analogsignal.cpp: Fix std::isnan() related compile issue on some systems

Re-do for recent source what commit f9abacf20c85 did to solve bug #531.
Explicitly use std::isnan() in checks. Avoid the 'using' directive since
not all platforms that are supported by sigrok do support it.

  pv/views/trace/analogsignal.cpp:54:12: error: 'isnan' is already declared in this scope

diff --git a/pv/views/trace/analogsignal.cpp b/pv/views/trace/analogsignal.cpp
index 67459c8ab5d7f80a570b9c6554ef092effe50ae8..1c0f0efa778ec5979ac199f92a4eb2823cfb9625 100644 (file)
--- a/pv/views/trace/analogsignal.cpp
+++ b/pv/views/trace/analogsignal.cpp
@@ -51,7 +51,8 @@
 using std::deque;
 using std::div;
 using std::div_t;
-using std::isnan;
+// Note that "using std::isnan;" is _not_ put here since that would break
+// compilation on some platforms. Use "std::isnan()" instead in checks below.
 using std::max;
 using std::make_pair;
 using std::min;
@@ -316,7 +317,7 @@ void AnalogSignal::paint_fore(QPainter &p, ViewItemPaintParams &pp)
                // Show the info section on the right side of the trace, including
                // the value at the hover point when the hover marker is enabled
                // and we have corresponding data available
-               if (show_hover_marker_ && !isnan(value_at_hover_pos_)) {
+               if (show_hover_marker_ && !std::isnan(value_at_hover_pos_)) {
                        infotext = QString("[%1] %2 V/div")
                                .arg(format_value_si(value_at_hover_pos_, SIPrefix::unspecified, 0, "V", false))
                                .arg(resolution_);
@@ -865,7 +866,7 @@ void AnalogSignal::process_next_sample_value(float x, float value)
 {
        // Note: NAN is used to indicate the non-existance of a value at this pixel
 
-       if (isnan(prev_value_at_pixel_)) {
+       if (std::isnan(prev_value_at_pixel_)) {
                if (x < 0) {
                        min_value_at_pixel_ = value;
                        max_value_at_pixel_ = value;
@@ -879,7 +880,7 @@ void AnalogSignal::process_next_sample_value(float x, float value)
 
        if (pixel_pos > current_pixel_pos_) {
                if (pixel_pos - current_pixel_pos_ == 1) {
-                       if (isnan(prev_value_at_pixel_)) {
+                       if (std::isnan(prev_value_at_pixel_)) {
                                value_at_pixel_pos_.push_back(prev_value_at_pixel_);
                        } else {
                                // Average the min/max range to create one value for the previous pixel