Initial import.

src/libdraw/loadimage.c

@@ -0,0 +1,54 @@
+#include <u.h>
+#include <libc.h>
+#include <draw.h>
+
+int
+loadimage(Image *i, Rectangle r, uchar *data, int ndata)
+{
+	long dy;
+	int n, bpl;
+	uchar *a;
+	int chunk;
+
+	chunk = i->display->bufsize - 64;
+
+	if(!rectinrect(r, i->r)){
+		werrstr("loadimage: bad rectangle");
+		return -1;
+	}
+	bpl = bytesperline(r, i->depth);
+	n = bpl*Dy(r);
+	if(n > ndata){
+		werrstr("loadimage: insufficient data");
+		return -1;
+	}
+	ndata = 0;
+	while(r.max.y > r.min.y){
+		dy = r.max.y - r.min.y;
+		if(dy*bpl > chunk)
+			dy = chunk/bpl;
+		if(dy <= 0){
+			werrstr("loadimage: image too wide for buffer");
+			return -1;
+		}
+		n = dy*bpl;
+		a = bufimage(i->display, 21+n);
+		if(a == nil){
+			werrstr("bufimage failed");
+			return -1;
+		}
+		a[0] = 'y';
+		BPLONG(a+1, i->id);
+		BPLONG(a+5, r.min.x);
+		BPLONG(a+9, r.min.y);
+		BPLONG(a+13, r.max.x);
+		BPLONG(a+17, r.min.y+dy);
+		memmove(a+21, data, n);
+		ndata += n;
+		data += n;
+		r.min.y += dy;
+	}
+	if(flushimage(i->display, 0) < 0)
+		return -1;
+	return ndata;
+}