From 9f54e0e84f93ca4773994d4ee3c2cf3d8989790b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?poljar=20=28Damir=20Jeli=C4=87=29?= <poljar@poljar.org>
Date: Tue, 14 Jan 2014 23:03:10 +0100
Subject: [PATCH] demo: Add analog sawtooth pattern.

---
 hardware/demo/demo.c | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/hardware/demo/demo.c b/hardware/demo/demo.c
index 0fc5011d..cf82630a 100644
--- a/hardware/demo/demo.c
+++ b/hardware/demo/demo.c
@@ -79,6 +79,7 @@ enum {
 	PATTERN_SQUARE,
 	PATTERN_SINE,
 	PATTERN_TRIANGLE,
+	PATTERN_SAWTOOTH,
 };
 
 static const char *logic_pattern_str[] = {
@@ -93,6 +94,7 @@ static const char *analog_pattern_str[] = {
 	"square",
 	"sine",
 	"triangle",
+	"sawtooth",
 };
 
 struct analog_gen {
@@ -233,6 +235,21 @@ static void generate_analog_pattern(const struct sr_probe_group *probe_group, ui
 						asin(sin(2 * M_PI * frequency * t));
 		}
 
+		ag->num_samples = num_samples;
+		break;
+
+	case PATTERN_SAWTOOTH:
+		frequency = sample_rate / ANALOG_SAMPLES_PER_PERIOD;
+
+		while (num_samples % ANALOG_SAMPLES_PER_PERIOD != 0)
+			num_samples--;
+
+		for (i = 0; i < num_samples; i++) {
+			t = (double) i / (double) sample_rate;
+			ag->pattern_data[i] = 2 * ANALOG_AMPLITUDE *
+						((t * frequency) - floor(0.5f + t * frequency));
+		}
+
 		ag->num_samples = num_samples;
 		break;
 	}