+groundloopright:
+ ld c,b ;push b for groundloopup
+ pop hl \ inc hl ;get screen position and go one right
+ pop de \ inc de ;get height info and set to the next byte
+ psh de \ psh hl ;save these for the next time
+ ld a,(de) ;height of current byte
+ ld b,a ;save in b
+
+ ld de,-scrwidth ;to substract to go one line up
+ ld a,%11111111 ;bitmask black
+groundloopup:
+ ld (hl),a ;display black byte
+ add hl,de ;go up (sbc must be used for 16-bit sub)
+ dnz groundloopup ;and loop >groundpos< times
+
+ ld b,c ;pop b used by groundloopup
+ dnz groundloopright ;loop right for entire screen (16x)
+ pop hl \ pop hl ;restore stack
+
+CheckGround: ;check for collision with the ground
+ ld a,(x)
+ srl a
+ srl a
+ srl a
+ inc a
+ ld l,a
+ ld h,0
+ ld de,groundpos
+ add hl,de
+ ld a,(y)
+ sub 57-7
+ neg
+ cp (hl)
+ ret nc
+ ld b,auch_ground
+ jp damage_you
+
+;--------------------------- move stars --------------------------------------
+
+DisplayStars: ;inputs: hl=starx# a=stars# b=nrstars#
+ ld e,(hl)
+ inc hl
+ ld d,(hl)
+ ld (de),a
+ inc hl
+ dnz DisplayStars
+ ret ;let's comment this: returns
+
+movestars2:
+ ld ix,starx2
+ ld a,(stars2)
+ rlca ;move bits (star) left
+ ld (stars2),a
+ ret nc ;if star didn't went from left to right bit
+ ld b,nrstars2 ;otherwise move all stars one byte left
+ jr movestars_loop
+
+movestars1:
+ ld ix,starx1
+ ld a,(timer)
+ rra
+ ld a,(stars1)
+ ret c ;once every other turn...
+ rlca
+ ld (stars1),a
+ ret nc
+ ld b,nrstars1
+
+movestars_loop:
+ ld h,(ix+1)
+ ld l,(ix) ;star (ix) pos in hl
+ dec hl ;one byte left (hl--)
+
+ ld a,dispbuffer/256-1 ;screen high byte minus one (it may be equal)
+ cp h ;compare w/ star high byte
+ jr c,newstarok ;screen<star: still on screen
+ cal RandomY ;otherwise create new position hl
+
+newstarok:
+ ld (ix),l ;save star's new position (ix)=hl
+ ld (ix+1),h
+ inc ix \ inc ix ;next star (2 bytes/star)
+ dnz movestars_loop ;repeat for each star
+ ret ;...here's another comment... :P
+
+;--------------------------- pause -------------------------------------------
+
+Pause:
+ ld hl,_txt_pause
+ ld (_penCol),hl
+ ld hl,txt_pause
+ rcl _vputs ;display small font
+ ld hl,_txt_pressenter ;top centered
+ ld (_curRow),hl
+ ld hl,txt_pressenter ;"Enter to continue"
+ rcl _puts ;display message
+pause:
+ cal getsomekeys ;GET_KEY w/ halts and checks for enter
+ ret z ;enter/second pressed: continue game
+#ifdef invertable
+ cp K_F1 ;F1 pressed?
+ jr nz,notinvert
+ cal do_invert ;if so then change invert screen (AF saved)
+ cal mode_invert ;and screen mode (will be saved)
+notinvert:
+#endif
+ ld hl,CONTRAST ;contrast setting (0-31)
+ ld b,(hl) ;load contrast into b
+ cp K_UP ;+ key changes contrast up
+ jr nz,contr_not_up
+ inc b ;increase contrast
+ jr setcontrast ;set
+contr_not_up:
+ cp K_DOWN ;- key
+ jr nz,pause ;nope: loop
+ dec b ;decrease contrast
+setcontrast:
+ ld a,b
+ ld (hl),a
+ out (2),a ;and set it
+ cal releasekeys
+ jr pause ;and loop
+
+;--------------------------- teacher -----------------------------------------
+
+#ifdef teacherkey ;can be disabled to save space if not needed
+Teacher:
+ ld (iy+12),5 ;enable flashing cursor
+ rcl _clrWindow ;top left
+ ld hl,txt_teacher
+ rcl _puts ;display message
+ cal releasekeys
+
+teacherloop:
+ rcl _getkey ;enter low-power mode and wait for key
+ cp kEnter ;enter pressed?
+ jr z,teacherans
+ cp kGrMenu ;keypressed = graph?
+ jr nz,teacherloop ;no, wait some more
+
+ ld (iy+12),0 ;disable cursor
+ cal releasekeys
+ jp disp_icons ;+ret
+
+teacherans: ;enter displays the answer
+ ld a,' ' ;the cursor could still be displayed (█)
+ rcl _putc ;so remove it by displaying a ' ' over it
+
+ ld hl,$0701
+ ld (_curRow),hl ;below the equation, aligned right
+ ld hl,txt_teacherans ;the answer text
+ rcl _puts ;display
+ jr teacherloop ;and continue loop
+#endif
+
+;--------------------------- exit --------------------------------------------
+
+quit:
+#ifdef fixkeys
+ im 1 ;release keyfix procedure
+#endif
+#ifdef TI86
+ xor a
+ ld (_asapvar+1),a ;next Asm( run will reload the program
+ res 5,(iy) ;don't display "Done" in TI-OS :P
+ set 2,(iy+13) ;set back screen scrolling again
+#endif
+#ifdef TI83
+ res 7,(iy+20) ;_vputs will now write directly to LCD again
+ set 6,(iy+9) ;finished with statmem
+#endif
+#ifdef clearbuffer ;should we clear the display buffer?
+ ld hl,dispbuffer ;graph-screen location
+ ld de,dispbuffer+1
+ ld (hl),a ;set to 0 (zero, nothing, nada, empty..)
+ ld bc,1024-1 ;do it 1024 times = entire screen
+ ldir ;load that first 0 into the entire area
+#endif
+ jp _clrWindow ;as _clrLCD but also clears TEXT_MEM (like the
+ ;_clrScrn) AND also executes _homeup and ret
+
+;--------------------------- display -----------------------------------------
+
+Display_Screen:
+#ifdef TI83
+fastCopy:
+ jp ionFastCopy
+ ld a,$80 ; 7
+ out ($10),a ; 11
+ ld hl,dispbuffer+2-16-(-(16*64)+1) ; 10
+ ld a,$20 ; 7
+ ld c,a ; 4 ; 43
+fastCopyAgain:
+ ld b,64 ; 7
+ inc c ; 4
+ ld de,-(16*64)+1 ; 10
+ out ($10),a ; 11
+ add hl,de ; 11
+ ld de,15 ; 10
+fastCopyLoop:
+ add hl,de ; 11
+ inc hl ; 6
+ ret c ; 5
+ ld a,(hl) ; 7
+ out ($11),a ; 11
+ dnz fastCopyLoop ; 13/8 ; 3392
+ ld a,c ; 4
+ cp $2B+1 ; 7
+ jr nz,fastCopyAgain; 12/7
+ ret ; 11 ; 18
+
+#endif
+ ld hl,dispbuffer ;from buffer (top left)
+ ld de,VIDEO_MEM ;to real screen (top left)
+ ld c,56 ;display height = 64 bytes (minus 8 for bar)
+displayloop:
+ ld b,16 ;display width = 16 bytes (16*8bits=256pixels)
+displaytloop:
+ ld a,(hl) ;copy byte from (hl)
+_invert: ;SMC: cpl <-> or a
+ cpl ;xor $ff: invert byte (white<=>black)
+ ld (de),a ;to (de)
+ inc hl \ inc de ;next byte
+ dnz displaytloop ;16x hl >> de
+ dec c ;next line
+ jr nz,displayloop ;loop 56x
+
+ ld hl,time2invert
+ ld a,(hl)
+ or a ;(time2invert)=0:
+ jr z,noinvert ; do nothing
+ dec a ;otherwise decrease
+ cal z,do_invert ;if it became 0 then invert
+ ld (hl),a ;save new value
+noinvert:
+
+ ld hl,$396b ;Display Score
+ ld (_penCol),hl ;bottom right of screen
+ ld hl,(your_score)
+
+_D_HL_DECI: ;------- display 5-digit value -------
+ ld de,savestr+4 ;savenr saves number string
+ ld b,5 ;five digits
+ldhld: rcl UNPACK_HL ;one digit of hl
+ add a,'0' ;make number
+ ld (de),a ;save into savenr
+ dec de ;point to next digit
+ dnz ldhld ;repeat for all digits
+
+ ld hl,savestr ;we (the program) saved the value righthere
+ jp _vputs ;the only thing left to do is to display it
+
+savestr: ;@here the score will be stored
+ .db "00000",0 ;don't worry, it's just temporary
+
+;------------------------- handle ship ---------------------------------------
+
+Handle_Ship:
+ ld a,(your_occ) ;are
+ or a ;you
+ jr z,ok ;ok?
+
+ inc a ;no! next (explosion)frame
+ ld (your_occ),a ;save
+
+ cp 63+1 ;last explosion frame?
+ jp c,exploding_you ;not yet: display explosion
+ cp 64+16 ;delay finished?
+ ret nz ;no, don't display anything (&return)
+ pop hl ;restore stack (cuzzof call)
+ jp z,You_die ;yes = game over
+
+;----move----
+ok: ;we are
+ ld a,%01111110 ;get arrow keys
+ out (1),a ;it's cold outside
+ ld hl,y ;instead of nop\nop do something usefull
+ in a,(1) ;come back in
+
+ ld b,a ;psh a (keys)
+ xor -1 ;inverted a: 0 if arrow-key has been pressed
+ ld a,(your_multiples) ;(btw: CPL doesn't set any flags)
+ res 7,a ;reset move bit (no flags changed)
+ jr z,adv_ok ;if so, leave the multiples where they are
+ set 7,a ;set move bit
+adv_ok: ld (your_multiples),a
+
+ ld a,(timer) ;framecounter
+ and %1 ;switches 0<>1 each frame
+ inc a ;a = 1 or 2 (1.5 avg)
+ ld c,a ;c = your_speed
+
+ ld a,b ;pop a (keys)
+ rra ;rotate right (put last bit in c)
+ ld b,a ;we need a later
+
+ jr c,no_down
+ ld a,(hl)
+ add a,c
+ cp 50 ;56-6 = bottom of screen
+ jr nc,no_down
+ ld (hl),a
+no_down:
+ dec hl
+ rr b ;because we now use b, it's rr instead of rra
+ jr c,no_left
+ ld a,(hl)
+ sub c ;<dec a> doesn't affect c-flag
+ jr c,no_left ;-1 = left side
+ ld (hl),a
+no_left:
+ rr b
+ jr c,no_right
+ ld a,(hl)
+ add a,c
+ cp 122 ;128-6 = right side
+ jr nc,no_right
+ ld (hl),a
+no_right:
+ ld d,(hl) ;d=x
+ inc hl
+ rr b
+ jr c,no_up
+ ld a,(hl)
+ sub c ;<dec a> doesn't affect carry-flag
+ jr c,no_up ;-1 = top of screen
+ ld (hl),a ;save new y
+
+no_up: ld e,(hl) ;e=y
+ ld ix,spr_ship01 ;normal ship sprite
+your_shipspr =$-2
+ ld hl,your_shield ;shielded?
+ ld a,(hl) ;load time in a
+ or a ;is it 0?
+ jr z,disp_ship ;yes so ship = normal (display \ continue)
+
+ ld a,(timer) ;load frame nr.
+ and %00000111 ;a=0 once every four frames
+ jr nz,not_time ;a<>0 = not time to update counter
+ dec (hl) ;decrease inv-time left
+not_time:
+ and %00000100 ;a switches 0<->1 every 2 frames
+ jr z,disp_ship ;show normal ship
+inv_flicker:
+ ld bc,spr_ship01i-spr_ship01
+ add ix,bc ;display invulnerable ship
+disp_ship:
+ cal safeputsprite ;display your ship; save de
+
+;----multiples----
+
+handle_multiples:
+ ld a,(your_multiples) ;do you have multiples
+ ld b,a ;save a for 2nd check
+ and %1111 ;no? (last four bits = nr of multiples)
+ ret z ;then don't handle them either
+ bit 7,b ;move the multiples??? (=move bit set?)
+ jr z,mult_adv ;nope, just let them (saves (y)in y, (x)in x)
+
+ psh de ;current position = needed later
+ ld hl,mm*14+1+your_prevpos ;previous positions
+ ld de,mm*14+3+your_prevpos ;move all positions one back
+ ld bc,mm*14+2
+ lddr ;change 0-57 -> 2-59 (if mm=4 that is)
+ inc hl ;your_prevpos+0
+ pop de
+ ld (hl),d ;x-pos
+ inc hl ;=current position
+ ld (hl),e ;y-pos
+
+mult_adv:
+ ld ix,spr_multiple ;normal sprite
+ ld hl,timer
+ bit 3,(hl) ;change sprites every 8 turns
+ jr z,disp_multiples
+ ld ix,spr_multiple2 ;second sprite
+disp_multiples:
+ ld hl,your_prevpos+16 ;first pos.
