscore,255,0,255
MaskImage menu_lastscore,255,0,255 ;you could perform some checks at the end of loading all the images, so that you know they've all been loaded
MaskImage game_radar,255,0,255 ;successfully. If they haven't then you could end the program properly and tell the user that they've got
MaskImage game_shields,255,0,255 ;corrupt or missing files!
MaskImage game_jumps,255,0,255
MaskImage game_cloak,255,0,255 ;as you'll see, I haven't bothered! :)
MaskImage game_boosters,255,0,255
MaskImage game_score,255,0,255
MaskImage game_hiscore,255,0,255
MaskImage game_background,255,0,255
MaskImage game_gameover,255,0,255
MaskImage game_paused,255,0,255
MaskImage game_levels,255,0,255
;Right! That's it, we've set up *everything* we're going to need from outside the program.
menu_loop() ;start the proper program loop by 'calling' the function called "menu_loop()" - which, conveniently, is just coming up!!!
;this function keeps the menu loop going.. It starts playing tunes and sets a couple of variables.
;Then it goes into a never ending loop which carries out a sequence of checks and function calls.
Function menu_loop() ;Start of the Function whose name is "menu_loop()"
FLAG_MENUON = 1 ;tells the program that the menu is running, for use in the REPEAT..FOREVER statement in a sec..
music_menu = PlayMusic("SndRes/Danube.mid") ;start playing the music file "Danube.mid" (found in the SndRes folder) on channel "music_menu"
menu_ship_hor = (SCREEN_WIDTH/2)-(ImageWidth(menu_ship1)/2) ;this sets the starting horizontal position of the big ship on the menu
menu_ship_ver = SCREEN_HEIGHT+1 ;this sets the vertical starting position of the big ship on the menu at one pixel off the bottom of the screen.
;notice that images are (by default) handled from the TOP-LEFT pixel, so, horizontally, I offset the value
;to the left, by half the width of the ship image.
menu_ship_type = 1 ;set up some initial values for these counters
menu_frame = 1
menu_start_stat = 0
menu_accept_quit = 0
music_menu_level = 1 ;this value will be used to set the volume of the music track in a minute..
Repeat ;a REPEAT.. FOREVER loop will carry out the code in between for as long as the program is running..
If FLAG_MENUON = 1 Then ;If the FLAG_MENUON flag is set to 1 then "do" the following..
menu_loop_update() ;call function "menu_loop_update()"
;this IF statement checks to see if the game music is playing (as it will be when you quit the game)
If ChannelPlaying(music_game) = True Then ;if it is, then..
music_game_level = music_game_level -.01 ;decrease the value of this variable by .01
ChannelVolume music_game, music_game_level ;set the volume of this channel "music_game" to the value of music_game_level
If music_game_level <= 0 Then ;if the value of "music_game_level" is 0 or less, then
StopChannel(music_game) ;stop the sounds playing on channel "music_game"
End If ;notice I've used an IF statement inside of another IF statement.. You'll be doing this a lot, it's called "Nesting"
End If
Else ;if the FLAG_MENUON flag wasn't set to 1 then "do" the following..
SCORE_FILE = WriteFile("rift.dat") ;Open file "rift.dat" for WRITing (using the variable "SCORE_FILE" as a reference number
WriteLine SCORE_FILE,Str(HI_SCORE) ;Write the value of HI_SCORE (as a STRing) into the file
WriteLine SCORE_FILE,Str(LAST_SCORE) ;Write the value of LAST_SCORE (as a STRing) into the file
CloseFile(SCORE_FILE) ;Close the file, as we've finished with it
End ;END the program
End If
If ChannelPlaying(music_menu) = False Then ;checks to see if the menu music has finished playing on channel "music_menu", if so, restart it!
music_menu = PlayMusic("SndRes/Danube.mid")
End If
Forever ;end of the REPEAT.. FOREVER loop
End Function ;End of the function
;"menu_loop_update()" checks for key-presses, alters position coordinates on the screen
;and various variables/flags for use in "menu_draw_update()" and the game functions too.
;in fact, you'll see that this has the same organisational structure as the proper game loop (albeit much less complex!)
Function menu_loop_update()
frames = WaitTimer(timer) ;returns a value to "frames" for how many video screen refreshes (The MHz of your monitor) occured since the last call to our timer
For i = 1 To frames ;update the screen positions for "frames" number of changes.. This enables drawing frames to be skipped on slower machines.
If KeyDown(KEY_QUIT) ;If the user presses the "QUIT" button on the keyboard, then..
FlushKeys ;(when using SCAN CODES, flush the keyboard buffer after each successful "Have they pressed a particular key" question.)
If menu_accept_quit = 1 Then ;If the variable "menu_accept_quit" is 1, then set the FLAG_MENUON to 0.
FLAG_MENUON = 0 ;back in the "menu_loop()" function, this will cause the program to end!
End If
End If
If KeyDown(KEY_FIRE) ;If the user presses the "FIRE" button on the keyboard, then..
FlushKeys
FLAG_DEBUG = 0
FLAG_GAMESTARTER = 1
hypercount = 102
FLAG_PAUSE = 0
game_loop() ;call the function called "game_loop()" (the game will run, but once it has ended, we'll find ourselves back here...)
menu_ship_ver = SCREEN_HEIGHT+1
menu_frame = 1
menu_start_stat = 0
menu_accept_quit = 0 ;by setting this to 0, we'll stop the program ending by any surplus "QUIT" keystrokes carrying over from the game, by
;using the menu_frame counter at the end of this FOR loop.
