From 9296cfd334f93c86d26d610d1956471c1fd5f1b2 Mon Sep 17 00:00:00 2001
From: zsilencer <zsilencergame@gmail.com>
Date: Wed, 29 Apr 2015 17:29:37 -0600
Subject: [PATCH 1/2] fix audio panning

---
 src/audio/mixer.cpp | 29 +++++++++++++++++++----------
 src/audio/mixer.h   |  1 +
 src/ride/ride.c     | 38 ++++++++++++++++++++------------------
 3 files changed, 40 insertions(+), 28 deletions(-)

diff --git a/src/audio/mixer.cpp b/src/audio/mixer.cpp
index 247e1aa395..fa2d1d1109 100644
--- a/src/audio/mixer.cpp
+++ b/src/audio/mixer.cpp
@@ -341,6 +341,8 @@ Channel::Channel()
 	SetRate(1);
 	SetVolume(SDL_MIX_MAXVOLUME);
 	oldvolume = 0;
+	oldvolume_l = 0;
+	oldvolume_r = 0;
 	SetPan(0.5f);
 	done = true;
 	stopping = false;
@@ -395,8 +397,15 @@ void Channel::SetPan(float pan)
 	if (pan < 0) {
 		Channel::pan = 0;
 	}
-	volume_l = (float)sin((1.0 - Channel::pan) * M_PI / 2.0);
-	volume_r = (float)sin(Channel::pan * M_PI / 2.0);
+	double decibels = (abs(Channel::pan - 0.5) * 2.0) * 100.0;
+	double attenuation = pow(10, decibels / 20.0);
+	if (Channel::pan <= 0.5) {
+		volume_l = 1.0;
+		volume_r = float(1.0 / attenuation);
+	} else {
+		volume_r = 1.0;
+		volume_l = float(1.0 / attenuation);
+	}
 }
 
 bool Channel::IsPlaying()
@@ -692,6 +701,8 @@ void Mixer::MixChannel(Channel& channel, uint8* data, int length)
 		} while(loaded < length && channel.loop != 0 && !channel.stopping);
 
 		channel.oldvolume = channel.volume;
+		channel.oldvolume_l = channel.volume_l;
+		channel.oldvolume_r = channel.volume_r;
 		if (channel.loop == 0 && channel.offset >= channel.source->Length()) {
 			channel.done = true;
 		}
@@ -700,21 +711,19 @@ void Mixer::MixChannel(Channel& channel, uint8* data, int length)
 
 void Mixer::EffectPanS16(Channel& channel, sint16* data, int length)
 {
-	float left = channel.volume_l;
-	float right = channel.volume_r;
 	for (int i = 0; i < length * 2; i += 2) {
-		data[i] = (sint16)(data[i] * left);
-		data[i + 1] = (sint16)(data[i + 1] * right);
+		float t = (float)i / (length * 2);
+		data[i] = (sint16)(data[i] * ((1.0 - t) * channel.oldvolume_l + t * channel.volume_l));
+		data[i + 1] = (sint16)(data[i + 1] * ((1.0 - t) * channel.oldvolume_r + t * channel.volume_r));
 	}
 }
 
 void Mixer::EffectPanU8(Channel& channel, uint8* data, int length)
 {
-	float left = channel.volume_l;
-	float right = channel.volume_r;
 	for (int i = 0; i < length * 2; i += 2) {
-		data[i] = (uint8)(data[i] * left);
-		data[i + 1] = (uint8)(data[i + 1] * right);
+		float t = (float)i / (length * 2);
+		data[i] = (uint8)(data[i] * ((1.0 - t) * channel.oldvolume_l + t * channel.volume_l));
+		data[i + 1] = (uint8)(data[i + 1] * ((1.0 - t) * channel.oldvolume_r + t * channel.volume_r));
 	}
 }
 
diff --git a/src/audio/mixer.h b/src/audio/mixer.h
index e62dd3cad0..6575401262 100644
--- a/src/audio/mixer.h
+++ b/src/audio/mixer.h
@@ -133,6 +133,7 @@ private:
 	double rate;
 	int volume;
 	float volume_l, volume_r;
+	float oldvolume_l, oldvolume_r;
 	float pan;
 	bool done;
 	bool deleteondone;
diff --git a/src/ride/ride.c b/src/ride/ride.c
index a703dbf104..395223874e 100644
--- a/src/ride/ride.c
+++ b/src/ride/ride.c
@@ -2447,32 +2447,34 @@ int ride_music_params_update(sint16 x, sint16 y, sint16 z, uint8 rideIndex, uint
 
 		uint8 vol1 = -1;
 		uint8 vol2 = -1;
-		if (pany < 0) {
-			pany = -pany;
+		int panx2 = panx;
+		int pany2 = pany;
+		if (pany2 < 0) {
+			pany2 = -pany2;
 		}
-		if (pany > 6143) {
-			pany = 6143;
+		if (pany2 > 6143) {
+			pany2 = 6143;
 		}
-		pany -= 2048;
-		if (pany > 0) {
-			pany = -((pany / 4) - 1024) / 4;
-			vol1 = (uint8)pany;
-			if (pany >= 256) {
+		pany2 -= 2048;
+		if (pany2 > 0) {
+			pany2 = -((pany2 / 4) - 1024) / 4;
+			vol1 = (uint8)pany2;
+			if (pany2 >= 256) {
 				vol1 = -1;
 			}
 		}
 
-		if (panx < 0) {
-			panx = -panx;
+		if (panx2 < 0) {
+			panx2 = -panx2;
 		}
-		if (panx > 6143) {
-			panx = 6143;
+		if (panx2 > 6143) {
+			panx2 = 6143;
 		}
-		panx -= 2048;
-		if (panx > 0) {
-			panx = -((panx / 4) - 1024) / 4;
-			vol2 = (uint8)panx;
-			if (panx >= 256) {
+		panx2 -= 2048;
+		if (panx2 > 0) {
+			panx2 = -((panx2 / 4) - 1024) / 4;
+			vol2 = (uint8)panx2;
+			if (panx2 >= 256) {
 				vol2 = -1;
 			}
 		}

From bcad8c200eae8cd1b085e7ec7b9249a20a385845 Mon Sep 17 00:00:00 2001
From: zsilencer <zsilencergame@gmail.com>
Date: Wed, 6 May 2015 19:14:41 -0600
Subject: [PATCH 2/2] #1042

---
 src/audio/mixer.cpp | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/audio/mixer.cpp b/src/audio/mixer.cpp
index fa2d1d1109..87105a355c 100644
--- a/src/audio/mixer.cpp
+++ b/src/audio/mixer.cpp
@@ -268,8 +268,10 @@ bool Source_SampleStream::LoadWAV(SDL_RWops* rw)
 		log_verbose("Could not find FMT chunk");
 		return false;
 	}
+	Uint64 chunkstart = SDL_RWtell(rw);
 	PCMWAVEFORMAT waveformat;
 	SDL_RWread(rw, &waveformat, sizeof(waveformat), 1);
+	SDL_RWseek(rw, chunkstart + fmtchunk_size, RW_SEEK_SET);
 	if (waveformat.wf.wFormatTag != WAVE_FORMAT_PCM) {
 		log_verbose("Not in proper format");
 		return false;