+dispmultiplesloop:
+ psh af
+ psh hl
+ ld d,(hl) ;load coords
+ inc hl
+ ld e,(hl)
+ psh ix
+ cal putsprite ;display
+ pop ix ;same sprite next time ;)
+ pop hl
+ ld de,14
+ add hl,de ;next multiple
+ pop af ;counter
+ dec a
+ ret z ;return if all done
+ jr dispmultiplesloop ;loop
+
+;----explode----
+
+exploding_you:
+ srl a ;half the framerate
+ srl a ;and half that framerate
+ ld hl,x-1
+ ld ix,spr_yexplosion ;base sprite
+
+explosion_stuff: ;in:a=frame*2+(0 to 1); (hl)=xpos-- ix=sprite
+ and %11111110
+ add a,a
+ add a,a ;frame*8
+ ld c,a
+ ld b,0 ;bc=a
+ add ix,bc ;go to correct sprite (each spr. is 8 bytes)
+ inc hl ;@x
+ ld d,(hl) ;load xpos
+ inc hl ;@y
+ ld e,(hl) ;and y
+ jp putsprite ;and display it too
+
+;----hit----
+
+damage_you: ;damages you B points
+ ld a,(your_occ) ;return if already dead (prevents exploding
+ or a ; twice, or stucking in exploding state)
+ ret nz ;0 = you're normal
+
+ ld a,(hardcore) ;hardcore mode?
+ or a
+ jr z,damageok ;0 = no = don't modify
+; sla b ;1 = yes = double tha damage (b shifted left)
+ .db $CB,$30 ;sll b ;damage=2b|1 (CB3r = unsupported SLL r)
+damageok:
+ ld a,(your_shield) ;shield left?
+ or a
+ jr z,dothadamage ;no shield
+ srl b ;shield: half the damage
+dothadamage:
+ ld hl,time2invert
+ xor a ;a=0
+ cp (hl) ;not already inverted?
+ cal z,do_invert ;then invert screen
+ ld (hl),2 ;change back 2 frames from now
+
+ ld hl,your_armor ;armor left
+ ld a,(hl) ;load hp in A
+ sub b ;decrease hp by B
+ jr nc,newarmor ;>=0hp left so don't explode
+ ld a,%01 ;occ %xxxxxx01 = explode
+ ld (your_occ),a ;too bad, you're dead meat
+newarmor:
+ ld (hl),a ;save decreased hp
+ jp disp_armor ;and display new value
+
+;------------------------- place multiples -----------------------------------
+
+Place_multiples:
+ ld hl,your_prevpos ;place all previous positions
+ ld b,mm*7+2 ;all saved positions of them (14 per multiple)
+place_multiples:
+ ld (hl),e ;set prev-x to d
+ inc hl ;next
+ ld (hl),d ;set prev-y to e
+ inc hl ;next
+ dnz place_multiples ;repeat
+ ret
+
+;------------------------- select upgrade ------------------------------------
+
+inc_armor:
+ ld a,(your_armor) ;load current armor
+ cp maxarmor-5 ;may not become >=maxarmor
+ jr c,doincarmor ;ok then just add 6
+ ld a,maxarmor-6 ;set to maximum (6 will be added below)
+doincarmor:
+ add a,6 ;add 6 to armor
+ ld (your_armor),a ;change armor
+ ret
+
+select:
+ ld de,your_weapon ;current weapon, required for most selections
+ ld hl,your_pickup ;select pickups
+ ld a,(hl) ;load pickups taken so far
+ dec a ;is it 1?
+ ret m ;return if it's 0 (no pickups)
+
+ ld (hl),0 ;reset pickups
+ jr nz,selectlaser ;no, carry on again
+selectbeam:
+ ld a,(de) ;(your_weapon)
+ inc a ;next
+ cp maxweapon
+ jr c,selectedbeam ;weapon OK
+ jr z,disp_icons ;weapon maxed out
+ xor a ;laser was selected: set to first weapon
+selectedbeam:
+ ld (de),a ;set new weapon
+ cal loadweapon ;load it (damage and stuff)
+ jr disp_icons ;display n return
+selectlaser:
+ dec a ;is it 2?
+ jr nz,selectextra ;no, carry on
+ ld (your_extra),a ;no extra beams (tailbeam/up-double)
+ ld a,(de) ;(your_weapon)
+ cp maxweapon ;upgrade from bullet?
+ jr nc,upgradelaser ;nope, just upgrade
+ ld a,maxweapon-1 ;yes, set laser #1
+upgradelaser:
+ inc a ;next laser
+ cp maxlaser
+ jr nc,disp_icons ;laser maxed out
+ ld (de),a
+ cal loadweapon
+ jr disp_icons ;display + return
+selectextra:
+; ld a,(de) ;(your_weapon)
+; cp maxweapon+1 ;laser or beams?
+; jr c,selectXbeam ;if beamweap then no multiples but extra beam
+ ld hl,your_multiples
+ ld a,(hl) ;multiples you already got
+ and %1111 ;reset movebit so (your_multiples)=real value
+ inc a ;one more
+ cp mm+1
+ jr nc,enoughmultiples ;maxed out
+ ld (hl),a
+enoughmultiples:
+ ld de,(x)
+ dec a ;if this is your first multiple then...
+ cal z,Place_multiples ;reset multiples positions
+; jr disp_icons ;display, return
+;selectXbeam:
+; ld a,1 ;updouble
+; ld (your_extra),a ;ready extra beam
+; jr disp_icons ;display 'n return
+
+;--------------------------- show icon ---------------------------------------
+
+disp_icons: ;destroyes: abcdehlix
+#ifdef TI86 ;-------86
+
+ ld a,VIDEO_MEM/$400 ;directly on screen
+ ld (PutWhere),a ;place icons at normal screen
+ ld hl,VIDEO_MEM+(scrwidth*56);56 rows down = eight rows from bottom
+ ld b,scrwidth ;draw 16x (screen width)
+ ld a,%11111111 ;horizontal line mask
+ cal drawline ;draw divider-line
+
+ ld b,scrwidth*7 ;draw 16x (screen width) 7x (height)
+ xor a ;blank line mask
+ cal drawline ;clear scorebar
+
+disp_lives:
+ ld de,$003C ;(0,4)
+ ld a,(your_lives) ;nr of lives
+ or a
+ jr z,displivesdone ;no lives
+ ld b,a
+displivesloop:
+ psh bc
+ ld ix,spr_lship
+ cal safeputsprite ;put li'l ship
+ ld a,lshipsize+1
+ add a,d
+ ld d,a ;x=x+5
+ pop bc
+ dnz displivesloop ;one ship per life
+displivesdone:
+ cal disp_armor ;display bar
+
+ ld ix,spr_icon00 ;emptyIcon
+ ld a,(your_weapon) ;ur weapon
+ cp maxweapon ;bullets?
+ psh af ;a=(your_weapon); cf=bullets
+ jr nc,no_bullets ;=laser
+ ld hl,$3945 ;position to display bullet-type digit
+ inc a ;1 = weapon #1 (=0)
+ ld (_penCol),hl ;set location
+ add a,'0' ;make digit
+ rcl _vputmap ;display char
+ ld ix,spr_icon04 ;bulletIcon
+no_bullets:
+ ld de,$3939 ;icon #2
+ cal putwidesprite ;(beamweap)
+
+ ld ix,spr_icon00
+ pop af ;ld a,(your_weapon) \ cp maxweapon
+ jr c,no_laser ;popped carry
+ ld hl,$3955 ;position to display laser-type digit
+ ld (_penCol),hl ;set location
+ sub maxweapon-1 ;1 = laser #1 (=maxweapon)
+ add a,'0' ;make digit
+ rcl _vputmap ;display char
+ ld ix,spr_icon03 ;laserIcon
+no_laser:
+ ld de,$4939 ;icon #1
+ cal putwidesprite ;display icon (laser)
+
+ ld ix,spr_icon00 ;emptyIcon
+ ld a,(your_multiples) ;number of multiples
+ and %111 ;<8
+ jr z,no_multiples ;none (empty)
+ ld ix,spr_icon05 ;multiples-icon
+no_multiples: ;no multiples
+ ld de,$5939 ;icon #3
+ cal putwidesprite
+
+ ld ix,spr_dividerline
+ ld de,$6939
+ cal putwidesprite
+
+ ld a,(your_pickup) ;pickups taken
+ add a,a ;picks*2 (sets z-flag)
+ jr z,iconsdone ;return if no pickups
+ add a,a ;picks*4
+ add a,a ;picks*8
+ add a,a ;picks*$10
+ add a,$29 ;add 29h
+ ld d,a ;y-pos = picks * $10 + $29 (3a,4a,5a)
+ ld e,$39 ;x-pos = bottom (3a39,4a39,5a39)
+
+ ld ix,spr_icon
+ cal putwidesprite
+iconsdone:
+ ld a,dispbuffer/$400 ;normal game-screen
+ ld (PutWhere),a ;set sprite-position to normal screen
+ jp disp_charge ;display weapon charge bar
+
+#else ;-------------83
+
+ ld hl,VIDEO_MEM+(scrwidth*56);56 rows down = eight rows from bottom
+ ld b,scrwidth ;draw 12x (screen width)
+ ld a,%11111111 ;horizontal line mask
+ cal drawline ;draw divider-line
+
+ ld b,scrwidth*7 ;draw 12x (screen width) 7x (height)
+ xor a ;blank line mask
+ cal drawline ;clear scorebar
+
+disp_lives:
+ ld de,$003C ;(0,4)
+ ld a,(your_lives) ;nr of lives
+ or a
+ jr z,displivesdone ;no lives
+ ld b,a
+displivesloop:
+ psh bc
+ ld ix,spr_lship
+ cal safeputsprite ;put li'l ship
+ ld a,lshipsize+1
+ add a,d
+ ld d,a ;x=x+5
+ pop bc
+ dnz displivesloop ;one ship per life
+displivesdone:
+ cal disp_armor ;display bar
+
+ ld ix,spr_icon00 ;emptyIcon
+ ld a,(your_weapon) ;ur weapon
+ cp maxweapon ;bullets?
+ psh af ;a=(your_weapon); cf=bullets
+ jr nc,no_bullets ;=laser
+ ld hl,$3935 ;position to display bullet-type digit
+ inc a ;1 = weapon #1 (=0)
+ ld (_penCol),hl ;set location
+ add a,'0' ;make digit
+ rcl _vputmap ;display char
+ ld ix,spr_icon04 ;bulletIcon
+no_bullets:
+ ld de,$2F39 ;icon #2
+ cal putwidesprite ;(beamweap)
+
+ ld ix,spr_icon00
+ pop af ;ld a,(your_weapon) \ cp maxweapon
+ jr c,no_laser ;popped carry
+ ld hl,$393F ;position to display laser-type digit
+ ld (_penCol),hl ;set location
+ sub maxweapon-1 ;1 = laser #1 (=maxweapon)
+ add a,'0' ;make digit
+ rcl _vputmap ;display char
+ ld ix,spr_icon03 ;laserIcon
+no_laser:
+ ld de,$3939 ;icon #1
+ cal putwidesprite ;display icon (laser)
+
+ ld ix,spr_icon00 ;emptyIcon
+ ld a,(your_multiples) ;number of multiples
+ and %111 ;<8
+ jr z,no_multiples ;none (empty)
+ ld ix,spr_icon05 ;multiples-icon
+no_multiples: ;no multiples
+ ld de,$4339 ;icon #3
+ cal putwidesprite
+
+ ld ix,spr_dividerline
+ ld de,$4D39
+ cal putwidesprite
+
+ ld a,(your_pickup) ;pickups taken
+ add a,a ;picks*2 (sets z-flag)
+ ld e,a ;save 2*picks
+ jr z,iconsdone ;return if no pickups
+ add a,a ;picks*4
+ add a,a ;picks*8
+ add a,e ;picks*10 (8+2=10)
+ add a,$26 ;add 26h
+ ld d,a ;y-pos = picks * 10 + $29 (3a,45,4e)
+ ld e,$39 ;x-pos = bottom (3a39,4539,4e39)
+
+ ld ix,spr_icon
+ cal putwidesprite
+iconsdone:
+ jp disp_charge ;display weapon charge bar
+
+#endif ;------------^^
+
+drawline:
+ ld (hl),a ;draw one piece of the divider-line
+ inc hl ;move right (8 pixels = 1 byte)
+ dnz drawline ;repeat (16bytes * 8pixels =128= screen width)
+ ret
+
+
+disp_armor:
+ ld de,scrwidth ;line size
+#ifdef TI86
+ ld hl,VIDEO_MEM+(58*scrwidth)+6
+#else
+ ld hl,VIDEO_MEM+(58*scrwidth)+5
+#endif
+ ld a,(your_armor) ;load your armor (<maxarmor)
+ srl a ;divide by 2 (barsize halved)
+ psh af
+ and %111 ;display last bits of armor
+ jr z,armorbarbitok ;if b=0 then prevent looping 256x
+ ld b,a ;into B
+ xor a ;bit = %00000000
+armorbarbit:
+ scf ;set carry flag
+ rla ;rotates A left and sets bit 0 (c-flag)
+ dnz armorbarbit ;repeat B times (so if B=6 then a=%00111111)
+armorbarbitok: ; (an if B=3 then a=%00000111)
+ ld c,a ;save last bit in c
+ pop af ;now we'll make the byte
+ and %11111000 ;clear last three bits
+ rra ;so we can use rotate instead of shift right
+ rra ;which saves 3(-2) bytes and speed
+ rra ;/8: don't display last 3 bits of a (later)
+
+ ld b,5 ;bar height
+armorbarloop1:
+ psh bc ;yloop counter
+ psh hl ;begin x-position
+ ld b,a ;loop b=a times per line
+ or a ;<1 bytes
+ jr z,lastarmorbit ;then don't display bytes (would be 256x)
+armorbarbyte:
+ ld (hl),%11111111 ;draw a piece of the bar
+ dec hl ;next position
+ dnz armorbarbyte ;loop it b times
+lastarmorbit:
+ ld (hl),c ;draw the last byte
+ dec hl
+ ld (hl),0 ;empty byte before to remove any remainders
+ pop hl ;recall first byte
+ add hl,de ;one down
+ pop bc ;recall yloop-counter
+ dnz armorbarloop1 ;display again
+
+#ifdef TI86
+ ld hl,(56*scrwidth)+VIDEO_MEM+7
+#else
+ ld hl,(56*scrwidth)+VIDEO_MEM+6
+#endif
+ ld a,%01010101
+armorbarY:
+ cal drawbarrow ;display "grey" mask
+ cal drawbarrow ;display "grey" mask
+ add hl,de
+ add hl,de
+ add hl,de
+ cal drawbarrow
+drawbarrow: ;ORs an entire row with A
+ add hl,de ;one down
+ ld b,4 ;four bytes right
+ psh hl
+armorbarX:
+ dec hl ;next byte
+ psh af
+ or (hl)
+ ld (hl),a ;clear
+ pop af
+ dnz armorbarX ;4x
+ pop hl ;old position
+ ret
+
+;------------------------- fire bullet ---------------------------------------
+
+fire_multiple:
+ psh af
+ psh ix ;save ix for next fire
+ cal fireany ;fire from multiple position
+ pop ix ;saving ix is much faster than recalculating
+ pop af ;number of multiples
+ dec a ;one just displayed
+ pop hl ;ret
+ ret z ;ret2 if none left
+ jp (hl) ;real ret
+
+fire_multiples:
+ ld hl,(your_prevpos+16);then, fire from multiple position
+ cal fire_multiple
+ ld hl,(your_prevpos+30)
+ cal fire_multiple
+ ld hl,(your_prevpos+44)
+ cal fire_multiple
+ ld hl,(your_prevpos+58)
+ cal fire_multiple ;no JP: that messes up the stack
+ ret
+
+Fire_bullet:
+ ld hl,just_fired ;=for how long you may hold fire (2nd)
+ ld a,(hl) ;a = time left
+ dec a ;decrease timer
+ ret z ;may not fire when (just_fired) became 0
+ ld (hl),a ;save new decreased value
+
+ ld a,(your_weapon) ;if you have bullets.....
