a

libmemdraw/cload.c

@@ -0,0 +1,68 @@
+#include <u.h>
+#include <libc.h>
+#include <draw.h>
+#include <memdraw.h>
+
+int
+_cloadmemimage(Memimage *i, Rectangle r, uchar *data, int ndata)
+{
+	int y, bpl, c, cnt, offs;
+	uchar mem[NMEM], *memp, *omemp, *emem, *linep, *elinep, *u, *eu;
+
+	if(!rectinrect(r, i->r))
+		return -1;
+	bpl = bytesperline(r, i->depth);
+	u = data;
+	eu = data+ndata;
+	memp = mem;
+	emem = mem+NMEM;
+	y = r.min.y;
+	linep = byteaddr(i, Pt(r.min.x, y));
+	elinep = linep+bpl;
+	for(;;){
+		if(linep == elinep){
+			if(++y == r.max.y)
+				break;
+			linep = byteaddr(i, Pt(r.min.x, y));
+			elinep = linep+bpl;
+		}
+		if(u == eu){	/* buffer too small */
+			return -1;
+		}
+		c = *u++;
+		if(c >= 128){
+			for(cnt=c-128+1; cnt!=0 ;--cnt){
+				if(u == eu){		/* buffer too small */
+					return -1;
+				}
+				if(linep == elinep){	/* phase error */
+					return -1;
+				}
+				*linep++ = *u;
+				*memp++ = *u++;
+				if(memp == emem)
+					memp = mem;
+			}
+		}
+		else{
+			if(u == eu)	/* short buffer */
+				return -1;
+			offs = *u++ + ((c&3)<<8)+1;
+			if(memp-mem < offs)
+				omemp = memp+(NMEM-offs);
+			else
+				omemp = memp-offs;
+			for(cnt=(c>>2)+NMATCH; cnt!=0; --cnt){
+				if(linep == elinep)	/* phase error */
+					return -1;
+				*linep++ = *omemp;
+				*memp++ = *omemp++;
+				if(omemp == emem)
+					omemp = mem;
+				if(memp == emem)
+					memp = mem;
+			}
+		}
+	}
+	return u-data;
+}