now version controlled.

1 files changed, 83 insertions, 0 deletions

diff --git a/colgrad.c b/colgrad.c
new file mode 100644
index 0000000..a122a49
--- /dev/null
+++ b/colgrad.c
@@ -0,0 +1,83 @@
+#include <u.h>
+#include <libc.h>
+#include <draw.h>
+
+enum { SEC = 1000 };
+
+enum {
+	Cred,
+	Cgrn,
+	Cblu,
+
+	Cgx,
+	Cgy,
+	Cend
+};
+Image *col[Cend];
+
+int dx, dy;
+
+void *
+emalloc(ulong n)
+{
+	void *p;
+
+	p = malloc(n);
+	if(p == nil)
+		sysfatal("malloc: %r");
+	memset(p, 0, n);
+	setmalloctag(p, getcallerpc(&n));
+	return p;
+}
+
+Image *
+eallocimage(Display *d, Rectangle r, ulong chan, int repl, ulong col)
+{
+	Image *i;
+
+	i = allocimage(d, r, chan, repl, col);
+	if(i == nil)
+		sysfatal("allocimage: %r");
+	return i;
+}
+
+void
+usage(void)
+{
+	fprint(2, "usage: colgrad\n");
+	exits("usage");
+}
+
+void
+main(int argc, char *argv[])
+{
+	int i;
+	uchar *gx, *gy;
+
+	ARGBEGIN{
+	default: usage();
+	}ARGEND;
+
+	if(initdraw(nil, nil, "colgrad") < 0)
+		sysfatal("initdraw: %r");
+	dx = Dx(screen->r), dy = Dy(screen->r);
+	col[Cred] = eallocimage(display, Rect(0, 0, 1, 1), RGB24, 1, DRed);
+	col[Cgrn] = eallocimage(display, Rect(0, 0, 1, 1), RGB24, 1, DGreen);
+	col[Cblu] = eallocimage(display, Rect(0, 0, 1, 1), RGB24, 1, DBlue);
+	col[Cgx] = eallocimage(display, Rect(0, 0, dx, 1), GREY8, 1, DNofill);
+	col[Cgy] = eallocimage(display, Rect(0, 0, 1, dy), GREY8, 1, DNofill);
+	gx = emalloc(dx);
+	gy = emalloc(dy);
+	for(i = 0; i < dx; i++)
+		gx[i] = 255.0 * i/(dx-1);
+	for(i = 0; i < dy; i++)
+		gy[i] = 255.0 * i/(dy-1);
+	loadimage(col[Cgx], col[Cgx]->r, gx, dx);
+	loadimage(col[Cgy], col[Cgy]->r, gy, dy);
+	draw(screen, screen->r, col[Cred], nil, ZP);
+	draw(screen, screen->r, col[Cgrn], col[Cgx], ZP);
+	draw(screen, screen->r, col[Cblu], col[Cgy], ZP);
+	flushimage(display, 1);
+	sleep(5*SEC);
+	exits(0);
+}