1 files changed, 206 insertions, 0 deletions
diff --git a/src/libdraw/arith.c b/src/libdraw/arith.c
new file mode 100644
index 00000000..41b30620
--- /dev/null
+++ b/src/libdraw/arith.c
@@ -0,0 +1,206 @@
+#include <u.h>
+#include <libc.h>
+#include <draw.h>
+
+Point
+Pt(int x, int y)
+{
+	Point p;
+
+	p.x = x;
+	p.y = y;
+	return p;
+}
+
+Rectangle
+Rect(int x, int y, int bx, int by)
+{
+	Rectangle r;
+
+	r.min.x = x;
+	r.min.y = y;
+	r.max.x = bx;
+	r.max.y = by;
+	return r;
+}
+
+Rectangle
+Rpt(Point min, Point max)
+{
+	Rectangle r;
+
+	r.min = min;
+	r.max = max;
+	return r;
+}
+
+Point
+addpt(Point a, Point b)
+{
+	a.x += b.x;
+	a.y += b.y;
+	return a;
+}
+
+Point
+subpt(Point a, Point b)
+{
+	a.x -= b.x;
+	a.y -= b.y;
+	return a;
+}
+
+Rectangle
+insetrect(Rectangle r, int n)
+{
+	r.min.x += n;
+	r.min.y += n;
+	r.max.x -= n;
+	r.max.y -= n;
+	return r;
+}
+
+Point
+divpt(Point a, int b)
+{
+	a.x /= b;
+	a.y /= b;
+	return a;
+}
+
+Point
+mulpt(Point a, int b)
+{
+	a.x *= b;
+	a.y *= b;
+	return a;
+}
+
+Rectangle
+rectsubpt(Rectangle r, Point p)
+{
+	r.min.x -= p.x;
+	r.min.y -= p.y;
+	r.max.x -= p.x;
+	r.max.y -= p.y;
+	return r;
+}
+
+Rectangle
+rectaddpt(Rectangle r, Point p)
+{
+	r.min.x += p.x;
+	r.min.y += p.y;
+	r.max.x += p.x;
+	r.max.y += p.y;
+	return r;
+}
+
+int
+eqpt(Point p, Point q)
+{
+	return p.x==q.x && p.y==q.y;
+}
+
+int
+eqrect(Rectangle r, Rectangle s)
+{
+	return r.min.x==s.min.x && r.max.x==s.max.x &&
+	       r.min.y==s.min.y && r.max.y==s.max.y;
+}
+
+int
+rectXrect(Rectangle r, Rectangle s)
+{
+	return r.min.x<s.max.x && s.min.x<r.max.x &&
+	       r.min.y<s.max.y && s.min.y<r.max.y;
+}
+
+int
+rectinrect(Rectangle r, Rectangle s)
+{
+	return s.min.x<=r.min.x && r.max.x<=s.max.x && s.min.y<=r.min.y && r.max.y<=s.max.y;
+}
+
+int
+ptinrect(Point p, Rectangle r)
+{
+	return p.x>=r.min.x && p.x<r.max.x &&
+	       p.y>=r.min.y && p.y<r.max.y;
+}
+
+Rectangle
+canonrect(Rectangle r)
+{
+	int t;
+	if (r.max.x < r.min.x) {
+		t = r.min.x;
+		r.min.x = r.max.x;
+		r.max.x = t;
+	}
+	if (r.max.y < r.min.y) {
+		t = r.min.y;
+		r.min.y = r.max.y;
+		r.max.y = t;
+	}
+	return r;
+}
+
+void
+combinerect(Rectangle *r1, Rectangle r2)
+{
+	if(r1->min.x > r2.min.x)
+		r1->min.x = r2.min.x;
+	if(r1->min.y > r2.min.y)
+		r1->min.y = r2.min.y;
+	if(r1->max.x < r2.max.x)
+		r1->max.x = r2.max.x;
+	if(r1->max.y < r2.max.y)
+		r1->max.y = r2.max.y;
+}
+
+u32int
+drawld2chan[] = {
+	GREY1,
+	GREY2,
+	GREY4,
+	CMAP8,
+};
+
+int log2[] = { -1, 0, 1, -1, 2, -1, -1, -1, 3, -1, -1, -1, -1, -1, -1, -1, 4, -1, -1, -1, -1, -1, -1, -1, 4 /* BUG */, -1, -1, -1, -1, -1, -1, -1, 5 };
+
+u32int
+setalpha(u32int color, uchar alpha)
+{
+	int red, green, blue;
+
+	red = (color >> 3*8) & 0xFF;
+	green = (color >> 2*8) & 0xFF;
+	blue = (color >> 1*8) & 0xFF;
+	/* ignore incoming alpha */
+	red = (red * alpha)/255;
+	green = (green * alpha)/255;
+	blue = (blue * alpha)/255;
+	return (red<<3*8) | (green<<2*8) | (blue<<1*8) | (alpha<<0*8);
+}
+
+Point	ZP;
+Rectangle ZR;
+int
+Rfmt(Fmt *f)
+{
+	Rectangle r;
+
+	r = va_arg(f->args, Rectangle);
+	return fmtprint(f, "%P %P", r.min, r.max);
+}
+
+int
+Pfmt(Fmt *f)
+{
+	Point p;
+
+	p = va_arg(f->args, Point);
+	return fmtprint(f, "[%d %d]", p.x, p.y);
+}
+