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iss_m68k.pas
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{
Copyright (c) 1998-2001,2014 Karoly Balogh <[email protected]>
Permission to use, copy, modify, and/or distribute this software for
any purpose with or without fee is hereby granted, provided that the
above copyright notice and this permission notice appear in all copies.
THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL
WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL
THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR
CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
}
{ * ISS_MIX .PAS - Software mixer for non-wavetable devices }
{ OS - Platform Independent }
{ CPU - Motorola 680x0 }
{ * NOTE: The code contained by this unit is in ALPHA stage. May and WILL }
{ change without warning. Make sure your own software don't rely }
{ on this code. }
{$INCLUDE ISS_SET.INC}
{$WARNINGS ON}
{$MODE FPC}
Unit ISS_Mix;
Interface
Uses ISS_Var;
Type ISS_TMixChannel = Record
MixSmpPtr : ISS_PSample;
MixSmpPos : DWord; { * Current sample position * }
MixSmpRate : DWord;
MixSmpHighStep : DWord;
MixSmpLowStep : DWord;
MixSmpInc : DWord;
MixSmpPan : Word;
MixSmpVol : Word;
MixSmpVolL : Word;
MixSmpVolR : Word;
MixSmpEnd : DWord;
MixDebug : DWord;
End;
ISS_TMixer = Record
MixRate : DWord; { * Mixing rate * }
MixBufSize : DWord; { * Mixing buffer size * }
MixBufCount : DWord; { * Current bufferpos counter * }
MixBufPtr : Pointer; { * Address of the buffer * }
MixLenPos : DWord; { * Current position between the syscalls * }
MixBufOffs : DWord; { * Mixer targetbuffer offset * }
MixBufSel : Word; { * Mixer targetbuffer selector * }
MixBufType : Word; { * Mixer targetbuffer type * }
MixRevStereo : Boolean; { * Reversing stereo * }
{ * Independent data for each channel * }
MixChannels : Array[0..ISS_MaxSSChannels-1] Of ISS_TMixChannel;
End;
ISS_PMixer = ^ISS_TMixer;
Var ISS_MixerData : ISS_PMixer;
ISS_MixerOK : Boolean;
ISS_MixVolTab : Array[0..64,0..255] Of Word;
Function ISS_MixerInit(MixFreq : DWord; BufSize : DWord;
TSelector : Word; TOffset : DWord;
Mode : Word) : Boolean;
Function ISS_MixerDone : Boolean;
Function ISS_MixerLoadSample(SStruc : ISS_PSample) : Boolean;
Function ISS_MixerFreeSample(SStruc : ISS_PSample) : Boolean;
Procedure ISS_MixerUpdateOutput;
Implementation
Procedure MixCalcVolumeTable;
Var Counter,Counter2 : DWord;
Begin
For Counter:=0 To 64 Do Begin
For Counter2:=0 To 255 Do Begin
ISS_MixVolTab[Counter,Counter2]:=((Counter2 Shl 8)*Counter) Div 64;
End;
End;
End;
Function ISS_MixerInit(MixFreq : DWord; BufSize : DWord;
TSelector : Word; TOffset : DWord;
Mode : Word) : Boolean;
Begin
ISS_MixerInit:=False;
If ISS_MixerOK Then Exit;
New(ISS_MixerData);
FillChar(ISS_MixerData^,SizeOf(ISS_TMixer),#0);
With ISS_MixerData^ Do Begin
MixRate:=MixFreq;
MixBufSize:=BufSize;
{ * Allocating Memory for mixer buffer * }
GetMem(MixBufPtr,MixBufSize*8);
