sointu/test_chords.wat
Peter Salomonsen 1ca16043bc wasm-music
2023-04-06 12:12:24 +00:00

442 lines
20 KiB
Plaintext

(module
;;------------------------------------------------------------------------------
;; Import the difficult math functions from javascript
;; (seriously now, it's 2020)
;;------------------------------------------------------------------------------
(func $pow (import "m" "pow") (param f32) (param f32) (result f32))
(func $log2 (import "m" "log2") (param f32) (result f32))
(func $sin (import "m" "sin") (param f32) (result f32))
;;------------------------------------------------------------------------------
;; Types. Only useful to define the jump table type, which is
;; (int stereo) void
;;------------------------------------------------------------------------------
(type $opcode_func_signature (func (param i32)))
;;------------------------------------------------------------------------------
;; The one and only memory
;;------------------------------------------------------------------------------
(memory (export "m") 15)
;;------------------------------------------------------------------------------
;; Globals. Putting all with same initialization value should compress most
;;------------------------------------------------------------------------------
(global $WRK (mut i32) (i32.const 0))
(global $COM (mut i32) (i32.const 0))
(global $VAL (mut i32) (i32.const 0))
(global $COM_instr_start (mut i32) (i32.const 0))
(global $VAL_instr_start (mut i32) (i32.const 0))
(global $globaltick (mut i32) (i32.const 0))
(global $row (mut i32) (i32.const 0))
(global $pattern (mut i32) (i32.const 0))
(global $sample (mut i32) (i32.const 0))
(global $voice (mut i32) (i32.const 0))
(global $voicesRemain (mut i32) (i32.const 0))
(global $randseed (mut i32) (i32.const 1))
(global $sp (mut i32) (i32.const 384))
(global $outputBufPtr (mut i32) (i32.const 131712))
;; TODO: only export start and length with certain compiler options; in demo use, they can be hard coded
;; in the intro
(global $outputStart (export "s") i32 (i32.const 131712))
(global $outputLength (export "l") i32 (i32.const 846720))
(global $output16bit (export "t") i32 (i32.const 0))
;;------------------------------------------------------------------------------
;; Functions to emulate FPU stack in software
;;------------------------------------------------------------------------------
(func $peek (result f32)
(f32.load (global.get $sp))
)
(func $peek2 (result f32)
(f32.load offset=4 (global.get $sp))
)
(func $pop (result f32)
(call $peek)
(global.set $sp (i32.add (global.get $sp) (i32.const 4)))
)
(func $push (param $value f32)
(global.set $sp (i32.sub (global.get $sp) (i32.const 4)))
(f32.store (global.get $sp) (local.get $value))
)
;;------------------------------------------------------------------------------
;; Helper functions
;;------------------------------------------------------------------------------
(func $swap (param f32 f32) (result f32 f32) ;; x,y -> y,x
local.get 1
local.get 0
)
(func $scanValueByte (result i32) ;; scans positions $VAL for a byte, incrementing $VAL afterwards
(i32.load8_u (global.get $VAL)) ;; in other words: returns byte [$VAL++]
(global.set $VAL (i32.add (global.get $VAL) (i32.const 1))) ;; $VAL++
)
;;------------------------------------------------------------------------------
;; "Entry point" for the player
;;------------------------------------------------------------------------------
(start $render) ;; we run render automagically when the module is instantiated
(func $render (param)
loop $pattern_loop
(global.set $row (i32.const 0))
loop $row_loop
(call $su_update_voices)
(global.set $sample (i32.const 0))
loop $sample_loop
(global.set $COM (i32.const 51))
(global.set $VAL (i32.const 58))
(global.set $COM_instr_start (global.get $COM))
(global.set $VAL_instr_start (global.get $VAL))
(global.set $WRK (i32.const 576))
(global.set $voice (i32.const 576))
(global.set $voicesRemain (i32.const 3))
(call $su_run_vm)
(i64.store (global.get $outputBufPtr) (i64.load (i32.const 544))) ;; load the sample from left & right channels as one 64bit int and store it in the address pointed by outputBufPtr
(global.set $outputBufPtr (i32.add (global.get $outputBufPtr) (i32.const 8))) ;; advance outputbufptr
(i64.store (i32.const 544) (i64.const 0)) ;; clear the left and right ports
(global.set $sample (i32.add (global.get $sample) (i32.const 1)))
(global.set $globaltick (i32.add (global.get $globaltick) (i32.const 1)))
(br_if $sample_loop (i32.lt_s (global.get $sample) (i32.const 6615)))
end
(global.set $row (i32.add (global.get $row) (i32.const 1)))
