Minor glitch with item selection

[PowerWyrm]

When you use a tileset with tile height greater than 1 (32x32 tileset for example), the portion containing item selection choices is not "rectangular".

The problem comes from this code in Term_erase():

        /* Fast access */
        scr_aa = Term->scr->a[y];
        scr_cc = Term->scr->c[y];

        scr_taa = Term->scr->ta[y];
        scr_tcc = Term->scr->tc[y];

        if ((n > 0) && (scr_aa[x] == 255))
        {
            x--;
            n++;
        }

Removing the "if" block fixes the problem (and I don't really see the purpose of that "if" block -- but I could be wrong).

[PowerWyrm]

Browsing spells using 32x32 tileset in "nice graphics" mode (6x3 tiles) produces the same effect, in a worse way (description is not properly updated when moving the cursor). See attached screenshot.

[PowerWyrm]

There are two problems here:

1) The irregular display of the left border is due to the code in Term_erase() which only works if tile width is 2 (the code has not been changed since bigtile mode -- double tile width -- was removed in favor of variable tile width/height.

This is fixed by adapting the code above to start on the x axis at the beginning of a tile:

        /* Hack -- Always start at the beginning of a tile in bigtile mode */
        if ((n > 0) && (scr_aa[x] == 255))
        {
            int x0 = ((x - COL_MAP) / tile_width) * tile_width + COL_MAP;

            x = x0;
            n = n + x - x0;
        }

2) The problem with spell description not properly updated when switching to another spell is the same, but this time on the y axis. I tried to fix it in the same function, but gave up after failing miserably (seems *really* tricky to fix). A proposed workaround is to fix the problem directly in the spell menu browser (spell_menu_browser method) by putting more empty lines under spell descriptions until the end of a tile is reached:

    /* XXX */
    text_out_pad = 0;
    text_out_indent = 0;

    Term_locate(&x, &y);

    /* Hack -- Always finish at the end of a tile in bigtile mode */
    if (tile_height > 1)
    {
        int ymax = ((y - ROW_MAP) / tile_height) * tile_height + ROW_MAP + tile_height - 1;

        while (++y <= ymax) Term_erase(x - 1, y, 255);
    }