/* ------------- rect.c --------------- */

#include "dflat.h"

/*
 * Produce the vector end points produced by the overlap
 * of two other vectors
 */
static void subVector(int *v1, int *v2,
                        int t1, int t2, int o1, int o2)
{
    *v1 = *v2 = -1;
    if (within(o1, t1, t2))    {
        *v1 = o1;
        if (within(o2, t1, t2))
            *v2 = o2;
        else
            *v2 = t2;
    }
    else if (within(o2, t1, t2))    {
        *v2 = o2;
        if (within(o1, t1, t2))
            *v1 = o1;
        else
            *v1 = t1;
    }
    else if (within(t1, o1, o2))    {
        *v1 = t1;
        if (within(t2, o1, o2))
            *v2 = t2;
        else
            *v2 = t2;
    }
    else if (within(t2, o1, o2))    {
        *v2 = t2;
        if (within(t1, o1, o2))
            *v1 = t1;
        else
            *v1 = o1;
    }
}

/*
 * Return the rectangle produced by the overlap
 * of two other rectangles
 */
RECT subRectangle(RECT r1, RECT r2)
{
    RECT r = {0,0,0,0};
    subVector((int *) &RectLeft(r), (int *) &RectRight(r),
        RectLeft(r1), RectRight(r1),
        RectLeft(r2), RectRight(r2));
    subVector((int *) &RectTop(r), (int *) &RectBottom(r),
        RectTop(r1), RectBottom(r1),
        RectTop(r2), RectBottom(r2));
    if (RectRight(r) == -1 || RectTop(r) == -1)
        RectRight(r) =
        RectLeft(r) =
        RectTop(r) =
        RectBottom(r) = 0;
    return r;
}

/*
 * Assumes that r1 is a proper subset of r2
 * Returns rectangle that is relative position of r1 within r2
 */
RECT RelativeRectangle(RECT r1, RECT r2)
{
    RECT rc;
    RectLeft(rc) = RectLeft(r1) - RectLeft(r2);
    RectTop(rc) = RectTop(r1) - RectTop(r2);
    RectBottom(rc) = RectTop(rc) + RectHeight(r1) - 1;
    RectRight(rc) = RectLeft(rc) + RectWidth(r1) - 1;
    return rc;
}

/* ---------- return the client rectangle of a window ------ */
RECT ClientRect(void *wnd)
{
    RECT rc = ((WINDOW)wnd)->rc;
    if (TestAttribute((WINDOW)wnd, HASBORDER))    {
        RectLeft(rc)++;
        RectRight(rc)--;
    }
    if (WindowHeight((WINDOW)wnd) > 1 &&
        (GetClass((WINDOW)wnd) != EDITBOX ||
            TestAttribute((WINDOW)wnd, MULTILINE)))    {
        RectTop(rc)++;
        RectBottom(rc)--;
        if (TestAttribute((WINDOW)wnd, HASMENUBAR))
            RectTop(rc)++;
    }
    return rc;
}

/*
 * Initialize a rectangle
 */
RECT SetRect(int lf, int tp, int rt, int bt)
{
    RECT rc;
    rc.lf = lf;
    rc.tp = tp;
    rc.rt = rt;
    rc.bt = bt;
    return rc;
}