Anton Baskanov : dsound: Limit the Doppler shift to +-0.5 speed of sound.

[Alexandre Julliard]

Module: wine
Branch: master
Commit: 315e998951b2e4aca7c56cbb4c2f988bf508b481
URL:    https://gitlab.winehq.org/wine/wine/-/commit/315e998951b2e4aca7c56cbb4c2f988...

Author: Anton Baskanov <baskanov(a)gmail.com>
Date:   Mon Apr 24 09:19:43 2023 +0700

dsound: Limit the Doppler shift to +-0.5 speed of sound.

---

 dlls/dsound/sound3d.c    | 5 +++--
 dlls/dsound/tests/ds3d.c | 2 --
 2 files changed, 3 insertions(+), 4 deletions(-)

diff --git a/dlls/dsound/sound3d.c b/dlls/dsound/sound3d.c
index 7cccef6cfe4..9a975324607 100644
--- a/dlls/dsound/sound3d.c
+++ b/dlls/dsound/sound3d.c
@@ -168,7 +168,7 @@ void DSOUND_Calc3DBuffer(IDirectSoundBufferImpl *dsb)
 	float a, ingain;
 	/* doppler shift related stuff */
 	D3DVECTOR vRelativeVel;
-	D3DVALUE flFreq, flRelativeVel;
+	D3DVALUE flFreq, flRelativeVel, flLimitedVel;
 
 	TRACE("(%p)\n",dsb);
 
@@ -307,8 +307,9 @@ void DSOUND_Calc3DBuffer(IDirectSoundBufferImpl *dsb)
 		   NOTE: if buffer moves TOWARDS the listener, its velocity component is NEGATIVE
 		         if buffer moves AWAY from listener, its velocity component is POSITIVE */
 		flRelativeVel = ProjectVector(&vRelativeVel, &vDistance);
+		flLimitedVel = max(-DEFAULT_VELOCITY/2, min(DEFAULT_VELOCITY/2, flRelativeVel));
 		/* formula taken from Gianicoli D.: Physics, 4th edition: */
-		flFreq = dsb->ds3db_freq * (DEFAULT_VELOCITY/(DEFAULT_VELOCITY + flRelativeVel));
+		flFreq = dsb->ds3db_freq * (DEFAULT_VELOCITY/(DEFAULT_VELOCITY + flLimitedVel));
 		TRACE("doppler: Relative velocity (component) = %f => Doppler shift: %ld Hz -> %f Hz\n",
 		      flRelativeVel, dsb->ds3db_freq, flFreq);
 		dsb->freq = flFreq;
diff --git a/dlls/dsound/tests/ds3d.c b/dlls/dsound/tests/ds3d.c
index 99a1f16cf8e..e7e1ab7ab81 100644
--- a/dlls/dsound/tests/ds3d.c
+++ b/dlls/dsound/tests/ds3d.c
@@ -1446,9 +1446,7 @@ static void test_doppler(GUID *guid, BOOL play)
     check_doppler(dsound, listener, play, DS3DMODE_NORMAL, 0, -90, 1, 0, 22050, 17640);
 
     /* The Doppler shift is limited to +-0.5 speed of sound. */
-    /* Wine TODO: The frequency is not limited. */
     check_doppler(dsound, listener, play, DS3DMODE_NORMAL, 0, 0, 1, -240, 22050, 44100);
-    /* Wine TODO: The frequency is not limited. */
     check_doppler(dsound, listener, play, DS3DMODE_NORMAL, 0, 0, 1, 240, 22050, 14700);
 
     IDirectSound3DListener_Release(listener);