mirror of
https://github.com/irmen/prog8.git
synced 2024-12-27 20:33:39 +00:00
140 lines
4.5 KiB
Lua
140 lines
4.5 KiB
Lua
%target c64
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%import syslib
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%import textio
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%import test_stack
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%zeropage basicsafe
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; note: The flickering in the scrolling is caused by the CPU requiring
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; too long to scroll the characters + the colors in course scroll.
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; This takes nearly a full frame to accomplish, and causes tearing.
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; It's very difficult to remove this flicker: it requires double buffering
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; and splitting the coarse character scrolling on multiple phases...
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main {
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ubyte perform_scroll = false
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sub start() {
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c64.SPRPTR[0] = $0f00 / 64
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c64.SPENA = 1
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c64.SP0COL = 14
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c64.SPXY[0] = 80
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c64.SPXY[1] = 100
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c64.SCROLX &= %11110111 ; 38 column mode
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c64.set_rasterirq(&irq.irq, 200, false) ; enable animation via raster interrupt
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ubyte target_height = 10
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ubyte active_height = 24
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ubyte upwards = true
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repeat {
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;txt.plot(0,0)
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;test_stack.test()
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ubyte mountain = 223 ; slope upwards
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if active_height < target_height {
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active_height++
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upwards = true
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} else if active_height > target_height {
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mountain = 233 ; slope downwards
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active_height--
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upwards = false
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} else {
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target_height = 8 + fastrnd8() % 16
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if upwards
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mountain = 233
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else
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mountain = 223
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}
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while not perform_scroll {
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; let the raster irq do its timing job
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}
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perform_scroll = false
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txt.scroll_left(true)
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; float the balloon
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if fastrnd8() & %10000
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c64.SPXY[1] ++
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else
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c64.SPXY[1] --
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ubyte yy
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for yy in 0 to active_height-1 {
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txt.setcc(39, yy, 32, 2) ; clear top of screen
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}
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txt.setcc(39, active_height, mountain, 8) ; mountain edge
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for yy in active_height+1 to 24 {
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txt.setcc(39, yy, 160, 8) ; draw mountain
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}
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yy = fastrnd8()
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if yy > 100 {
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; draw a star
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txt.setcc(39, yy % (active_height-1), '.', fastrnd8())
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}
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if yy > 200 {
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; draw a tree
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ubyte tree = 30
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ubyte treecolor = 5
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if yy & %01000000 != 0
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tree = 88
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else if yy & %00100000 != 0
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tree = 65
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if fastrnd8() > 130
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treecolor = 13
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txt.setcc(39, active_height, tree, treecolor)
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}
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if yy > 235 {
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; draw a camel
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txt.setcc(39, active_height, 94, 9)
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}
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}
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}
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}
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spritedata $0f00 {
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; this memory block contains the sprite data
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; it must start on an address aligned to 64 bytes.
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%option force_output ; make sure the data in this block appears in the resulting program
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ubyte[] balloonsprite = [ %00000000,%01111111,%00000000,
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%00000001,%11111111,%11000000,
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%00000011,%11111111,%11100000,
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%00000011,%11100011,%11100000,
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%00000111,%11011100,%11110000,
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%00000111,%11011101,%11110000,
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%00000111,%11011100,%11110000,
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%00000011,%11100011,%11100000,
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%00000011,%11111111,%11100000,
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%00000011,%11111111,%11100000,
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%00000010,%11111111,%10100000,
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%00000001,%01111111,%01000000,
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%00000001,%00111110,%01000000,
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%00000000,%10011100,%10000000,
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%00000000,%10011100,%10000000,
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%00000000,%01001001,%00000000,
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%00000000,%01001001,%00000000,
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%00000000,%00111110,%00000000,
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%00000000,%00111110,%00000000,
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%00000000,%00111110,%00000000,
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%00000000,%00011100,%00000000 ]
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}
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irq {
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ubyte smoothx=0
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sub irq() {
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smoothx = (smoothx-1) & 7
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main.perform_scroll = smoothx==7
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c64.SCROLX = (c64.SCROLX & %11111000) | smoothx
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}
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}
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