FLAG_PAUSE = 0
If PLAYER_SCORE > HI_SCORE Then ;checks to see if the PLAYER_SCORE from the last game is higher than the currently held "HI SCORE", if it is, then
HI_SCORE = PLAYER_SCORE ;that PLAYER_SCORE becomes the new HI SCORE!
End If
LAST_SCORE = PLAYER_SCORE ;the LAST SCORE is always set to the PLAYER SCORE from the last game! :)
FlushKeys
End If
If KeyDown(KEY_DEBUG) ;if the user presses the "DEBUG" button on the keyboard, then..
FlushKeys
FLAG_DEBUG = 1 ;this is all exactly the same as "FIRE" above, but now FLAG_DEBUG is set to 1.
FLAG_GAMESTARTER = 1 ;later on, you'll see that we use this to turn on, or off, some overlayed displays in the game loop!
hypercount = 102
FLAG_PAUSE = 0
game_loop()
menu_ship_ver = SCREEN_HEIGHT+1
menu_frame = 1
menu_start_stat = 0
menu_accept_quit = 0
FLAG_PAUSE = 0
If PLAYER_SCORE > HI_SCORE Then
HI_SCORE = PLAYER_SCORE
End If
LAST_SCORE = PLAYER_SCORE
FlushKeys
End If
If KeyDown(KEY_SAVESCREEN) ;if the user presses the "SAVESCREEN" button on the keyboard, then..
FlushKeys
FLAG_SAVESCREEN = 1 ;just sets FLAG_SAVESCREEN to 1. You'll see this used in the next function.
End If
If menu_ship_ver > (-50 - ImageHeight(menu_ship1)) ;if the bottom of the (largest) ship picture gets to 50 pixels above the top of the screen
Select menu_ship_type ;A SELECT..CASE statement is like an IF statement, but only performs 1 check, i.e.: "What is the value of I?"
Case 1 ;if "menu_ship_type" is 1 then..
menu_ship_ver = menu_ship_ver - .3 ;how fast menuship1 moves up the screen
Case 2 ;if "menu_ship_type" is 1 then..
menu_ship_ver = menu_ship_ver - .8 ;how fast menuship2 moves up the screen
End Select
Else
menu_ship_ver = SCREEN_HEIGHT+1 ;reset the vertical position so that the top of the ship is at the bottom of the screen
menu_ship_hor = Rnd(0,SCREEN_WIDTH-ImageWidth(menu_ship1)) ;create a random horizontal position
menu_ship_type = Int(Rnd(1,2)) ;randomly choose between values 1 or 2
End If
menu_frame = menu_frame + 1 ;increase the value of "menu_frame" by 1
If menu_frame = 25 Then ;if the value of "menu_frame" gets to 25 then reset it to 1
menu_frame = 1
menu_accept_quit = 1 ;now we've turned the user's ability to press the "QUIT" button back on (see the IF statement in the KeyDown(KEY_QUIT) statement above!
If menu_start_stat = 1 Then ;this bit just switches the value of "menu_start_stat" between 1 and 0, i.e. :If it's 1, then make it 0, if it's 0, then make it 1 etc.
menu_start_stat = 0 ;this will be used in the next function to flash the "PRESS FIRE TO START" caption on and off!
Else
menu_start_stat = 1
End If
End If
Next
If HI_SCORE < 10 Then ;remember this from before? I was saying it could've been done in a function?
HI_SCORE_STR = "000000"+Str(HI_SCORE) ;exactly the same code.. (just converts the number 103 to the string "0000103")
ElseIf HI_SCORE >=10 And HI_SCORE < 100 Then
HI_SCORE_STR = "00000"+Str(HI_SCORE)
ElseIf HI_SCORE >=100 And HI_SCORE < 1000 Then
HI_SCORE_STR = "0000"+Str(HI_SCORE)
ElseIf HI_SCORE >=1000 And HI_SCORE < 10000 Then
HI_SCORE_STR = "000"+Str(HI_SCORE)
ElseIf HI_SCORE >=10000 And HI_SCORE < 100000 Then
HI_SCORE_STR = "00"+Str(HI_SCORE)
ElseIf HI_SCORE >=100000 And HI_SCORE < 1000000 Then
HI_SCORE_STR = "0"+Str(HI_SCORE)
ElseIf HI_SCORE >=100000 And HI_SCORE < 10000000 Then
HI_SCORE_STR = Str(HI_SCORE)
Else
HI_SCORE_STR = "9999999"
End If
If LAST_SCORE < 10 Then
LAST_SCORE_STR = "000000"+Str(LAST_SCORE)
ElseIf LAST_SCORE >=10 And LAST_SCORE < 100 Then
LAST_SCORE_STR = "00000"+Str(LAST_SCORE)
ElseIf LAST_SCORE >=100 And LAST_SCORE < 1000 Then
LAST_SCORE_STR = "0000"+Str(LAST_SCORE)
ElseIf LAST_SCORE >=1000 And LAST_SCORE < 10000 Then
LAST_SCORE_STR = "000"+Str(LAST_SCORE)
ElseIf LAST_SCORE >=10000 And LAST_SCORE < 100000 Then
LAST_SCORE_STR = "00"+Str(LAST_SCORE)
ElseIf LAST_SCORE >=100000 And LAST_SCORE < 1000000 Then
LAST_SCORE_STR = "0"+Str(LAST_SCORE)
ElseIf LAST_SCORE >=100000 And LAST_SCORE < 10000000 Then
LAST_SCORE_STR = Str(LAST_SCORE)
Else
LAST_SCORE_STR = "9999999"
End If
menu_draw_update() ;call the function "menu_draw_update" which draws all these new things on the screen
End Function
;"menu_draw_update()" just draws things on your monitor, using values set and altered in the last function (menu_loop_update).
