## plmtex3, plptex3 demo
##
## Copyright (C) 2007 Alan Irwin 
## Copyright (C) 2007 Andrew Ross 
##
##
## This file is part of PLplot.
##
## PLplot is free software; you can redistribute it and/or modify
## it under the terms of the GNU Library General Public License as published
## by the Free Software Foundation; either version 2 of the License, or
## (at your option) any later version.
##
## PLplot is distributed in the hope that it will be useful,
## but WITHOUT ANY WARRANTY; without even the implied warranty of
## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
## GNU Library General Public License for more details.
##
## You should have received a copy of the GNU Library General Public License
## along with PLplot; if not, write to the Free Software
## Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
##

1;

## Demonstrate plotting text in 3D

function ix28c

## Choose these values to correspond to tick marks
  XPTS = 2;
  YPTS = 2;
  NREVOLUTION = 16;
  NROTATION = 8;
  NSHEAR = 8;

  ## PLplot constants used in this example
  DRAW_LINEXY = 3;

  xmin = 0.0;
  xmax = 1.0;
  xmid = 0.5*(xmin+xmax);
  xrange = xmax-xmin;

  ymin = 0.0;
  ymax = 1.0;
  ymid = 0.5*(ymin+ymax);
  yrange = ymax-ymin;

  zmin = 0.0;
  zmax = 1.0;
  zmid = 0.5*(zmin+zmax);
  zrange = zmax-zmin;

  ysmin = ymin + 0.1 * yrange;
  ysmax = ymax - 0.1 * yrange;
  ysrange = ysmax - ysmin;
  dysrot = ysrange / ( NROTATION - 1 );
  dysshear = ysrange / ( NSHEAR - 1 );
  zsmin = zmin + 0.1 * zrange;
  zsmax = zmax - 0.1 * zrange;
  zsrange = zsmax - zsmin;
  dzsrot = zsrange / ( NROTATION - 1 );
  dzsshear = zsrange / ( NSHEAR - 1 );

  pstring = "The future of our civilization depends on software freedom.";

  x = xmin + (0:(XPTS-1))*xrange/(XPTS-1);
  y = ymin + (0:(XPTS-1))*yrange/(YPTS-1);

  z = zeros(XPTS,YPTS);
  
  ## Parse and process command line arguments

  ## (void) plparseopts(&argc, argv, PL_PARSE_FULL);

  plinit();

  ## Page 1: Demonstrate inclination and shear capability pattern.
  
  pladv(0);
  plvpor(-0.15, 1.15, -0.05, 1.05);
  plwind(-1.2, 1.2, -0.8, 1.5);
  plw3d(1.0, 1.0, 1.0, xmin, xmax, ymin, ymax, zmin, zmax, 20., 45.);
   
  plcol0(2);
  plbox3("b", "", xrange, 0,
	 "b", "", yrange, 0,
	 "bcd", "", zrange, 0);

  ## z = zmin. 
  plschr(0., 1.0);
  for i = 0:NREVOLUTION-1
    omega = 2.*pi*(i/NREVOLUTION);
    sin_omega = sin(omega);
    cos_omega = cos(omega);
    x_inclination = 0.5*xrange*cos_omega;
    y_inclination = 0.5*yrange*sin_omega;
    z_inclination = 0.;
    x_shear = -0.5*xrange*sin_omega;
    y_shear = 0.5*yrange*cos_omega;
    z_shear = 0.;
    plptex3(xmid, ymid, zmin,
	    x_inclination, y_inclination, z_inclination,
	    x_shear, y_shear, z_shear,
	    0.0, "  revolution");
  endfor
  ## x = xmax.
  plschr(0., 1.0);
  for i=0:NREVOLUTION-1
    omega = 2.*pi*(i/NREVOLUTION);
    sin_omega = sin(omega);
    cos_omega = cos(omega);
    x_inclination = 0.;
    y_inclination = -0.5*yrange*cos_omega;
    z_inclination = 0.5*zrange*sin_omega;
    x_shear = 0.;
    y_shear = 0.5*yrange*sin_omega;
    z_shear = 0.5*zrange*cos_omega;
    plptex3(xmax, ymid, zmid,
	    x_inclination, y_inclination, z_inclination,
	    x_shear, y_shear, z_shear,
	    0.0, "  revolution");
  endfor

  ## y = ymax. 
  plschr(0., 1.0);
  for i = 0:NREVOLUTION-1
    omega = 2.*pi*(i/NREVOLUTION);
    sin_omega = sin(omega);
    cos_omega = cos(omega);
    x_inclination = 0.5*xrange*cos_omega;
    y_inclination = 0.;
    z_inclination = 0.5*zrange*sin_omega;
    x_shear = -0.5*xrange*sin_omega;
    y_shear = 0.;
    z_shear = 0.5*zrange*cos_omega;
    plptex3(
	    xmid, ymax, zmid,
	    x_inclination, y_inclination, z_inclination,
	    x_shear, y_shear, z_shear,
	    0.0, "  revolution");
  endfor
  ## Draw minimal 3D grid to finish defining the 3D box.
  plmesh(x', y', z', DRAW_LINEXY);

