AnalogSignal: Apply scale handle dragging

diff --git a/pv/view/analogsignal.cpp b/pv/view/analogsignal.cpp
index df1edcf9739906316269259c9c9418947816625b..218a959dd422aed5e6560398bb436a85b86317d5 100644 (file)
--- a/pv/view/analogsignal.cpp
+++ b/pv/view/analogsignal.cpp
@@ -22,6 +22,8 @@
 
 #include <cassert>
 #include <cmath>
+#include <cstdlib>
+#include <limits>
 
 #include "analogsignal.hpp"
 #include "pv/data/analog.hpp"
@@ -58,7 +60,8 @@ AnalogSignal::AnalogSignal(
        shared_ptr<data::Analog> data) :
        Signal(session, channel),
        data_(data),
-       scale_(1.0f)
+       scale_index_(0),
+       scale_index_drag_offset_(0)
 {
        colour_ = SignalColours[channel_->index() % countof(SignalColours)];
 }
@@ -79,17 +82,25 @@ shared_ptr<pv::data::Analog> AnalogSignal::analog_data() const
 
 std::pair<int, int> AnalogSignal::v_extents() const
 {
-       return make_pair(-NominalHeight / 2, NominalHeight / 2);
+       const int h = NominalHeight / 2;
+       return make_pair(-h, h);
 }
 
 int AnalogSignal::scale_handle_offset() const
 {
-       return -NominalHeight / 3;
+       return ((scale_index_drag_offset_ - scale_index_) *
+               NominalHeight / 4) - NominalHeight / 2;
 }
 
 void AnalogSignal::scale_handle_dragged(int offset)
 {
-       (void)offset;
+       scale_index_ = scale_index_drag_offset_ -
+               (offset + NominalHeight / 2) / (NominalHeight / 4);
+}
+
+void AnalogSignal::scale_handle_drag_release()
+{
+       scale_index_drag_offset_ = scale_index_;
 }
 
 void AnalogSignal::paint_back(QPainter &p, const ViewItemPaintParams &pp)
@@ -144,6 +155,7 @@ void AnalogSignal::paint_trace(QPainter &p,
        int y, int left, const int64_t start, const int64_t end,
        const double pixels_offset, const double samples_per_pixel)
 {
+       const float scale = this->scale();
        const int64_t sample_count = end - start;
 
        const float *const samples = segment->get_samples(start, end);
@@ -158,7 +170,7 @@ void AnalogSignal::paint_trace(QPainter &p,
                const float x = (sample / samples_per_pixel -
                        pixels_offset) + left;
                *point++ = QPointF(x,
-                       y - samples[sample - start] * scale_);
+                       y - samples[sample - start] * scale);
        }
 
        p.drawPolyline(points, point - points);
@@ -174,6 +186,8 @@ void AnalogSignal::paint_envelope(QPainter &p,
 {
        using pv::data::AnalogSegment;
 
+       const float scale = this->scale();
+
        AnalogSegment::EnvelopeSection e;
        segment->get_envelope_section(e, start, end, samples_per_pixel);
 
@@ -194,8 +208,8 @@ void AnalogSignal::paint_envelope(QPainter &p,
 
                // We overlap this sample with the next so that vertical
                // gaps do not appear during steep rising or falling edges
-               const float b = y - max(s->max, (s+1)->min) * scale_;
-               const float t = y - min(s->min, (s+1)->max) * scale_;
+               const float b = y - max(s->max, (s+1)->min) * scale;
+               const float t = y - min(s->min, (s+1)->max) * scale;
 
                float h = b - t;
                if (h >= 0.0f && h <= 1.0f)
@@ -212,5 +226,15 @@ void AnalogSignal::paint_envelope(QPainter &p,
        delete[] e.samples;
 }
 
+float AnalogSignal::scale() const
+{
+       const float seq[] = {1.0f, 2.0f, 5.0f};
+       const int offset = std::numeric_limits<int>::max() / (2 * countof(seq));
+       const std::div_t d = std::div(
+               (int)(scale_index_ + countof(seq) * offset),
+               countof(seq));
+       return powf(10.0f, d.quot - offset) * seq[d.rem];
+}
+
 } // namespace view
 } // namespace pv

diff --git a/pv/view/analogsignal.hpp b/pv/view/analogsignal.hpp
index 58c2d3cb7b622e419ce1fcb19d83ed5edf7480fb..aa53f9ddb25ab49c500a93c56f6c4660c879eab5 100644 (file)
--- a/pv/view/analogsignal.hpp
+++ b/pv/view/analogsignal.hpp
@@ -70,6 +70,11 @@ public:
         */
        void scale_handle_dragged(int offset);
 
+       /**
+        * @copydoc pv::view::Signal::signal_scale_handle_drag_release()
+        */
+       void scale_handle_drag_release();
+
        /**
         * Paints the background layer of the signal with a QPainter
         * @param p the QPainter to paint into.
@@ -95,9 +100,16 @@ private:
                int y, int left, const int64_t start, const int64_t end,
                const double pixels_offset, const double samples_per_pixel);
 
+       /**
+        * Computes the scale factor from the scale index.
+        */
+       float scale() const;
+
 private:
        std::shared_ptr<pv::data::Analog> data_;
-       float scale_;
+
+       int scale_index_;
+       int scale_index_drag_offset_;
 };
 
 } // namespace view