Function menu_draw_update()
SetBuffer BackBuffer() ;draw all of the following to the backbuffer() which is an area video memory which is not shown on screen.
;the idea is that you draw everything here, then SHOW it to the user when the full picture is complete.
ClsColor 0,0,0 ;changes the CLearScreen colour to black (0,0,0)
;Color commands use the 3 parameters as RED value, GREEN value, BLUE value
;which is how pixel colours are made up on the monitor. If you're familiar with
;any PC Paint Packages, you'll probably be quite familiar with this.
Cls ;CLears the Screen
;this next section draws all of the pictures on to the backbuffer() at the specified coordinates.
;notice that the pictures are drawn in sequence, with the backmost things drawn first and the foremost things drawn last
;kind of like making a collage!
DrawImage menu_logo,(SCREEN_WIDTH/2)-(ImageWidth(menu_logo)/2),0 ;this draws the menu_logo image at "x","y"
;I've used EQUATIONS to make up x and y for all the images in this project, so that when you change
;the resolution values (back at the beginning of the code) everything still appears at the correct position
;on the screen. If you know what resolution you'll be working at, then you can quite happily put x and y as
;ordinary numbers in here.
;For example, at 800*600, the menu_logo image will be drawn at:
;SCREEN_WIDTH = 800
;800/2 = 400
;ImageWidth(menu_logo) is the width (in pixels) of this particular image (which is 547 pixels)
;547/2 = 273.5
;(800 - 273.5 = 126.5)
;So, menu_logo would be drawn at 127,0 (because Blitz requires whole number coordinates, it will automatically
;Remember when we checked to see if the user had pressed the "SAVESCREEN" button, earlier?
;if they did, we set FLAG_SAVESCREEN to 1. Now this is where that takes effect..
If FLAG_SAVESCREEN=1 Then
SaveBuffer (BackBuffer(),"CRMenuScreen.bmp")
;the SaveBuffer command outputs the contents of the named buffer (in this case "BackBuffer()") to the named file, in a BMP format.
FLAG_SAVESCREEN = 0
;after we've saved the screen, we reset the FLAG to 0, so that when we come back for the next "menu_draw_update", it won't save
;another picture. (i.e.: it only saves 1 picture for each keypress of the "SAVESCREEN" button!)
;This is useful for getting working screenshots of your project to impress your mates!! :)
End If
Flip ;finally, FLIP everything on the backbuffer() and show it on the frontbuffer(), i.e.: your monitor!!
End Function
;this function keeps the game loop going.. It starts playing tunes and sets a couple of variables.
;Then it goes into a never ending loop which carries out a sequence of checks and function calls, until such time as we want to stop it!
Function game_loop()
FLAG_GAMEON = 1 ;tells the program that the game is running.
game_initialise() ;calls a function called "game_initialise()" (which is next in the code) which
;just gives the player full energy and a score of 0 etc..)
music_game_level = 0.3 ;the XM tune I've used is an old Amiga Module from a game called Dynablaster
;it's a bit loud to go with the game, though, so I want it's volume to be lower than
;normal.. see in a second..
sound_hyperjump_channel = PlaySound(sound_hyperjump) ;The game starts in what seems to be mid-hyperjump, but because
;this sound is normally called after a keypress, I've got to do it manually
;just this once! ;)
Repeat ;as with the menu, we want to cycle though the process of updating/drawing forever, until such time as the game has ended.
If FLAG_GAMEON = 1 Then ;.. so, if FLAG_GAMEON is 1, then "do" the following.
game_loop_update() ;call the game_loop_update() function
If ChannelPlaying(music_menu) = True Then ;this bit slowly turns down the menu music, until the music_menu_level is 0..
music_menu_level = music_menu_level -.01
ChannelVolume music_menu, music_menu_level
If music_menu_level <= 0 Then ;.. then turns it off completely!
StopChannel(music_menu)
End If
End If
Else
FlushKeys ;if FLAG_GAMEON isn't 1, then instead of ENDing the program (as we did from the menu), this time
Exit ;we EXIT the function, which effectively takes us back to the line after "game_loop()" was originally
;called, back in "menu_loop_update()"
End If
If ChannelPlaying(music_game) = False Then ;once again, this checks if the game music has finished playing
music_game = PlayMusic("Dynablaster.xm") ;and starts it again..
ChannelVolume music_game, music_game_level ;remembering that we want to play it quieter, so set it's CHANNELVOLUME to music_game_level (as set a second ago!)
End If
Forever
End Function
;As described a minute ago, this function sets up the game variables as they should be
;at the start of every game, i.e.: Player Shields are full, the score is 0 etc..
