From 34341af17d8cd46812f07d4b82044ff07fd3225c Mon Sep 17 00:00:00 2001
From: Pierre Bourdon <delroth@gmail.com>
Date: Sat, 20 Dec 2014 04:11:10 +0100
Subject: [PATCH] Zelda HLE: Implement saw wave generation (sample source
 0001).

Fixes issue 7961.
---
 Source/Core/Core/HW/DSPHLE/UCodes/Zelda.cpp | 18 +++++++++++++++++-
 1 file changed, 17 insertions(+), 1 deletion(-)

diff --git a/Source/Core/Core/HW/DSPHLE/UCodes/Zelda.cpp b/Source/Core/Core/HW/DSPHLE/UCodes/Zelda.cpp
index a679f55149..5f99618a7d 100644
--- a/Source/Core/Core/HW/DSPHLE/UCodes/Zelda.cpp
+++ b/Source/Core/Core/HW/DSPHLE/UCodes/Zelda.cpp
@@ -476,8 +476,12 @@ struct ZeldaAudioRenderer::VPB
 
 	enum SamplesSourceType
 	{
-		// Simple square wave at 50% amplitude and 16KHz.
+		// Simple square wave at 50% amplitude and frequency controlled via the
+		// resampling ratio.
 		SRC_SQUARE_WAVE = 0,
+		// Simple saw wave at 100% amplitude and frequency controlled via the
+		// resampling ratio.
+		SRC_SAW_WAVE = 1,
 		// Samples stored in ARAM at a rate of 16 samples/9 bytes, AFC encoded,
 		// at an arbitrary sample rate (resampling is applied).
 		SRC_AFC_HQ_FROM_ARAM = 9,
@@ -772,6 +776,18 @@ void ZeldaAudioRenderer::LoadInputSamples(MixingBuffer* buffer, VPB* vpb)
 			break;
 		}
 
+		case VPB::SRC_SAW_WAVE:
+		{
+			u32 pos = vpb->current_pos_frac;
+			for (size_t i = 0; i < buffer->size(); ++i)
+			{
+				(*buffer)[i] = pos & 0xFFFF;
+				pos += (vpb->resampling_ratio) >> 1;
+			}
+			vpb->current_pos_frac = pos & 0xFFFF;
+			break;
+		}
+
 		case VPB::SRC_AFC_HQ_FROM_ARAM:
 			DownloadAFCSamplesFromARAM(raw_input_samples.data() + 4, vpb,
 			                           NeededRawSamplesCount(*vpb));