(br_if $row_loop (i32.lt_s (global.get $row) (i32.const 16)))
end
(global.set $pattern (i32.add (global.get $pattern) (i32.const 1)))
(br_if $pattern_loop (i32.lt_s (global.get $pattern) (i32.const 1)))
end
)
;; the simple implementation of update_voices: each track has exactly one voice
(func $su_update_voices (local $si i32) (local $di i32) (local $tracksRemaining i32) (local $note i32)
(local.set $tracksRemaining (i32.const 3))
(local.set $si (global.get $pattern))
(local.set $di (i32.const 576))
loop $track_loop
(i32.load8_u offset=48 (local.get $si))
(i32.mul (i32.const 16))
(i32.add (global.get $row))
(i32.load8_u offset=0)
(local.tee $note)
(if (i32.ne (i32.const 1))(then
(i32.store offset=4 (local.get $di) (i32.const 1)) ;; release the note
(if (i32.gt_u (local.get $note) (i32.const 1))(then
(memory.fill (local.get $di) (i32.const 0) (i32.const 4096))
(i32.store (local.get $di) (local.get $note))
))
))
(local.set $di (i32.add (local.get $di) (i32.const 4096)))
(local.set $si (i32.add (local.get $si) (i32.const 1)))
(br_if $track_loop (local.tee $tracksRemaining (i32.sub (local.get $tracksRemaining) (i32.const 1))))
end
)
;;-------------------------------------------------------------------------------
;; su_run_vm function: runs the entire virtual machine once, creating 1 sample
;;-------------------------------------------------------------------------------
(func $su_run_vm (local $opcodeWithStereo i32) (local $opcode i32) (local $paramNum i32) (local $paramX4 i32) (local $WRKplusparam i32)
loop $vm_loop
(local.set $opcodeWithStereo (i32.load8_u (global.get $COM)))
(global.set $COM (i32.add (global.get $COM) (i32.const 1))) ;; move to next instruction
(global.set $WRK (i32.add (global.get $WRK) (i32.const 64))) ;; move WRK to next unit
(if (local.tee $opcode (i32.shr_u (local.get $opcodeWithStereo) (i32.const 1)))(then ;; if $opcode = $opcodeStereo >> 1; $opcode != 0 {
(local.set $paramNum (i32.const 0))
(local.set $paramX4 (i32.const 0))
loop $transform_values_loop
(if (i32.lt_u (local.get $paramNum) (i32.load8_u offset=82 (local.get $opcode)))(then ;;(i32.ge (local.get $paramNum) (i32.load8_u (local.get $opcode))) /*TODO: offset to transformvalues
(local.set $WRKplusparam (i32.add (global.get $WRK) (local.get $paramX4)))
(f32.store offset=384
(local.get $paramX4)
(f32.add
(f32.mul
(f32.convert_i32_u (call $scanValueByte))
(f32.const 0.0078125) ;; scale from 0-128 to 0.0 - 1.0
)
(f32.load offset=32 (local.get $WRKplusparam)) ;; add modulation
)
)
(f32.store offset=32 (local.get $WRKplusparam) (f32.const 0.0)) ;; clear modulations
(local.set $paramNum (i32.add (local.get $paramNum) (i32.const 1))) ;; $paramNum++
(local.set $paramX4 (i32.add (local.get $paramX4) (i32.const 4)))
br $transform_values_loop ;; continue looping
))
;; paramNum was >= the number of parameters to transform, exiting loop
end
(call_indirect (type $opcode_func_signature) (i32.and (local.get $opcodeWithStereo) (i32.const 1)) (local.get $opcode))
)(else ;; advance to next voice
(global.set $voice (i32.add (global.get $voice) (i32.const 4096))) ;; advance to next voice
(global.set $WRK (global.get $voice)) ;; set WRK point to beginning of voice
(global.set $voicesRemain (i32.sub (global.get $voicesRemain) (i32.const 1)))
(if (i32.and (i32.shr_u (i32.const 6) (global.get $voicesRemain)) (i32.const 1))(then
(global.set $VAL (global.get $VAL_instr_start))
(global.set $COM (global.get $COM_instr_start))
))
(global.set $VAL_instr_start (global.get $VAL))
(global.set $COM_instr_start (global.get $COM))
(br_if 2 (i32.eqz (global.get $voicesRemain))) ;; if no more voices remain, return from function
))
br $vm_loop
end
)
;;-------------------------------------------------------------------------------
;; MULP opcode: multiply the two top most signals on the stack and pop
;;-------------------------------------------------------------------------------
;; Mono: a b -> a*b
;; Stereo: a b c d -> a*c b*d
;;-------------------------------------------------------------------------------
(func $su_op_mulp (param $stereo i32)
call $pop ;; a
call $pop ;; b a
call $swap ;; a b
call $pop ;; c a b
f32.mul ;; c*a b
call $swap ;; b c*a
call $pop ;; d b c*a
f32.mul ;; d*b c*a
call $push ;; c*a
call $push
)
;;-------------------------------------------------------------------------------
;; ENVELOPE opcode: pushes an ADSR envelope value on stack [0,1]
;;-------------------------------------------------------------------------------
;; Mono: push the envelope value on stack
;; Stereo: push the envelope valeu on stack twice
;;-------------------------------------------------------------------------------
