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Irmen de Jong 2020-12-14 21:57:16 +01:00
parent 0baa2c8b23
commit cd28d0c0e0
1 changed files with 9 additions and 3 deletions
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12
examples/balloonflight.p8
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@ -4,6 +4,12 @@
%import test_stack %import test_stack
%zeropage basicsafe %zeropage basicsafe
; note: The flickering in the scrolling is caused by the CPU requiring
; too long to scroll the characters + the colors in course scroll.
; This takes nearly a full frame to accomplish, and causes tearing.
; It's very difficult to remove this flicker: it requires double buffering
; and splitting the coarse character scrolling on multiple phases...
main { main {
ubyte perform_scroll = false ubyte perform_scroll = false
@ -17,7 +23,7 @@ main {
c64.SCROLX &= %11110111 ; 38 column mode c64.SCROLX &= %11110111 ; 38 column mode
c64.set_rasterirq(40) ; enable animation c64.set_rasterirq(200) ; enable animation
ubyte target_height = 10 ubyte target_height = 10
ubyte active_height = 24 ubyte active_height = 24
@ -123,10 +129,10 @@ spritedata $0f00 {
irq { irq {
ubyte smoothx=7 ubyte smoothx=0
sub irq() { sub irq() {
smoothx = (smoothx-1) & 7 smoothx = (smoothx-1) & 7
main.perform_scroll = smoothx==0 main.perform_scroll = smoothx==7
c64.SCROLX = (c64.SCROLX & %11111000) | smoothx c64.SCROLX = (c64.SCROLX & %11111000) | smoothx
} }
} }