Function game_initialise()
PLAYER_SCORE = 0
PLAYER_TIME = 0
PLAYER_ANGLE = 0
PLAYER_SPEED = 0
PLAYER_SHIELD = 192 ;the width of the game_level image is 192. Rather than working out a percentage of 100, it's much
PLAYER_BOOSTERS = 192 ;easier to use the width of the image on such BAR type displays.
PLAYER_CLOAK = 192
PLAYER_JUMPS = 5
gameovercounter = 0
player_explosion_frame = 0
game_player_randomize() ;calls a function that randomizes a player's position on the map
game_stars_randomize() ;calls a function that randomizes the star positions
;this next bit is the first time you'll have seen a TYPE cycle.
;Just like a normal "For i = 0 to 20" loop, this goes through each Version of a type
;and set's it's properties. (i.e.: That FISH type has a SCALES property. Here we tell it that this particular Fish's Scales are GOLD!)
For enemy.enemies=Each enemies
enemy\x=Rnd(0,GAME_AREA_X) ;randomizes each "enemies"'s position on the map!
enemy\y=Rnd(0,GAME_AREA_Y)
enemy\energy = 100 ;gives each "enemies" a full shield strength of 100
enemy\angle = Int(Rnd(0,72)) * 5 ;gives each "enemies" a random angle between 0 and 360, at increments of 5 degrees
enemy\maxspeed = Rnd(20,40) ;gives each "enemies" a random maximum speed between 20 and 40 (a bit slower, and a bit faster than the player's
;maximum speed (as originally coded by me. If you change the player's maximum speed, it will have no effect on 'them'!)
enemy\speed = 0
enemy\style = 1 ;sets the "enemies"'s style to 1. Remember before when I said it would be easily possible to implement new styles of enemy?
;well, this would be your starting point! :)
enemy\exp_frame = 0 ;like the player, an "enemies" has an explosion frame which is always zero(0) until it is ready to explode!
;see later for the code which fire's an "enemies"'s final demise.
enemy\dist_to_go = Rnd(ENEMY_MIN_DIST,ENEMY_MAX_DIST) ;The "enemies"'s distance to go defines how far it will fly on it's current course, before it
;retargets and turns towards you. This is a fairly simple, but reasonably effective enemy A.I.
enemy\dist_travelled = 0 ;directly related to the "enemies"'s distance to go, is how far it has travelled up to now.
enemy\gen = 1 ;a last minute addition, when an enemy dies and regenerates, it is worth more points to kill next time around, thanks to its GEN number.
Next
For icon.icons = Each icons
icon\x = Rnd(0,GAME_AREA_X) ;for each of the 4 icons on the play area at any one point, we need a random x and y position.
icon\y = Rnd(0,GAME_AREA_Y)
Next
End Function
;once again, like it's menu equivalent, "game_loop_update()" is a function which analyses player input, working out all the new
;coordinate positions and anything else which needs deciding before updating the screen display.
Function game_loop_update()
frames = WaitTimer(timer)
For i = 1 To frames
If KeyDown(KEY_PAUSE) ;checks to see if the user has pressed the "PAUSE" key
FlushKeys
If game_accept_pause = 1 And gameovercounter = 0 ;the "game_accept_pause" variable is used in the same way as "menu_accept_quit" earlier.
;because we're using SCANCODES, the program will register a number of qualifying cases where
;when this check is performed, the key is still held down (at 50 frames per second, if the user
;held down the key for half a second, the KEYDOWN function would fire around 25 times!)
;A check is made on the value of "game_over_counter" to see if the player has died - in which
;case Pausing the game is not allowed.
If FLAG_PAUSE = 0 Then ;If FLAG_PAUSE is 0 then..
FLAG_PAUSE = 1 ;make FLAG_PAUSE = 1
game_accept_pause = 0 ;don't accept any more "PAUSE" button presses until "game_accept_pause" is set back to 1
game_pause_frame = 1 ;make "game_pause_frame" = 1 which, similarly to "menu_frame" earlier will enable the flashing of "PAUSED".
Else
FLAG_PAUSE = 0 ;If FLAG_PAUSE isn't 0 (the game was paused) then..
game_accept_pause = 0 ;do exactly the same, but set FLAG_PAUSE to 0.
game_pause_frame = 1
End If
End If
End If
If KeyDown(KEY_SAVESCREEN) ;If the "SCREENSAVE" button is pressed..
FlushKeys ;this functions exactly the same as in menu_loop_update()
FLAG_SAVESCREEN = 1
End If
If KeyDown(KEY_QUIT) ;If the "QUIT" button is pressed..
FlushKeys
hypercount = 0
cloakon = 0
FLAG_GAMEON=0 ;set FLAG_GAMEON to equal 0. Back in the "game_loop()" function, this will cause the code to jump back to the menu.
End If
If FLAG_PAUSE = 0 Then ;this is really easy! If the game is paused then *don't* do any of the following code. No values will change,
;hence nothing will move on the screen when it comes to updating it later! :)
If gameovercounter = 0 Then ;if the game is still in progress, i.e.: "gameovercounter" = 0 (the player is still alive) then
;check for the following keypresses from the user - otherwise there's no point!
If KeyDown(KEY_HYPER) ;if the "HYPER" key is pressed then..
