Sample_Buffer.display_Start Is Read Only

Renoise Tool Development
1

The parameter sample_buffer.display_start is read only.

Writing to it gives the following error:

>>> renoise.song().selected_sample.sample_buffer.display_start = 1  
*** std::logic_error: 'invalid display_start index '1'. no display_start's are available. 0 may be allowed.'  
*** stack traceback:  
*** [C]: ?  
*** [C]: in function '__newindex'  
*** [string "do..."]:22: in function   
*** [string "renoise.song().selected_sample.sample_buffe..."]:1: in main chunk
2

Hmm, that seems to be a very cryptic way of saying that the sample you’re trying to zoom in on is empty. Are you sure this sample has data?

Or alternatively that the display_length is too short. If the sample is valid, does it work if you set display_length before display_start?

Or even more alternatively, can you try setting the display_range instead?

3

Cannot replicate this bug now.

Trying to set display_start when there is no sample results in the following:

*** std::logic_error: 'can not access properties of a sample buffer with no sample data.'  
*** stack traceback:  
*** [C]: ?  
*** [C]: in function '__index'  
*** [string "do..."]:36: in function   
*** TestPad.lua:3: in main chunk
4

I can reliably replicate this bug now:

Load a sample into an instrument (I just dragged from the filebrowser into the sample editor window).

Then the following will occur:

>>> oprint(renoise.song().selected_sample.sample_buffer.display_length)  
160364  
>>> renoise.song().selected_sample.sample_buffer.display_start = 20000  
*** std::logic_error: 'invalid display_start index '20000'. no display_start's are available. 0 may be allowed.'  
*** stack traceback:  
*** [C]: ?  
*** [C]: in function '__newindex'  
*** [string "do..."]:22: in function   
*** [string "renoise.song().selected_sample.sample_buffe..."]:1: in main chunk  
  
>>> renoise.song().selected_sample.sample_buffer.display_length = 20000  
>>> renoise.song().selected_sample.sample_buffer.display_start = 10000

It looks like you cannot set display_start until you set display_length.

5

Yes, you can not set a “display_start” which would invalidate the end, would move it past the right boundary of the sample because of the “display_length”.
Probably should not be so picky here and internally clip the length then, or even remove “display_start” property completely in favor of “display_range”.

So for now use “display_range” instead please, which allows setting both properties atomically.