Initial stab at tempo ramps.

Replaces the list of points in TempoMap with TempoSection functions, which
compute tempo-at or tick-at time relative to tempo section start.
TempoMap consults them additively to determine things like bbt_time(),
frame_time() get_grid() etc.
This has a marked effect on scrolling speed along with the code simplification
in the places it has been attempted.

Several things are broken here.
Currently every ramp except the last one is an exponential ramp. this may
be simple to fix :).
Mouse-over midi grid doesn't match mouse click grid. should also be simple.

Many things seem to work, but their accuracy should be in question until
each area has been addressed.

1 files changed, 21 insertions, 19 deletions

diff --git a/gtk2_ardour/tempo_lines.cc b/gtk2_ardour/tempo_lines.cc
index bb86011458..c320486108 100644
--- a/gtk2_ardour/tempo_lines.cc
+++ b/gtk2_ardour/tempo_lines.cc
@@ -54,12 +54,12 @@ TempoLines::hide ()
 }
 
 void
-TempoLines::draw_ticks (const ARDOUR::TempoMap::BBTPointList::const_iterator& b,
-                        unsigned                                              divisions,
+TempoLines::draw_ticks (std::vector<ARDOUR::TempoMap::BBTPoint>& grid,
+			unsigned                                              divisions,
                         framecnt_t                                            leftmost_frame,
                         framecnt_t                                            frame_rate)
 {
-	const double   fpb  = b->tempo->frames_per_beat(frame_rate);
+	const double   fpb  = grid.begin()->tempo->frames_per_beat(frame_rate);
 	const uint32_t base = UIConfiguration::instance().color_mod("measure line beat", "measure line beat");
 
 	for (unsigned l = 1; l < divisions; ++l) {
@@ -74,7 +74,8 @@ TempoLines::draw_ticks (const ARDOUR::TempoMap::BBTPointList::const_iterator& b,
 		/* draw line with alpha corresponding to coarsest level */
 		const uint8_t    a = max(8, (int)rint(UINT_RGBA_A(base) / (0.8 * log2(level))));
 		const uint32_t   c = UINT_RGBA_CHANGE_A(base, a);
-		const framepos_t f = b->frame + (l * (fpb / (double)divisions));
+		const framepos_t f = grid.begin()->frame + (l * (fpb / (double)divisions));
+		//const framepos_t f = frame_at_tick (last_beat_in_ticks + (l * (BBT_Time::ticks_per_beat / (double)divisions)));
 		if (f > leftmost_frame) {
 			lines.add (PublicEditor::instance().sample_to_pixel_unrounded (f), 1.0, c);
 		}
@@ -82,13 +83,12 @@ TempoLines::draw_ticks (const ARDOUR::TempoMap::BBTPointList::const_iterator& b,
 }
 
 void
-TempoLines::draw (const ARDOUR::TempoMap::BBTPointList::const_iterator& begin,
-                  const ARDOUR::TempoMap::BBTPointList::const_iterator& end,
-                  unsigned                                              divisions,
+TempoLines::draw (std::vector<ARDOUR::TempoMap::BBTPoint>& grid,
+		  unsigned                                              divisions,
                   framecnt_t                                            leftmost_frame,
                   framecnt_t                                            frame_rate)
 {
-	ARDOUR::TempoMap::BBTPointList::const_iterator i;
+	std::vector<ARDOUR::TempoMap::BBTPoint>::const_iterator i;
 	double  beat_density;
 
 	uint32_t beats = 0;
@@ -97,10 +97,10 @@ TempoLines::draw (const ARDOUR::TempoMap::BBTPointList::const_iterator& begin,
 
 	/* get the first bar spacing */
 
-	i = end;
+	i = grid.end();
 	i--;
-	bars = (*i).bar - (*begin).bar;
-	beats = distance (begin, end) - bars;
+	bars = (*i).bar - (*grid.begin()).bar;
+	beats = distance (grid.begin(), grid.end()) - bars;
 
 	beat_density = (beats * 10.0f) / lines.canvas()->width();
 
@@ -116,15 +116,14 @@ TempoLines::draw (const ARDOUR::TempoMap::BBTPointList::const_iterator& begin,
 	}
 
 	lines.clear ();
-
-	if (beat_density <= 0.12 && begin != end && begin->frame > 0) {
-		/* draw subdivisions of the beat before the first visible beat line */
-		ARDOUR::TempoMap::BBTPointList::const_iterator prev = begin;
-		--prev;
-		draw_ticks(prev, divisions, leftmost_frame, frame_rate);
+	if (beat_density <= 0.12 && grid.begin() != grid.end() && grid.begin()->frame > 0) {
+		/* draw subdivisions of the beat before the first visible beat line XX this shouldn't happen now */
+		std::vector<ARDOUR::TempoMap::BBTPoint> vec;
+		vec.push_back (*i);
+		draw_ticks (vec, divisions, leftmost_frame, frame_rate);
 	}
 
-	for (i = begin; i != end; ++i) {
+	for (i = grid.begin(); i != grid.end(); ++i) {
 
 		if ((*i).is_bar()) {
 			color = UIConfiguration::instance().color ("measure line bar");
@@ -141,7 +140,10 @@ TempoLines::draw (const ARDOUR::TempoMap::BBTPointList::const_iterator& begin,
 
 		if (beat_density <= 0.12) {
 			/* draw subdivisions of this beat */
-			draw_ticks(i, divisions, leftmost_frame, frame_rate);
+			std::vector<ARDOUR::TempoMap::BBTPoint> vec;
+			vec.push_back (*i);
+
+			draw_ticks(vec, divisions, leftmost_frame, frame_rate);
 		}
 	}
 }