+ cp maxweapon
+ jr nc,fireOK ;>weapons = laser
+ ld (hl),1 ;bullet may last one turn (just fire 1 bullet)
+fireOK:
+ ld a,(your_weapon) ;weapon nr.
+ ld ix,weapondata+2
+ add a,a ;weap*2
+ add a,a ; *4
+ add a,a ; *8
+ ld c,a
+ ld b,0 ;go to current weapon (bc=a)
+ add ix,bc ;ix=weapon ptr
+
+ ld a,(your_multiples) ;any multiples?
+ and %1111 ;nr. of multiples
+ cal nz,fire_multiples ;if >0 then fire them too
+ ld hl,(x) ;fire from ship position (x)
+fireany: ;HL=(x,y)
+ ld (firex),hl ;set position to fire from
+ ld b,3 ;or use the proc at fireOK with ld ix,weapondata+2-(256*3)
+fire_weapon:
+ psh bc ;save counter
+ ld a,(ix) ;load this weapon
+ ld c,a ;save bulletType in c
+ and %11100000 ;%111?????=laser
+ cp %11100000 ;is it?
+ cal z,fire_laser ;fire laser (will set c=0 when done)
+ xor a ;<>0=bullet
+ cp c ;c<>0?
+ cal nz,fire_ybullet ;then fire bullet
+ inc ix ;otherwise fire next weapon
+ inc ix
+ pop bc ;weapon counter (do 3 weapons)
+ dnz fire_weapon
+
+fire_tail:
+ ld ix,extrabulletpos-1 ;extra bullet's position
+ ld hl,your_extra ;data
+ ld a,(hl)
+ or a
+ ret z
+; ld c,tailbeam ;tailbeam weapon data
+; dec a ;(your_extra)=1
+; jr z,fire_ybullet ;=tail
+ ld c,doublebeam ;up double data
+ ;(your_extra)=2 =double
+;-----fire BULLETs-----
+
+fire_ybullet: ;fire bullet type=C dam=(curweapdamage) at (firex/y)
+ ld hl,ybullets ;check for unused bullet
+ ld de,4
+ ld b,nrybuls
+find_ybullet:
+ ld a,(hl)
+ or a
+ jr z,found_ybullet ;0 = no bullet here
+ add hl,de
+ dnz find_ybullet ;look next bullet
+ ret ;none found, return don't fire
+
+found_ybullet:
+ ld (hl),c ;use the bullet and set correct bullet-type
+ inc hl ;@damage
+ ld (hl),1 ;set bullet damage
+curweapdamage =$-1
+ ld a,(firex) ;your x-pos
+ add a,5 ;place bullet in front of you
+ inc hl ;go to bullet-x
+ ld (hl),a ;set x
+
+ ld a,(firey) ;your y-pos
+ add a,(ix+1) ;place bullet at the middle of your ship
+ inc hl ;go to bullet-y
+ ld (hl),a ;set y
+
+ xor a
+ ld (weapincs),a ;reset damage
+ ret
+
+;-----fire LASER-----
+
+fire_laser:
+ ld b,0 ;overflow counter
+ ld hl,firex
+ ld d,(hl) ;d = your x-pos
+ inc hl
+
+ ld a,(hl) ;base y-coord (firey)
+ add a,(ix+1) ;at specified offset (most likely the middle)
+ ld e,a ;save laser-y in e
+ psh de ;save unmodified (x,y)
+ add a,a ;y*2
+#ifdef TI86
+ add a,a ;y*4 (86)
+#else
+ add a,e ;y*3 (83)
+#endif
+ add a,a ;y*8 (86) | y*6 (83)
+ rl b ;b (=0) =b*2+overflow (if y>32 then bc=bc+256)
+ add a,a ;width of screen (y*16 (86) | y*12 (83))
+ rl b ;b=b*2+overflow (if y>64 then bc=bc+512)
+ inc a ;8 pixels to right (a=even so no overflow)
+
+ srl d ;X/2
+ srl d ;X/4
+ srl d ;X/8
+ add a,d ;a = (Y*16+X/8) mod 256 (c set on overflow)
+
+ jr nc,_nolc ;jump if no carry = no overflow = a<=255
+ inc b ;a>255 so increase bc by 256
+_nolc: ld c,a ;c = (Y*16+X/8) mod 256
+ ld hl,dispbuffer ;save-location
+ add hl,bc ;bc = Y*16+X/8: hl=screen address
+ ld a,scrwidth-1 ;128/8=16=screen width ** minus one (inc a ^^)
+ sub d ;minus x-start (d=X/8)
+ jr z,handle_laser ;if size=0=256x (right edge) then skip display
+ ld b,a
+drawlaser:
+ ld (hl),%11111111
+ inc hl ;Go to next byte
+ dnz drawlaser
+handle_laser:
+ pop de ;de=(firex): x-pos unmodified
+
+check_laserhits: ;de = (x,y)
+ psh ix
+ ld b,nrenemies ;check all enemies
+ ld hl,enemies+1 ;enemy#1+occ/hp00
+laserhits: ;hits with normal enemies
+ psh hl
+ ld a,(hl) ;occ+hp00
+ and %11 ;normal enemy occ = %11
+ cp %11
+ jr nz,nolashit ;no hit when enemy_occ <> 11
+
+ inc hl ;@type
+ cal find_sprite ;ix=sprite to enemy (hl)
+ inc hl ;@x
+ ld a,(hl) ;check x
+ sub d
+ jr c,nolashit ;no hit when enemy is left of you
+ inc hl ;@y
+ ld a,(hl) ;check y
+ sub e
+ jr z,enemy_lashit ;a-e=0 = laser on top line of enemy = hit
+ jr nc,nolashit ;a-e>0 = enemy above laser = no hit
+ dec a ;minus one
+ add a,(ix+1) ;add enemy height (according to sprite @ix)
+ jp m,nolashit ;a-e>0 = hit
+enemy_lashit:
+ psh hl ;pointer to enemy destroyed by putsprite
+ psh bc ;safe enemy counter
+ psh de ; and Ur position (used for further compares)
+ dec e ;adjust y-position
+ dec e
+ dec e ;hit sprite centered at e (height=6)
+ dec hl ;@x
+ ld d,(hl) ;x-position of hit (enemy's x-pos)
+ ld ix,spr_lashit ;laserHit sprite
+ cal putsprite ;display this frame only unlike bullethit ani
+ pop de ;restore regs
+ pop bc
+ pop hl
+ ld a,(curweapdamage) ;damage
+ cal enemy_hit ;inflict (hl=enemy+y)
+nolashit:
+ pop hl ;enemy+1
+ ld a,b ;psh bc
+ ld bc,enemysize
+ add hl,bc ;go to next enemy
+ ld b,a ;pop bc
+ dnz laserhits ;check all enemies
+ xor a
+ ld (weapincs),a ;reset damage
+ pop ix
+ ld c,a ;c=0
+ ret
+
+;------------------------ handle bullets -------------------------------------
+
+Handle_bullets:
+ ld hl,ybullets
+ ld b,nrybuls
+scan_bullets:
+ ld a,(hl) ;@bulletType
+ or a ;bulletType=0 >> no bullet
+ jp z,next_ybullet+2 ;skip pops (+2); jP for speed
+
+ psh bc ;bullet counter
+ psh hl ;save enemy+type
+ ld (temp1),hl ;needed for check_bullethits
+ inc hl ;@damage
+ ld c,(hl) ;damage
+ dec c ;c=damage-1
+ jp m,bullethitbullet ;damage<=0 (=no bullet)
+ inc hl ;@x
+
+;move_bullet
+ ld c,a ;c=type
+ and %11111 ;pixels to move
+ add a,(hl) ;a = X + (hl) to the right
+ sub 16 ;and 16 to the left (so -16..+15)
+ jr c,remove_bullet ;remove if x<0
+ cp 8*scrwidth
+ jr nc,remove_bullet ;or x>=128
+ ld (hl),a ;save new pos.
+ ld d,a ;d = X
+
+ inc hl ;@y-pos
+ ld a,c
+#ifdef TI86
+ rcl _shracc ;%11100000->1110
+;Note: a _shracc procedure inside Nemesis itself would be 27 cycles faster
+#else
+ srl a \ srl a \ srl a \ srl a ;83 doesn't have a shracc call
+#endif
+ srl a ;%1110->111
+ dec a
+ jr z,bullet_noymove ;1=straight forward
+ dec a
+ jr z,bullet_up ;2=up
+ dec a
+ jr z,bullet_halfup ;3=1/2up
+ dec a
+ jr z,bullet_down ;4=down
+bullet_halfdown: ;5=1/2down
+ ld a,(timer)
+ rra ;carry once every other turn
+ jr c,bullet_noymove
+bullet_down:
+ ld a,(hl)
+ inc a
+ cp 55
+ jr z,bullet_noymove
+ ld (hl),a
+bullet_halfup:
+ ld a,(timer)
+ rra ;CF every other turn
+ jr c,bullet_noymove
+bullet_up:
+ ld a,(hl)
+ dec a
+ jr z,bullet_noymove
+ ld (hl),a
+bullet_noymove:
+ ld e,(hl) ;e = Y
+
+display_bullet:
+ dec hl ;@x
+ dec hl ;@damage
+ ld a,(hl) ;bullet damage=size
+ ld hl,bullettable ;pointer to first bullet
+ srl a
+ srl a ;per 4
+ ld b,0
+ ld c,a ;->16bit (de=a)
+ add hl,bc ;point to correct bullet offset
+ ld a,(hl) ;load bullet offset
+ ld c,a ;convert to 16bit (d=0)
+ ld ix,spr_bullet01 ;first sprite
+ add ix,bc ;add offset (go to correct sprite)
+
+ ld a,(ix) ;bullet x-size
+ ld (bulletxsize),a ;used at check_bullethits
+ ld a,(ix+1) ;bullet y-size...
+ ld (bulletysize),a ;...too
+
+ cal safeputsprite ;display bullet; DE used for check_bullethits
+
+ cal check_bullethits
+
+next_ybullet:
+ pop hl ;restore enemy+type
+ pop bc ;b=counter
+ ld de,4
+ add hl,de
+ dnz scan_bullets ;next bullet (loop)
+ ret
+
+remove_bullet:
+ pop hl ;enemy+type
+ ld (hl),0 ;dump this bullet!
