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vumeter colors

This commit is contained in:
Irmen de Jong 2024-04-17 00:13:31 +02:00
parent 2675623aea
commit d6a67f5f2b
1 changed files with 36 additions and 12 deletions
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48
examples/cx16/pcmaudio/vumeter.p8
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@ -6,13 +6,13 @@
; play a raw pcm stereo 16 bit audio file at 16021 hz,
; with real-time VU meters and sample waveform displays.
; TODO add peak level indicator
; TODO nicer color gradient for the bars
; Left as an excercise for the reader: add peak level indicator.
; that would require use of more sprites though, because it has to appear on top of the blocking black sprites.
main {
const ubyte vera_rate = 42 ; 16021 hz
str pcmfile = "thriller-16k.pcm"
str pcmfile = "thriller-16k.pcm" ; should be raw pcm, 16 bits signed integer, stereo, 16021 hz.
sub start() {
setup()
@ -23,7 +23,18 @@ main {
void cx16.screen_mode(128, false)
cx16.GRAPH_set_colors(0,0,0)
cx16.GRAPH_clear()
cx16.rombank(0) ; activate kernal bank for faster calls
cx16.GRAPH_set_colors(47,0,0)
cx16.r0 = 250
cx16.r1 = 10
for cx16.r9L in iso:"made in Prog8"
cx16.GRAPH_put_next_char(cx16.r9L)
cx16.r0 = 250
cx16.r1 = 20
for cx16.r9L in iso:"16kHz stereo"
cx16.GRAPH_put_next_char(cx16.r9L)
cx16.rombank(0) ; activate kernal bank for faster calls
void diskio.fastmode(1)
cx16.VERA_AUDIO_RATE = 0 ; halt playback
@ -39,13 +50,25 @@ main {
for cx16.r9 in $3000 to $3000+32*64/2 {
cx16.vpoke(1, cx16.r9, $ff)
}
; move the vu sprites to the base positions
update_vu()
; draw vu gradient
for cx16.r9L in 239 downto 80 {
cx16.GRAPH_set_colors(cx16.r9L, 1, 2)
cx16.GRAPH_draw_line(160-32-16, cx16.r9L, 160-32+15, cx16.r9L)
cx16.GRAPH_draw_line(160+32-16, cx16.r9L, 160+32+15, cx16.r9L)
; draw vu gradient bars.
; 18 bars from the bottom are gradient from green to red
; 4 bars on top of that are just red for the extremes
ubyte[18] gradient_colors_outline = [ 2, 2, 2, 2, 51, 51, 8, 8, 5, 5, 5, 5, 141, 141, 141, 141, 140, 140]
ubyte[18] gradient_colors_fill = [59, 59, 52, 52, 8, 8, 80, 80, 13, 13, 13, 13, 143, 143, 143, 143, 142, 142]
for cx16.r9L in 0 to len(gradient_colors_fill)-1 {
cx16.GRAPH_set_colors(gradient_colors_outline[cx16.r9L], gradient_colors_fill[cx16.r9L], 0)
cx16.GRAPH_draw_rect(160-32-16, cx16.r9L * 8 + $0060, 32, 7, 0, true)
cx16.GRAPH_draw_rect(160+32-16, cx16.r9L * 8 + $0060, 32, 7, 0, true)
}
for cx16.r9L in 0 to 3 {
cx16.GRAPH_set_colors(gradient_colors_outline[0], gradient_colors_fill[0], 0)
cx16.GRAPH_draw_rect(160-32-16, cx16.r9L * 8 + $0040, 32, 7, 0, true)
cx16.GRAPH_draw_rect(160+32-16, cx16.r9L * 8 + $0040, 32, 7, 0, true)
}
; waveform sprites 32x64
@ -58,7 +81,7 @@ main {
sprites.pos(16, 160-100-16, 120)
sprites.pos(17, 160+100-16, 120)
; irq handlers
; activate irq handlers
cx16.enable_irq_handlers(true)
cx16.set_aflow_irq_handler(interrupts.aflow_handler)
cx16.set_vsync_irq_handler(interrupts.vsync_handler)
@ -228,8 +251,9 @@ main {
}
sub update_vu() {
word aleft = $00a0 as word - msb(avg_vol_left)
word aright = $00a0 as word - msb(avg_vol_right)
; determine vu 'level' in steps of 8 pixels
word aleft = ($00a0 as word - msb(avg_vol_left)) & %11111111_11111000
word aright = ($00a0 as word - msb(avg_vol_right)) & %11111111_11111000
for cx16.r9L in 0 to 3 {
; note: sprites overlap a bit to avoid scanlines peeping through when updating outside of vblank
sprites.pos(cx16.r9L, 160-32-16, aleft)