SoftSynth.bi

'-----------------------------------------------------------------------------------------------------------------------
' Simple floatimg-point stereo PCM software synthesizer
' Copyright (c) 2024 Samuel Gomes
'-----------------------------------------------------------------------------------------------------------------------

$INCLUDEONCE

'$INCLUDE:'Common.bi'
'$INCLUDE:'Types.bi'
'$INCLUDE:'Math/Math.bi'
'$INCLUDE:'PointerOps.bi'

CONST SOFTSYNTH_VOICE_PLAY_FORWARD = 0 ' single-shot forward playback
CONST SOFTSYNTH_VOICE_PLAY_FORWARD_LOOP = 1 ' forward-looping playback
CONST SOFTSYNTH_VOICE_VOLUME_MAX! = 1! ' this is the maximum volume of any sample
CONST SOFTSYNTH_VOICE_PAN_LEFT! = -1! ' leftmost pannning position
CONST SOFTSYNTH_VOICE_PAN_RIGHT! = 1! ' rightmost pannning position
CONST SOFTSYNTH_GLOBAL_VOLUME_MAX! = 1! ' max global volume
CONST SOFTSYNTH_MASTER_VOLUME_MAX! = 1! ' max master volume
CONST SOFTSYNTH_SOUND_BUFFER_CHANNELS = 2 ' 2 channels (stereo)
CONST SOFTSYNTH_SOUND_BUFFER_SAMPLE_SIZE = _SIZE_OF_SINGLE ' 4 bytes (32-bits floating point)
CONST SOFTSYNTH_SOUND_BUFFER_FRAME_SIZE = SOFTSYNTH_SOUND_BUFFER_SAMPLE_SIZE * SOFTSYNTH_SOUND_BUFFER_CHANNELS
CONST SOFTSYNTH_SOUND_BUFFER_TIME_DEFAULT! = 0.05! ' we will check that we have this amount of time left in the playback buffer

TYPE __SoftSynthType
    soundBufferFrames AS _UNSIGNED LONG ' size of the render buffer in frames
    soundBufferSamples AS _UNSIGNED LONG ' size of the render buffer in samples
    soundBufferBytes AS _UNSIGNED LONG ' size of the render buffer in bytes
    soundMasterVolume AS SINGLE ' the master volume of the QB64 sound pipe
    soundHandle AS LONG ' QB64 sound pipe that we will use to stream the mixed audio
END TYPE

DECLARE LIBRARY "SoftSynth"
    FUNCTION SoftSynth_BytesToFrames~& (BYVAL bytes AS _UNSIGNED LONG, BYVAL bytesPerSample AS _UNSIGNED _BYTE, BYVAL channels AS _UNSIGNED _BYTE)
    FUNCTION __SoftSynth_Initialize%% (BYVAL sampleRate AS _UNSIGNED LONG)
    SUB __SoftSynth_Finalize
    FUNCTION SoftSynth_IsInitialized%%
    SUB __SoftSynth_Update (buffer AS SINGLE, BYVAL frames AS _UNSIGNED LONG)
    SUB SoftSynth_SetVoiceVolume (BYVAL voice AS _UNSIGNED LONG, BYVAL volume AS SINGLE)
    FUNCTION SoftSynth_GetVoiceVolume! (BYVAL voice AS _UNSIGNED LONG)
    SUB SoftSynth_SetVoiceBalance (BYVAL voice AS _UNSIGNED LONG, BYVAL balance AS SINGLE)
    FUNCTION SoftSynth_GetVoiceBalance! (BYVAL voice AS _UNSIGNED LONG)
    SUB SoftSynth_SetVoiceFrequency (BYVAL voice AS _UNSIGNED LONG, BYVAL frequency AS _UNSIGNED LONG)
    FUNCTION SoftSynth_GetVoiceFrequency~& (BYVAL voice AS _UNSIGNED LONG)
    SUB SoftSynth_StopVoice (BYVAL voice AS _UNSIGNED LONG)
    SUB SoftSynth_PlayVoice (BYVAL voice AS _UNSIGNED LONG, BYVAL snd AS LONG, BYVAL position AS _UNSIGNED LONG, BYVAL mode AS LONG, BYVAL startFrame AS _UNSIGNED LONG, BYVAL endFrame AS _UNSIGNED LONG)
    SUB SoftSynth_SetGlobalVolume (BYVAL volume AS SINGLE)
    FUNCTION SoftSynth_GetGlobalVolume!
    FUNCTION SoftSynth_GetSampleRate~&
    FUNCTION SoftSynth_GetTotalSounds~&
    FUNCTION SoftSynth_GetTotalVoices~&
    SUB SoftSynth_SetTotalVoices (BYVAL voices AS _UNSIGNED LONG)
    FUNCTION SoftSynth_GetActiveVoices~&
    SUB __SoftSynth_LoadSound (BYVAL snd AS LONG, buffer AS STRING, BYVAL bytes AS _UNSIGNED LONG, BYVAL bytesPerSample AS _UNSIGNED _BYTE, BYVAL channels AS _UNSIGNED _BYTE)
    FUNCTION SoftSynth_PeekSoundFrameSingle! (BYVAL snd AS LONG, BYVAL position AS _UNSIGNED LONG)
    SUB SoftSynth_PokeSoundFrameSingle (BYVAL snd AS LONG, BYVAL position AS _UNSIGNED LONG, BYVAL frame AS SINGLE)
    FUNCTION SoftSynth_PeekSoundFrameInteger% (BYVAL snd AS LONG, BYVAL position AS _UNSIGNED LONG)
    SUB SoftSynth_PokeSoundFrameInteger (BYVAL snd AS LONG, BYVAL position AS _UNSIGNED LONG, BYVAL frame AS INTEGER)
    FUNCTION SoftSynth_PeekSoundFrameByte%% (BYVAL snd AS LONG, BYVAL position AS _UNSIGNED LONG)
    SUB SoftSynth_PokeSoundFrameByte (BYVAL snd AS LONG, BYVAL position AS _UNSIGNED LONG, BYVAL frame AS _BYTE)
END DECLARE

DIM __SoftSynth AS __SoftSynthType ' holds the softsynth state
REDIM __SoftSynth_SoundBuffer(0 TO 0) AS SINGLE ' mixer buffer (stereo interleaved)