If PLAYER_JUMPS > 0 Then
If hypercount = 0 Then ;(if "hypercount" is 0, then we're not already in the middle of a HyperJump, so let's set things off!)
hypercount = 1 ;by setting "hypercount" to 1, we'll set off a chain of events later on..
sound_hyperjump_channel = PlaySound(sound_hyperjump) ;play the Hyperjump soundeffect on the appropriate channel reference
PLAYER_JUMPS = PLAYER_JUMPS - 1 ;subtract the number of Jumps a player has left by 1
If PLAYER_JUMPS <= 0 Then ;if the number of jumps left is 0 or less, then the above subtraction will make it "-1", so..
PLAYER_JUMPS = 0 ;put it back to 0.
End If
End If
End If
FlushKeys
End If
If hypercount = 0 Then ;as long as we're not in the middle of a hyperjump, do the following..
If KeyDown(KEY_CLOAK) ;if the CLOAK key is pressed then
If PLAYER_CLOAK > 2 Then ;if the player has enough (2 points of) PLAYER_CLOAK left, then..
cloakon = cloakon + 1 ;the cloakon value is incremented so that later on, we can do the flickering effect
PLAYER_CLOAK = PLAYER_CLOAK - INCR_CLOAK_DOWN ;subtract some PLAYER_CLOAK ability at a rate of "INCR_CLOAK_DOWN"
If ChannelPlaying(sound_cloak_channel) = False Then ;because the sound effect is triggered by a KeyDown event, it will fire repeatedly,
sound_cloak_channel = PlaySound(sound_cloak) ;which makes an almighty noise as the echo of the sound effect builds on top of
End If ;eachother! By using this "If it's playing then do nothing, otherwise Play it again"
;peice of code, the sample plays once, then if the key is still held down, then it'll
;play it another once.. and so on.. (Take out the IF and the END IF to see what I mean!)
Else ;if the player doesn't have enough PLAYER_CLOAK left then
cloakon = 0 ;reset the "cloakon" value to 0
PLAYER_CLOAK = 0 ;Keep the PLAYER_CLOAK value at 0, so that it doesn't build up...
End If
FlushKeys
Else ;if the CLOAK key isn't pressed then
cloakon = 0 ;reset the "cloakon" value to 0
If PLAYER_CLOAK < 192 ;if the player has less than the top value (192 points) of PLAYER_CLOAK then..
PLAYER_CLOAK = PLAYER_CLOAK + INCR_CLOAK_UP ;Slowly build up the PLAYER_CLOAK value.
Else
PLAYER_CLOAK = 192 ;otherwise cap the PLAYER_CLOAK value at 192 points.
End If
FlushKeys
End If
If KeyDown(KEY_BOOST) ;the BOOST key works in exactly the same way as the CLOAK key
If PLAYER_BOOSTERS > 2 Then
If PLAYER_SPEED < (SPEED_MAX*3) Then
PLAYER_SPEED = PLAYER_SPEED + (INCR_SPEED * 3)
End If
If ChannelPlaying(sound_boosters_channel) = False Then
If PLAYER_X < 0 Then ;if the PLAYER_X value is less than 0, then wrap your position around the map
PLAYER_X = (PLAYER_X + GAME_AREA_X) ;by adding the GAME_AREA_X value to the negative value, i.e.: -5 becomes 19995 on a 20000 X pixel map.
End If
If PLAYER_X > GAME_AREA_X Then ;the same in reverse, i.e. 20004 becomes 4 on the same map.
PLAYER_X = (PLAYER_X - GAME_AREA_X)
End If
If PLAYER_Y < 0 Then ;and now the same for the Y direction
PLAYER_Y = (PLAYER_Y + GAME_AREA_Y)
End If
If PLAYER_Y > GAME_AREA_Y Then
PLAYER_Y = (PLAYER_Y - GAME_AREA_Y)
End If
End If ;end of the "If the game is still running ('gameovercounter')" IF Statement
For icon.icons=Each icons ;the "icons" don't move from their randomly set x,y position, so all we need to do for them is
icon\frame = icon\frame+.5 ;update their animation frame number. There are 6 frames, and we're incrementing at 0.5 frames per update.
If Int(icon\frame) = 6 Then ;in real terms, this means we'll be updating the frame number every 2 updates.
icon\frame = 0 ;Because the icon animations are simple 0 to 5 cycling animations, when the frame number reaches 6, we flip it back to 0
End If ;to start the sequence again.
Next
;the following code section is probably the most complex in the game, because it's the Enemy Artificial Intelligence
;Reader's of a nervous disposition might want to skip this - I know I did! :)))
For enemy.enemies=Each enemies ;for each version of the "enemies" type..
If enemy\exp_frame > 0 Then ;remember before, I said we were going to blow up the player and enemies, just by setting a value?
enemy\exp_frame = enemy\exp_frame + .5 ;well, this is it! if this "enemies" exp_frame is greater than 0, then start increasing the Explosion
End If ;animation frame number (notice the same "update every two screen refreshes" technique?)
If cloakon = 0 ;if the player's CLOAKing device is off, then do the following bit. Otherwise, ignore it..
;indeed. This next bit makes the enemies home in on you and shoot you to peices. If your cloak is on, they can't see you, so don't do the intelligence tests
If enemy\exp_frame = 0 Then ;as long as this version of "enemies" isn't busy exploding..
