From: Jaroslav Kysela <perex@perex.cz>
Date: Fri, 5 Mar 2004 09:11:13 +0000 (+0000)
Subject: Maarten de Boer <mdeboer@iua.upf.es>
X-Git-Tag: v1.0.4~28
X-Git-Url: https://git.alsa-project.org/?a=commitdiff_plain;h=23ed7623c6d5f08b51d837db1146070bff1c20a1;p=alsa-lib.git

Maarten de Boer <mdeboer@iua.upf.es>
The attached patch makes the alsa-lib/test/pmc.c generate_sine code
slightly more simple, efficient and readable (but not less accurate),
taking quite some calculation out of the loop.
---

diff --git a/test/pcm.c b/test/pcm.c
index 07ea7daf..fec36b51 100644
--- a/test/pcm.c
+++ b/test/pcm.c
@@ -29,9 +29,9 @@ static void generate_sine(const snd_pcm_channel_area_t *areas,
 			  snd_pcm_uframes_t offset,
 			  int count, double *_phase)
 {
+	static double max_phase = 2. * M_PI;
 	double phase = *_phase;
-	double max_phase = 1.0 / freq;
-	double step = 1.0 / (double)rate;
+	double step = max_phase*freq/(double)rate;
 	double res;
 	signed short *samples[channels];
 	int steps[channels];
@@ -53,7 +53,7 @@ static void generate_sine(const snd_pcm_channel_area_t *areas,
 	}
 	/* fill the channel areas */
 	while (count-- > 0) {
-		res = sin((phase * 2 * M_PI) / max_phase - M_PI) * 32767;
+		res = sin(phase) * 32767;
 		ires = res;
 		for (chn = 0; chn < channels; chn++) {
 			*samples[chn] = ires;