The Trunk: Sound-eem.75.mcz

Eliot Miranda uploaded a new version of Sound to project The Trunk:
http://source.squeak.org/trunk/Sound-eem.75.mcz

==================== Summary ====================

Name: Sound-eem.75
Author: eem
Time: 22 September 2020, 11:47:06.322437 am
UUID: a4d7e0e8-269c-432f-ac18-25d2d7d1ff44
Ancestors: Sound-eem.74

In deference to strong opinions voice on squeak-dev reimplement teh 64-bit alternative for SampledSound>>mixSampleCount:into:startingAt:leftVol:rightVol:, and consequently fix a non-obvious regression in the 64-bit alternative.

=============== Diff against Sound-eem.74 ===============

Item was changed:
  ----- Method: AbstractSound class>>translatedPrimitives (in category 'primitive generation') -----
  translatedPrimitives
  ^#(
  (FMSound mixSampleCount:into:startingAt:leftVol:rightVol:)
  (PluckedSound mixSampleCount:into:startingAt:leftVol:rightVol:)
  (LoopedSampledSound mixSampleCount:into:startingAt:leftVol:rightVol:)
  (SampledSound mixSampleCount:into:startingAt:leftVol:rightVol:)
- (SampledSound _64bitMixSampleCount:into:startingAt:leftVol:rightVol:)
  (ReverbSound applyReverbTo:startingAt:count:)
  ).
  !

Item was removed:
- ----- Method: SampledSound>>_64bitMixSampleCount:into:startingAt:leftVol:rightVol: (in category 'playing') -----
- _64bitMixSampleCount: n into: aSoundBuffer startingAt: startIndex leftVol: leftVol rightVol: rightVol
- "Mix the given number of samples with the samples already in the given buffer starting at the given index.
- Assume that the buffer size is at least (index + count) - 1."
-
- | lastIndex outIndex sampleIndex sample i s |
- <inline: #always>
- <var: #aSoundBuffer type: #'short int *'>
- <var: #samples type: #'short int *'>
-
- lastIndex := (startIndex + n) - 1.
- outIndex := startIndex.    "index of next stereo output sample pair"
- sampleIndex := indexHighBits + (scaledIndex >> IncrementFractionBits).
- [(sampleIndex <= samplesSize) and: [outIndex <= lastIndex]] whileTrue:
- [sample := ((samples at: sampleIndex) * scaledVol) // ScaleFactor.
- leftVol > 0 ifTrue:
- [i := (2 * outIndex) - 1.
- s := (aSoundBuffer at: i) + ((sample * leftVol) // ScaleFactor).
- s >  32767 ifTrue: [s :=  32767].  "clipping!!"
- s < -32767 ifTrue: [s := -32767].  "clipping!!"
- aSoundBuffer at: i put: s].
- rightVol > 0 ifTrue:
- [i := 2 * outIndex.
- s := (aSoundBuffer at: i) + ((sample * rightVol) // ScaleFactor).
- s >  32767 ifTrue: [s :=  32767].  "clipping!!"
- s < -32767 ifTrue: [s := -32767].  "clipping!!"
- aSoundBuffer at: i put: s].
-
- scaledVolIncr ~= 0 ifTrue:
- [scaledVol := scaledVol + scaledVolIncr.
- ((scaledVolIncr > 0 and: [scaledVol >= scaledVolLimit]) or:
- [scaledVolIncr < 0 and: [scaledVol <= scaledVolLimit]])
- ifTrue:  "reached the limit; stop incrementing"
- [scaledVol := scaledVolLimit.
- scaledVolIncr := 0]].
-
- scaledIndex := scaledIndex + scaledIncrement.
-
- sampleIndex := indexHighBits + (scaledIndex >> IncrementFractionBits).
- outIndex := outIndex + 1].
- count := count - n
- !

