From 45b87490718f05da549cdd89f63ff70fccb42485 Mon Sep 17 00:00:00 2001
From: "Ryan C. Gordon" <icculus@icculus.org>
Date: Sun, 22 Jan 2017 20:18:59 -0500
Subject: [PATCH] audio: don't cast to double in SDL_ConvertStereoToMono().

It's expensive and (hopefully) unnecessary. If this becomes an overflow
problem, we could multiply both values by 0.5f before adding them, but let's
see if we can get by without the extra multiplication first.
---
 src/audio/SDL_audiocvt.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/audio/SDL_audiocvt.c b/src/audio/SDL_audiocvt.c
index a922fd3e1..1c3d56a66 100644
--- a/src/audio/SDL_audiocvt.c
+++ b/src/audio/SDL_audiocvt.c
@@ -41,7 +41,7 @@ SDL_ConvertStereoToMono(SDL_AudioCVT * cvt, SDL_AudioFormat format)
     SDL_assert(format == AUDIO_F32SYS);
 
     for (i = cvt->len_cvt / 8; i; --i, src += 2) {
-        *(dst++) = (float) ((((double) src[0]) + ((double) src[1])) * 0.5);
+        *(dst++) = (src[0] + src[1]) * 0.5f;
     }
 
     cvt->len_cvt /= 2;