MixBufOffs:=TOffset;
MixBufSel:=TSelector;
MixBufType:=Mode;
End;
MixCalcVolumeTable;
ISS_MixerOK:=True;
ISS_MixerInit:=True;
End;
Function ISS_MixerDone : Boolean;
Begin
ISS_MixerDone:=False;
If Not ISS_MixerOK Then Exit;
With ISS_MixerData^ Do Begin
{ * Freeing up memory for mixer buffer * }
FreeMem(MixBufPtr,MixBufSize*8);
End;
Dispose(ISS_MixerData);
ISS_MixerOK:=False;
ISS_MixerDone:=True;
End;
Function ISS_MixerLoadSample(SStruc : ISS_PSample) : Boolean;
Type PByte = ^Byte;
PInteger = ^Integer;
Var SmpRealLength : DWord;
SmpLoopLength : DWord;
SmpPointer : Pointer;
Counter : DWord;
Begin
ISS_MixerLoadSample:=False;
With SStruc^ Do Begin
{ * Unrolling bidirectional loops, so main mixing routine will be * }
{ * much simpler (and faster) * }
If (SType And (ISS_SmpPingPongLoop-ISS_SmpForwardLoop))>0 Then Begin
{ * Calculating unrolled sample size * }
SmpLoopLength:=SLoopEnd-SLoopStart;
SmpRealLength:=SLoopEnd+SmpLoopLength;
{ * Allocating memory * }
GetMem(SmpPointer,SmpRealLength); If SmpPointer=Nil Then Exit;
{ * Unrolling loop * }
If (SType And ISS_Smp16BitData)>0 Then Begin
For Counter:=0 To (SLoopEnd Div 2)-1 Do Begin
PInteger(SmpPointer)[Counter]:=PInteger(SData)[Counter];
End;
For Counter:=0 To (SmpLoopLength Div 2)-1 Do Begin
PInteger(SmpPointer)[(SLoopEnd Div 2)+Counter]:=PInteger(SData)[(SLoopEnd Div 2)-Counter];
End;
End Else Begin
For Counter:=0 To SLoopEnd-1 Do Begin
PByte(SmpPointer)[Counter]:=PByte(SData)[Counter];
End;
For Counter:=0 To SmpLoopLength-1 Do Begin
PByte(SmpPointer)[SLoopEnd+Counter]:=PByte(SData)[SLoopEnd-Counter];
End;
End;
{ * Converting loop values * }
SLoopEnd:=SLoopEnd+SmpLoopLength;
{ * When unrolling is done, we assign the samplepointer * }
SDRAMOffs:=DWord(SmpPointer);
End Else Begin
{ * If there is no bidi loop, it's not needed to unroll the sampledata * }
{ * so we simply assign the pointer * }
SDRAMOffs:=DWord(SData);
End;
End;
ISS_MixerLoadSample:=True;
End;
Function ISS_MixerFreeSample(SStruc : ISS_PSample) : Boolean;
Var SmpRealLength : DWord;
SmpLoopLength : DWord;
SmpPointer : Pointer;
Begin
ISS_MixerFreeSample:=False;
With SStruc^ Do Begin
{ * We only free up the samples with unrolled loops * }
If (SType And (ISS_SmpPingPongLoop-ISS_SmpForwardLoop))>0 Then Begin
{ * Calculating rolled sample size * }
SmpLoopLength:=SLoopEnd-SLoopStart;
SmpLoopLength:=SmpLoopLength Div 2;
SLoopEnd:=SLoopStart+SmpLoopLength;
SmpRealLength:=SLoopEnd+SmpLoopLength;
DWord(SmpPointer):=SDRAMOffs;
SDRAMOffs:=0;
If SmpPointer=Nil Then Exit;
{ * Deallocating memory * }
FreeMem(SmpPointer,SmpRealLength);
End;
End;
ISS_MixerFreeSample:=True;
End;
{ * >>> A D D I T I O N A L M I X I N G F U N C T I O N S * <<< }
Procedure ISS_MixerClearBuffer(OutputType : Word); Assembler;
Asm
move.l ISS_MixerData,a0
move.l 12(a0),a1
move.l 4(a0),d1
moveq.l #0,d0
move.w OutputType,d0
andi.l #ISS_DevStereo,d0
beq @NotStereo
lsl.l #1,d1
@NotStereo:
