fix symmetric fade-shape (still variable number of steps)

diff --git a/libs/ardour/audioregion.cc b/libs/ardour/audioregion.cc
index a40168ea9f4d91988fedbaf6a7ec967a19272bc3..97e63b5e8cf4e3916b3fbb74f858c9670c5f6c40 100644 (file)
--- a/libs/ardour/audioregion.cc
+++ b/libs/ardour/audioregion.cc
@@ -1032,10 +1032,10 @@ AudioRegion::set_fade_in (FadeShape shape, framecnt_t len)
                _fade_in->fast_simple_add (0.5 * len, 0.6);
                //now generate a fade-out curve by successively applying a gain drop
                const double breakpoint = 0.7;  //linear for first 70%
-               for (int i = 2; i < num_steps; i++) {
+               for (int i = max(2, (int)ceil(num_steps / 9.0)); i < num_steps; i++) {
                        const double offset = 1.0 - breakpoint;
                        float coeff = 1.0 - breakpoint;
-                       coeff *= powf(0.5, (i-1) * 7.0 / (double)num_steps); // -6dB per step for 7 steps
+                       coeff *= powf(0.5, i * 9.0 / (double)num_steps); // -6dB per step for 7 steps
                        _fade_in->fast_simple_add (len * (breakpoint + (offset * (double)i / (double)num_steps)), coeff);
                }
                _fade_in->fast_simple_add (len, VERY_SMALL_SIGNAL);
@@ -1111,10 +1111,10 @@ AudioRegion::set_fade_out (FadeShape shape, framecnt_t len)
 
                //now generate a fade-out curve by successively applying a gain drop
                const double breakpoint = 0.7;  //linear for first 70%
-               for (int i = 2; i < num_steps; i++) {
+               for (int i = max(2, (int)ceil(num_steps / 9.0)); i < num_steps; i++) {
                        const double offset = 1.0 - breakpoint;
                        float coeff = 1.0 - breakpoint;
-                       coeff *= powf(0.5, (i-1) * 7.0 / (double)num_steps); // -6dB per step for 7 steps
+                       coeff *= powf(0.5, i * 9.0 / (double)num_steps); // -6dB per step for 7 steps
                        _fade_out->fast_simple_add (len * (breakpoint + (offset * (double)i / (double)num_steps)), coeff);
                }
                _fade_out->fast_simple_add (len, VERY_SMALL_SIGNAL);