alignment.txt

for each inline span on the line
    set height rel to baseline if possible
get highest of ones that are set
get lowest of ones that are set
set height
of ones that aren't set, set y based on height



baseline = set rel to baseline
middle = parent font and parent baseline
sub = rel to line's baseline
super = rel to line's baseline
text-top = rel to line's baseline and parent's font
text-bottom = rel to line's baseline and parent's font
top = rel to line's box (height)
bottom = rel to line's box (height)

at inline box creation time
    need line and parent font height
    if vertical align = baseline, middle, sub, super, text-top, text-bottom
        then set the inline.y relative to the line.baseline
        set the baseline too
    calculate the height of the inline
    
    
at save line time
    get the top of the highest inline
    get the bottom of the lowest inline
    // top and bottom are dist from baseline
    int top = 0;
    int bot = 0;
    int hi = 0;
    for(int i=0; i<inlines.size(); i++) {
        InlineBox inline = (InlineBox)inlines.get(i);
        if(inline.vset) {
            // compare the top of the box
            if(inline.y < itop)
                itop = inline.y;
            }
            // compare the bottom of the box
            if(inline.y + inline.height > ibot) {
                ibot = inline.y + inline.height;
            }
        } else {
        // if it's not one of the baseline derived vertical aligns
            // then just compare the straight height of the inline
            if(inline.height > hi) {
                hi = inline.height;
            }
        }
    }
    
    if(bot-top > height) {
        line.height = bot-top;
    } else {
        line.height = height;
    }
    
    line.baseline = line.height - font.baseline
    
    // loop through all inlines to set the last ones
    for(int i=0; i<inlines.size(); i++) {
        InlineBox inline = (InlineBox)inlines.get(i);
        if(!inline.vset) {
            inline.vset;
            if(inline.topalign) {
                inline.y = -line.baseline;
            }
            if(inline.bottomalign) {
                inline.y = line.height-line.baseline
            }
        }
    }
    
    // done