;this bit checks the distances to the left, right, top and bottom of the enemy, relative to the player, to decide which way to fly would be the best
;intercept route. I tell you, these are vicious dedicated little oiks! :)
temp_x1# = PLAYER_X - enemy\x ;x distance to player on the right
temp_y1# = PLAYER_Y - enemy\y ;y distance to player on the top
temp_x2# = enemy\x - PLAYER_X ;x distance to player on the left
temp_y2# = enemy\y - PLAYER_Y ;y distance to player on the bottom
If temp_x1# < 0 Then ;if the values are bigger than the game area, or less than 0, then wrap them
temp_x1# = temp_x1# + GAME_AREA_X ;around the game map, like with the player before.
End If
If temp_x1# > GAME_AREA_X Then
temp_x1# = temp_x1# - GAME_AREA_X
End If
If temp_y1# < 0 Then
temp_y1# = temp_y1# + GAME_AREA_Y
End If
If temp_x1# > GAME_AREA_X Then
temp_y1# = temp_y1# - GAME_AREA_Y
End If
If temp_x2# < 0 Then
temp_x2# = temp_x2# + GAME_AREA_X
End If
If temp_x2# > GAME_AREA_X Then
temp_x2# = temp_x2# - GAME_AREA_X
End If
If temp_y2# < 0 Then
temp_y2# = temp_y2# + GAME_AREA_Y
End If
If temp_x2# > GAME_AREA_X Then
temp_y2# = temp_y2# - GAME_AREA_Y
End If
;this bit compares the two x directions to see which one is smaller
If Abs(temp_x1#) < Abs(temp_x2#) Then ;the ABS function always gives you the "+VE" version of a number, so -1 comes out as 1 and 2 comes out as 2
temp_x# = Abs(temp_x1#) ;if "Temp_x1" is the smallest, make this the "best" x distance
xdir = -1
Else
temp_x# = Abs(temp_x2#) ;otherwise if "Temp_x2" is the smallest, make this the "best" x distance
xdir = 1
End If
If Abs(temp_y1#) < Abs(temp_y2#) Then ;same with the y directions
temp_y# = Abs(temp_y1#)
ydir = -1
Else
temp_y# = Abs(temp_y2#)
ydir = 1
End If
;because we used the ABS function, we've lost the original direction of the value's units, so using the xdir and ydir
;values we just set over there, we can rebuild that directional picture
If xdir = 1 And ydir = 1 Then
sector = 4 ;top left
ElseIf xdir = 1 And ydir = -1 Then
sector = 3 ;bottom left
ElseIf xdir = -1 And ydir = -1 Then
sector = 2 ;bottom right
ElseIf xdir = -1 And ydir = 1 Then
sector = 1 ;top right
End If
;finally, we're going to use our knowledge of the shortest distance between this "enemies" and the player
;using PYTHAGORAS theorum to get the angle between them.
temp_x# = Abs(temp_x# / 200) ;this bit just makes the number's smaller and more manageable
temp_y# = Abs(temp_y# / 200)
temp_hyp# = (temp_x#*temp_x#) + (temp_y#*temp_y#) ;PYTHAGORAS would be proud
temp_hyp# = Sqr(temp_hyp#) ;.. oh and Mrs Pennington, my Maths teacher! :)
enemy\dest_adj = temp_x# ;these Type properties aren't used anymore, except in the DEBUG version
enemy\dest_opp = temp_y#
enemy\dest_hyp = temp_hyp#
enemy\dest_angle = ASin(temp_y#/temp_hyp#) ;finally, back to Trigonometry, the angle is revealed.
;now, once again, because we lost the directions of the original value's units, the angle we've just got will only be between 0 and 90 degrees
;consequently, we've got to decide how to get 91 to 359 degrees back, which we can do with our "sector" values
Select sector
Case 1
enemy\dest_angle = 90-enemy\dest_angle ;between 0 and 90
Case 2
enemy\dest_angle = 90+enemy\dest_angle ;between 90 and 180
Case 3
enemy\dest_angle = 270-enemy\dest_angle ;between 180 and 270
Case 4
enemy\dest_angle = 270+enemy\dest_angle ;between 270 and 360
End Select
;so, now our enemies know where to point themselves, let's not allow them to just mindlessly run into you!
If temp_hyp# < Rnd(1,1.5) And gameovercounter = 0 Then ;if the distance between you and them is less than (a small, but random distance)
;and the player is alive..
If enemy\bulletlimiter = 0 Then ;exactly like the player shooting, the enemie's bullet needs limiting
Else ;if the "enemies" has not reached his destination "distance to go" value then
If slowdown = 1 Then
If enemy\speed < enemy\maxspeed Then ;speed up the enemy until he reaches maximum speed
enemy\speed = enemy\speed + (5*INCR_SPEED)
Else
enemy\speed = enemy\maxspeed
End If
Else ;if he's within a certain distance, only allow him to
If enemy\speed < enemy\maxspeed/2 Then ;fly at half speed
enemy\speed = enemy\speed + (5*INCR_SPEED)
Else
enemy\speed = enemy\maxspeed / 2
End If
End If
End If
End If ;end of the "is enemy in the middle of exploding" IF statement
End If ;end of the "is the Player's CLOAKing device on?" IF statement
enemy\x = enemy\x + (enemy\speed*(Sin(enemy\angle)/2)) ;update the "enemies" x and y positions, relative to its Speed and Angle
enemy\y = enemy\y - (enemy\speed*(Cos(enemy\angle)/2)) ;exactly the same code as the Player's positions, earlier
If enemy\x < 0 Then
enemy\x = (enemy\x + GAME_AREA_X)
End If
If enemy\x > GAME_AREA_X Then
enemy\x = (enemy\x - GAME_AREA_X)
End If
If enemy\y < 0 Then
enemy\y = (enemy\y + GAME_AREA_X)
End If
If enemy\y > GAME_AREA_Y Then
enemy\y = (enemy\y - GAME_AREA_Y)
End If
Next ;end of the ENEMIES for loop
;this next bit of code creates the "simple but effective" Hyperjump event, based entirely on the value of "hypercount" being set to 1, earlier in the code.
