twiddle with one test explanation to help paul reason about it

[ardour.git] / libs / ardour / test / framewalk_to_beats_test.cc

diff --git a/libs/ardour/test/framewalk_to_beats_test.cc b/libs/ardour/test/framewalk_to_beats_test.cc
index c7fb45cada29ab785d256a26f6214040d9f8c706..2385dd53c94bf7316d2dae72dffe07044962468e 100644 (file)
--- a/libs/ardour/test/framewalk_to_beats_test.cc
+++ b/libs/ardour/test/framewalk_to_beats_test.cc
@@ -23,11 +23,115 @@ FramewalkToBeatsTest::singleTempoTest ()
        map.add_meter (meter, BBT_Time (1, 1, 0));
        map.add_tempo (tempo, BBT_Time (1, 1, 0));
 
-       /* Add 1 beats-worth of frames to a 2 beat starting point */
+       /* Walk 1 beats-worth of frames from beat 3 */
        double r = map.framewalk_to_beats (frames_per_beat * 2, frames_per_beat * 1);
-       CPPUNIT_ASSERT (r == 1);
+       CPPUNIT_ASSERT_EQUAL (1.0, r);
 
-       /* Add 6 beats-worth of frames to a 3 beat starting point */
+       /* Walk 6 beats-worth of frames from beat 4 */
        r = map.framewalk_to_beats (frames_per_beat * 3, frames_per_beat * 6);
-       CPPUNIT_ASSERT (r == 6);
+       CPPUNIT_ASSERT_EQUAL (6.0, r);
+
+       /* Walk 1.5 beats-worth of frames from beat 3 */
+       r = map.framewalk_to_beats (frames_per_beat * 2, frames_per_beat * 1.5);
+       CPPUNIT_ASSERT_EQUAL (1.5, r);
+
+       /* Walk 1.5 beats-worth of frames from beat 2.5 */
+       r = map.framewalk_to_beats (frames_per_beat * 2.5, frames_per_beat * 1.5);
+       CPPUNIT_ASSERT_EQUAL (1.5, r);
+}
+
+void
+FramewalkToBeatsTest::doubleTempoTest ()
+{
+       int const sampling_rate = 48000;
+
+       TempoMap map (sampling_rate);
+       Meter meter (4, 4);
+       map.add_meter (meter, BBT_Time (1, 1, 0));
+
+       /*
+         120bpm at bar 1, 240bpm at bar 4
+         
+         120bpm = 24e3 samples per beat
+         240bpm = 12e3 samples per beat
+       */
+       
+
+       /*
+         
+         120bpm                                          240bpm
+         0 beats                                         12 beats
+         0 frames                                        288e3 frames
+         24e3 frames per beat                            12e3 frames per beat
+         |               |               |               |               |
+         1.1 1.2 1.3 1.4 2.1 2.2 2.3 2.4 3.1 3.2 3.3 3.4 4.1 4.2 4.3 4.4 5.1
+         0   1   2   3   4   5   6   7   8   9   10  11  12  13  14  15  16
+
+       */
+
+       Tempo tempoA (120);
+       map.add_tempo (tempoA, BBT_Time (1, 1, 0));
+       Tempo tempoB (240);
+       map.add_tempo (tempoB, BBT_Time (4, 1, 0));
+
+       /* Now some tests */
+
+       /* Walk 1 beat from 1|2 */
+       double r = map.framewalk_to_beats (24e3, 24e3);
+       CPPUNIT_ASSERT_EQUAL (1.0, r);
+
+       /* Walk 2 beats from 3|3 to 4|1 (over the tempo change) */
+       r = map.framewalk_to_beats (240e3, (24e3 + 24e3));
+       CPPUNIT_ASSERT_EQUAL (2.0, r);
+
+       /* Walk 2.5 beats from 3|3.5 to 4.2 (over the tempo change) */
+       r = map.framewalk_to_beats (264e3 - 12e3, (24e3 + 12e3 + 12e3));
+       CPPUNIT_ASSERT_EQUAL (2.5, r);
+       /* Walk 3 beats from 3|4.5 to 4|3.5 (over the tempo change) */
+       r = map.framewalk_to_beats (264e3 - 12e3, (24e3 + 12e3 + 12e3 + 6e3));
+       CPPUNIT_ASSERT_EQUAL (3.0, r);
+
+       /* Walk 3.5 beats from 3|4.5 to 4.4 (over the tempo change) */
+       r = map.framewalk_to_beats (264e3 - 12e3, (24e3 + 12e3 + 12e3 + 12e3));
+       CPPUNIT_ASSERT_EQUAL (3.5, r);
+}
+
+void
+FramewalkToBeatsTest::tripleTempoTest ()
+{
+       int const sampling_rate = 48000;
+
+       TempoMap map (sampling_rate);
+       Meter meter (4, 4);
+       map.add_meter (meter, BBT_Time (1, 1, 0));
+
+       /*
+         120bpm at bar 1, 240bpm at bar 2, 160bpm at bar 3
+         
+         120bpm = 24e3 samples per beat
+         160bpm = 18e3 samples per beat
+         240bpm = 12e3 samples per beat
+       */
+       
+
+       /*
+         
+         120bpm            240bpm            160bpm
+         0 beats           4 beats           8 beats
+         0 frames          96e3 frames       144e3 frames
+         |                 |                 |                 |                 |
+         | 1.1 1.2 1.3 1.4 | 2.1 2.2 2.3.2.4 | 3.1 3.2 3.3 3.4 | 4.1 4.2 4.3 4.4 |
+
+       */
+
+       Tempo tempoA (120);
+       map.add_tempo (tempoA, BBT_Time (1, 1, 0));
+       Tempo tempoB (240);
+       map.add_tempo (tempoB, BBT_Time (2, 1, 0));
+       Tempo tempoC (160);
+       map.add_tempo (tempoC, BBT_Time (3, 1, 0));
+
+       /* Walk from 1|3 to 4|1 */
+       double r = map.framewalk_to_beats (2 * 24e3, (2 * 24e3) + (4 * 12e3) + (4 * 18e3));
+       CPPUNIT_ASSERT_EQUAL (10.0, r);
 }