luaproc: assert instance access

[ardour.git] / scripts / amp2.lua

diff --git a/scripts/amp2.lua b/scripts/amp2.lua
index f6328ff404994ae960fb394df3a62e95c02288a7..42316af493e071bb2557e774b8be0372e4700e8f 100644 (file)
--- a/scripts/amp2.lua
+++ b/scripts/amp2.lua
@@ -34,8 +34,17 @@ end
 
 function dsp_runmap (bufs, in_map, out_map, n_samples, offset)
        for c = 1,audio_ins do
-               local b = in_map:get(ARDOUR.DataType("audio"), c - 1); -- get id of mapped buffer
-               local a = bufs:get_audio(b):data(offset):array() -- get a reference (pointer to array)
+               -- ensure that processing does happen in-place
+               local ib = in_map:get(ARDOUR.DataType("audio"), c - 1); -- get id of mapped input buffer for given cannel
+               local ob = out_map:get(ARDOUR.DataType("audio"), c - 1); -- get id of mapped output buffer for given cannel
+               assert (ib ~= ARDOUR.ChanMapping.Invalid);
+               assert (ob ~= ARDOUR.ChanMapping.Invalid);
+
+               local bi = bufs:get_audio(ib)
+               local bo = bufs:get_audio(ob)
+               assert (bi:sameinstance(bo))
+
+               local a = bufs:get_audio(ib):data(offset):array() -- get a reference (pointer to array)
                for s = 1,n_samples do
                        a[s] = a[s] * 2; -- modify data in-place (shared with ardour)
                end