moveq.l #0,d0
@ClearLoop:
move.l d0,(a1)+
move.l d0,(a1)+
move.l d0,(a1)+
move.l d0,(a1)+
subq.l #4,d1
bne @ClearLoop
End;
{ * Possible buffer conversions * }
{ * 16bit signed -> 16bit signed (no conversion) * }
{ * 16bit signed -> 8bit signed * }
{ * 16bit signed -> 8bit unsigned * }
Procedure ISS_MixerMakeClip(OutputType : Word); Assembler;
Asm
move.l ISS_MixerData,a0
move.l 4(a0),d7 { MixBufSize }
move.l 12(a0),a1 { MixBufPtr }
move.l 20(a0),a2 { MixBufOffs }
moveq #0,d0
move.w OutputType,d0
move.l d0,d1
andi.l #ISS_DevStereo,d1
beq @NotStereo
lsl.l #1,d7
@NotStereo:
move.l #$00008000,d5
move.l #$FFFF8000,d6
moveq.l #0,d4
move.l d0,d1
andi.l #ISS_Dev16Bit,d1
beq @Dev8Bit
@LoopHead16Bit: { * 16bit signed -> 16bit signed * }
move.l (a1)+,d1
move.l (a1)+,d2
asr.l #1,d1
asr.l #1,d2
add.l d4,d1 { Noise reduction code! }
move.b d1,d4
asr.l #8,d1
add.l d4,d2
move.b d2,d4
asr.l #8,d2
move.l d1,d0
move.l d2,d3
ext.l d0
ext.l d3
cmp.l d0,d1
beq @CheckOk16_01
and.l d5,d1
sne d1
extb.l d1
eor.l d6,d1
@CheckOk16_01:
cmp.l d3,d2
beq @CheckOk16_02
and.l d5,d2
sne d2
extb.l d2
eor.l d6,d2
@CheckOk16_02:
ror.w #8,d1
ror.w #8,d2
swap d1
move.w d2,d1
move.l d1,(a2)+
subq.l #2,d7
bne @LoopHead16Bit
bra @Exit
@Dev8Bit:
move.l d0,d1
andi.l #ISS_DevSigned,d1
beq @LoopHead8BitUnsigned
@LoopHead8BitSigned:
move.l (a1)+,d1
move.l (a1)+,d2
asr.l #1,d1
asr.l #1,d2
add.l d4,d1 { Noise reduction code! }
move.b d1,d4
asr.l #8,d1
add.l d4,d2
move.b d2,d4
asr.l #8,d2
move.l d1,d0
move.l d2,d3
ext.l d0
ext.l d3
cmp.l d0,d1
beq @CheckOk8S_01
and.l d5,d1
sne d1
extb.l d1
eor.l d6,d1
@CheckOk8S_01:
cmp.l d3,d2
beq @CheckOk8S_02
and.l d5,d2
sne d2
extb.l d2
eor.l d6,d2
@CheckOk8S_02:
lsr.l #8,d2
move.b d2,d1
swap d1
move.l d1,a3 { !!! Store previous word... }
move.l (a1)+,d1
move.l (a1)+,d2
asr.l #1,d1
asr.l #1,d2
add.l d4,d1 { Noise reduction code! }
move.b d1,d4
asr.l #8,d1
add.l d4,d2
move.b d2,d4
asr.l #8,d2
move.l d1,d0
move.l d2,d3
ext.l d0
ext.l d3
cmp.l d0,d1
beq @CheckOk8S_03
and.l d5,d1
sne d1
extb.l d1
eor.l d6,d1
@CheckOk8S_03:
cmp.l d3,d2
beq @CheckOk8S_04
and.l d5,d2
sne d2
extb.l d2
eor.l d6,d2
@CheckOk8S_04:
lsr.l #8,d2
move.l a3,d0
move.b d2,d1
move.w d1,d0
move.l d0,(a2)+
subq.l #4,d7
bne @LoopHead8BitSigned
bra @Exit
@LoopHead8BitUnsigned:
move.l (a1)+,d1
move.l (a1)+,d2
asr.l #1,d1
asr.l #1,d2
add.l d4,d1 { Noise reduction code! }
move.b d1,d4
asr.l #8,d1
add.l d4,d2
move.b d2,d4
asr.l #8,d2
move.l d1,d0
move.l d2,d3
ext.l d0
ext.l d3
cmp.l d0,d1
beq @CheckOk8US_01
and.l d5,d1
sne d1
extb.l d1
eor.l d6,d1
@CheckOk8US_01:
cmp.l d3,d2
beq @CheckOk8US_02
and.l d5,d2
sne d2
extb.l d2
eor.l d6,d2
@CheckOk8US_02:
lsr.l #8,d2
add.w #$8000,d1
add.b #128,d2
move.b d2,d1
swap d1
move.l d1,a3 { !!! Store previous word... }
move.l (a1)+,d1
move.l (a1)+,d2
asr.l #1,d1
asr.l #1,d2
add.l d4,d1 { Noise reduction code! }
move.b d1,d4
asr.l #8,d1
add.l d4,d2
move.b d2,d4
asr.l #8,d2
move.l d1,d0
move.l d2,d3