If hypercount > 0 Then
If (hypercount/2 = Int(hypercount/2)) Then ;this line says "If the value of 'hypercount' is an EVEN number"
;because 5 (an odd number) would be 2.5 when devided by 2, but conversion to an INTeger gives 3.
;2.5 does NOT equal 3!
;all of this simply rotates the HyperJump ships in different offset directions
;the only difference is, we're not bothering with degrees here, just animation frame numbers, i.e.: 355 degrees is frame 71 (i.e.: 355/5 degree increment)
frame1 = frame1 + 3
frame2 = frame2 - 3
frame3 = frame1 + 9
frame4 = frame2 - 9
frame5 = frame1 + 36
frame6 = frame2 - 36
frame7 = frame1 + 54
frame8 = frame2 - 54
If frame1 >=72 Then
frame1 = frame1-72
End If
If frame1 < 0 Then
frame1 = frame1+72
End If
If frame2 >=72 Then
frame2 = frame2-72
End If
If frame2 < 0 Then
frame2 = frame2+72
End If
If frame3 >=72 Then
frame3 = frame3-72
End If
If frame3 < 0 Then
frame3 = frame3+72
End If
If frame4 >=72 Then
frame4 = frame4-72
End If
If frame4 < 0 Then
frame4 = frame4+72
End If
If frame5 >=72 Then
frame5 = frame5-72
End If
If frame5 < 0 Then
frame5 = frame5+72
End If
If frame6 >=72 Then
frame6 = frame6-72
End If
If frame6 < 0 Then
frame6 = frame6+72
End If
If frame7 >=72 Then
frame7 = frame7-72
End If
If frame7 < 0 Then
frame7 = frame7+72
End If
If frame8 >=72 Then
frame8 = frame8-72
End If
If frame8 < 0 Then
frame8 = frame8+72
End If
End If ;end of the "if hypercount is EVEN" IF statement
;this bit increases the value of "hypercount" until it reaches 200
hypercount = hypercount + 1
If hypercount > 0 And hypercount <= 102 Then ;between 0 and 102, the player speed increases
PLAYER_SPEED = PLAYER_SPEED + 2
ElseIf hypercount > 102 And hypercount < 200 Then ;between 102 and 200, the player speed decreases (but only if FLAG_GAMESTARTER is 0)
If FLAG_GAMESTARTER = 0 Then ;this is because when the game starts, the player speed is 0, but we've faked being in
PLAYER_SPEED = PLAYER_SPEED - 2 ;the middle of a hyperjump. Without this FLAG, the player ship would start each game
End If ;travelling at about -90 speed backwards, which would just be weird! :)
End If
If hypercount = 100 Then
game_stars_randomize() ;half way through the Hyperjump sequence, the "game_starts_randomize()" function is called, which changes all the star positions
;and depths, to give the impression we've moved to a completely different part of space
End If
If hypercount/10 = Int(hypercount/10) Then
game_player_randomize() ;every 10 updates, the function "game_player_randomize()" is called. This randomly jumps the player around the map
;and confuses the hell out of the bad guys! ;))
End If
If hypercount = 200 Then ;if the "hypercount" variable reaches 200, then stop the sequence and reset the value back to 0
hypercount = 0
FLAG_GAMESTARTER = 0 ;also, when the game first starts we were in the middle of a hyperjump. Resetting this FLAG back to 0 means that
;the next hyperjump sequence will decrease the speed after "hypercount" gets to 103
End If
Else ;if we're not in the middle of a hyperjump event, then:
frame1=game_player_frame-1 ;this bit is just for the DEBUG mode. It was designed to check that 360 degrees became 0 degrees and vice versa correctly
frame2=game_player_frame+1
If frame1 < 0 Then
frame1 = frame1 + 72
End If
If frame2 >= 72 Then
frame2 = frame2 - 72
End If
End If ;end of the "Are we in the middle of a Hyperjump" IF statement
;the parralex stars move relative to the player and is just the same "menustars" number of stars
;scrolled at various speeds, wrapping around the screen.
;it's a fairly cheap, but effective way of creating a nice illusion of speed!
If starson=1 Then ;if, at the beginning of the program, you set "starson" to 0, the stars will disappear.
;the game would also feel pretty bloody wierd.. hold on.. yep.. Absolutely mad! Try it! :)
For star.stars=Each stars
;the following two lines move each version of the "stars" Type an x and y distance relative to the player's speed and angle
;with a devision relative to the depth of the star to make the smallest stars move slower than the biggest
;thus we have our parallex effect.
;it might be of interest to know that these two lines were based on the OLDSKOOL demo which comes with Blitz Basic
;and was the starting point for the whole CELESTIAL RIFT game concept! Thanks a lot, Mr Mikkel L°kke!! :)
enemy\gen=enemy\gen +1 ;remember before, I said that the enemy would be worth more points as it regenerated?
