force waveform images to be least 1px wide

[ardour.git] / libs / canvas / wave_view.cc

diff --git a/libs/canvas/wave_view.cc b/libs/canvas/wave_view.cc
index ca026e978803427106e7df05115ddcbe9137344d..c8b8b9042c3cf885adec7a84a114bd52aab46585 100644 (file)
--- a/libs/canvas/wave_view.cc
+++ b/libs/canvas/wave_view.cc
@@ -985,7 +985,7 @@ WaveView::generate_image (boost::shared_ptr<WaveViewThreadRequest> req, bool in_
 
                framepos_t sample_start = max (_region_start, (center - image_samples));
                framepos_t sample_end = min (center + image_samples, region_end());
-               const int n_peaks = llrintf ((sample_end - sample_start)/ (req->samples_per_pixel));
+               const int n_peaks = std::max (1LL, llrint (ceil ((sample_end - sample_start) / (req->samples_per_pixel))));
 
                assert (n_peaks > 0 && n_peaks < 32767);