[V8i MDL] White as transparent color for mdlImage_extCreateFileFromRGB

I'm using mdlImage_extCreateFileFromRGB to export design file as image with setting Preferences -> Black background -> White set to true. So I have white background in my view.


What I need is to set white background to be transparent when exported to image, but I'm not sure how to set this transparencyP parameter. From Docs:



As for black background this works fine:

Point2d imageSize;
byte *transp = (byte*)malloc(4);

byte *inputMap = (byte*)malloc(3 * g_tileCols * g_tileRows);

imageSize.x = 500;

imageSize.y = 500;

mdlImage_saveViewToRGB( &inputMap, &imageSize, WIREFRAME, FALSE, 0, viewIdx);
results = mdlImage_extCreateFileFromRGB (fn, g_fileFormat, g_colorMode, &imageSize, inputMap, g_Compression, transp, NULL);