Item was changed:
  ----- Method: SampledSound>>mixSampleCount:into:startingAt:leftVol:rightVol: (in category 'playing') -----
  mixSampleCount: n into: aSoundBuffer startingAt: startIndex leftVol: leftVol rightVol: rightVol
  "Mix the given number of samples with the samples already in the given buffer starting at the given index.
  Assume that the buffer size is at least (index + count) - 1."
 
  | lastIndex outIndex sampleIndex sample i s overflow |
  <primitive:'primitiveMixSampledSound' module: 'SoundGenerationPlugin'>
  <var: #aSoundBuffer type: #'short int *'>
  <var: #samples type: #'short int *'>
 
+ lastIndex := startIndex + n - 1.
- SmallInteger maxVal > 16r3FFFFFFF ifTrue: "In 64-bits we don't have to worry about 2^15 * 2^15 overflow"
- [^self _64bitMixSampleCount: n into: aSoundBuffer startingAt: startIndex leftVol: leftVol rightVol: rightVol].
- lastIndex := (startIndex + n) - 1.
  outIndex := startIndex.    "index of next stereo output sample pair"
  sampleIndex := indexHighBits + (scaledIndex >> IncrementFractionBits).
+ [sampleIndex <= samplesSize and: [outIndex <= lastIndex]] whileTrue:
+ [sample := (samples at: sampleIndex) * scaledVol // ScaleFactor.
+ leftVol > 0 ifTrue:
+ [i := 2 * outIndex - 1.
+ s := (aSoundBuffer at: i) + (sample * leftVol // ScaleFactor).
+ "clip the result!!!!"
+ aSoundBuffer at: i put: (s > 32767 ifTrue: [32767] ifFalse: [s < -32767 ifTrue: [-32767] ifFalse: [s]])].
+ rightVol > 0 ifTrue:
+ [i := 2 * outIndex.
+ s := (aSoundBuffer at: i) + (sample * rightVol // ScaleFactor).
+ "clip the result!!!!"
+ aSoundBuffer at: i put: (s > 32767 ifTrue: [32767] ifFalse: [s < -32767 ifTrue: [-32767] ifFalse: [s]])].
- [(sampleIndex <= samplesSize) and: [outIndex <= lastIndex]] whileTrue: [
- sample := ((samples at: sampleIndex) * scaledVol) // ScaleFactor.
- leftVol > 0 ifTrue: [
- i := (2 * outIndex) - 1.
- s := (aSoundBuffer at: i) + ((sample * leftVol) // ScaleFactor).
- s >  32767 ifTrue: [s :=  32767].  "clipping!!"
- s < -32767 ifTrue: [s := -32767].  "clipping!!"
- aSoundBuffer at: i put: s].
- rightVol > 0 ifTrue: [
- i := 2 * outIndex.
- s := (aSoundBuffer at: i) + ((sample * rightVol) // ScaleFactor).
- s >  32767 ifTrue: [s :=  32767].  "clipping!!"
- s < -32767 ifTrue: [s := -32767].  "clipping!!"
- aSoundBuffer at: i put: s].
 
+ scaledVolIncr ~= 0 ifTrue:
+ [scaledVol := scaledVol + scaledVolIncr.
+ (scaledVolIncr > 0
+ ifTrue: [scaledVol >= scaledVolLimit]
+ ifFalse: [scaledVol <= scaledVolLimit])
+ ifTrue:  "reached the limit; stop incrementing"
+ [scaledVol := scaledVolLimit.
- scaledVolIncr ~= 0 ifTrue: [
- scaledVol := scaledVol + scaledVolIncr.
- ((scaledVolIncr > 0 and: [scaledVol >= scaledVolLimit]) or:
- [scaledVolIncr < 0 and: [scaledVol <= scaledVolLimit]])
- ifTrue: [  "reached the limit; stop incrementing"
- scaledVol := scaledVolLimit.
  scaledVolIncr := 0]].
 
  scaledIndex := scaledIndex + scaledIncrement.
+ "In 64-bits we don't have to worry about scaled indexes overflowing,
+ and in the primitive this is guard evaluated at compile time."
+ (SmallInteger maxVal <= 16r3FFFFFFF
+ and: [scaledIndex >= ScaledIndexOverflow]) ifTrue:
+ [overflow := scaledIndex >> IncrementFractionBits.
- scaledIndex >= ScaledIndexOverflow ifTrue: [
- overflow := scaledIndex >> IncrementFractionBits.
  indexHighBits := indexHighBits + overflow.
  scaledIndex := scaledIndex - (overflow << IncrementFractionBits)].
 
  sampleIndex := indexHighBits + (scaledIndex >> IncrementFractionBits).
  outIndex := outIndex + 1].
+ "But we still have to update indexHighBits and scaledIndex correctly outside the loop..."
+ SmallInteger maxVal > 16r3FFFFFFF ifTrue:
+ [overflow := scaledIndex >> IncrementFractionBits.
+ indexHighBits := indexHighBits + overflow.
+ scaledIndex := scaledIndex - (overflow << IncrementFractionBits)].
  count := count - n!