ext.l d0
ext.l d3
cmp.l d0,d1
beq @CheckOk8US_03
and.l d5,d1
sne d1
extb.l d1
eor.l d6,d1
@CheckOk8US_03:
cmp.l d3,d2
beq @CheckOk8US_04
and.l d5,d2
sne d2
extb.l d2
eor.l d6,d2
@CheckOk8US_04:
lsr.l #8,d2
add.w #$8000,d1
add.b #128,d2
move.l a3,d0
move.b d2,d1
move.w d1,d0
move.l d0,(a2)+
subq.l #4,d7
bne @LoopHead8BitUnsigned
@Exit:
End;
{ * >>> S T E R E O M I X I N G F U N C T I O N S <<< * }
{ * Mixes a 8bit sample into a stereo buffer * }
Function MixChannel8BitSampleSTEREO(MChIndexPtr : Pointer) : DWord; Assembler;
Asm
move.l MChIndexPtr,a0
move.l (a0),a1 { * a1 = MixSmpPtr * }
move.l 48(a1),a2 { * SDRAMOffs * }
move.l ISS_MixerData,a3
move.l 12(a3),a4 { * a4 = MixBufPtr * }
move.l 4(a0),d2 { * MixSmpPos * }
move.l 20(a0),d6 { * MixSmpInc * }
move.l 12(a0),d3 { * MixSmpHighStep * }
move.l 16(a0),d5 { * MixSmpLowStep * }
move.l 4(a3),d7 { 680x0 mixer uses d7 register as MixCounter instead of a variable }
move.l d5,d0 { * MixSmpLowStep * }
move.l d3,d1 { * MixSmpHighStep * }
mulu.l d7,d0
swap d1
mulu.l d7,d1
add.l d0,d1
add.l d6,d1
move.l d1,d0
lsr.l #8,d1
lsr.l #8,d1
add.l d2,d1
cmp.l 32(a0),d1
ble @NoChk
@LoopHead:
{ * Getting out samplevalue * }
move.b (a2,d2),d0
extb.l d0
asl.l #8,d0
{ * Mix sample with volume * }
move.w 28(a0),d1 { * MixSmpVolL * }
muls.w d0,d1
move.w 30(a0),d4 { * MixSmpVolR * }
muls.w d0,d4
{ * Adding current sample value to buffer position * }
add.l d1,(a4)+
add.l d4,(a4)+
{ * Calculating stepping rate step two * }
{ * Getting the real step value from the fixedpoint rate * }
{ * calculated previously * }
add.w d5,d6 { * MixSmpLowStep * }
addx.l d3,d2 { * Increasing sample position /w MixSmpHighStep + Carry * }
{ * Checking sample limits * }
cmp.l 32(a0),d2 { * MixSmpEnd * }
blt @SmpOk
move.b 38(a1),d1 { * SType * }
andi.b #ISS_SmpPingPongLoop,d1
beq @SmpEnd
move.l 28(a1),d2 { * SLoopStart * }
bra @SmpOk
@SmpEnd:
move.l 24(a1),d2 { * SLength * }
move.l #$10000,d0
bra @LoopExit
@SmpOk:
subq.l #1,d7
bne @LoopHead
bra @LoopExit
@NoChk:
{ * Checking for zero volume * }
move.w 28(a0),d1
move.w 30(a0),d4
add.w d1,d4
bne @NoChkLoopHead
andi.l #$0000FFFF,d0
move.l d1,d2
move.l d0,d6
bra @LoopExit
@NoChkLoopHead:
{ * Getting out samplevalue * }
move.b (a2,d2),d0
extb.l d0
asl.l #8,d0
{ * Mix sample with volume * }
move.w 28(a0),d1 { * MixSmpVolL * }
muls.w d0,d1
move.w 30(a0),d4 { * MixSmpVolR * }
muls.w d0,d4
{ * Adding current sample value to buffer position * }
add.l d1,(a4)+
add.l d4,(a4)+
{ * Calculating stepping rate step two * }
{ * Getting the real step value from the fixedpoint rate * }
{ * calculated previously * }
add.w d5,d6 { * MixSmpLowStep * }
addx.l d3,d2 { * Increasing sample position /w MixSmpHighStep + Carry * }
{ * No need for checking sample limits here... * }
subq.l #1,d7
bne @NoChkLoopHead
@LoopExit:
{ * Moving new sample pos into the record * }
move.l d6,20(a0) { * MixSmpInc * }
move.l d2,4(a0) { * MixSmpPos * }
End;
