Function allocate_offscreen_world

outdated/sys/mac/mactty.c:121–166

* Set up a GWorld in the record */

 * Set up a GWorld in the record
 */
static short
allocate_offscreen_world(tty_record *record)
{
    GWorldPtr gw = (GWorldPtr) 0;
    GWorldFlags world_flags = 0;
    long mem_here, mem_there, other, required_mem;
    Point p = { 0, 0 };
    Rect r_screen;
    GDHandle gdh;
    short s_err;

    select_onscreen_window(record);
    LocalToGlobal(&p);
    r_screen = record->its_bits.bounds;
    OffsetRect(&r_screen, p.h, p.v);

    gdh = GetMaxDevice(&r_screen);
    required_mem = (long) (*((*gdh)->gdPMap))->pixelSize
                       * ((long) record->its_bits.bounds.right
                          * record->its_bits.bounds.bottom)
                   >> 3;

    PurgeSpace(&other, &mem_here);
    if (other < mem_here + MEMORY_MARGIN) {
        mem_here = other - MEMORY_MARGIN;
    }
    dprintf("Heap %ld Required %ld", mem_here, required_mem);
    if (required_mem > mem_here) {
        mem_there = required_mem;
        if (required_mem > TempMaxMem(&mem_there)) {
            dprintf("No memory");
            return memFullErr;
        }
        world_flags |= useTempMem;
    }
    s_err = NewGWorld(&gw, 0, &r_screen, (CTabHandle) 0, (GDHandle) 0,
                      world_flags);
    if (!s_err) {
        record->offscreen_world = gw;
        select_offscreen_port(record);
        SetOrigin(0, 0);
        select_onscreen_window(record);
        dprintf("New GWorld @ %lx;dm", gw);
    }
    return s_err;
}

/*
 * Done with GWorld, release data