--- ray/src/rt/rview.c	1990/03/09 14:00:06	1.11
+++ ray/src/rt/rview.c	1991/05/03 16:12:34	1.14
@@ -55,6 +55,10 @@ PNODE  ptrunk;				/* the base of our image */
 RECT  pframe;				/* current frame boundaries */
 int  pdepth;				/* image depth in current frame */
 
+static char  *reserve_mem = NULL;	/* pre-allocated reserve memory */
+
+#define RESERVE_AMT	8192		/* amount of memory to reserve */
+
 #define  CTRL(c)	('c'-'@')
 
 
@@ -112,15 +116,15 @@ rview()				/* do a view */
 	char  buf[32];
 
 	devopen(devname);		/* open device */
-	newimage();			/* set up image */
+	newimage();			/* start image (calls fillreserves) */
 
 	for ( ; ; ) {			/* quit in command() */
-		while (hresolu <= 1<<pdepth &&
-				vresolu <= 1<<pdepth)
+		while (hresolu <= 1<<pdepth && vresolu <= 1<<pdepth)
 			command("done: ");
-
-		if (hresolu <= psample<<pdepth &&
-				vresolu <= psample<<pdepth) {
+		while (reserve_mem == NULL)
+			command("out of memory: ");
+		errno = 0;
+		if (hresolu <= psample<<pdepth && vresolu <= psample<<pdepth) {
 			sprintf(buf, "%d sampling...\n", 1<<pdepth);
 			(*dev->comout)(buf);
 			rsample();
@@ -129,14 +133,33 @@ rview()				/* do a view */
 			(*dev->comout)(buf);
 			refine(&ptrunk, 0, 0, hresolu, vresolu, pdepth+1);
 		}
-		if (dev->inpready)
+		if (errno == ENOMEM)		/* ran out of memory */
+			freereserves();
+		else if (dev->inpready)		/* noticed some input */
 			command(": ");
-		else
+		else				/* finished this depth */
 			pdepth++;
 	}
 }
 
 
+fillreserves()			/* fill memory reserves */
+{
+	if (reserve_mem != NULL)
+		return;
+	reserve_mem = malloc(RESERVE_AMT);
+}
+
+
+freereserves()			/* free memory reserves */
+{
+	if (reserve_mem == NULL)
+		return;
+	free(reserve_mem);
+	reserve_mem = NULL;
+}
+
+
 command(prompt)			/* get/execute command */
 char  *prompt;
 {
@@ -268,9 +291,11 @@ rsample()			/* sample the image */
 	xsiz = (((pframe.r-pframe.l)<<pdepth)+hresolu-1) / hresolu;
 	ysiz = (((pframe.u-pframe.d)<<pdepth)+vresolu-1) / vresolu;
 	rl = (RECT *)malloc(xsiz*sizeof(RECT));
+	if (rl == NULL)
+		return;
 	pl = (PNODE **)malloc(xsiz*sizeof(PNODE *));
-	if (rl == NULL || pl == NULL)
-		error(SYSTEM, "out of memory in rsample");
+	if (pl == NULL)
+		return;
 	/*
 	 * Initialize the bottom row.
 	 */
@@ -357,7 +382,7 @@ int  pd;
 	if (p->kid == NULL) {			/* subdivide */
 
 		if ((p->kid = newptree()) == NULL)
-			error(SYSTEM, "out of memory in refine");
+			return(growth);
 		/*
 		 *  The following paint order can leave a black pixel
 		 *  when redraw() is called in (*dev->paintr)().