mirror of
https://github.com/irmen/prog8.git
synced 2024-07-09 17:29:46 +00:00
149 lines
3.3 KiB
Lua
149 lines
3.3 KiB
Lua
%import palette
|
|
%import textio
|
|
|
|
|
|
; TODO WORK IN PROGRESS...
|
|
; want to make Amiga 'copper' bars color cycling effects
|
|
|
|
|
|
main {
|
|
sub start() {
|
|
txt.plot(5,5)
|
|
txt.print("amiga-like raster blinds effect (work in progress)")
|
|
|
|
irq.make_new_gradient()
|
|
cx16.set_rasterirq(&irq.irqhandler, 100)
|
|
|
|
repeat {
|
|
}
|
|
}
|
|
|
|
}
|
|
|
|
irq {
|
|
ubyte color_ix = 0
|
|
uword next_irq_line = 100
|
|
ubyte gradient_counter = 0
|
|
|
|
sub irqhandler() {
|
|
palette.set_color(0, colors.get_colorword(color_ix))
|
|
color_ix++
|
|
|
|
if color_ix==32 {
|
|
next_irq_line = 100
|
|
color_ix = 0
|
|
|
|
; just arbitrary mechanism for now, to change to a new gradient after a short while
|
|
gradient_counter++
|
|
if gradient_counter & 16 {
|
|
make_new_gradient()
|
|
gradient_counter = 0
|
|
}
|
|
|
|
} else {
|
|
next_irq_line += 2 ; code needs 2 scanlines per color transition
|
|
}
|
|
|
|
cx16.set_rasterline(next_irq_line)
|
|
}
|
|
|
|
sub make_new_gradient() {
|
|
colors.random_half_bar()
|
|
colors.mirror_bar()
|
|
}
|
|
}
|
|
|
|
|
|
colors {
|
|
ubyte target_red
|
|
ubyte target_green
|
|
ubyte target_blue
|
|
ubyte[32] reds
|
|
ubyte[32] greens
|
|
ubyte[32] blues
|
|
|
|
sub random_rgb12() {
|
|
do {
|
|
uword rr = rndw()
|
|
target_red = msb(rr) & 15
|
|
target_green = lsb(rr)
|
|
target_blue = target_green & 15
|
|
target_green >>= 4
|
|
} until target_red+target_green+target_blue >= 12
|
|
}
|
|
|
|
sub mirror_bar() {
|
|
; mirror the top half bar into the bottom half
|
|
ubyte ix=14
|
|
ubyte mix=16
|
|
do {
|
|
reds[mix] = reds[ix]
|
|
greens[mix] = greens[ix]
|
|
blues[mix] = blues[ix]
|
|
mix++
|
|
ix--
|
|
} until ix==255
|
|
reds[mix] = 0
|
|
greens[mix] = 0
|
|
blues[mix] = 0
|
|
}
|
|
|
|
sub random_half_bar() {
|
|
; fade black -> color then fade color -> white
|
|
; gradient calculations in 8.8 bits fixed-point
|
|
; could theoretically be 4.12 bits for even more fractional accuracy
|
|
random_rgb12()
|
|
uword r = $000
|
|
uword g = $000
|
|
uword b = $000
|
|
uword dr = target_red
|
|
uword dg = target_green
|
|
uword db = target_blue
|
|
ubyte ix = 1
|
|
|
|
; gradient from black to halfway color
|
|
reds[0] = 0
|
|
greens[0] = 0
|
|
blues[0] = 0
|
|
dr <<= 5
|
|
dg <<= 5
|
|
db <<= 5
|
|
continue_gradient()
|
|
|
|
; gradient from halfway color to white
|
|
dr = (($f00 - r) >> 3) - 1
|
|
dg = (($f00 - g) >> 3) - 1
|
|
db = (($f00 - b) >> 3) - 1
|
|
continue_gradient()
|
|
return
|
|
|
|
sub continue_gradient() {
|
|
repeat 8 {
|
|
reds[ix] = msb(r)
|
|
greens[ix] = msb(g)
|
|
blues[ix] = msb(b)
|
|
r += dr
|
|
g += dg
|
|
b += db
|
|
ix++
|
|
}
|
|
}
|
|
}
|
|
|
|
asmsub get_colorword(ubyte color_ix @Y) -> uword @AY {
|
|
; uword color = mkword(reds[ix], (greens[ix] << 4) | blues[ix] )
|
|
%asm {{
|
|
lda colors.reds,y
|
|
pha
|
|
lda colors.greens,y
|
|
asl a
|
|
asl a
|
|
asl a
|
|
asl a
|
|
ora colors.blues,y
|
|
ply
|
|
rts
|
|
}}
|
|
}
|
|
}
|