I found these in mlv_rec.c
for(int32_t k = 0; k < scale; k++)
{
draw_line(x, y+5, x, y+17, color);
x++;
}
if (prev_x && (prev_x < x))
{
if(prev_fill_y)
{
draw_line(prev_x, prev_fill_y, x, y_fill, COLOR_GREEN1);
}
if(prev_rate_0_y && y_rate_0 != ymax)
{
draw_line(prev_x, prev_rate_0_y, x, y_rate_0, COLOR_RED);
}
if(card_spanning && prev_rate_1_y && y_rate_1 != ymax)
{
draw_line(prev_x, prev_rate_1_y, x, y_rate_1, COLOR_BLUE);
}
}
Hope it helps.