Initial revision

src/libdraw/writecolmap.c

@@ -0,0 +1,35 @@
+#include <u.h>
+#include <libc.h>
+#include <draw.h>
+
+/*
+ * This code (and the devdraw interface) will have to change
+ * if we ever get bitmaps with ldepth > 3, because the
+ * colormap will have to be written in chunks
+ */
+
+void
+writecolmap(Display *d, RGB *m)
+{
+	int i, n, fd;
+	char buf[64], *t;
+	ulong r, g, b;
+
+	sprint(buf, "/dev/draw/%d/colormap", d->dirno);
+	fd = open(buf, OWRITE);
+	if(fd < 0)
+		drawerror(d, "wrcolmap: open colormap failed");
+	t = malloc(8192);
+	n = 0;
+	for(i = 0; i < 256; i++) {
+		r = m[i].red>>24;
+		g = m[i].green>>24;
+		b = m[i].blue>>24;
+		n += sprint(t+n, "%d %lud %lud %lud\n", 255-i, r, g, b);
+	}
+	i = write(fd, t, n);
+	free(t);
+	close(fd);
+	if(i != n)
+		drawerror(d, "wrcolmap: bad write");
+}