diff options
| author | hrydgard <hrydgard@gmail.com> | 2009-07-01 22:26:01 +0000 |
|---|---|---|
| committer | hrydgard <hrydgard@gmail.com> | 2009-07-01 22:26:01 +0000 |
| commit | 0008d5ef77983c4b7bfa4fde4401fb5ea1e6535c (patch) | |
| tree | 38ba82b71743a6dde55f2bcb2fb4d387c382be7e /docs | |
| parent | f6af7794cd91f6a78241c4988ee6521ee14679b4 (diff) | |
DSPHLE: Preserve fractional sample position between voice render calls. sounds slightly, slightly cleaner :P
git-svn-id: https://dolphin-emu.googlecode.com/svn/trunk@3637 8ced0084-cf51-0410-be5f-012b33b47a6e
Diffstat (limited to 'docs')
| -rw-r--r-- | docs/DSP/DSP_UC_Zelda.txt | 31 |
1 files changed, 19 insertions, 12 deletions
diff --git a/docs/DSP/DSP_UC_Zelda.txt b/docs/DSP/DSP_UC_Zelda.txt index 9b3e4b5703..29771968bb 100644 --- a/docs/DSP/DSP_UC_Zelda.txt +++ b/docs/DSP/DSP_UC_Zelda.txt @@ -2880,15 +2880,23 @@ void 087c_DefaultDecoder() 087c 8100 clr $ACC0 // ACC0 = 0
087d 1f5e mrr $AX0.H, $AC0.M
087e 00d8 0402 lr $AX0.L, @0x0402 // AX0.L = PB.RatioInt
- 0880 00dc 0430 lr $AC0.L, @0x0430 // AC0.L = PB.RatioFrac
+
+ // Sample fraction is stored in a common way, but sample position is not, so
+ // it's in the individual decoders. Some decoders, like square wave, only care about
+ // fractional sample position. So here we just load up the fractional sample
+ // position before handing control over.
+ 0880 00dc 0430 lr $AC0.L, @0x0430 // AC0.L = PB.CurSampleFrac
0882 0080 0520 lri $AR0, #0x0520 // AR0 = 0x0520
- 0884 00df 0480 lr $AC1.M, @0x0480
- 0886 1501 lsl $ACC1, #1 // AC1.M = (PB.Format << 1)
- 0887 0340 007e andi $AC1.M, #0x007e // AC1.M &= 0x007e
- 0889 0300 0891 addi $AC1.M, #0x0891 // AC1.M += 0x0891
- 088b 1c5f mrr $AR2, $AC1.M // AR2 = AC1.M
- 088c 175f callr $AR2 // (*$AR2)() <-- See jump table at 0x0891
- 088d 00fc 0430 sr @0x0430, $AC0.L // PB.RatioFrac = AC0.L
+
+ // 0884 00df 0480 lr $AC1.M, @0x0480
+ // 0886 1501 lsl $ACC1, #1 // AC1.M = (PB.Format << 1)
+ // 0887 0340 007e andi $AC1.M, #0x007e // AC1.M &= 0x007e
+ // 0889 0300 0891 addi $AC1.M, #0x0891 // AC1.M += 0x0891
+ // 088b 1c5f mrr $AR2, $AC1.M // AR2 = AC1.M
+ // 088c 175f callr $AR2 // (*$AR2)() <-- See jump table at 0x0891
+ JumpTable0891(PB.Format);
+
+ 088d 00fc 0430 sr @0x0430, $AC0.L // PB.CurSampleFrac = AC0.L
// 088f 029f 02d8 jmp 0x02d8
GOTO ContinueWithBlock: // in SyncFrame
@@ -2916,7 +2924,7 @@ void 087c_DefaultDecoder() 08b1 02df ret
void 08b2_Decoder0x0_SquareWave() {
- 08b2 1401 lsl $ACC0, #1 // t = PB.RatioFrac * 2
+ 08b2 1401 lsl $ACC0, #1 // t = samplePosition * 2
// Set up sound buffers
//08b3 009b c000 lri $AX1.H, #0xc000
@@ -2934,16 +2942,15 @@ void 08b2_Decoder0x0_SquareWave() { else
*$AR0++ = 0xc000;
- 08bf 4800 addax $ACC0, $AX0.L // t += PB.RatioInt
+ 08bf 4800 addax $ACC0, $AX0.L // t += PB.Ratio
}
08c0 147f lsr $ACC0, #-1 // t /= 2
- // Where ACC0 gets stored after this is interesting.
// 08c1 02df ret
}
void 08c2_Decoder0x3_RectangleWave() {
- 08c2 1402 lsl $ACC0, #2 // t = PB.RatioFrac * 4
+ 08c2 1402 lsl $ACC0, #2 // t = PB.CurSampleFrac * 4
08c3 8900 clr $ACC1 // ACC1 = 0
08c4 1fb8 mrr $AC1.L, $AX0.L // AC1.L = PB.RatioInt
08c5 1501 lsl $ACC1, #1 // ACC1 *= 2
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