From 0373255087377122eeb10e006ffb8aa1b57e611c Mon Sep 17 00:00:00 2001
From: rgl <devnull@localhost>
Date: Mon, 3 Feb 2020 22:42:28 +0100
Subject: after a year or so of work, i dare create a proper repo.

---
 libgeometry/rframe.c | 51 +++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 51 insertions(+)
 create mode 100644 libgeometry/rframe.c

(limited to 'libgeometry/rframe.c')

diff --git a/libgeometry/rframe.c b/libgeometry/rframe.c
new file mode 100644
index 0000000..06d63f2
--- /dev/null
+++ b/libgeometry/rframe.c
@@ -0,0 +1,51 @@
+#include <u.h>
+#include <libc.h>
+#include "../geometry.h"
+
+Point2
+rframexform(Point2 p, RFrame rf)
+{
+	Matrix m = {
+		rf.bx.x, rf.bx.y, -dotvec2(rf.bx, rf.p),
+		rf.by.x, rf.by.y, -dotvec2(rf.by, rf.p),
+		0, 0, 1,
+	};
+	return xform(p, m);
+}
+
+Point3
+rframexform3(Point3 p, RFrame3 rf)
+{
+	Matrix3 m = {
+		rf.bx.x, rf.bx.y, rf.bx.z, -dotvec3(rf.bx, rf.p),
+		rf.by.x, rf.by.y, rf.by.z, -dotvec3(rf.by, rf.p),
+		rf.bz.x, rf.bz.y, rf.bz.z, -dotvec3(rf.bz, rf.p),
+		0, 0, 0, 1,
+	};
+	return xform3(p, m);
+}
+
+Point2
+invrframexform(Point2 p, RFrame rf)
+{
+	Matrix m = {
+		rf.bx.x, rf.bx.y, -dotvec2(rf.bx, rf.p),
+		rf.by.x, rf.by.y, -dotvec2(rf.by, rf.p),
+		0, 0, 1,
+	};
+	invm(m);
+	return xform(p, m);
+}
+
+Point3
+invrframexform3(Point3 p, RFrame3 rf)
+{
+	Matrix3 m = {
+		rf.bx.x, rf.bx.y, rf.bx.z, -dotvec3(rf.bx, rf.p),
+		rf.by.x, rf.by.y, rf.by.z, -dotvec3(rf.by, rf.p),
+		rf.bz.x, rf.bz.y, rf.bz.z, -dotvec3(rf.bz, rf.p),
+		0, 0, 0, 1,
+	};
+	invm3(m);
+	return xform3(p, m);
+}
-- 
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