+ jr next_ybullet+1 ;+1:skip pop hl at next_ybullet
+
+bullethitbullet: ;"bullet" just displaying a bullet hit
+ inc c ;restore damage (to -5..0)
+ jp z,remove_bullet ;if it's 0 remove it
+ inc c ;increase to next frame
+ ld (hl),c ;save new
+ ld a,c
+ neg ;make positive value (frame nr. 0..4)
+ add a,a ;*2
+ ld e,a
+ add a,a ;*4
+ add a,e ;*6
+ ld e,a
+ ld d,0 ;de=a
+ ld ix,spr_hit ;first hit sprite
+ add ix,de ;add frame nr*8 (goto correct sprite)
+ inc hl ;@x
+ ld d,(hl)
+ inc hl ;@y
+ ld e,(hl) ;load position into de
+ cal putsprite ;display hit-sprite
+ jr next_ybullet ;handle the other bullets
+
+;--------------------------- check bullethits --------------------------------
+
+check_bullethits: ;INPUT: de=X,Y; (temp1)=bullet
+ ld b,nrenemies
+ ld hl,enemies+1
+
+hit_enemies: ;Hits with normal enemies
+ psh bc ;enemy counter
+ psh hl
+
+ ld a,(hl)
+ and %11
+ cp %11
+ jr nz,nohit ;no hit when enemy_occ <> %11
+
+ inc hl ;enemy type
+ cal find_sprite ;set ix to the sprite of this enemy
+
+ inc hl ;@x
+ ld a,(hl) ;check x
+ sub d ;minus bullet x-position
+ ld b,a ;psh a
+ sub 5 ;minus bullet x-size
+bulletxsize =$-1
+ jp p,nohit ;miss
+ ld a,b ;pop a
+ add a,(ix) ;add enemy width
+ jp m,nohit ;miss
+
+ inc hl ;@y
+ ld a,(hl) ;check y
+ sub e ;minus bullet y-position
+ ld b,a ;psh a
+ sub 3 ;substract bullet height
+bulletysize =$-1
+ jp p,nohit ;nope, missed it
+ ld a,b ;pop a
+ add a,(ix+1) ;add enemy height
+ dec a ;minus one
+ jp m,nohit ;missed after all
+
+ ;---bullet hits enemy (auch-time!)---
+ psh hl
+ ld hl,0 ;@bulletType
+temp1 =$-2
+ inc hl ;@damage
+ ld a,(hl) ;damage to inflict on enemy
+ ld (hl),-(hitsprites+1);make this bullet exploding (damage = -5)
+ pop hl ;enemy+y
+ cal enemy_hit
+nohit:
+ pop hl
+ ld bc,enemysize
+ add hl,bc
+ pop bc
+ dnz hit_enemies ;check next enemy
+ ret
+
+enemy_hit: ;*in:a=damage;hl=enemy+y
+ add a,a ;a=damage to inflict
+ add a,a ;first 2 bits used for occ.
+ ld b,a
+
+ dec hl ;@x
+ dec hl ;@sprite+1
+ dec hl ;@sprite
+ dec hl ;@hp00 (occ)
+ ld a,(hl) ;load hp00
+ sub b ;decrease HP (if <0xx then c is set)
+ ld (hl),a ;save (no flag-changes)
+ dec hl ;@hp64; no change in c
+ ld a,(hl) ;load; no c-change
+ sbc a,0 ;if cf then decrease a
+ ld (hl),a ;save back the new value
+ ret nc ;if a>=0 then return, otherwise explode
+
+ inc hl ;goto occ again
+ ld (hl),%01 ;set to explode
+
+ ld a,(pickuptimer) ;counts enemies destroyed
+ dec a ;enough destroyed for a pickup?
+ psh af ;save flags and a=0
+ jr nz,pickupdone ;otherwise just explode
+ ld a,pickupfreq ;reset enemies counter
+pickupdone:
+ ld (pickuptimer),a ;save new enemiescounter value
+ inc hl ;@sprite (=explosionFrame)
+ ld (hl),0 ;explosionFrame 0 or enemy #0=pickup
+ pop af
+ cal z,place_enemy ;place pickup (enemy#=0=a cuz ZF)
+
+ ld hl,1 ;increase score by one
+ jp scoreInc ;+ret
+
+;--------------------------- level events ------------------------------------
+
+Level_event:
+ ld a,0 ;time to next event
+nextevent =$-1
+ dec a ;decrease counter
+ ld (nextevent),a ;store new value
+ ret nz ;hasn't reached zero yet: get outta here!
+
+ ld bc,0 ;enemy frequency (lvl)
+eventtime =$-2
+ cal Random
+ ld (nextevent),a ;set time to next event
+ ld hl,eventleft
+ dec (hl) ;update enemy-counter
+
+ ld a,(hl) ;look at counter
+ or a ;has it reached 0?
+ jp z,Next_level ;yes: level finished
+ dec a ;has it reached 1?
+ jr z,standby_event ;yes: wait until no enemies present/left
+ dec a ;has it reached 2?
+ jr z,place_boss ;yep: place the BigBossTM!
+ dec a ;has it reached 3?
+ jr nz,place_ranenemy ;nope: >3 = place an enemy
+ inc hl ;nextevent located behind eventleft
+ ld (hl),193 ;3: set delay for next boss to appear
+ ret ;don't place any more enemies
+
+standby_event:
+ ld b,nrenemies
+ ld hl,enemies+1-enemysize
+ ld de,enemysize
+ xor a
+chk_enemyleft:
+ add hl,de ;go to next enemy
+ cp (hl) ;0 = no enemy present
+ jr nz,enemyleft ;if enemy present (<>0) then quit checking
+ dnz chk_enemyleft ;loop for all enemies
+ ld hl,nextevent ;time 'til next event
+ ld (hl),157 ;next time to check is in 157 turns/frames
+ ld a,(your_weapon)
+ cp maxweapon ;you have bullets?
+ jr nc,placebigupgrade ;if not just place the big upgrade
+ ld a,(level)
+ rra ;if level&1=0 (even levels)
+ ret nc ;then dont place a pickup (=50%)
+placebigupgrade
+ ld a,1 ;no enemies left: place upgrade pickup
+ jr place_enemy ;place enemy #1(=a) = big pickup
+enemyleft:
+ ld hl,eventleft
+ inc (hl)
+ ret
+
+
+place_ranenemy:
+ ld hl,1 ;increase score by 1
+ cal scoreInc
+ ld bc,0 ;0..nrlvlenemies
+nrlvlenemies =$-1 ;=nr of enemies minus 1
+ cal Random ;random enemy b..b+c = 0..nrenemies-1
+ ld b,0
+ ld c,a ;bc=a
+ ld hl,lvlenemies
+ add hl,bc ;go to a random enemy
+ ld a,(hl) ;load enemy nr of this mysterious random enemy
+ jr place_enemy
+
+place_boss:
+ ld hl,(levelp) ;the leveldata (including the boss)
+ dec hl ;points to leveldata\boss\enemynr
+ ld a,(hl) ;load enemy# of boss
+
+place_enemy: ;places enemy #=a (out:achl=?;b=0;de=@enemy+11)
+ psh af
+ ld hl,enemies+1-enemysize
+ ld bc,enemysize
+ xor a ;a=0
+chk_noenemy: ;find an unused (no) enemy
+ add hl,bc ;check next enemy
+ cp (hl) ;(hl) = 0 ??
+ jr nz,chk_noenemy ;jump if enemy present (non-0)
+ ex de,hl ;de=hl=usable enemy +1
+ pop af ;enemy# to place
+ cal findenemyspecs ;hl = enemy #a specs
+
+ dec de ;goto hp64 (before occ)
+ ldi ;set hp64
+ ldi ;set hitpoints+occ of enemy class
+ ld c,(hl)
+ ldi ;set sprite
+ ld b,(hl) ;bc=@enemy_sprite
+ inc bc ;@sprite-height
+ ld a,(bc)
+ ld b,a ;b = sprite-height
+ ldi ;set sprite + 1
+ ldi ;set x-position
+
+ ld a,(hl) ;load placeInfo
+ inc hl
+ inc a ;is it -1?
+ jr z,random_enemy ;yes: create random value <51 in a
+ inc a ;is it -2?
+ jr z,lure_enemy ;yes: create a 100% luring enemy
+ inc a ;is it -3?
+ jr z,lure_enemy ;yes: pick one (50% lure)
+ inc a ;is it -4?
+ jr z,ground_enemy ;yes: place @ current ground position
+ ;otherwise?
+yset_enemy: ;set 0+3..$FC+3 as y-position
+ ld (de),a
+ jr ypos_OK
+ground_enemy:
+ ld a,(groundpos+15) ;ground height
+ neg ;negative (high ground, low y-pos)
+ add a,50 ;at the bottom
+ ld (de),a ;is turret's position
+ jr ypos_OK
+halflure_enemy:
+ ld a,(timer) ;look at frame-number
+ rra ;make random if odd frame nr.
+ rra ;...well make that frame/2
+ jr nc,random_enemy ;1st possibility: random enemy
+lure_enemy: ;2nd possibility: luring enemy
+ ld a,(y) ;place at same y-pos as YOUR ship
+ jr ypos_OK
+random_enemy:
+ ld a,64-8 ;=57=screen height (8 is scorebar)
+ sub b ;minus sprite height=bottom
+ ld c,0 ;range=0 to...
+ ld b,a ;...57-y
+ cal Random ;random value on screen
+ypos_OK: ;random value successfully created
+ ld (de),a ;save y-position
+ inc de ;@movecounter
+ ldi ;set move-type
+ ld a,1 ;movecounter = 1
+ ld (de),a ;set
+ inc de ;@firecounter
+ ldi ;set time-to-1st-fire
+ ldi ;set firefreq
+ ldi ; " firetype
+ ret ;return
+
+;--------------------------- enemy fires -------------------------------------
+
+Enemy_fires: ;de = x,y; c = type; ix = enemy_sprite
+ ld hl,ebullets ;first bullet to check
+ ld b,nrebuls
+ dec d
+ dec d ;d = x of firing enemy minus 2
+
+ ld a,(ix+1) ;the height of the enemy firing this bullet
+ srl a ;halved
+ add a,e ;added to his y-position
+ ld e,a ;into e
+ dec e ;minus one (bullet height)
+
+enemy_fires_again: ;same but hl = first bullet possibly free
+ xor a
+find_ebullet:
+ cp (hl)
+ jr z,found_ebullet ;0 = not used
+ inc hl \ inc hl \ inc hl
+ dnz find_ebullet ;look next bullet
+ ret
+
+found_ebullet:
+ ld a,c
+ sub 6
+ jp c,bulletok ;type #0-5 = done (normal/diag)
+ or a
+ jp z,bulletaiming ;type #6 = aiming = type#2..5
+ dec a
+ jr z,bullettriple ;type #7 = triple
+ dec a
+ jr z,bulletdouble ;type #8 = double
+ dec a
+ jr z,bulletwide5 ;type #9 = wide 5x
+ dec a
+ jr z,bulletdquad ;type #10 = double-quad
+ dec a
+ jr z,bulletran ;type #11 = random
+ dec a
+ jr z,firesenemies ;type #12 = mine + Dquad
+ dec a
+ jr z,basefiresenemies ;type #13 = enemies + 10
+ dec a
+ jr z,randomfire ;type #14 = random @full height
+ dec a
+ jr z,bulletwide3 ;type #15 = wide triple
+ dec a
+ jr z,bulletfullfire ;type #16 = straight 5x
+
+randomfire:
+ ld c,0
+ ld b,62
+ cal Random ;a=0..62
+ ld e,a
+ ld (hl),1
+ jp _bulletok
+
+basefiresenemies: ;type #13 = base
+ ld bc,$3A00
+ cal Random
+ ld e,a
+ cal random14
+ ld c,a
+ cal bulletok ;find and fire bullet
+
+ ld a,boss2enemy ;otherwise place enemy #[boss2enemy]
+ jp place_enemy
+
+firesenemies: ;type #12 = mine / Dquad
+ ld a,(timer)
+ rra ;if odd turn (50% chance)
+ jr c,bulletdquad ;then fire 6x
+ ld a,boss1enemy ;otherwise place enemy #[boss1enemy]
+ jp place_enemy
+
+bulletran: ;type #11 = fires bullets 1-5 at random
+ cal random14
+ ld (hl),a ;set type a=1..5
+ jr _bulletok
+
+bulletdquad: ;type #10 = double-quad
+ cal bulletwide5 ;fire type #1 to 5
+addedgebullets:
+ inc hl
+ ld a,e
+ sub 7
+ ld e,a ;offset 7 up
+ ld c,1 ;type #1 = normal
+ cal enemy_fires_again
+ inc hl
+ ld a,e
+ add a,14
+ ld e,a ;offset 14 down (7 total)
+_enemy_fires_again:
+ jr enemy_fires_again
+
+bulletwide5: ;type #9 = wide 5x (fires 4 dirs + 1 straight)
+ cal bullettriple ;fire type #1, 4 and 5
+ inc hl ;next bullet
+ ld c,2 ;type #2 = down
+ cal enemy_fires_again
+ inc hl
+ ld c,3 ;type #3 = up
+ jr _enemy_fires_again
+
+bulletfullfire: ;type #16 = straight 5 bullets
+ cal bullettriple ;fire 3 bullets at center (offset -2,+0,+2)
+ inc e \ inc e ;restore base (Y)position
+ jr addedgebullets ;fire 2 more bullets (at offsets -7 and +7)
+
+bullettriple: ;type #7 = triple
+ cal bulletdouble+1 ;fire double weapon (offset +0,+2)
+ dec e \ dec e ;two px back up
+ dec e \ dec e ;and another two up (offset -2)
+ inc hl ;next bullet position
+ ld c,1 ;type #1 = normal
+ jr _enemy_fires_again ;find and fire another bullet
+
+bulletdouble: ;type #8 = double
+ dec e ;one up (1st bullet not centered:offset -1,+1)
+ ld c,1 ;type #1 = straight
+ cal bulletok ;fire bullet
+ inc hl ;next bullet position
+ inc e
+ inc e ;two px down
+ jr _enemy_fires_again ;find and fire another bullet
+
+bulletwide3: ;type #15 = spread (3 bullets)
+ ld (hl),1 ;type #1 = normal
+ cal _bulletok ;fire
+ inc hl ;next bullet
+ ld c,4 ;type #4 = down 50%
+ cal enemy_fires_again
+ inc hl
+ ld c,5 ;type #5 = up 50%
+ jr _enemy_fires_again
+
+bulletaiming: ;type #6 = aiming = type#2..5
+ ld a,(y)
+ sub e ;a = yourY-bulY = pixels bullet is above you
+ add a,10
+ jp p,bulletnotup ;jump when 10 pixels below you or higher
+ ld (hl),5 ;go slightly down
+ add a,10 ;10 to 20 pixels below you
+ jp p,_bulletok ;yes: all done.
