draw_row() function can't draw short lines

[Smilei0]

Hello!
I am trying to make a litle snake game with the library and I noticed that the draw_row() function can't draw short lines ( 15px for example) and because of that small rectangles behave strange. If I remove the following lines it works correctly:

while (x0%32) {
ESPVGAX::putpixel(x0, line, c, op);
x0++;
sw--;
}

Can you check it please and thanks for the library !