From bac85749b75971ee75d635bea3117f8a4f640e1c Mon Sep 17 00:00:00 2001
From: Johannes Hofmann <Johannes.Hofmann@gmx.de>
Date: Sat, 24 May 2008 00:08:29 +0200
Subject: major simplification of rectilinear projection

---
 src/lsq_rectilinear.mac | 11 ++---------
 1 file changed, 2 insertions(+), 9 deletions(-)

diff --git a/src/lsq_rectilinear.mac b/src/lsq_rectilinear.mac
index 3c5b367..4ed1e09 100644
--- a/src/lsq_rectilinear.mac
+++ b/src/lsq_rectilinear.mac
@@ -12,15 +12,8 @@ c_x_rot : cos(c_nick) * c_x$ + sin(c_nick) * c_z$
 c_y_rot : c_y$
 c_z_rot : -sin(c_nick) * c_x + cos(c_nick) * c_z$
 
-/* back to spherical coordinates */
-a_h : \pi / 2 - acos(c_z_rot)$
-a_v : atan(c_y_rot / c_x_rot)$
-
-/* angle over horizon in view direction */
-a_h_dir : atan (tan (a_h) * sqrt(tan(a_v) ^2  + 1))$ 
-
-x : tan(a_v)$
-y : tan(-a_h_dir)$ 
+x : c_y_rot / c_x_rot$
+y : - c_z_rot / c_x_rot$ 
 x_rot : y * sin(c_tilt) + x * cos(c_tilt)+x0$
 y_rot : y * cos(c_tilt) - x * sin(c_tilt)$
 
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