;here it is! If this was the first time it had been killed, next time will be worth *TWICE* the points
;if it was the 5th time it had been killed, next time it will be worth *SIX* times the points etc..
End If
End If ;end of the "is this enemies exploding" IF statement
Next ;end of the "enemies" FOR loop
;now we'll do the same for all the bullets on (or off) the screen
For i = 0 To bulletnum-1 ;this cycles though the array from position 1 to the final bullet number in the array..
;we use "bulletnum - 1" because there are (for example) 600 possible bullets that are stored
;in an array as 0, 1, 2, 3 ... 596, 597, 598 and 599
Select bullets(i,4) ;whose bullet is it? remember when we originally DIMmed this Array, I said that 0 was off, 1 was a PLAYER bullet and 2 was an enemy bullet?
Case 1
;if it's a player bullet then..
;draw this bullet at it's position, relative to the player, in it's current animation frame
;just like in "menu_draw_update()", the user can press a key which just makes the value of "FLAG_SCREENSAVE" equal 1.
;when the code gets to here, it saves out the named Buffer as a BMP picture.
If FLAG_SAVESCREEN=1 Then
SaveBuffer (BackBuffer(),"CRGameScreen.bmp")
FLAG_SAVESCREEN = 0
End If
Flip ;as before in "menu_draw_update()", FLIP everything we've just drawn on the backbuffer and show it on the frontbuffer, i.e.: your monitor!!
End Function
;a little function which randomizes the x and y coordinates of each version of the "stars" Type, plus it's "depth" property
Function game_stars_randomize()
For star.stars=Each stars
star\x=Rnd(-5,SCREEN_WIDTH) ;create random x and y positions for all the stars
star\y=Rnd(-5,SCREEN_HEIGHT)
star\depth=Rnd(1,5) ;the depth of the stars results in our sexy parallex effect
Next
End Function
;an even littler function which just gives us random x and y coordinates for the player.
Function game_player_randomize()
PLAYER_X = Rand(0,GAME_AREA_X)
PLAYER_Y = Rand(0,GAME_AREA_Y)
End Function
;This is the last function and it's MARVELLOUS! :)
;This is the type of function that you should proactively *try* to write, because they're incredibly simple, yet incredibly effective
;and they impress the girls, I can tell you... Um.. No.. That's a lie..
;anyway the beauty of this function is that when you call it in the code above, you "feed" it some parameters.
;this one is expecting an X Coordinate, a Y Coordinate, an Angle value, a Speed value and a Style value.
;it doesn't care who or what they refer to, it just knows that it wants 5 numbers to work with.
;So, when a player requires two bullets to be made, I just give it "PLAYER_X, PLAYER_Y, PLAYER_ANGLE,
;PLAYER_SPEED and 1 (which just makes sure the correct bullet AnimImage is used!)
;When an enemy needs a bullet, I just give it "Enemy X, Enemy Y, Enemy Angle, Enemy Speed, 2"
;the createbullet() function does the rest and "produces" 2 bullets on the screen, starting at the end of the calling ship's laser.. BUT THAT'S ALL..
;After the bullet has been created, its "life" is calculated in another part of the code (it's x and y coordinates are altered based on the original angle and speed
;calculated in this function..) Enjoy
Function createbullet(x,y,angle,speed,style) ;creates 2 bullets starting on the end of a ship's lasers.
;there are "bulletnum" containers available in the "bullets()" array.
;if we've reached the maximum number of bullets, then the very first
;'bullet' will be overwritten with this new bullet.
;We do this by wrapping "nextbullet" back to 0, when it reaches bulletnum
If nextbullet = bulletnum-1 Then
nextbullet = 0
End If
;we want to create a bullet for the RIGHT laser of a ship
;by messing with the angleoffset value during debugging, I was able to come up with the
;correct values that looked right on screen (30 for this angle and 28 for the next calculation)
angleoffset = angle - 30
bullets(nextbullet,0) = x + 28*Cos(angleoffset) ;this sets the x and y pixel offset from the ship's game coordinates
bullets(nextbullet,1) = y + 28*Sin(angleoffset) ;in this case 28*Cos/Sin of the angle offset
;these next bits are just setting the origin of the bullets, including it's start position, speed and angle
;this is so the bullets can fly independently of the PLAYER's ship's Angle and speed (unlike everything else in the game)
bullets(nextbullet,2) = angle
If speed <= 0 Then ;this bit essentially stops the player catching up to his bullets, or bullets flying backwards
bullets(nextbullet,3) = 25 ;if the ship is still, or moving backwards, then a bullet fires off at a speed of 25
Else
bullets(nextbullet,3) = speed + 25 ;otherwise, if a ship is moving forwards, then the bullet flys off at a speed of 25, PLUS the ship's speed
End If
bullets(nextbullet,4) = style ;used to decide which bullet AnimImage should be used
bullets(nextbullet,5) = 0 ;used to keep track of the frame of animation a bullet is on
bullets(nextbullet,6) = bullets(nextbullet,0) ;used to know where a bullet began it's life in x and y coordinates
bullets(nextbullet,7) = bullets(nextbullet,1)
nextbullet = nextbullet+1 ;we've successfully created a bullet (whose 'life' from now on will be calculated back
;in "game_loop_update()", so now we move the "nextbullet" value on by 1
;ready for creation of the next bullet!
If nextbullet = bulletnum-1 Then ;exactly the same process, but with a 120 degree offset for the left hand laser