+ ld (hl),3 ;otherwise move down even more
+ jr _bulletok
+bulletnotup:
+ ld (hl),1 ;normal bullet...
+ sub 20 ;...when...
+ jp m,_bulletok ;...10 pixels below you to 20 pixels above
+ ld (hl),4 ;bullet going slightly up...
+ sub 10 ;...when...
+ jr c,_bulletok ;...20 to 30 pixels above you
+ ld c,2 ;else (more than 30 pixels) move up more
+
+bulletok:
+ ld (hl),c ;set bullet direction
+_bulletok:
+ inc hl
+ ld (hl),d ;set x-pos
+ inc hl
+ ld a,58-5 ;bottom
+ cp e ;bullet-y...
+ jr nc,bulletonscreen ;<bottom (=on screen) is ok (skip next part)
+ ld e,a ;otherwise set y-pos to bottom of screen
+bulletonscreen:
+ ld (hl),e ;set y-pos
+ ret
+
+;----------------------------- enemy bullets ---------------------------------
+
+Enemy_bullets:
+ ld hl,ebullets ;hl=bullet pointer
+ ld b,nrebuls ;number of bullets (or _possible_ bullets)
+handle_bullet:
+ psh bc
+ psh hl
+ ld a,(hl) ;load bulletType in a
+ or a ;bullet present?
+ cal nz,enemy_bullet ;non-0: handle bullet
+ pop hl ;enemy_bullet could've added one or two to hl
+ pop bc ;bullet counter
+ inc hl \ inc hl \ inc hl ;next bullet (3 bytes per bullet)
+ dnz handle_bullet ;loop for each and every bullet
+ ret
+
+enemy_bullet:
+ inc hl ;@x
+ ld d,(hl) ;check if it has reached the left side of scrn
+ bit 7,d ;x<0?
+ jr nz,remove_ebullet ;yes, remove bullet
+ dec d ;move one pixel left
+ dec d ;and another one (that makes 2)
+ ld (hl),d ;save new x-coordinate in (HL) and D
+ inc hl ;@y (BTW: x >= -2)
+ ld e,(hl) ;e=y
+
+ dec a
+ jr z,ebullet_common ;type 1: normal bullet
+ dec a
+ jr z,ebullet_down ;type 2: moving down
+ dec a
+ jr z,ebullet_up ;type 3: moving up
+
+ ld b,a ;save bulletType
+ ld a,(timer) ;load timer
+ rra ;half speed (CF set every other turn)
+ jr c,ebullet_common ;if bit then normal bullet
+
+ dec b
+ jr z,ebullet_down ;type 4: moving down 50%
+ ;type 5: moving up 50%
+ebullet_up:
+ dec e ;move up
+ jp m,ebullet_common ;y<top; don't save new value (so y=0)
+ ld (hl),e
+ jr ebullet_common
+ebullet_down:
+ inc e ;move down
+ ld a,e ;a=y too
+ cp 58-4 ;y>=bottom?
+ jr nc,ebullet_common ;then keep it there
+ ld (hl),e ;otherwise save new y
+
+ebullet_common:
+ ld ix,spr_bullete1 ;display enemy bullet
+ psh hl
+ cal putsprite
+ pop hl ;we'll need it again
+
+ebullet_hits:
+ ld a,(your_occ)
+ or a
+ ret nz ;0 = you're normal
+
+ ld a,(y) ;check y collision
+ sub (hl)
+ add a,6
+ ret m
+ cp 9
+ ret nc
+
+ dec hl ;check x
+ ld a,(x)
+ sub (hl)
+ add a,6
+ ret m
+ cp 9
+ ret nc
+
+ ld b,auch_bullet ;set damage-amount
+ psh hl
+ cal damage_you ;HIT!!
+ pop hl ;save hl to remove the bullet
+remove_ebullet:
+ dec hl ;points to bullettype again
+ ld (hl),0 ;bullet > unused
+ ret
+
+;--------------------------- handle enemies ----------------------------------
+
+Handle_enemies:
+ ld hl,enemies+1
+ ld b,nrenemies ;handle all enemies
+
+handle_enemy:
+ psh bc
+ psh hl
+
+ ld a,(hl)
+ and %11
+ jr z,next_enemy ;occ "no enemy" 00
+ dec a
+ jr z,exploding_enemy ;occ "exploding" 01
+
+normal_enemy:
+ ld c,a ;c = occ-1 = %10 (normal) or %01 (pickup)
+ inc hl ;@sprite
+ cal find_sprite
+
+ inc hl ;@x
+ ld d,(hl) ;x
+ inc hl ;@y
+ ld e,(hl) ;y
+
+ inc hl ;@movetype
+ cal moving_enemy
+ dec hl
+
+ ld a,e ;new y value
+ cp 57
+ jr c,enemyonscreenY ;=on screen
+ cp -20 ;moved off at top
+ ld e,0 ;reset to top
+ jr nc,enemyonscreenY
+ ld e,57 ;otherwise reset to bottom
+enemyonscreenY:
+ ld (hl),e ;store new y
+ dec hl ;@x
+
+ ld a,d ;new x value
+ cp 129 ;x<=128
+ jr c,enemyonscreenX ;=on screen
+ cp -7 ;x<=-8
+ jr c,remove_enemy ;=off screen
+enemyonscreenX:
+ ld (hl),d ;store new x
+ dec c ;is this a pickup? (c=%01 so ZF=1)
+ jr nz,check_enemyfire ;no, a normal enemy; let em fire
+ jr firing_done ;continue
+
+check_enemyfire:
+ ld bc,4 ;4x inc hl
+ add hl,bc ;@firecount
+ ld a,(hl) ;counter till next blast
+ dec a ;decrease it
+ ld (hl),a ;save new value
+ jr nz,firing_done ;finished if not reached 0 yet
+
+ inc hl ;@firefreq
+ ld a,(hl) ;=time 'til next blast
+ inc hl ;@firetype
+ ld c,(hl) ;in c
+ dec hl
+ dec hl ;@firecount again
+ ld (hl),a ;reset counter for next blast
+ psh de ;save registers for firing-use
+ cal Enemy_fires ;fires bullet
+ pop de ;restore (destroyed by Enemy_fires)
+firing_done:
+ cal putwidesprite ;display sprite @ix
+
+next_enemy:
+ pop hl
+ ld bc,enemysize
+ add hl,bc
+ pop bc
+ dnz handle_enemy
+ ret
+
+exploding_enemy:
+ inc hl
+ ld a,(hl)
+ cp 16
+ jr nz,keep_enemy ;remove when at last frame
+remove_enemy:
+ pop hl
+ ld (hl),$0000 ;bye bye enemy
+ jr next_enemy+1 ;continue AFTER pop hl (already done)
+keep_enemy:
+ inc a
+ ld (hl),a ;next frame
+ dec a ;1-16 -> 0-15
+ ld ix,spr_explosion ;base sprite
+ inc hl ;@x
+ cal explosion_stuff ;display explosion
+ jr next_enemy
+
+;--------------------------- moving enemies ----------------------------------
+
+moving_enemy:
+ dec d ;move left once
+ ld a,(hl) ;how does this enemy move?
+ and a
+ ret z ;0 = (1<)
+ ld b,a
+ ld a,(timer)
+ dec b
+ jp z,movetype_updown ;1 = (1<) up / down
+ dec b
+ jr z,movetype_vslow ;2 = (.25<)
+ dec b
+ jr z,movetype_slow ;3 = (.5 <)
+ dec b
+ jr z,movetype_lslow ;4 = (.75<)
+ dec b
+ jr z,movetype_mfast ;5 = (1.25<)
+ dec b
+ jr z,movetype_fast ;6 = (1.5<)
+ dec b
+ jr z,movetype_vfast ;7 = (2 <)
+ dec b
+ jr z,movetype_xfast ;8 = (3 <)
+ dec b
+ jr z,movetype_slowlure ;9 = (1<) move y towards you 50%
+
+ inc d ;speed 0
+ dec b
+ jr z,movetype_lure ;10 = (0) move y towards you
+ dec b
+ jr z,movetype_slowlure ;11 = (0) lure 1/2 speed
+ dec b
+ jr z,movetype_fulllure ;12 = x+y towards you 1/2 speed
+ dec b
+ jr z,movetype_right ;13 = (.5>)
+ dec b
+ jr z,movetype_fright ;14 = (1>)
+ dec b
+ jr z,movetype_right ;15 = (0)
+ dec b
+ ret z ;16 =
+
+movetype_lboss:
+ ld a,104
+ cp d
+ jr c,dothemovethingy
+ inc d ;x<110: move right
+dothemovethingy:
+ jr movetype_updown ;move up and down and up and down and...
+
+movetype_right:
+ rra
+ ret c ;speed 0 50%
+movetype_fright:
+ inc d ;move right one px
+ ret
+
+movetype_fulllure:
+ rra
+ ret c ;50% speed
+ cal movetype_lure
+ ld a,(x)
+ cp d
+ jr c,movetype_vfast ;moves left (again)
+lure_right:
+ inc d ;move right
+ ret
+
+movetype_slowlure:
+ rra ;half the time
+ ret c
+movetype_lure:
+ ld a,110
+ cp d
+ jr nc,dothelurethingy
+ dec d ;x>109: move left
+dothelurethingy:
+ ld a,(y)
+ cp e
+ ret z ;don't move vertically if equal
+ jr c,lure_up ;below you then move up
+lure_down: ;above then move down
+ inc e
+ ret
+lure_up:dec e
+ ret
+
+movetype_smart:
+ inc hl ;@movecount
+ ld a,(hl)
+ inc a
+ and %1111
+ ld (hl),a
+
+ or a ;reset carry flag
+ dec hl ;reset hl to <y>
+ and %11111100
+ jr z,movetype_fast
+
+movetype_lslow:
+ and %11
+ ret nz
+ inc d ;don't move 25% of the time
+ ret
+movetype_slow:
+ rra
+ ret c
+ inc d ;don't move 50%
+ ret
+movetype_vslow:
+ and %11
+ ret z
+ inc d ;don't move 75%
+ ret
+
+movetype_mfast:
+ rra
+ ret c ;50% chance (makes it 25% total)
+movetype_fast:
+ rra
+ ret c ;once every other turn
+movetype_vfast:
+ dec d ;move left twice
+ ret
+movetype_xfast:
+ dec d ;woowoo, now that's fast!
+ dec d ;move left trice!
