Postgres95 1.01 Distribution - Virgin Sources

src/backend/access/rtree/rtproc.c

@@ -0,0 +1,150 @@
+/*-------------------------------------------------------------------------
+ *
+ * rtproc.c--
+ *    pg_amproc entries for rtrees.
+ *
+ * Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *    $Header: /cvsroot/pgsql/src/backend/access/rtree/Attic/rtproc.c,v 1.1.1.1 1996/07/09 06:21:13 scrappy Exp $
+ *
+ *-------------------------------------------------------------------------
+ */
+#include <math.h>
+#include <string.h>
+
+#include "postgres.h"
+
+#include "utils/elog.h"
+#include "utils/geo-decls.h"
+#include "utils/palloc.h"
+
+BOX
+*rt_box_union(BOX *a, BOX *b)
+{
+    BOX *n;
+    
+    if ((n = (BOX *) palloc(sizeof (*n))) == (BOX *) NULL)
+	elog(WARN, "Cannot allocate box for union");
+    
+    n->xh = Max(a->xh, b->xh);
+    n->yh = Max(a->yh, b->yh);
+    n->xl = Min(a->xl, b->xl);
+    n->yl = Min(a->yl, b->yl);
+    
+    return (n);
+}
+
+BOX *
+rt_box_inter(BOX *a, BOX *b)
+{
+    BOX *n;
+    
+    if ((n = (BOX *) palloc(sizeof (*n))) == (BOX *) NULL)
+	elog(WARN, "Cannot allocate box for union");
+    
+    n->xh = Min(a->xh, b->xh);
+    n->yh = Min(a->yh, b->yh);
+    n->xl = Max(a->xl, b->xl);
+    n->yl = Max(a->yl, b->yl);
+    
+    if (n->xh < n->xl || n->yh < n->yl) {
+	pfree(n);
+	return ((BOX *) NULL);
+    }
+    
+    return (n);
+}
+
+void
+rt_box_size(BOX *a, float *size)
+{
+    if (a == (BOX *) NULL || a->xh <= a->xl || a->yh <= a->yl)
+	*size = 0.0;
+    else
+	*size = (float) ((a->xh - a->xl) * (a->yh - a->yl));
+    
+    return;
+}
+
+/*
+ *  rt_bigbox_size() -- Compute a size for big boxes.
+ *
+ *	In an earlier release of the system, this routine did something
+ *	different from rt_box_size.  We now use floats, rather than ints,
+ *	as the return type for the size routine, so we no longer need to
+ *	have a special return type for big boxes.
+ */
+void
+rt_bigbox_size(BOX *a, float *size)
+{
+    rt_box_size(a, size);
+}
+
+POLYGON *
+rt_poly_union(POLYGON *a, POLYGON *b)
+{
+    POLYGON *p;
+    
+    p = (POLYGON *)PALLOCTYPE(POLYGON);
+    
+    if (!PointerIsValid(p))
+	elog(WARN, "Cannot allocate polygon for union");
+    
+    memset((char *) p, 0, sizeof(POLYGON));	/* zero any holes */
+    p->size = sizeof(POLYGON);
+    p->npts = 0;
+    p->boundbox.xh = Max(a->boundbox.xh, b->boundbox.xh);
+    p->boundbox.yh = Max(a->boundbox.yh, b->boundbox.yh);
+    p->boundbox.xl = Min(a->boundbox.xl, b->boundbox.xl);
+    p->boundbox.yl = Min(a->boundbox.yl, b->boundbox.yl);
+    return p;
+}
+
+void
+rt_poly_size(POLYGON *a, float *size)
+{
+    double xdim, ydim;
+    
+    size = (float *) palloc(sizeof(float));
+    if (a == (POLYGON *) NULL || 
+	a->boundbox.xh <= a->boundbox.xl || 
+	a->boundbox.yh <= a->boundbox.yl)
+	*size = 0.0;
+    else {
+	xdim = (a->boundbox.xh - a->boundbox.xl);
+	ydim = (a->boundbox.yh - a->boundbox.yl);
+	
+	*size = (float) (xdim * ydim);
+    }
+    
+    return;
+}
+
+POLYGON *
+rt_poly_inter(POLYGON *a, POLYGON *b)
+{
+    POLYGON *p;
+    
+    p = (POLYGON *) PALLOCTYPE(POLYGON);
+    
+    if (!PointerIsValid(p))
+	elog(WARN, "Cannot allocate polygon for intersection");
+    
+    memset((char *) p, 0, sizeof(POLYGON));	/* zero any holes */
+    p->size = sizeof(POLYGON);
+    p->npts = 0;
+    p->boundbox.xh = Min(a->boundbox.xh, b->boundbox.xh);
+    p->boundbox.yh = Min(a->boundbox.yh, b->boundbox.yh);
+    p->boundbox.xl = Max(a->boundbox.xl, b->boundbox.xl);
+    p->boundbox.yl = Max(a->boundbox.yl, b->boundbox.yl);
+    
+    if (p->boundbox.xh < p->boundbox.xl || p->boundbox.yh < p->boundbox.yl)
+	{
+	    pfree(p);
+	    return ((POLYGON *) NULL);
+	}
+    
+    return (p);
+}