revert drawing of rectified waves back to previous approach since it (might be) sligh...

diff --git a/libs/canvas/wave_view.cc b/libs/canvas/wave_view.cc
index 76daf32076fa6084afc5c14edbcebe4be4c80ce2..1952770fa336600c36ac40bdfc69c4c6388893f5 100644 (file)
--- a/libs/canvas/wave_view.cc
+++ b/libs/canvas/wave_view.cc
@@ -512,52 +512,90 @@ WaveView::draw_image (Cairo::RefPtr<Cairo::ImageSurface>& image, PeakData* _peak
        context->set_line_width (0.5);
        context->translate (0.5, 0.0);
 
-       /* draw the lines */
-
 
        /* the height of the clip-indicator should be at most 7 pixels,
         * or 5% of the height of the waveview item.
         */
+
        const double clip_height = min (7.0, ceil (_height * 0.05));
        
+       /* There are 3 possible components to draw at each x-axis position: the
+          waveform "line", the zero line and an outline/clip indicator.  We
+          have to decide which of the 3 to draw at each position, pixel by
+          pixel. This makes the rendering less efficient but it is the only
+          way I can see to do this correctly.
+
+          With only 1 pixel of spread between the top and bottom of the line,
+          we just draw the upper outline/clip indicator.
+
+          With 2 pixels of spread, we draw the upper and lower outline clip
+          indicators. 
+          
+          With 3 pixels of spread we draw the upper and lower outline/clip 
+          indicators and at least 1 pixel of the waveform line.
+          
+          With 5 pixels of spread, we draw all components.
+
+          We can do rectified as two separate passes because we have a much
+          easier decision regarding whether to draw the waveform line. We
+          always draw the clip/outline indicators.
+       */
+
        if (_shape == WaveView::Rectified) {
 
                for (int i = 0; i < n_peaks; ++i) {
 
+                       /* waveform line */
+
                        if (tips[i].spread >= 2.0) {
                                context->move_to (i, tips[i].top);
                                context->line_to (i, tips[i].bot);
-                               context->stroke ();
                        }
-                       
-                       context->save ();
+               }
+
+               context->stroke ();
+
+               /* outline/clip indicators */
+
+               set_source_rgba (context, _outline_color);
+               
+               for (int i = 0; i < n_peaks; ++i) {
+
                        context->move_to (i, tips[i].top);
                        
                        if (_global_show_waveform_clipping && (tips[i].clip_max || tips[i].clip_min)) {
                                /* clip-indicating upper terminal line */
                                set_source_rgba (context, _clip_color);
-                               context->rel_line_to (0, clip_height);
+                               context->rel_line_to (0, min (clip_height, floor (tips[i].spread)));
                                context->stroke ();
+                               set_source_rgba (context, _outline_color);
                        } else {
                                /* normal upper terminal dot */
-                               set_source_rgba (context, _outline_color);
                                context->rel_line_to (0, 1.0);
                                context->stroke ();
                        }
-
-                       context->restore ();
                }
                
        } else {
+
+               /* Note the use of cairo save/restore pairs to retain the drawing
+                  context for the waveform lines, which is already set
+                  correctly when we reach here.
+               */
+
                for (int i = 0; i < n_peaks; ++i) {
 
+                       /* waveform line */
+
                        if (tips[i].spread >= 3.0) {
                                context->move_to (i, tips[i].top);
                                context->line_to (i, tips[i].bot);
                                context->stroke ();
                        }
 
-                       if (tips[i].spread >= 3.0 && show_zero_line()) {
+                       /* zero line */
+
+                       if (tips[i].spread >= 5.0 && show_zero_line()) {
                                context->save ();
                                set_source_rgba (context, _zero_color);
                                context->move_to (0, _height/2.0);
@@ -568,11 +606,13 @@ WaveView::draw_image (Cairo::RefPtr<Cairo::ImageSurface>& image, PeakData* _peak
                        
                        context->save ();
 
+                       /* upper outline/clip indicator */
+
                        context->move_to (i, tips[i].top);
                        if (_global_show_waveform_clipping && ((_shape == WaveView::Rectified && (tips[i].clip_max || tips[i].clip_min)) || tips[i].clip_max)) {
                                /* clip-indicating upper terminal line */
                                set_source_rgba (context, _clip_color);
-                               context->rel_line_to (0, clip_height);
+                               context->rel_line_to (0, min (clip_height, floor (tips[i].spread)));
                                context->stroke ();
                        } else {
                                /* normal upper terminal dot */
@@ -584,12 +624,15 @@ WaveView::draw_image (Cairo::RefPtr<Cairo::ImageSurface>& image, PeakData* _peak
                        context->restore ();
                        
                        if (tips[i].spread >= 2.0) {
+
+                               /* lower outline/clip indicator */
+
                                context->save ();
                                context->move_to (i, tips[i].bot);
                                if (_global_show_waveform_clipping && _shape != WaveView::Rectified && tips[i].clip_min) {
                                        /* clip-indicating lower terminal line */
                                        set_source_rgba (context, _clip_color);
-                                       context->rel_line_to (0, -clip_height);
+                                       context->rel_line_to (0, -(min (clip_height, floor (tips[i].spread))));
                                        context->stroke ();
                                } else {
                                        /* normal lower terminal dot */