{ * Mixes a 16bit sample into a stereo buffer * }
Function MixChannel16BitSampleSTEREO(MChIndexPtr : Pointer) : DWord; Assembler;
Asm
move.l MChIndexPtr,a0
move.l (a0),a1 { * a1 = MixSmpPtr * }
move.l 48(a1),a2 { * SDRAMOffs * }
move.l ISS_MixerData,a3
move.l 12(a3),a4 { * a4 = MixBufPtr * }
move.l 4(a0),d2 { * MixSmpPos * }
move.l 20(a0),d6 { * MixSmpInc * }
move.l 12(a0),d3 { * MixSmpHighStep * }
move.l 16(a0),d5 { * MixSmpLowStep * }
move.l 4(a3),d7 { 680x0 mixer uses d7 register as MixCounter instead of a variable }
move.l d5,d0 { * MixSmpLowStep * }
move.l d3,d1 { * MixSmpHighStep * }
mulu.l d7,d0
swap d1
mulu.l d7,d1
add.l d0,d1
add.l d6,d1
move.l d1,d0
lsr.l #8,d1
lsr.l #8,d1
add.l d2,d1
lsl.l #1,d1
cmp.l 32(a0),d1
ble @NoChk
@LoopHead:
{ * Getting out samplevalue * }
move.w (a2,d2),d0
ext.l d0
{ * Mix sample with volume * }
move.w 28(a0),d1 { * MixSmpVolL * }
muls.w d0,d1
move.w 30(a0),d4 { * MixSmpVolR * }
muls.w d0,d4
{ * Adding current sample value to buffer position * }
add.l d1,(a4)+
add.l d4,(a4)+
{ * Calculating stepping rate step two * }
{ * Getting the real step value from the fixedpoint rate * }
{ * calculated previously * }
moveq.l #0,d0
add.w d5,d6 { * MixSmpLowStep * }
addx.l d3,d0 { * MixSmpHighStep + Carry * }
lsl.l #1,d0
{ * Increasing sample position * }
add.l d0,d2
{ * Checking sample limits * }
cmp.l 32(a0),d2 { * MixSmpEnd * }
blt @SmpOk
move.b 38(a1),d1 { * SType * }
andi.b #ISS_SmpPingPongLoop,d1
beq @SmpEnd
move.l 28(a1),d2 { * SLoopStart * }
bra @SmpOk
@SmpEnd:
move.l 24(a1),d2 { * SLength * }
move.l #$10000,d0
bra @LoopExit
@SmpOk:
subq.l #1,d7
bne @LoopHead
bra @LoopExit
@NoChk:
{ * Checking for zero volume * }
move.w 28(a0),d1
move.w 30(a0),d4
add.w d1,d4
bne @NoChkLoopHead
andi.l #$0000FFFF,d0
move.l d1,d2
move.l d0,d6
bra @LoopExit
@NoChkLoopHead:
{ * Getting out samplevalue * }
move.w (a2,d2),d0
ext.l d0
{ * Mix sample with volume * }
move.w 28(a0),d1 { * MixSmpVolL * }
muls.w d0,d1
move.w 30(a0),d4 { * MixSmpVolR * }
muls.w d0,d4
{ * Adding current sample value to buffer position * }
add.l d1,(a4)+
add.l d4,(a4)+
{ * Calculating stepping rate step two * }
{ * Getting the real step value from the fixedpoint rate * }
{ * calculated previously * }
moveq.l #0,d0
add.w d5,d6 { * MixSmpLowStep * }
addx.l d3,d0 { * MixSmpHighStep + Carry * }
lsl.l #1,d0
{ * Increasing sample position * }
add.l d0,d2
{ * No need for checking sample limits here... * }
subq.l #1,d7
bne @NoChkLoopHead
@LoopExit:
{ * Moving new sample pos into the record * }
move.l d6,20(a0) { * MixSmpInc * }
move.l d2,4(a0) { * MixSmpPos * }
End;
Procedure ISS_MixerUpdateBufferSTEREO;
Var ChannelCounter : DWord;
MChIndexPtr : Pointer;
MixedLength : DWord;
Begin
With ISS_MixerData^ Do Begin
{ * Clearing mixer buffer * }
ISS_MixerClearBuffer(ISS_DevStereo);
{ * Main mixing loop * }
{ * Going through all the active channels * }
For ChannelCounter:=0 To ISS_ActiveSSChannels-1 Do Begin
