NO-OP: whitespace

[ardour.git] / libs / ardour / parameter_descriptor.cc

diff --git a/libs/ardour/parameter_descriptor.cc b/libs/ardour/parameter_descriptor.cc
index 9e02bc01ab1d3953a043af612cfbc599e29685f4..4f26af997d843087dca66a5c4d4ea6f5a7620ee6 100644 (file)
--- a/libs/ardour/parameter_descriptor.cc
+++ b/libs/ardour/parameter_descriptor.cc
@@ -157,13 +157,22 @@ ParameterDescriptor::update_steps()
        if (toggled || enumeration) {
                logarithmic = false;
        }
+       if (logarithmic && sr_dependent && upper > lower && lower == 0) {
+               /* work-around for plugins with a log-scale control 0..SR; log (0) is not defined */
+               lower = upper / 1000.f;
+       }
        if (logarithmic && (upper <= lower || lower * upper <= 0)) {
+               /* log-scale params need upper > lower and both values need the same sign */
                logarithmic = false;
        }
        if (rangesteps < 2) {
                rangesteps = 0;
        }
        if (enumeration) {
+               /* enums need scale-points.
+                * The GUI is more restrictive, a dropdown is displayed
+                * IIF  scale_points.size() == (1 + upper - lower)
+                */
                if (!scale_points || scale_points->empty ()) {
                        enumeration = false;
                }
@@ -174,6 +183,13 @@ ParameterDescriptor::update_steps()
                }
        }
 
+       /* upper == lower does not make any sense */
+       if (lower == upper) {
+               upper = lower + 0.01; // add some arbitrary value
+       }
+
+       /* set steps */
+
        if (unit == ParameterDescriptor::MIDI_NOTE) {
                step      = smallstep = 1;  // semitone
                largestep = 12;             // octave
@@ -184,45 +200,39 @@ ParameterDescriptor::update_steps()
                largestep = position_to_gain (dB_coeff_step(upper));
                step      = position_to_gain (largestep / 10.0);
                smallstep = step;
+       } else if (logarithmic) {
+               /* ignore logscale rangesteps. {small|large}steps are used with the spinbox.
+                * gtk-spinbox shows the internal (not interface) value and up/down
+                * arrows linearly increase.
+                * The AutomationController uses internal_to_interface():
+                *   ui-step [0..1] -> log (1 + largestep / lower) / log (upper / lower)
+                * so we use a step that's a multiple of "lower" for the interface step:
+                *   log (1 + x) / log (upper / lower)
+                */
+               smallstep = step = lower / 11;
+               largestep = lower / 3;
+               /* NOTE: the actual value does use rangesteps via
+                * logscale_to_position_with_steps(), position_to_logscale_with_steps()
+                * when it is converted.
+                */
        } else if (rangesteps > 1) {
                const float delta = upper - lower;
-
-               step = smallstep = (delta / (rangesteps - 1)); // XXX
-               largestep = std::min ((delta / 5.0f), 10.f * smallstep); // XXX
-
-               if (logarithmic) {
-                       smallstep = smallstep / logf (rangesteps); // XXX
-                       step      = step      / logf (rangesteps);
-                       largestep = largestep / logf (rangesteps);
-               } else if (integer_step) {
-                       smallstep = 1.0;
-                       step      = std::max(1.f, rintf (rangesteps));
-                       largestep = std::max(1.f, rintf (largestep));
+               if (integer_step) {
+                       smallstep = step = 1.0;
+                       largestep = std::max(1.f, rintf (delta / (rangesteps - 1.f)));
+               } else {
+                       step = smallstep = delta / (rangesteps - 1.f);
+                       largestep = std::min ((delta / 4.0f), 10.f * smallstep);
                }
        } else {
                const float delta = upper - lower;
-
-               /* 30 happens to be the total number of steps for a fader with default
-                  max gain of 2.0 (6 dB), so we use 30 here too for consistency. */
-               step      = smallstep = (delta / 300.0f);
-               largestep = (delta / 30.0f);
-
-               if (logarithmic) {
-                       /* Steps are linear, but we map them with pow like values (in
-                          internal_to_interface).  Thus, they are applied exponentially,
-                          which means too few steps.  So, divide to get roughly the
-                          desired number of steps (30).  This is not mathematically
-                          precise but seems to be about right for the controls I tried.
-                          If you're reading this, you've probably found a case where that
-                          isn't true, and somebody needs to sit down with a piece of paper
-                          and actually do the math. */
-                       smallstep = smallstep / logf(30.0f);
-                       step      = step      / logf(30.0f);
-                       largestep = largestep / logf(30.0f);
-               } else if (integer_step) {
-                       smallstep = 1.0;
-                       step      = std::max(1.f, rintf (step));
-                       largestep = std::max(1.f, rintf (largestep));
+               /* 30 steps between min/max (300 for fine-grained) */
+               if (integer_step) {
+                       smallstep = step = 1.0;
+                       largestep = std::max(1.f, rintf (delta / 30.f));
+               } else {
+                       step      = smallstep = (delta / 300.0f);
+                       largestep = (delta / 30.0f);
                }
        }
 }
@@ -383,10 +393,10 @@ ParameterDescriptor::from_interface (float val) const
                                 * e.g. 5 integers 0,1,2,3,4 are mapped to a fader
                                 * [0.0 .. 0.2 | 0.2 .. 0.4 | 0.4 .. 0.6 | 0.6 .. 0.8 | 0.8 .. 1.0]
                                 */
-                               val =  round (lower + val * (1.f + upper - lower) - .5f);
+                               val = floor (lower + val * (1.f + upper - lower));
                        } else if (rangesteps > 1) {
                                /* similar to above, but for float controls */
-                               val = floor (val * (rangesteps - 1.f)) / (rangesteps - 1.f); // XXX
+                               val = round (val * (rangesteps - 1.f)) / (rangesteps - 1.f); // XXX
                                val = val * (upper - lower) + lower;
                        } else {
                                val = val * (upper - lower) + lower;