/*
 * Copyright 2006-2009 Johannes Hofmann <Johannes.Hofmann@gmx.de>
 */

/*
 * cylindrical projection model
 */

x : m_view - c_view$
y : tan(c_nick - m_nick)$ 
x_rot : y * sin(c_tilt) + x * cos(c_tilt)$
y_rot : y * cos(c_tilt) - x * sin(c_tilt)$
x_scale : x_rot * scale$
y_scale : y_rot * scale$

/*
 * Some mangling for C code generation
 */

load("expr2c.mac")$

x_expand : trigexpand(x_scale)$
y_expand : trigexpand(y_scale)$

args: "double c_view, double c_nick, double c_tilt, double scale, double k0, double k1, double x0, double m_view, double m_nick"$

expr2c("ProjectionCylindrical::mac_x", args, x_expand)$
expr2c("ProjectionCylindrical::mac_y", args, y_expand)$

expr2c("ProjectionCylindrical::mac_x_dc_view", args, diff(x_expand, c_view))$
expr2c("ProjectionCylindrical::mac_x_dc_nick", args, diff(x_expand, c_nick))$
expr2c("ProjectionCylindrical::mac_x_dc_tilt", args, diff(x_expand, c_tilt))$
expr2c("ProjectionCylindrical::mac_x_dscale", args, diff(x_expand, scale))$
expr2c("ProjectionCylindrical::mac_y_dc_view", args, diff(y_expand, c_view))$
expr2c("ProjectionCylindrical::mac_y_dc_nick", args, diff(y_expand, c_nick))$
expr2c("ProjectionCylindrical::mac_y_dc_tilt", args, diff(y_expand, c_tilt))$
expr2c("ProjectionCylindrical::mac_y_dscale", args, diff(y_expand, scale))$