From: Joel Holdsworth <redacted>
Date: Sat, 16 Mar 2013 15:03:48 +0000 (+0000)
Subject: Implemented AnalogSnapshot::get_envelope_section
X-Git-Tag: pulseview-0.1.0~73
X-Git-Url: https://sigrok.org/gitweb/?p=pulseview.git;a=commitdiff_plain;h=9320072da54c5f1614779512d8c8d3bac6743419

Implemented AnalogSnapshot::get_envelope_section
---

diff --git a/pv/data/analogsnapshot.cpp b/pv/data/analogsnapshot.cpp
index c052782e..bec65065 100644
--- a/pv/data/analogsnapshot.cpp
+++ b/pv/data/analogsnapshot.cpp
@@ -85,6 +85,30 @@ const float* AnalogSnapshot::get_samples(
 	return data;
 }
 
+void AnalogSnapshot::get_envelope_section(EnvelopeSection &s,
+	uint64_t start, uint64_t end, float min_length) const
+{
+	assert(end <= get_sample_count());
+	assert(start <= end);
+	assert(min_length > 0);
+
+	lock_guard<recursive_mutex> lock(_mutex);
+
+	const unsigned int min_level = max((int)floorf(logf(min_length) /
+		LogEnvelopeScaleFactor) - 1, 0);
+	const unsigned int scale_power = (min_level + 1) *
+		EnvelopeScalePower;
+	start >>= scale_power;
+	end >>= scale_power;
+
+	s.start = start << scale_power;
+	s.scale = 1 << scale_power;
+	s.length = end - start;
+	s.samples = new EnvelopeSample[s.length];
+	memcpy(s.samples, _envelope_levels[min_level].samples + start,
+		s.length * sizeof(EnvelopeSample));
+}
+
 void AnalogSnapshot::reallocate_envelope(Envelope &e)
 {
 	const uint64_t new_data_length = ((e.length + EnvelopeDataUnit - 1) /
diff --git a/pv/data/analogsnapshot.h b/pv/data/analogsnapshot.h
index 59c43187..74d26763 100644
--- a/pv/data/analogsnapshot.h
+++ b/pv/data/analogsnapshot.h
@@ -35,13 +35,22 @@ namespace data {
 
 class AnalogSnapshot : public Snapshot
 {
-private:
+public:
 	struct EnvelopeSample
 	{
 		float min;
 		float max;
 	};
 
+	struct EnvelopeSection
+	{
+		uint64_t start;
+		unsigned int scale;
+		uint64_t length;
+		EnvelopeSample *samples;
+	};
+
+private:
 	struct Envelope
 	{
 		uint64_t length;
@@ -66,6 +75,9 @@ public:
 	const float* get_samples(int64_t start_sample,
 		int64_t end_sample) const;
 
+	void get_envelope_section(EnvelopeSection &s,
+		uint64_t start, uint64_t end, float min_length) const;
+
 private:
 	void reallocate_envelope(Envelope &l);