From 8a8f9cc87fcc371e4f3fc26a08d149faeb5d54e4 Mon Sep 17 00:00:00 2001
From: Alexander Kojevnikov <alexander@kojevnikov.com>
Date: Sat, 2 Apr 2016 20:12:52 -0700
Subject: [PATCH] Add SoX palette
Closes #96.
---
src/spek-palette.cc | 34 ++++++++++++++++++++++++++++++++++
src/spek-palette.h | 3 ++-
2 files changed, 36 insertions(+), 1 deletion(-)
diff --git a/src/spek-palette.cc b/src/spek-palette.cc
index 3c52e9a..838cee3 100644
--- a/src/spek-palette.cc
+++ b/src/spek-palette.cc
@@ -1,4 +1,5 @@
#include <assert.h>
+#include <math.h>
#include "spek-palette.h"
@@ -44,6 +45,37 @@ static uint32_t spectrum(double level)
return (rr << 16) + (gg << 8) + bb;
}
+// The default palette used by SoX and written by Rob Sykes.
+static uint32_t sox(double level)
+{
+ double r = 0.0;
+ if (level >= 0.13 && level < 0.73) {
+ r = sin((level - 0.13) / 0.60 * M_PI / 2.0);
+ } else if (level >= 0.73) {
+ r = 1.0;
+ }
+
+ double g = 0.0;
+ if (level >= 0.6 && level < 0.91) {
+ g = sin((level - 0.6) / 0.31 * M_PI / 2.0);
+ } else if (level >= 0.91) {
+ g = 1.0;
+ }
+
+ double b = 0.0;
+ if (level < 0.60) {
+ b = 0.5 * sin(level / 0.6 * M_PI);
+ } else if (level >= 0.78) {
+ b = (level - 0.78) / 0.22;
+ }
+
+ // Pack RGB values into a 32-bit uint.
+ uint32_t rr = (uint32_t) (r * 255.0 + 0.5);
+ uint32_t gg = (uint32_t) (g * 255.0 + 0.5);
+ uint32_t bb = (uint32_t) (b * 255.0 + 0.5);
+ return (rr << 16) + (gg << 8) + bb;
+}
+
static uint32_t mono(double level)
{
uint32_t v = (uint32_t) (level * 255.0 + 0.5);
@@ -54,6 +86,8 @@ uint32_t spek_palette(enum palette palette, double level) {
switch (palette) {
case PALETTE_SPECTRUM:
return spectrum(level);
+ case PALETTE_SOX:
+ return sox(level);
case PALETTE_MONO:
return mono(level);
default:
diff --git a/src/spek-palette.h b/src/spek-palette.h
index b62b996..27434de 100644
--- a/src/spek-palette.h
+++ b/src/spek-palette.h
@@ -4,9 +4,10 @@
enum palette {
PALETTE_SPECTRUM,
+ PALETTE_SOX,
PALETTE_MONO,
PALETTE_COUNT,
- PALETTE_DEFAULT = PALETTE_SPECTRUM,
+ PALETTE_DEFAULT = PALETTE_SOX,
};
uint32_t spek_palette(enum palette palette, double level);