(func $su_op_envelope (param $stereo i32) (local $state i32) (local $level f32) (local $delta f32)
(if (i32.load offset=4 (global.get $voice)) (then ;; if voice.release > 0
(i32.store (global.get $WRK) (i32.const 3)) ;; set envelope state to release
))
(local.set $state (i32.load (global.get $WRK)))
(local.set $level (f32.load offset=4 (global.get $WRK)))
(local.set $delta (call $nonLinearMap (local.get $state)))
(if (local.get $state) (then
(if (i32.eq (local.get $state) (i32.const 1))(then ;; state is 1 aka decay
(local.set $level (f32.sub (local.get $level) (local.get $delta)))
(if (f32.le (local.get $level) (call $input (i32.const 2)))(then
(local.set $level (call $input (i32.const 2)))
(local.set $state (i32.const 2))
))
))
(if (i32.eq (local.get $state) (i32.const 3))(then ;; state is 3 aka release
(local.set $level (f32.sub (local.get $level) (local.get $delta)))
(if (f32.le (local.get $level) (f32.const 0)) (then
(local.set $level (f32.const 0))
))
))
)(else ;; the state is 0 aka attack
(local.set $level (f32.add (local.get $level) (local.get $delta)))
(if (f32.ge (local.get $level) (f32.const 1))(then
(local.set $level (f32.const 1))
(local.set $state (i32.const 1))
))
))
(i32.store (global.get $WRK) (local.get $state))
(f32.store offset=4 (global.get $WRK) (local.get $level))
(call $push (f32.mul (local.get $level) (call $input (i32.const 4))))
)
;;-------------------------------------------------------------------------------
;; OSCILLAT opcode: oscillator, the heart of the synth
;;-------------------------------------------------------------------------------
;; Mono: push oscillator value on stack
;; Stereo: push l r on stack, where l has opposite detune compared to r
;;-------------------------------------------------------------------------------
(func $su_op_oscillator (param $stereo i32) (local $flags i32) (local $detune f32) (local $phase f32) (local $color f32) (local $amplitude f32)
(local.set $flags (call $scanValueByte))
(local.set $detune (call $inputSigned (i32.const 1)))
(f32.store ;; update phase
(global.get $WRK)
(local.tee $phase
(f32.sub
(local.tee $phase
;; Transpose calculation starts
(f32.div
(call $inputSigned (i32.const 0))
(f32.const 0.015625)
) ;; scale back to 0 - 128
(f32.add (local.get $detune)) ;; add detune. detune is -1 to 1 so can detune a full note up or down at max
(f32.add (select
(f32.const 0)
(f32.convert_i32_u (i32.load (global.get $voice)))
(i32.and (local.get $flags) (i32.const 0x8))
)) ;; if lfo is not enabled, add the note number to it
(f32.mul (f32.const 0.0833333)) ;; /12, in full octaves
(call $pow2)
(f32.mul (select
(f32.const 0.000038) ;; pretty random scaling constant to get LFOs into reasonable range. Historical reasons, goes all the way back to 4klang
(f32.const 0.000092696138) ;; scaling constant to get middle-C to where it should be
(i32.and (local.get $flags) (i32.const 0x8))
))
(f32.add (f32.load (global.get $WRK))) ;; add the current phase of the oscillator
)
(f32.floor (local.get $phase))
)
)
)
(f32.add (local.get $phase) (call $input (i32.const 2)))
(local.set $phase (f32.sub (local.tee $phase) (f32.floor (local.get $phase)))) ;; phase = phase mod 1.0
(local.set $color (call $input (i32.const 3)))
(if (i32.and (local.get $flags) (i32.const 0x40)) (then
(local.set $amplitude (call $oscillator_sine (local.get $phase) (local.get $color)))
))
(call $waveshaper (local.get $amplitude) (call $input (i32.const 4)))
(call $push (f32.mul
(call $input (i32.const 5))
))
)
(func $oscillator_sine (param $phase f32) (param $color f32) (result f32)
(select
(f32.const 0)
(call $sin (f32.mul
(f32.div
(local.get $phase)
(local.get $color)
)
(f32.const 6.28318530718)
))
(f32.ge (local.get $phase) (local.get $color))
)
)
;;-------------------------------------------------------------------------------
;; OUT opcode: outputs and pops the signal
;;-------------------------------------------------------------------------------
;; Stereo: add ST0 to left out and ST1 to right out, then pop
;;-------------------------------------------------------------------------------
(func $su_op_out (param $stereo i32) (local $ptr i32)
(local.set $ptr (i32.const 544)) ;; synth.left
(f32.store (local.get $ptr)
(f32.add
(f32.mul
(call $pop)
(call $input (i32.const 0))
)
(f32.load (local.get $ptr))
)
)
(local.set $ptr (i32.const 548)) ;; synth.right, note that ATM does not seem to support mono ocpode at all
(f32.store (local.get $ptr)
(f32.add
(f32.mul
(call $pop)
(call $input (i32.const 0))
)
(f32.load (local.get $ptr))
)
)
)
;;-------------------------------------------------------------------------------
;; $input returns the float value of a transformed to 0.0 - 1.0f range.
