[Performous-commit] Lasse Karkkainen : Refined pitch rendering.

[Lasse Kärkkäi. <tr...@us...>]

Module: editor
Branch: master
Commit: 516376705e3470ffc0c21f4a526588b925436f09

Author: Lasse Karkkainen <tro...@tr...>
Date:   Mon Jan 10 23:25:27 2011 +0100

Refined pitch rendering.

---

 pitchvis.cc |   17 ++++++++++++-----
 pitchvis.hh |   26 ++++++++++++++++++--------
 2 files changed, 30 insertions(+), 13 deletions(-)

diff --git a/pitchvis.cc b/pitchvis.cc
index 77fe9c1..4d78d3e 100644
--- a/pitchvis.cc
+++ b/pitchvis.cc
@@ -26,7 +26,7 @@ PitchVis::PitchVis(std::string const& filename): height(512) {
 	try { readVec(filename, data); } catch(std::exception& e) { std::cerr << e.what() << std::endl; return; }
 	unsigned step = 1024;
 	unsigned width = data.size() / step;
-	img.resize(width * height);
+	img.resize(width * height, Pixel(0.5f, 0.5f, 0.5f, 1.0f));
 	Analyzer analyzer(44100, "");
 	MusicalScale scale;
 	QProgressDialog progress(tr("Analyzing and rendering pitch data..."), tr("&Abort"), 0, width, this);
@@ -40,10 +40,17 @@ PitchVis::PitchVis(std::string const& filename): height(512) {
 		analyzer.process();
 		Analyzer::Peaks peaks = analyzer.getPeaks();
 		for (unsigned i = 0; i < peaks.size(); ++i) {
-			unsigned y = static_cast<unsigned>(8.0 * (scale.getNote(peaks[i].freq)));
-			if (y >= height) continue;
-			float value = magn2dB(peaks[i].magnitude) + 80.0;
-			if (value > 0.0) (*this)(x, y).r += 0.01 * value;
+			unsigned y = height - static_cast<unsigned>(8.0 * (scale.getNote(peaks[i].freq)));
+			if (y == 0 || y >= height - 1) continue;
+			float value = 0.003 * (magn2dB(peaks[i].magnitude) + 80.0);
+			if (value < 0.0) continue;
+			Pixel p(value, value, value);
+			(*this)(x, y) += p;
+			p.r *= 0.5;
+			p.g *= 0.5;
+			p.b *= 0.5;
+			(*this)(x, y + 1) += p;
+			(*this)(x, y - 1) += p;
 		}
 	}
 	progress.setValue(width);
diff --git a/pitchvis.hh b/pitchvis.hh
index 639deec..a85a2ff 100644
--- a/pitchvis.hh
+++ b/pitchvis.hh
@@ -1,6 +1,8 @@
 #pragma once
 
+#include "util.hh"
 #include <QWidget>
+#include <cmath>
 #include <string>
 #include <vector>
 
@@ -8,16 +10,24 @@ struct Pixel {
 	float r,g,b,a;
 	Pixel(float r, float g, float b, float a = 1.0f): r(r), g(g), b(b), a(a) {}
 	Pixel(): r(), g(), b(), a(1.0f) {}
-	unsigned rgba() {
-		unsigned ret = 0;
-		for (unsigned i = 0; i < 4; ++i) {
-			float c = (*this)[i];
-			unsigned char byte = static_cast<unsigned char>(0.5 + 255.0 * c * c); // c² is gamma correction
-			ret |= byte << (i * 8);
-		}
-		return ret;
+	static unsigned char conv(float c, float a) {
+		return static_cast<unsigned char>(255.0 * a * std::sqrt(c)); // sqrt(c) is gamma correction
+	}
+	unsigned rgba() const {
+		unsigned char red = conv(r, a);
+		unsigned char green = conv(g, a);
+		unsigned char blue = conv(b, a);
+		unsigned char alpha = conv(1.0f, a);
+		return alpha << 24 | red << 16 | green << 8 | blue;
 	}
 	float& operator[](unsigned idx) { return (&r)[idx]; }
+	Pixel& operator+=(Pixel const& pix) {
+		r = clamp(r + pix.r);
+		g = clamp(g + pix.g);
+		b = clamp(b + pix.b);
+		a = clamp(a + pix.a);
+		return *this;
+	}
 };
 
 class PitchVis: public QWidget {