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

/*
 * cylindrical projection model
 */

x : m_view - c_view$
y : tan(c_pitch - m_elev)$ 
x_rot : y * sin(c_roll) + x * cos(c_roll)$
y_rot : y * cos(c_roll) - x * sin(c_roll)$
x_scale : x_rot * scale$
y_scale : y_rot * scale$

/*
 * Some mangling for C code generation
 */

load("expr2rust.mac")$

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

args: "c_view: f64, c_pitch: f64, c_roll: f64, scale: f64, k0: f64, k1: f64, x0: f64, m_view: f64, m_elev: f64"$

expr2rust("mac_x", args, x_expand)$
expr2rust("mac_y", args, y_expand)$

expr2rust("mac_x_dc_view", args, diff(x_expand, c_view))$
expr2rust("mac_x_dc_pitch", args, diff(x_expand, c_pitch))$
expr2rust("mac_x_dc_roll", args, diff(x_expand, c_roll))$
expr2rust("mac_x_dscale", args, diff(x_expand, scale))$
expr2rust("mac_y_dc_view", args, diff(y_expand, c_view))$
expr2rust("mac_y_dc_pitch", args, diff(y_expand, c_pitch))$
expr2rust("mac_y_dc_roll", args, diff(y_expand, c_roll))$
expr2rust("mac_y_dscale", args, diff(y_expand, scale))$