With ISS_VirtualChannels^[ChannelCounter] Do Begin
{ * If channel is active, then updating... * }
If (VChControl And ISS_CCActive)>0 Then Begin
With MixChannels[ChannelCounter] Do Begin
With MixSmpPtr^ Do Begin
If (SType And ISS_SmpPingPongLoop)>0 Then Begin
MixSmpEnd:=SLoopEnd;
End Else Begin
MixSmpEnd:=SLength;
End;
MChIndexPtr:=@MixChannels[ChannelCounter];
If (SType And ISS_Smp16BitData)>0 Then Begin
MixedLength:=MixChannel16BitSampleSTEREO(MChIndexPtr);
End Else Begin
MixedLength:=MixChannel8BitSampleSTEREO(MChIndexPtr);
End;
If MixedLength=$10000 Then Dec(VChControl,ISS_CCActive);
End;
End;
End;
End;
End;
End;
End;
{ * >>> M O N O M I X I N G F U N C T I O N S <<< * }
{ * Mixes a 8bit sample into a mono buffer * }
Function MixChannel8BitSampleMONO(MChIndexPtr : Pointer) : DWord; Assembler;
Asm
move.l MChIndexPtr,a0
move.l (a0),a1 { * a1 = MixSmpPtr * }
move.l 48(a1),a2 { * SDRAMOffs * }
move.l ISS_MixerData,a3
move.l 12(a3),a4 { * a4 = MixBufPtr * }
move.l 4(a0),d2 { * MixSmpPos * }
move.l 20(a0),d6 { * MixSmpInc * }
moveq.l #0,d7 { 680x0 mixer uses d7 register as MixCounter instead of a variable }
@LoopHead:
{ * Getting out samplevalue * }
move.b (a2,d2),d0
extb.l d0
asl.l #8,d0
{ * Mix sample with volume * }
moveq.l #0,d1
move.w 26(a0),d1 { * MixSmpVol * }
muls.l d1,d0
{ * Adding current sample value to buffer position * }
add.l d0,(a4)+
{ * Calculating stepping rate step two * }
{ * Getting the real step value from the fixedpoint rate * }
{ * calculated previously * }
add.l 16(a0),d6 { * MixSmpLowStep * }
move.l d6,d0
lsr.l #8,d0
lsr.l #8,d0
and.l #$0000FFFF,d6
add.l 12(a0),d0 { * MixSmpHighStep * }
{ * Increasing sample position * }
add.l d0,d2
{ * Checking sample limits * }
cmp.l 32(a0),d2 { * MixSmpEnd * }
blt @SmpOk
move.b 38(a1),d3 { * SType * }
andi.b #ISS_SmpPingPongLoop,d3
beq @SmpEnd
move.l 28(a1),d2 { * SLoopStart * }
bra @SmpOk
@SmpEnd:
move.l 24(a1),d2 { * SLength * }
move.l #$0FFFF,d7
@SmpOk:
addq.l #1,d7
cmp.l 4(a3),d7
blt @LoopHead
{ * Moving new sample pos into the record * }
move.l d6,20(a0) { * MixSmpInc * }
move.l d2,4(a0) { * MixSmpPos * }
move.l d7,d0
End;
{ * Mixes a 16bit sample into a mono buffer * }
Function MixChannel16BitSampleMONO(MChIndexPtr : Pointer) : DWord; Assembler;
Var MixCounter : DWord;
Asm
move.l MChIndexPtr,a0
move.l (a0),a1 { * a1 = MixSmpPtr * }
move.l 48(a1),a2 { * SDRAMOffs * }
move.l ISS_MixerData,a3
move.l 12(a3),a4 { * a4 = MixBufPtr * }
move.l 4(a0),d2 { * MixSmpPos * }
move.l 20(a0),d6 { * MixSmpInc * }
moveq.l #0,d7 { 680x0 mixer uses d7 register as MixCounter instead of a variable }
@LoopHead:
{ * Getting out samplevalue * }
move.w (a2,d2),d0
ext.l d0
{ * Mix sample with volume * }
moveq.l #0,d1
move.w 26(a0),d1 { * MixSmpVol * }
muls.l d1,d0
{ * Adding current sample value to buffer position * }
add.l d0,(a4)+
{ * Calculating stepping rate step two * }
{ * Getting the real step value from the fixedpoint rate * }