+ ret
+
+movetype_updown:
+ inc hl ;@movecount
+ ld a,(hl)
+ dec a
+ and 127 ;range 0..127
+ ld (hl),a ;store new movecounter
+ dec hl ;reset hl to @movetype
+ and %00100000 ;ZF changes once every 64 turns
+ ld a,e ;load current y-position
+ jr z,movedown
+moveup: dec a ;decrease y-pos (=move up)
+ ret m ;don't move off the screen (y<0)
+ dec e ;save new y-pos
+ ret ;finish
+movedown:
+ inc a ;increase y-pos
+ cp 55 ;compare with bottom
+ ret nc ;return if it has passed that line (>40)
+ inc e ;otherwise save new position
+ ret ;and return
+
+;--------------------------- check collision ---------------------------------
+
+Enemies_hit:
+ ld hl,(x) ;e = X, d = Y
+ ld de,$0707 ;add 7 to both d and e
+ add hl,de
+ ex de,hl ;e = X+7, d = Y+7
+
+ ld hl,enemies+1
+ ld b,nrenemies ;check all 20 enemies
+check_collision:
+ psh bc ;counter
+ psh hl ;pointer
+ ld a,(hl)
+ and %10 ;enemy status (%11=normal; %10=pickup)
+ jr z,check_next ;2 or 3 = ok, otherwise: next enemy
+ inc hl ;@sprite
+
+collide_enemy: ;&&& include in Handle_enemy proc
+ cal find_sprite
+
+ inc hl ;@x
+ ld a,(hl) ;check x match
+ sub e ;enemy position minus yours minus 7
+ jp p,check_next
+ add a,6
+ add a,(ix) ;enemy width
+ jp m,check_next
+
+ inc hl ;@y
+ ld a,(hl) ;check y match
+ sub d ;same as with x-check
+ jr nc,check_next ;(=jp p)
+ add a,6
+ add a,(ix+1) ;enemy height
+ jp m,check_next
+ dec hl ;@x
+ dec hl ;@sprite+1
+ dec hl ;@sprite
+ dec hl ;@occ
+
+take_pickup:
+ ld a,(hl) ;load enemy occ
+ rra ;if occ = %10 (can't be %00) then pickup
+ jr c,collide ;otherwise normal enemy so you collide
+ ld (hl),0 ;remove
+ rra ;skip this bit (=%1)
+ rra ;this bit specifies the pickup ID (big/small)
+ jr nc,armorpickup ;%0 = pickup increases armor and shield
+ ;%1 = pickup selects (next) upgrade
+ ld hl,your_pickup ;your pickups
+ ld a,(hl) ;current
+ inc a ;go to next
+ cp 4 ;pickups >=4?
+ jr c,not_maxpickup
+ psh hl ;too much pickups
+ ld hl,250
+ cal scoreInc ;increase score by 250
+ pop hl
+ ld a,1 ;and reset to pickup #1
+not_maxpickup:
+ ld (hl),a ;save new
+ psh de
+ cal disp_icons ;display altered pickupicons
+ pop de ;ld de,$0707
+ jr check_next ;all done, next..
+
+armorpickup:
+ cal inc_armor ;increase armor (like at end of level)
+ ld a,30 ;activate shield for 30*4=120 frames
+ ld (your_shield),a
+ cal disp_icons ;display status bar (new armor value)
+ jr check_next
+
+collide:
+ ld a,(hl)
+ sub auch_ecollide
+ ld (hl),a
+ jr nc,enemydamaged ;enemy still ok (HP>=0)
+ ld (hl),%01 ;set to explode
+ inc hl
+ ld (hl),0 ;explosionFrame 0
+enemydamaged: ;damage to enemy delivered
+ ld b,auch_collide ;your damage
+ cal damage_you
+
+check_next:
+ pop hl ;current enemy base (unaltered)
+ ld bc,enemysize ;bytes per enemy
+ add hl,bc ;pointer to next enemy
+ pop bc ;restore counter
+ dnz check_collision ;loop for all enemies
+ ret
+
+;--------------------------- story -------------------------------------------
+
+dostory:
+#ifdef story
+ cal storyPage ;do some story
+ ld a,(hl) ;load next byte in a
+ inc a ;set z-flag if a = $ff
+ jr nz,dostory ;otherwise loop
+ inc hl
+ inc hl ;set hl to beginning of the level
+ ld (levelp),hl ;set the level-pointer
+ ret ;and return
+
+storyPage:
+ psh hl ;hl will be destroyed by _clrLCD
+ rcl _clrLCD ;clear screen
+ pop hl
+ ld a,(hl)
+ ld (curline),a ;begin line for special effect
+storyLine:
+ ld d,(hl) ;vertical position of text
+ inc hl
+ ld e,(hl) ;horizontal text-position
+ ld (_penCol),de ;set position
+ inc hl
+ rcl _vputs ;display text
+
+ ld a,(hl) ;load next byte
+ inc hl
+ or a ;0 means more text
+ jr z,storyLine ;loop if there is
+
+ psh af
+ psh hl
+ ld hl,VIDEO_MEM ;copy text
+ ld de,dispbuffer ;to GRAPH_MEM
+ ld bc,1024 ;entire screen
+ ldir
+ rcl _clrLCD ;clear VIDEO_MEM
+ pop hl
+ pop bc ;last byte (<>0) is lines to SFX
+ psh hl
+ cal DoSFX ;do special effects
+ cal getsomekeys ;wait for a key
+ pop hl
+ ret
+
+DoSFX: psh bc ;in:(curline)=beginLine;b=nrOfLines
+
+ ld a,0 ;get line number
+curline =$-1
+ inc a ;go to the next line
+ ld (curline),a ;update
+ ld l,a
+ ld h,0 ;hl=a
+ add hl,hl
+ add hl,hl
+ add hl,hl
+ add hl,hl ;*16 (a pixels down=a*16)
+ sub 64 ;a=a-64
+ neg ;a=64-a (lines from bottom)
+
+ ld b,h ;save hl for later
+ ld c,l
+ ld de,VIDEO_MEM ;where to put sfx
+ add hl,de ;go to ymin
+ ex de,hl ;put into de again
+ ld hl,dispbuffer ;source of original
+ add hl,bc ;hl->source
+
+sfxlaserdisp: ;display this frame on screen
+ ld bc,16 ;one line (=16 bytes, you'd know by now)
+ ldir ;display (copy actually)
+ ld bc,-16 ;go up one line (not on screen)
+ add hl,bc ;so the same line will be displayed
+ dec a ;counter
+ jr nz,sfxlaserdisp ;repeat until whole screen is displayed
+
+ ld b,11 ;11x 1/200sec = ~20 frames/s
+sfxlaserdelay:
+ halt ;delay
+ dnz sfxlaserdelay ;8x
+
+ pop bc ;counter
+ dnz DoSFX
+ ret
+#else
+ rcl _clrWindow
+ ld hl,welldone
+ rcl _puts
+ jp getsomekeys ;wait for a key
+welldone:
+ .db "-CONGRATULATIONS!-",0
+#endif
+
+;--------------------------- proc --------------------------------------------
+
+random14: ;random 1..1+4
+ ld c,1
+ ld b,4
+; cal Random
+Random: ;a=c<random<b+c; destr:none
+ psh hl
+ ld hl,rancount ;amount to increase with (0-255)
+randomloop:
+ inc (hl) ;change for next time
+ ld a,r ;value $0-7F (can be _anything_ so watch out!)
+ add a,0 ;add to last random value
+ranseed =$-1 ;SMC :P
+ add a,(hl) ;add the changing increase value
+ ;(this is because R can be anything;
+ ; ie always be even so freeze when a must be 1<=a<=1)
+ ld (ranseed),a ;save for next time
+ cp b ;a>=b
+ jr nc,randomloop ;then add again
+ add a,c ;a<b; a=a+c
+ pop hl
+ ret
+rancount: .db 0
+
+RandomY: ;HL = random Y 0..50 right side ((1..51)*16-1)
+#ifdef TI86
+ psh bc
+ ld bc,50*256+1 ;range=1..51
+ cal Random ;a = 1..51
+ add a,a
+ add a,a
+ ld h,0
+ ld l,a ;hl = 1..51
+ add hl,hl
+ add hl,hl ;hl = 1..51 * 16 (left side at random y)
+ dec hl ;hl = 0..50 * 16 (" at right side of screen)
+ ld de,dispbuffer
+ add hl,de ;position on screen
+ pop bc
+ ret
+#else
+ psh bc
+ ld bc,50*256+1 ;range=1..51
+ cal Random ;a = 1..51
+ ld d,a ;*1
+ add a,a ;*2
+ add a,d ;*3
+ ld h,0
+ ld l,a ;hl = 1..51 * 3
+ add hl,hl
+ add hl,hl ;hl = 1..51 * 12 (left side at random y)
+ dec hl ;hl = 0..50 * 12 (" at right side of screen)
+ ld de,dispbuffer
+ add hl,de ;position on screen
+ pop bc
+ ret
+#endif
+
+scoreInc: ;increase score by HL
+ psh bc ;don't destroy bc (or any registers Xcept hl)
+ ld bc,(your_score) ;your current score in bc
+ psh af ;don't destroy a either
+ ld a,(hardcore) ;load hardcore mode settings in a
+ or a ;is it zero?
+ jr z,scoreincok ;then skip the next instruction (score = ok)
+ add hl,hl ;otherwise (hardcore) double the inc.score
+scoreincok:
+ pop af ;restore a register
+ add hl,bc ;add bc to hl (or vice versa)
+ ld (your_score),hl ;save new increased score
+ pop bc ;all registers to what they were
+ ret
+
+find_sprite: ;in:hl=enemy+type | out:ix=sprite to enemy
+ ld a,(hl) ;sprite byte #1
+ .db $DD,$6F ;ld hx,a
+ inc hl ;@sprite+1
+ ld a,(hl) ;sprite byte #2
+ .db $DD,$67 ;ld lx,a ;ld ix,(hl)
+ ret
+
+BLACKLCD:
+ ld hl,VIDEO_MEM ;screen location (top left)
+ ld de,VIDEO_MEM+1
+ ld (hl),%11111111
+ ld bc,scrwidth*64-1 ;do it 1024 times = entire screen
+ ldir
+#ifdef TI83
+ cal fastCopy
+#endif
+ set 3,(iy+5) ;set white on black
+ ret
+
+getsomekeys:
+ halt ;wait a li'l while and save batteries :P
+ halt
+ rcl GET_KEY ;input keys
+ or a
+ jr z,getsomekeys ;wait if none
+ cp K_SECOND ;2nd pressed?
+ ret z ;then return with zf set
+ cp K_ENTER ;enter pressed
+ ret ;then return with zf set, otherwise zf reset
+
+releasekeys:
+ halt
+ ld a,%10000000 ;all key-masks
+ out (1),a
+ in a,(1)
+ inc a ;cp %11111111 (no keys pressed)
+ jr nz,releasekeys ;keep waitin
+ jp GET_KEY ;clear buffer
+
+findenemyspecs: ;enemy #a specs in (hl); in:b=0; out:ac=?