;; The transformed values start at 512 (TODO: change magic constants somehow)
;;-------------------------------------------------------------------------------
(func $input (param $inputNumber i32) (result f32)
(f32.load offset=384 (i32.mul (local.get $inputNumber) (i32.const 4)))
)
;;-------------------------------------------------------------------------------
;; $inputSigned returns the float value of a transformed to -1.0 - 1.0f range.
;;-------------------------------------------------------------------------------
(func $inputSigned (param $inputNumber i32) (result f32)
(f32.sub (f32.mul (call $input (local.get $inputNumber)) (f32.const 2)) (f32.const 1))
)
;;-------------------------------------------------------------------------------
;; $nonLinearMap: x -> 2^(-24*input[x])
;;-------------------------------------------------------------------------------
(func $nonLinearMap (param $value i32) (result f32)
(call $pow2
(f32.mul
(f32.const -24)
(call $input (local.get $value))
)
)
)
;;-------------------------------------------------------------------------------
;; $pow2: x -> 2^x
;;-------------------------------------------------------------------------------
(func $pow2 (param $value f32) (result f32)
(call $pow (f32.const 2) (local.get $value))
)
;;-------------------------------------------------------------------------------
;; Waveshaper(x,a): "distorts" signal x by amount a
;; Returns x*a/(1-a+(2*a-1)*abs(x))
;;-------------------------------------------------------------------------------
(func $waveshaper (param $signal f32) (param $amount f32) (result f32)
(local.set $signal (call $clip (local.get $signal)))
(f32.mul
(local.get $signal)
(f32.div
(local.get $amount)
(f32.add
(f32.const 1)
(f32.sub
(f32.mul
(f32.sub
(f32.add (local.get $amount) (local.get $amount))
(f32.const 1)
)
(f32.abs (local.get $signal))
)
(local.get $amount)
)
)
)
)
)
;;-------------------------------------------------------------------------------
;; Clip(a : f32) returns min(max(a,-1),1)
;;-------------------------------------------------------------------------------
(func $clip (param $value f32) (result f32)
(f32.min (f32.max (local.get $value) (f32.const -1.0)) (f32.const 1.0))
)
(func $stereoHelper (param $stereo i32) (param $tableIndex i32)
(if (local.get $stereo)(then
(call $pop)
(global.set $WRK (i32.add (global.get $WRK) (i32.const 16)))
(call_indirect (type $opcode_func_signature) (i32.const 0) (local.get $tableIndex))
(global.set $WRK (i32.sub (global.get $WRK) (i32.const 16)))
(call $push)
))
)
;;-------------------------------------------------------------------------------
;; The opcode table jump table. This is constructed to only include the opcodes
;; that are used so that the jump table is as small as possible.
;;-------------------------------------------------------------------------------
(table 5 funcref)
(elem (i32.const 1) ;; start the indices at 1, as 0 is reserved for advance
$su_op_envelope
$su_op_oscillator
$su_op_mulp
$su_op_out
)
;; All data is collected into a byte buffer and emitted at once
(data (i32.const 0) "\40\00\00\00\44\00\00\00\42\00\00\00\45\00\00\00\00\44\00\00\47\00\00\00\45\00\00\00\49\00\00\00\00\00\47\00\4b\00\00\00\49\00\00\00\4c\00\00\00\00\01\02\02\02\04\04\07\09\00\40\40\40\40\20\40\40\40\40\20\58\40\00\80\40\80\40\58\40\00\80\40\80\40\80\05\06\00\01")
;;(data (i32.const 8388610) "\52\49\46\46\b2\eb\0c\20\57\41\56\45\66\6d\74\20\12\20\20\20\03\20\02\20\44\ac\20\20\20\62\05\20\08\20\20\20\20\20\66\61\63\74\04\20\20\20\e0\3a\03\20\64\61\74\61\80\eb\0c\20")
) ;; END MODULE