  ## Page 2: Demonstrate rotation of string around its axis.
  pladv(0);
  plvpor(-0.15, 1.15, -0.05, 1.05);
  plwind(-1.2, 1.2, -0.8, 1.5);
  plw3d(1.0, 1.0, 1.0, xmin, xmax, ymin, ymax, zmin, zmax, 20., 45.);
   
  plcol0(2);
  plbox3("b", "", xrange, 0,
	 "b", "", yrange, 0,
	 "bcd", "", zrange, 0);

  ## y = ymax.
  plschr(0., 1.0);
  x_inclination = 1.;
  y_inclination = 0.;
  z_inclination = 0.;
  x_shear = 0.;
  for i = 0:NROTATION-1
    omega = 2.*pi*(i/NROTATION);
    sin_omega = sin(omega);
    cos_omega = cos(omega);
    y_shear = 0.5*yrange*sin_omega;
    z_shear = 0.5*zrange*cos_omega;
    zs = zsmax - dzsrot*i;
    plptex3(
	    xmid, ymax, zs,
	    x_inclination, y_inclination, z_inclination,
	    x_shear, y_shear, z_shear,
	    0.5, "rotation for y = y#dmax#u");
  endfor

  ## x = xmax.
  plschr(0., 1.0);
  x_inclination = 0.;
  y_inclination = -1.;
  z_inclination = 0.;
  y_shear = 0.;
  for i = 0:NROTATION-1
    omega = 2.*pi*(i/NROTATION);
    sin_omega = sin(omega);
    cos_omega = cos(omega);
    x_shear = 0.5*xrange*sin_omega;
    z_shear = 0.5*zrange*cos_omega;
    zs = zsmax - dzsrot*i;
    plptex3(
	    xmax, ymid, zs,
	    x_inclination, y_inclination, z_inclination,
	    x_shear, y_shear, z_shear,
	    0.5, "rotation for x = x#dmax#u");
  endfor

  ## z = zmin.
  plschr(0., 1.0);
  x_inclination = 1.;
  y_inclination = 0.;
  z_inclination = 0.;
  x_shear = 0.;
  for i = 0:NROTATION-1
    omega = 2.*pi*(i/NROTATION);
    sin_omega = sin(omega);
    cos_omega = cos(omega);
    y_shear = 0.5*yrange*cos_omega;
    z_shear = 0.5*zrange*sin_omega;
    ys = ysmax - dysrot*i;
    plptex3(
	    xmid, ys, zmin,
	    x_inclination, y_inclination, z_inclination,
	    x_shear, y_shear, z_shear,
	    0.5, "rotation for z = z#dmin#u");
  endfor
  ## Draw minimal 3D grid to finish defining the 3D box.
  plmesh(x', y', z', DRAW_LINEXY);
  
  ## Page 3: Demonstrate shear of string along its axis.
  ## Work around xcairo and pngcairo (but not pscairo) problems for 
  ## shear vector too close to axis of string. (N.B. no workaround
  ## would be domega = 0.)
  domega = 0.05;
  pladv(0);
  plvpor(-0.15, 1.15, -0.05, 1.05);
  plwind(-1.2, 1.2, -0.8, 1.5);
  plw3d(1.0, 1.0, 1.0, xmin, xmax, ymin, ymax, zmin, zmax, 20., 45.);
   
  plcol0(2);
  plbox3("b", "", xrange, 0,
	 "b", "", yrange, 0,
	 "bcd", "", zrange, 0);

  ## y = ymax.
  plschr(0., 1.0);
  x_inclination = 1.;
  y_inclination = 0.;
  z_inclination = 0.;
  y_shear = 0.;
  for i = 0:NSHEAR-1
    omega = domega + 2.*pi*(i/NSHEAR);
    sin_omega = sin(omega);
    cos_omega = cos(omega);
    x_shear = 0.5*xrange*sin_omega;
    z_shear = 0.5*zrange*cos_omega;
    zs = zsmax-dzsshear*i;
    plptex3(
	    xmid, ymax, zs,
	    x_inclination, y_inclination, z_inclination,
	    x_shear, y_shear, z_shear,
	    0.5, "shear for y = y#dmax#u");
  endfor

  ## x = xmax.
  plschr(0., 1.0);
  x_inclination = 0.;
  y_inclination = -1.;
  z_inclination = 0.;
  x_shear = 0.;
  for i = 0:NSHEAR-1
    omega = domega + 2.*pi*(i/NSHEAR);
    sin_omega = sin(omega);
    cos_omega = cos(omega);
    y_shear = -0.5*yrange*sin_omega;
    z_shear = 0.5*zrange*cos_omega;
    zs = zsmax-dzsshear*i;
    plptex3(
	    xmax, ymid, zs,
	    x_inclination, y_inclination, z_inclination,
	    x_shear, y_shear, z_shear,
	    0.5, "shear for x = x#dmax#u");
  endfor