+ ld hl,enemyspecs ;enemy "0" specs
+ add a,a ;a=type*2
+ ld c,a ;b=0; bc=c=a=type*2
+ add hl,bc ;hl = enm#0 + type*2
+ add a,a ;a=type*4 (max.type<64)
+ ld c,a ;bc=type*4
+ add hl,bc ;hl = enm#0 + type*6
+ add hl,bc ;hl = enm#0 + type*10
+ ret ;hl = enemy specs
+
+;--------------------------- game over / new game / death --------------------
+
+#ifdef shiscore
+chartable: ;use chartable-1 and add GET_KEY scancode
+ .db ".<>!",0,0,0,0 ;down,L,R,up
+ .db 0,"xtoje0",0 ;enter..clear
+ .db " wsnid9",0 ;(-)..custom
+ .db "zvrmhc8",0 ;dot..del
+ .db "yuqlgb7#" ;0..xvar
+ .db $D9,"-pkfa6'" ;on..alpha
+ .db "54321",$D0,0,'*' ;F5..F1,2nd,exit,more
+
+save_lvl:
+ ld hl,storesave_end-storesave_start
+ psh hl ;size
+ ld hl,storesave_start
+ psh hl ;dest
+ ld hl,4+storesave_start-_asm_exec_ram
+ psh hl ;src
+ jr storesmtn
+
+save_hi:
+ ld hl,storehi_end-storehi_start
+ psh hl ;size
+ ld hl,storehi_start
+ psh hl ;destination
+ ld hl,4+storehi_start-_asm_exec_ram
+ psh hl ;source
+
+storesmtn: ;stores data [stack=src; stack+1=dest; stack+2=size]
+ ld hl,_asapvar ;find own variable
+ rst 20h ;cal _ABS_MOV10TOOP1
+ rst 10h ;cal _FINDSYM
+
+ xor a ;bde=pointer to begin of real program
+ pop hl ;data offset
+ add hl,de ;hl=pointer to data in real prog
+ adc a,b ;if hl overflow also increase a
+ rcl _SET_ABS_DEST_ADDR ;destination = real program = ahl
+ xor a ;RAM page #0
+ pop hl ;data position in normal program ($D748+)
+ rcl _SET_ABS_SRC_ADDR ;set as source (ahl)
+ pop hl ;size
+ rcl _SET_MM_NUM_BYTES ;set
+ rcl _mm_ldir ;copy data to real program
+ jp _RAM_PAGE_1 ;and finally: reset ram page
+#endif
+
+game_over: ;stack=+0
+ cal BLACKLCD ;clear screen
+#ifdef TI86
+ ld hl,$0603 ;centered on 86
+#else
+ ld hl,$0403 ;centered on 83 (smaller screen)
+#endif
+ ld (_curRow),hl ;center
+ ld hl,txt_gameover
+ rcl _puts ;display "GAME OVER"
+ cal releasekeys ;wait for all keys to be released
+
+ ld hl,$0007
+ ld (_curRow),hl
+#ifdef shiscore
+ ld de,(your_score) ;current score
+ ld hl,(hiscore) ;hiscore
+ rcl CP_HL_DE ;de<=hl means no hiscore (or same)
+ jr nc,no_hiscore ;skip the new hiscore part
+ ld (hiscore),de ;otherwise save current score as new hiscore
+
+ask_hiname: ;and ask for new hiscore name
+ ld ix,hiname ;where to store the hiscore name
+ ld a,9 ;max. length <9
+ ld (hiscorepos),a ;current char (counts backwards 9-1)
+enter_name_loop:
+ ld a,'_' ;cursor appearance
+ rcl _putmap ;display (do not advance cursorpos)
+nokeypressed:
+ cal getsomekeys ;wait for any key
+ jr z,nomore ;if [enter] or [2nd] pressed we're all done
+
+ ld hl,hiscorepos ;string position
+ cp K_DEL ;[DEL] functions as "backspace"
+ jr z,backup ;delete previous char if pressed
+ cp K_EXIT ;exit also ends name
+ jr z,nomore
+
+ ld b,(hl) ;(hiscorepos)
+ dec b ;next position (counts backwards)
+ jr z,nokeypressed ;if it's 1 (became 0) then don't add no more
+ ld (hl),b ;otherwise save new string position
+
+ ld hl,chartable-1 ;chars to add for each key
+ ld e,a
+ ld d,0 ;de = key pressed
+ add hl,de ;add so we know which char to add for this key
+ ld a,(hl) ;load in a
+ or a ;if it's 0 then
+ jr z,nokeypressed ;don't add anything afterall
+
+ ld (ix),a ;save new char
+ rcl _putc ;and also display on screen
+ inc ix ;goto next char
+ cal releasekeys ;wait for the key to be released
+ jr enter_name_loop ;and continue the loop
+
+backup: ;backspace
+ ld a,(hl) ;(hiscorepos)
+ cp 9 ;9 means begin (0 total chars)
+ jr nc,nokeypressed ;nothing to remove so continue loop
+ inc (hl) ;otherwise pos one back
+
+ dec ix ;and string to previous char as well
+ ld a,32 ;remove cursor
+ rcl _putmap ;by replacing it by ' '
+ ld hl,_curCol
+ dec (hl) ;cursor one back
+ jr enter_name_loop ;continue name loop
+
+nomore: ;name's done
+ ld a,' ' ;remove cursor
+ rcl _putc ;(or actually replace with ' ')
+ ld (ix),0 ;end of string marker (zero-terminated)
+ cal save_hi ;store hiscore with name in real program
+ jr hiscoredone ;continue with game over screen
+#endif
+no_hiscore: ;no new hiscore
+ ld hl,hiname ;just display old name
+ rcl _puts
+
+hiscoredone:
+ xor a ;clear a (Ahl will be displayed)
+ ld hl,$1006 ;bottom-1 right
+ ld (_curRow),hl ;set
+ ld hl,(your_score) ;your score
+ rcl _dispahl ;display it (a=0)
+
+#ifdef TI86
+ ld hl,$314b ;bottom-1 right before score ^^
+#else
+ ld hl,$312b
+#endif
+ ld (_penCol),hl ;set
+ ld hl,txt_score ;"Score"
+ rcl _vputs ;display (small)
+
+ ld hl,$1007 ;bottom right
+ ld (_curRow),hl ;set
+ ld hl,(hiscore) ;hi-score
+ rcl _dispahl ;display
+#ifdef TI86
+ ld hl,$3946 ;bottom right before hiscore ^^
+#else
+ ld hl,$3926
+#endif
+ ld (_penCol),hl ;set
+ ld hl,txt_hiscore ;"Hiscore"
+ rcl _vputs ;display (small)
+ res 3,(iy+5)
+
+ ld b,scrwidth
+ ld de,scrwidth
+ ld hl,VIDEO_MEM+(49*scrwidth)-1
+restore_line:
+ set 1,(hl)
+ add hl,de
+ dnz restore_line
+
+ cal getsomekeys ;wait for keypress
+ jp quit ;restore some things and return to TI-OS/shell
+
+invship: ;procedure used in New_game
+ psh af
+ inc b
+ ld de,12*scrwidth
+ ld hl,scrwidth*(3-12)+VIDEO_MEM;begin pos
+invshipinit:
+ add hl,de
+ dnz invshipinit
+ ld b,12*scrwidth ;12 lines down
+invshiploop:
+ ld a,(hl)
+ cpl ;invert byte
+ ld (hl),a
+ inc hl
+ dnz invshiploop ;loop
+ pop af
+ ret
+
+New_game: ;start a new game (SP=+0)
+ rcl _clrLCD
+#ifdef TI86
+ ld a,VIDEO_MEM/$400
+ ld (PutWhere),a ;will be reset after displaying iconbar
+#endif
+ ld ix,spr_ship01 ;first ship: sprite
+ ld de,$0105 ;position
+ ld b,4 ;number of ships to display
+dispshipsloop:
+ psh bc ;counter
+ psh de ;position
+ ld h,e
+#ifdef TI86
+ ld l,40 ;x=40
+#else
+ ld l,30
+#endif
+ ld (_penCol),hl ;small cursor position
+ psh ix ;ix destroyed by _vputmap
+ ld hl,txt_difhardcore ;hardcore ships text
+ ld a,b ;ship displaying (4 to 1)
+ dec a ;minus 1 (3..0)
+ psh af
+ and %10 ;gives 1,1,0,0 (for ships 0,0,1,1)
+ jr z,dispdifficulty ;0 indicates hardcore difficulty ship
+ ld hl,txt_difnormal ;normal difficulty ships text
+dispdifficulty:
+ rcl _vputs ;display difficulty
+#ifdef TI86
+ ld a,95
+#else
+ ld a,70
+#endif
+ ld (_penCol),a ;set x=95
+ pop af ;ship nr (backwards 3..0)
+ ld hl,txt_shpbeam ;updouble for ships 1
+ and %1 ;gives 0,1,0,1 (for ships 0,1,0,1)
+ jr nz,dispsbeam
+ ld hl,txt_shplaser ;tailbeam for ships 0
+dispsbeam:
+ rcl _vputs ;display special beam type
+ pop ix
+ pop de
+ psh de ;peek de
+ cal putwidesprite ;display ship
+ pop de
+
+ ld bc,spr_ship01i-spr_ship01+2
+ add ix,bc ;go to next ship
+ ld a,12 ;below the previous one
+ add a,e
+ ld e,a
+ pop bc
+ dnz dispshipsloop ;loop
+
+ ld b,0 ;menu pos.
+selectship:
+ psh bc
+ cal invship
+#ifdef TI83
+ cal fastCopy
+#endif
+ cal getsomekeys
+ pop bc
+ jr z,startthenewgame ;enter/2nd
+ cp K_EXIT
+ jp z,menuexit ;go game over when exit was pressed
+ psh bc
+ cal invship ;display selection bar on current ship
+ pop bc
+ cp K_DOWN ;down pressed?
+ jr nz,selnotdown
+ inc b ;move selection down
+selnotdown:
+ cp K_UP ;up pressed?
+ jr nz,selnotup
+ dec b ;move selection up
+selnotup:
+ ld a,b ;new selection
+ and %11 ;must be 0..3
+ ld b,a ;in b again
+ jr selectship ;loop
+
+startthenewgame:
+ ld hl,spr_ship01-(spr_ship02-spr_ship01)
+ ld de,spr_ship02-spr_ship01
+ psh bc ;save b (ship#)
+ inc b ;your ship #0-3++
+ ld a,b ;ship #1-4
+searchyourship:
+ add hl,de ;next ship
+ dnz searchyourship
+ ld (your_ship),hl
+ and 1 ;gives: 1,0,1,0 for the ships
+ xor 1 ;well, make it 0,1,0,1 :)
+ jr z,whichship ;ships 0 have bullets
+ ld a,maxweapon ;ships 1 have lasers (0,8,0,8)
+whichship:
+ ld (your_weapon),a ;set bullet#1 or laser#1 depending on ship
+ pop af ;ship# 0..3
+ and %10 ;ships give 0,0,1,1
+ ld (hardcore),a ;hardcore mode set for ships 3 and 4
+ xor a ;ld a,0
+ ld (your_score),a ;reset score
+ ld (your_score+1),a ;reset score (0)
+ ld (your_extra),a ;no extra beam
+ ld (your_pickup),a ;reset pickups
+ ld (your_multiples),a ;no multiples
+ inc a ;ld a,1
+ ld (level),a ;reset level nr (#1)
+ ld hl,levelstart ;set level pointer to level#1
+ ld (levelp),hl ;reset level pointer
+ ld a,4
+ ld (your_lives),a ;3 lives (4 will be decreased @ You_die)
+ ld (pickuptimer),a ;next pickup after 4 enemies destroyed
+
+You_die: ;stack must be +1
+ ld a,24
+ ld (your_armor),a ;24 HPs/shields
+ ld a,(your_lives) ;load lives left
+ dec a ;decrease lives
+ ld (your_lives),a ;if lives=0ffh GO
+ inc a ;if -1 then zf set now
+ jp z,game_over ;and game's over
+ jr samelevel
+
+;--------------------------- next level --------------------------------------
+
+Next_level: ;stack must be +1
+ pop hl
+
+ cal inc_armor ;increase armor
+
+ ld hl,(levelp) ;level pointer
+ ld b,0 ;advance one level
+ ld c,(hl)
+ add hl,bc ;passed the enemies
+ ld c,9
+ add hl,bc ;update to point to next level
+ ld (levelp),hl ;save
+
+ ld a,(level) ;level number
+ inc a ;next level #
+ cp endlevel+1 ;last level done?
+ jr c,gamenotdone ;no: continue game
+gamedone: ;yes:
+ cal dostory ;display end (hl=(levelp))
+ ld hl,500
+ cal scoreInc ;game complete bonus: 500
+ jp game_over ;game over (+hiscore)
+gamenotdone:
+ ld (level),a
+
+ add a,a
+ add a,a
+ ld h,0 ;increase score....
+ ld l,a ;by level number * 4
+ ld bc,20
+ add hl,bc ;plus 20
+ cal scoreInc ;update score
+
+samelevel:
+ ld hl,invertmode
+ ld de,_invert ;sets B<>W mode
+ ldi ;ld (_invert),(invertmode)
+ ld de,your_shipspr ;sets your ship's sprite
+ ldi ;ld (your_shipspr),(your_ship)
+ ldi ;and second byte (heh it's a word)
+
+ ld a,80
+ ld (nextevent),a ;time to first enemy appearance
+
+ ld hl,(levelp) ;level pointer
+#ifdef story
+ dec hl ;byte before level (boss byte)
+ xor a ;if it's zero it means here's a story
+ cp (hl)
+ inc hl ;begin of level
+ cal z,dostory ;do the story and set (levelp) to real level
+#endif
+
+ ld a,(hl) ;number of (different) enemies in this level
+ inc hl
+ ld c,a
+ ld (nrlvlenemies),a ;set nr of enemies-1
+ ld b,0 ;bc=c so we can use ldir
+ ld de,lvlenemies ;table of enemies
+ ldir ;load enemies to table
+ ld a,(hl) ;load new appearance-time
+ ld (eventtime),a
+ inc hl
+ ld a,(hl)
+ ld (eventtime+1),a ;set
+ inc hl
+ ld a,(hl) ;load nr of enemies in this level
+ ld (eventleft),a ;set nr of events left
+ inc hl
+ ld de,level_info
+ ld c,4 ;5xLDI: loads (level_info) (spacespace)
+ ldir ; (stars1) (stars2)
+ ld a,1
+ ld b,16 ;fill (groundpos)
+fillground:
+ ld (de),a
+ inc de
+ dnz fillground
+
+ ld ix,starx1
+ ld b,nrstars1
+ cal placestars
+ ld ix,starx2
+ ld b,nrstars2
+ cal placestars
+
+ xor a
+ ld (timer),a ;reset time
+ ld hl,your_occ ;hl = your_occ
+ ld (hl),a ;reset your ship (not exploding)
+ inc hl ;hl = your_shield
+ ld (hl),25 ;set 25*4=100 frames shielded
+ ld de,$1820
+ ld (x),de ;begin position (x,y)
+ cal Place_multiples ;place all multiple-positions at that (0,24)
+
+ cal loadweapon ;load (your_weapon)
+
+ xor a
+ ld hl,enemies ;remove all enemies and bullets
+ ld (hl),a ;clear first byte
+ ld de,enemies+1 ;copy this to the next byte
+#ifdef TI86 ;on '86 everything's located here
+ ld bc,(nrenemies*enemysize)+(nrybuls*4)+(nrebuls*3)-1
+#else ;on '83 it's a little harder...
+ ld bc,(nrenemies*enemysize)-1
+ ldir ;just clear the enemies
+ ld hl,ybullets ;now remove all the bullets (different loc.)
+ ld (hl),a ;clear 1st byte
+ ld de,ybullets+1 ;copy2next
+ ld bc,(nrybuls*4)+(nrebuls*3)-1
+#endif
+ ldir ;clear enemies + ybullets + ebullets
+
+;--------------------------- setup game --------------------------------------
+
+game_setup:
+ cal BLACKLCD ;white on black
+ ld hl,txt_level
+ ld de,$0703
+ ld (_curRow),de ;center
+ rcl _puts ;display "LEVEL "
+
+ ld a,(level) ;current level
+ ld l,a
+ ld h,0 ;in hl
+ rcl UNPACK_HL ;create first digit
+ add a,'0' ;0-9
+ ld b,a ;into b
+ rcl UNPACK_HL ;second digit
+ add a,'0' ;0-9
+ rcl _putc ;display second digit
+ ld a,b
+ rcl _putmap ;display first digit
+
+ ld hl,txt_lives ;bar text: "Lx0"...
