Converting Graphics to Audio
tof
Posts: 10
I am trying to convert graphics created from Graphics.spin into audio for an art project ( see here ).
I have a 470 ohm resistor and a 270 ohm resistor attached to pins 22 and 23 (to create a 2 bit dac). I want the code to read through the graphics/screen buffer and output a value through those pins.
The following code tries to read one line (long) of each tile. It starts by reading line 0 of tile 0, and then line 0 of tile 1, line 0 of tile 2 ... line 1 of tile 0, line 1 of tile 1, etc. The code then looks through that line and sums up all reference to color indices 1 or 2 (I do not want to output any sound for indices 0 or 3) into the value variable. This variable's value determines the output of the dac.
The code kind of works a bit, but definitely not how I am expecting it to. Any suggestions? Am i doing something wrong? Instead of reading the screen, should I read the bitmap instead?
The code ( the object expects a reference to the screen buffer ):
I have a 470 ohm resistor and a 270 ohm resistor attached to pins 22 and 23 (to create a 2 bit dac). I want the code to read through the graphics/screen buffer and output a value through those pins.
The following code tries to read one line (long) of each tile. It starts by reading line 0 of tile 0, and then line 0 of tile 1, line 0 of tile 2 ... line 1 of tile 0, line 1 of tile 1, etc. The code then looks through that line and sums up all reference to color indices 1 or 2 (I do not want to output any sound for indices 0 or 3) into the value variable. This variable's value determines the output of the dac.
The code kind of works a bit, but definitely not how I am expecting it to. Any suggestions? Am i doing something wrong? Instead of reading the screen, should I read the bitmap instead?
The code ( the object expects a reference to the screen buffer ):
CON
WIDTH = 16
HEIGHT = 12
VAR
long stack[32]
long cog
long graphics
long index
long screen
long value
PUB start(screen_ptr) : okay
' start a cog
stop
screen := screen_ptr
dira[22] := 1
dira[23] := 1
okay := cog := cognew(update, @stack) + 1
PUB stop
{{
stop cog if in use
}}
if cog
cogstop(cog~ - 1)
PUB update | col, pixels,color, line, pointer, out, row
col := 0
row := 0
line := 0
dira[22] := 1
dira[23] := 1
repeat
if col == width
col:=0
line++
if line > 15
line:=0
row++
if row == height
row:=0
'tile := (word[screen+((col)+(row*width))*2])
pointer := ( word[screen][col+(row*width)] & %00000011_11111111) << 6
'palette := long[tile >> 10]
pixels := long[pointer][line]
value := 0
repeat 16
if (pixels & %11) == 1 OR (pixels & %11) == 2
value++
pixels := pixels >> 2
if value > 12
outa[22] := 1
outa[23] := 1
elseif value > 8
outa[22] := 1
outa[23] := 0
elseif value > 4
outa[22] := 0
outa[23] := 1
else
outa[22] := 0
outa[23] := 0
col++