{ * calculated previously * }
add.l 16(a0),d6 { * MixSmpLowStep * }
move.l d6,d0
lsr.l #8,d0
lsr.l #8,d0
and.l #$0000FFFF,d6
add.l 12(a0),d0 { * MixSmpHighStep * }
lsl.l #1,d0
{ * Increasing sample position * }
add.l d0,d2
{ * Checking sample limits * }
cmp.l 32(a0),d2 { * MixSmpEnd * }
blt @SmpOk
move.b 38(a1),d3 { * SType * }
andi.b #ISS_SmpPingPongLoop,d3
beq @SmpEnd
move.l 28(a1),d2 { * SLoopStart * }
bra @SmpOk
@SmpEnd:
move.l 24(a1),d2 { * SLength * }
move.l #$0FFFF,d7
@SmpOk:
addq.l #1,d7
cmp.l 4(a3),d7
blt @LoopHead
{ * Moving new sample pos into the record * }
move.l d2,4(a0) { * MixSmpPos * }
move.l d7,d0
End;
Procedure ISS_MixerUpdateBufferMONO;
Var ChannelCounter : DWord;
MChIndexPtr : Pointer;
MixedLength : DWord;
Begin
With ISS_MixerData^ Do Begin
{ * Main mixing loop * }
{ * Going through all the active channels * }
For ChannelCounter:=0 To ISS_ActiveSSChannels-1 Do Begin
With ISS_VirtualChannels^[ChannelCounter] Do Begin
{ * If channel is active, then updating... * }
If (VChControl And ISS_CCActive)>0 Then Begin
With MixChannels[ChannelCounter] Do Begin
With MixSmpPtr^ Do Begin
If (SType And ISS_SmpPingPongLoop)>0 Then Begin
MixSmpEnd:=SLoopEnd;
End Else Begin
MixSmpEnd:=SLength;
End;
MChIndexPtr:=@MixChannels[ChannelCounter];
If (SType And ISS_Smp16BitData)>0 Then Begin
MixedLength:=MixChannel16BitSampleMONO(MChIndexPtr);
End Else Begin
MixedLength:=MixChannel8BitSampleMONO(MChIndexPtr);
End;
If MixedLength=$10000 Then Dec(VChControl,ISS_CCActive);
End;
End;
End;
End;
End;
End;
End;
Procedure ISS_MixerUpdateOutput;
Var ChannelCounter : DWord;
Begin
With ISS_MixerData^ Do Begin
{ * Start Voices Update * }
For ChannelCounter:=0 To ISS_ActiveSSChannels-1 Do Begin
With ISS_VirtualChannels^[ChannelCounter] Do Begin
With MixChannels[ChannelCounter] Do Begin
{ * Anything to do on this channel? * }
If (VChControl>1) And ((VChControl And ISS_CCActive)>0) Then Begin
{ * Stop Voice? * }
If (VChControl And ISS_CCStop)>0 Then Begin
Dec(VChControl,ISS_CCStop);
Dec(VChControl,ISS_CCActive);
End;
{ * Start a Sample ? * }
If (VChControl And ISS_CCSample)>0 Then Begin
Dec(VChControl,ISS_CCSample);
MixSmpPtr:=VChSmpAddr;
With MixSmpPtr^ Do Begin
{ * Offset limit checking * }
If (VChSmpOffs>=SLength) And
((SType And ISS_SmpPingPongLoop)>0) Then Begin
VChSmpOffs:=SLoopStart;
End;
End;
MixSmpPos:=VChSmpOffs;
If (MixSmpPtr<>Nil) And (MixSmpPtr^.SLength>0) Then
VChControl:=VChControl Or ISS_CCActive;
End;
{ * Change Channel Volume ? * }
{ * Change Channel Panning ? * }
If ((VChControl And ISS_CCVolume)>0) Or
((VChControl And ISS_CCPanning)>0) Then Begin
VChControl:=VChControl And Not ISS_CCVolume;
VChControl:=VChControl And Not ISS_CCPanning;
MixSmpVol:=VChFinalVolume;
MixSmpPan:=VChFinalPanning;
If Not MixRevStereo Then Begin
MixSmpVolL:=(MixSmpPan+1);
MixSmpVolR:=(256-MixSmpPan);
End Else Begin
MixSmpVolR:=(MixSmpPan+1);
MixSmpVolL:=(256-MixSmpPan);
End;