+ ld de,$0904
+ ld (_curRow),de ;display lives left below level nr
+ rcl _puts
+ ld a,(your_lives) ;lives left
+ add a,'0' ;make value 0='0'
+ rcl _putc
+
+ cal releasekeys ;wait for user to release all keys
+ ld hl,txt_savekey ;"Press [F1] to save"
+ ld de,$3A46 ;bottom-right
+ ld (_penCol),de
+ rcl _vputs
+
+ res 3,(iy+5) ;set white on black
+ cal getsomekeys ;wait for keypress
+#ifdef shiscore
+ cp K_F1
+ cal z,save_lvl
+#endif
+
+ rcl _clrLCD ;clear screen
+ cal disp_icons ;display bottom icons +ret
+ jp game_main_loop
+
+placestars:
+ cal RandomY ;a = random y-pos 1..bottom
+ ld a,b ;a = b = star nr. = 1..7
+ add a,a ;a = 2b = 2..14
+ ld d,0
+ ld e,a ;de = a = 2-14
+ or a
+ sbc hl,de ;substract from rand y => random pos anywhere
+
+ ld (ix),l ;save x-pos (l)
+ ld (ix+1),h ;save y-pos (h)
+ inc ix \ inc ix ;next star
+ dnz placestars ;repeat for all stars
+ ret
+
+loadweapon:
+ ld a,(your_weapon)
+ add a,a ;weap*2
+ add a,a ; *4
+ add a,a ; *8
+ ld c,a
+ ld b,0
+ ld hl,weapondata
+ add hl,bc
+ ld a,(hl)
+ ld (weapdamage),a ;damage of bullets
+ inc hl
+ ld a,(hl)
+ ld (weapdaminc),a ;damage increase
+ inc hl
+ ld a,(hl)
+ and %00011111 ;laser duration
+ ld (laserdur),a
+ ret
+
+;--misc--
+#ifdef TI83
+_clrLCD:
+ rcl _clrlcdf
+ ld hl,dispbuffer ;move from (hl) = top left
+ ld (hl),0 ;first pixel will be copied all over the screen
+ ld de,dispbuffer+1 ;(de) = next pixel, thus clearing whole screen
+ ld bc,scrwidth*64-1 ;loop 896 times = (128/8) * (64-8 for scorebar)
+ ldir ;all clear!
+ ret
+#endif
+
+;-----------------------------------------------------------------------------
+;--------------------------- putsprite ---------------------------------------
+;-----------------------------------------------------------------------------
+;in: de=(x,y); ix=sprite
+;out: ix=behind sprite; hl:a=right below sprite; b=0; d=width; ce=?
+
+#ifdef TI86
+putsprite:
+ ld c,(ix) ;save width
+_putsprite: ;putsprite with custom width
+ ld a,d ;a=X
+ bit 7,d ;check sign bit of X
+ jr z,CSpositive ;X>=0
+
+ neg ;a=|X|
+ cp (ix) ;off screen?
+ ret nc ;X<=-width: don't draw at all
+ ld b,a ;b=|X|mod 8=1..7=bits to draw
+ ld a,%11111111 ;all bits set (draw everything)
+CSclipleft:
+ srl a ;remove first bit in a for each b
+ dnz CSclipleft ;b=1: a=%01111111
+ ;b=2: a=%00111111
+ ;b=3: a=%00011111
+ ;b=4: a=%00001111
+ ;b=5: a=%00000111
+ ;b=6: a=%00000011
+ ;b=7: a=%00000001
+ res 7,d ;X+128 (right side of screen)
+ dec e ;Y--
+ jr CSdisplay ;done clipping
+
+CSpositive:
+ sub 129-8 ;minus (screen width - byte width)
+ ld b,a
+ ld a,%11111111 ;clipmask
+ jr c,CSdisplay ;x+width<128 then entire sprite is on screen
+ inc b ;b = number of pixels off screen
+CSclipright:
+ add a,a ;remove last bit in a for each b
+ dnz CSclipright ;b=1: a=%11111110
+ ;b=2: a=%11111100
+ ;b=3: a=%11111000
+ ;b=4: a=%11110000
+ ;b=5: a=%11100000
+ ;b=6: a=%11000000
+ ;b=7: a=%10000000
+ ;b>7: a=%00000000 = off screen
+
+CSdisplay: ;display the sprite ix at (d,e) masked
+ ld (CSclipmask),a ;set mask
+ cal findpixel ;convert de to screen location hl:a
+ ld (CSbitmask),a
+
+ ld d,c ;width
+ ld b,(ix+1) ;height
+CSyloop:
+ psh bc ;save rows to go
+ psh hl ;screen
+ ld b,d ;width
+ ld a,(ix+2) ;load image line
+ and 255 ;mask
+CSclipmask =$-1
+ ld c,a ;c=image
+ inc ix ;next
+CSbitmask =$+1
+ ld a,1 ;saved bitmask
+CSxloop:
+ sla c ;test leftmost pixel
+ jr nc,CSnodraw ;don't draw if it's 0
+ ld e,a ;psh af: save bitmask
+ or (hl)
+ ld (hl),a ;OR pixel with screen
+ ld a,e ;pop af
+CSnodraw:
+ rrca ;next bit
+ jr nc,CSbitdrawn ;carry set if bit "jumped"
+ inc hl ;next byte
+CSbitdrawn:
+ dnz CSxloop
+ pop hl ;screen at x-offset=0
+ ld bc,16
+ add hl,bc ;next line
+ pop bc ;rows counter
+ dnz CSyloop
+CSdone: ret
+#endif
+
+#ifdef TI83
+putsprite:
+ ld c,(ix) ;save width
+_putsprite: ;putsprite with custom width
+ ld a,d ;a=X
+ bit 7,d ;check sign bit of X
+ jr z,CSpositive ;X>=0
+
+ neg ;a=|X|
+ cp (ix) ;off screen?
+ ret nc ;X<=-width: don't draw at all
+ ld b,a ;b=|X|mod 8=1..7=bits to draw
+ psh bc
+ ld a,%11111111 ;all bits set (draw everything)
+CSclipleft:
+ srl a ;remove first bit in a for each b
+ dnz CSclipleft ;b=1: a=%01111111
+ ;b=2: a=%00111111
+ ;b=3: a=%00011111
+ ;b=4: a=%00001111
+ ;b=5: a=%00000111
+ ;b=6: a=%00000011
+ ;b=7: a=%00000001
+ pop bc
+ psh af
+ ld a,96
+ sub b
+ ld d,a
+ pop af
+ dec e ;Y--
+ jr CSdisplay ;done clipping
+
+CSpositive:
+ sub 97-8 ;minus (screen width - byte width)
+ ld b,a
+ ld a,%11111111 ;clipmask
+ jr c,CSdisplay ;x+width<128 then entire sprite is on screen
+ inc b ;b = number of pixels off screen
+CSclipright:
+ add a,a ;remove last bit in a for each b
+ dnz CSclipright ;b=1: a=%11111110
+ ;b=2: a=%11111100
+ ;b=3: a=%11111000
+ ;b=4: a=%11110000
+ ;b=5: a=%11100000
+ ;b=6: a=%11000000
+ ;b=7: a=%10000000
+ ;b>7: a=%00000000 = off screen
+
+CSdisplay: ;display the sprite ix at (d,e) masked
+ ld (CSclipmask),a ;set mask
+ cal findpixel ;convert de to screen location hl:a
+ ld (CSbitmask),a
+
+ ld d,c ;width
+ ld b,(ix+1) ;height
+CSyloop:
+ psh bc ;save rows to go
+ psh hl ;screen
+ ld b,d ;width
+ ld a,(ix+2) ;load image line
+ and 255 ;mask
+CSclipmask =$-1
+ ld c,a ;c=image
+ inc ix ;next
+CSbitmask =$+1
+ ld a,1 ;saved bitmask
+CSxloop:
+ sla c ;test leftmost pixel
+ jr nc,CSnodraw ;don't draw if it's 0
+ ld e,a ;psh af: save bitmask
+ or (hl)
+ ld (hl),a ;OR pixel with screen
+ ld a,e ;pop af
+CSnodraw:
+ rrca ;next bit
+ jr nc,CSbitdrawn ;carry set if bit "jumped"
+ inc hl ;next byte
+CSbitdrawn:
+ dnz CSxloop
+ pop hl ;screen at x-offset=0
+ ld bc,12
+ add hl,bc ;next line
+ pop bc ;rows counter
+ dnz CSyloop
+CSdone: ret
+#endif
+
+;--------------------------- putbigsprite -----------------------------------=
+
+putwidesprite:
+;destr: abcdehl+ix (ix=behind sprite; hl:a=right below sprite; b=0; d=width)
+ ld a,(ix) ;width
+ cp 9
+ jr c,putsprite ;width<=8: just draw the sprite
+
+ ld a,(ix)
+ sub 8 ;width>8
+ psh af
+ ld c,8
+ psh de
+ cal _putsprite ;otherwise draw one column (8 pixels wide)
+ pop de
+ inc ix ;no x-size to load
+ ld a,8 ;next
+ add a,d ;8 pixels right
+ ld d,a
+ pop bc ;then draw the remaining pixels (c=width-8)
+ ld c,b
+ jr _putsprite
+
+safeputsprite: ;cal putsprite with de intact
+ psh de
+ cal putsprite
+ pop de
+ ret
+
+;------------------------------- findpixel -----------------------------------
+;based upon CLEM's fp | 131 cycles | 28 bytes | in:(d,e); out:hla; destr:de
+
+#ifdef TI86
+findpixel:
+ ld a,e ;a=e=Y
+ add a,a
+ add a,a ;add a,a is 7 cycles faster than add hl,hl
+ ld h,dispbuffer/$400 ;switch to hl (Y<64) & set base to dispbuffer
+PutWhere =$-1 ;screen base position/$400 (where x+y=0)
+ ld l,a ;hl=4*Y
+ ld a,d ;a=d=X
+ rra ;RRA: carry flag must be reset!
+ add hl,hl ;that's what the adds are for :P
+ rra
+ add hl,hl ;hl=16*Y
+ rra ;a=X/8
+ or l
+ ld l,a ;hl=hl+a
+ ld a,d
+ and 7 ;a=X\8
+ cpl
+ rlca
+ rlca
+ rlca
+ ld (FPbit),a
+ xor a
+FPbit =$+1
+ set 0,a
+ ret
+#endif
+
+#ifdef TI83
+findpixel:
+ psh bc
+ psh de
+ ld a,d
+ cal ionGetPixel
+ pop de
+ pop bc
+ ret
+#endif
+
+;-----------------------------------------------------------------------------
+;------------------------------- sprites -------------------------------------
+;-----------------------------------------------------------------------------
+
+spr_ship01: ;(normal; up double)
+ .db 7,7 ;ship alpha class (vic viper)
+ .db %11000000 ;██
+ .db %11110000 ;████
+ .db %01111110 ; ██████
+ .db %11101000 ;███ █
+ .db %01111110 ; ██████
+ .db %11110000 ;████
+ .db %11000000 ;██
+spr_ship01i:
+ .db 8,7
+ .db %11001010 ;██ █ █
+ .db %11110101 ;████ █ █
+ .db %01111110 ; ██████
+ .db %11101001 ;███ █ █
+ .db %01111110 ; ██████
+ .db %11110101 ;████ █ █
+ .db %11001010 ;██ █ █
+
+spr_ship02: ;(normal; tail beam)
+ .db 7,7 ;ship gamma class
+ .db %11111000 ;█████
+ .db %01100000 ; ██
+ .db %11111100 ;██████
+ .db %11100110 ;███ ██
+ .db %11111100 ;██████
+ .db %01100000 ; ██
+ .db %11111000 ;█████
+spr_ship02i:
+ .db 8,7
+ .db %11111010 ;█████ █
+ .db %01100001 ; ██ █
+ .db %11111101 ;██████ █
+ .db %11100111 ;███ ███
+ .db %11111101 ;██████ █
+ .db %01100001 ; ██ █
+ .db %11111010 ;█████ █
+
+spr_ship03: ;(hardcore; up double)
+ .db 7,7 ;ship gamma class
+ .db %11111000 ;█████
+ .db %01100000 ; ██
+ .db %11111100 ;██████
+ .db %11100110 ;███ ██
+ .db %11111100 ;██████
+ .db %01100000 ; ██
+ .db %11111000 ;█████
+spr_ship03i:
+ .db 8,7
+ .db %11111010 ;█████ █
+ .db %01100001 ; ██ █
+ .db %11111101 ;██████ █
+ .db %11100111 ;███ ███
+ .db %11111101 ;██████ █
+ .db %01100001 ; ██ █
+ .db %11111010 ;█████ █
+
+ .db 7,7 ;ship delta class (lord british)
+ .db %11000000 ; ██