prog8/examples/skramble.p8
2020-03-24 02:42:32 +01:00

94 lines
2.4 KiB
Lua

; clone of the old Scramble arcade game.
; TODO work in progress...
%import c64lib
%import c64utils
%zeropage basicsafe
main {
ubyte perform_scroll = false
sub start() {
c64scr.plot(30,2)
c64scr.print("skramble !")
c64.SCROLX = c64.SCROLX & %11110111 ; 38 column mode
c64utils.set_rasterirq(1) ; enable animation
ubyte target_height = 10
ubyte active_height = 25
forever {
if active_height < target_height {
active_height++
} else if active_height > target_height {
active_height--
} else {
target_height = 8 + rnd() % 16
continue
}
while not perform_scroll {
; let the raster irq do its timing job
}
perform_scroll = false
c64scr.scroll_left_full(true)
ubyte yy
for yy in 0 to active_height-1 {
c64scr.setcc(39, yy, 32, 2) ; clear top
}
for yy in active_height to 24 {
c64scr.setcc(39, yy, 102, 8) ; draw mountain
}
yy = rnd()
if yy > 100 {
; draw a star
c64scr.setcc(39, yy % (active_height-1), '.', rnd())
}
if yy > 200 {
; draw a tree
ubyte tree = 30
ubyte treecolor = 5
if yy & %01000000 != 0
tree = 88
else if yy & %00100000 != 0
tree = 65
if rnd() > 130
treecolor = 13
c64scr.setcc(39, active_height-1, tree, treecolor)
}
if yy > 235 {
; draw a camel
c64scr.setcc(39, active_height-1, 94, 9)
}
; check ship crash
; ubyte shipchar3 = c64scr.getchr(2, 10)
; if (shipchar3!=@'.' and shipchar3!=@' ') {
; break ; game over
; }
; draw space ship
; c64scr.setcc(0, 10, @'*', 15)
; c64scr.setcc(1, 10, @'=', 15)
; c64scr.setcc(2, 10, @'>', 15)
}
}
}
irq {
ubyte smoothx=7
sub irq() {
smoothx = (smoothx-1) & 7
main.perform_scroll = smoothx==0
c64.SCROLX = (c64.SCROLX & %11111000) | smoothx
}
}