From a9a91053d97642d14f4959c61b0e0c68a8383563 Mon Sep 17 00:00:00 2001
From: Krzysztof Foltman <wdev@foltman.com>
Date: Sat, 6 Nov 2010 23:44:11 +0000
Subject: [PATCH] Use symmetric dB range for EQ plugins.

(cherry picked from commit cb3e7e001da3e0f43b3da8eed3f9660698f87ca2)
---
 plugins/ladspa_effect/calf/src/calf/giface.h  | 10 +++++-----
 plugins/ladspa_effect/calf/src/modules_eq.cpp |  4 ++--
 2 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/plugins/ladspa_effect/calf/src/calf/giface.h b/plugins/ladspa_effect/calf/src/calf/giface.h
index 4bb5df90e..746200bd5 100644
--- a/plugins/ladspa_effect/calf/src/calf/giface.h
+++ b/plugins/ladspa_effect/calf/src/calf/giface.h
@@ -634,22 +634,22 @@ public:
     
 extern const char *calf_copyright_info;
 
-bool get_freq_gridline(int subindex, float &pos, bool &vertical, std::string &legend, cairo_iface *context, bool use_frequencies = true);
+bool get_freq_gridline(int subindex, float &pos, bool &vertical, std::string &legend, cairo_iface *context, bool use_frequencies = true, float res = 256, float ofs = 0.4);
     
 /// convert amplitude value to normalized grid-ish value (0dB = 0.5, 30dB = 1.0, -30 dB = 0.0, -60dB = -0.5, -90dB = -1.0)
-static inline float dB_grid(float amp)
+static inline float dB_grid(float amp, float res = 256, float ofs = 0.4)
 {
-    return log(amp) * (1.0 / log(256.0)) + 0.4;
+    return log(amp) * (1.0 / log(res)) + ofs;
 }
 
 template<class Fx>
-static bool get_graph(Fx &fx, int subindex, float *data, int points)
+static bool get_graph(Fx &fx, int subindex, float *data, int points, float res = 256, float ofs = 0.4)
 {
     for (int i = 0; i < points; i++)
     {
         typedef std::complex<double> cfloat;
         double freq = 20.0 * pow (20000.0 / 20.0, i * 1.0 / points);
-        data[i] = dB_grid(fx.freq_gain(subindex, freq, fx.srate));
+        data[i] = dB_grid(fx.freq_gain(subindex, freq, fx.srate), res, ofs);
     }
     return true;
 }
diff --git a/plugins/ladspa_effect/calf/src/modules_eq.cpp b/plugins/ladspa_effect/calf/src/modules_eq.cpp
index 04cd0ae2d..35a1a80d9 100644
--- a/plugins/ladspa_effect/calf/src/modules_eq.cpp
+++ b/plugins/ladspa_effect/calf/src/modules_eq.cpp
@@ -248,7 +248,7 @@ bool equalizerNband_audio_module<BaseClass, has_lphp>::get_graph(int index, int
         return false;
     if (index == AM::param_p1_freq && !subindex) {
         context->set_line_width(1.5);
-        return ::get_graph(*this, subindex, data, points);
+        return ::get_graph(*this, subindex, data, points, 32, 0);
     }
     return false;
 }
@@ -259,7 +259,7 @@ bool equalizerNband_audio_module<BaseClass, has_lphp>::get_gridline(int index, i
     if (!is_active) {
         return false;
     } else {
-        return get_freq_gridline(subindex, pos, vertical, legend, context);
+        return get_freq_gridline(subindex, pos, vertical, legend, context, true, 32, 0);
     }
 }