  ## z = zmin.
  plschr(0., 1.0);
  x_inclination = 1.;
  y_inclination = 0.;
  z_inclination = 0.;
  z_shear = 0.;
  for i = 0:NSHEAR-1
    omega = domega + 2.*pi*(i/NSHEAR);
    sin_omega = sin(omega);
    cos_omega = cos(omega);
    y_shear = 0.5*yrange*cos_omega;
    x_shear = 0.5*xrange*sin_omega;
    ys = ysmax-dysshear*i;
    plptex3(
	    xmid, ys, zmin,
	    x_inclination, y_inclination, z_inclination,
	    x_shear, y_shear, z_shear,
	    0.5, "shear for z = z#dmin#u");
  endfor
  ## Draw minimal 3D grid to finish defining the 3D box.
  plmesh(x', y', z', DRAW_LINEXY);

  ## Page 4: Demonstrate drawing a string on a 3D path.
  pladv(0);
  plvpor(-0.15, 1.15, -0.05, 1.05);
  plwind(-1.2, 1.2, -0.8, 1.5);
  plw3d(1.0, 1.0, 1.0, xmin, xmax, ymin, ymax, zmin, zmax, 40., -30.);
  
  plcol0(2);
  plbox3("b", "", xrange, 0,
	 "b", "", yrange, 0,
	 "bcd", "", zrange, 0);

  plschr(0., 1.2);
  ## domega controls the spacing between the various characters of the
  ## string and also the maximum value of omega for the given number
  ## of characters in pstring.
  domega = 2.*pi/length(pstring);
  omega = 0.;
  ## 3D function is a helix of the given radius and pitch
  radius = 0.5;
  pitch = 1./(2.*pi);
  for i=1:length(pstring)
    sin_omega = sin(omega);
    cos_omega = cos(omega);
    xpos = xmid + radius*sin_omega;
    ypos = ymid - radius*cos_omega;
    zpos = zmin + pitch*omega;
    ## In general, the inclination is proportional to the derivative of 
    ## the position wrt theta.
    x_inclination = radius*cos_omega;
    y_inclination = radius*sin_omega;
    z_inclination = pitch;
    ## The shear vector should be perpendicular to the 3D line with Z
    ## component maximized, but for low pitch a good approximation is
    ## a constant vector that is parallel to the Z axis.
    x_shear = 0.;
    y_shear = 0.;
    z_shear = 1.;
    p1string = pstring(i:i);
    plptex3(
	    xpos, ypos, zpos,
	    x_inclination, y_inclination, z_inclination,
	    x_shear, y_shear, z_shear,
	    0.5, p1string);
    omega += domega;
  endfor
  ## Draw minimal 3D grid to finish defining the 3D box.
  plmesh(x', y', z', DRAW_LINEXY);

  ## Page 5: Demonstrate plmtex3 axis labelling capability
  pladv(0);
  plvpor(-0.15, 1.15, -0.05, 1.05);
  plwind(-1.2, 1.2, -0.8, 1.5);
  plw3d(1.0, 1.0, 1.0, xmin, xmax, ymin, ymax, zmin, zmax, 20., 45.);
  
  plcol0(2);
  plbox3("b", "", xrange, 0,
	 "b", "", yrange, 0,
	 "bcd", "", zrange, 0);

  plschr(0., 1.0);
  plmtex3("xp", 3.0, 0.5, 0.5, "Arbitrarily displaced");
  plmtex3("xp", 4.5, 0.5, 0.5, "primary X-axis label");
  plmtex3("xs", -2.5, 0.5, 0.5, "Arbitrarily displaced");
  plmtex3("xs", -1.0, 0.5, 0.5, "secondary X-axis label");
  plmtex3("yp", 3.0, 0.5, 0.5, "Arbitrarily displaced");
  plmtex3("yp", 4.5, 0.5, 0.5, "primary Y-axis label");
  plmtex3("ys", -2.5, 0.5, 0.5, "Arbitrarily displaced");
  plmtex3("ys", -1.0, 0.5, 0.5, "secondary Y-axis label");
  plmtex3("zp", 4.5, 0.5, 0.5, "Arbitrarily displaced");
  plmtex3("zp", 3.0, 0.5, 0.5, "primary Z-axis label");
  plmtex3("zs", -2.5, 0.5, 0.5, "Arbitrarily displaced");
  plmtex3("zs", -1.0, 0.5, 0.5, "secondary Z-axis label");
  ## Draw minimal 3D grid to finish defining the 3D box.
  plmesh(x', y', z', DRAW_LINEXY);

  ## Clean up.

  plend1();

endfunction

ix28c
