If I use bmap_process(BMAP* bmDest, BMAP* bmSrc, MATERIAL* mtl); after copying text into a bmSrc, I miss the text in the bmDest.

A. First I copy a small bitmap into a big buffer bitmap...
Code
bmap_blit(bmapBuffer_800x600, bmapPhoto_40x40, vector(10,10,0), vector(0,0,0));  //I copy a photo into the buffer bitmap

B. 2nd I copy a text into the same big buffer bitmap...
Code
textHalloWorld.target_map = bmapBuffer_800x600; //I copy a text into the same buffer bitmap

As far the big buffer bitmap 'bmapBuffer_800x600' contains small bitmap 'bmapPhoto_40x40' as well as the text 'textHalloWorld'[i].

C.After using a shader on [i]'bmapBuffer_800x600' and store the result in another bit bitmap 'bmapShader', the text is missing in the new 'bmapShader'.
Code
bmap_process(bmapShader, bmapBuffer_800x600, mtl_sepia); //text missing!

Don't take the cake to the party.