gl-select.cc

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/*

Copyright (C) 2011-2015 Michael Goffioul

This file is part of Octave.

Octave is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by the
Free Software Foundation; either version 3 of the License, or (at your
option) any later version.

Octave 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 General Public License
for more details.

You should have received a copy of the GNU General Public License
along with Octave; see the file COPYING.  If not, see
<http://www.gnu.org/licenses/>.

*/

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include "gl-select.h"

#include <iostream>

void
opengl_selector::apply_pick_matrix (void)
{
  GLdouble p_matrix[16];
  GLint viewport[4];

  glGetDoublev (GL_PROJECTION_MATRIX, p_matrix);
  glGetIntegerv (GL_VIEWPORT, viewport);
  glMatrixMode (GL_PROJECTION);
  glLoadIdentity ();
  gluPickMatrix (xp, yp, size, size, viewport);
  glMultMatrixd (p_matrix);
  glMatrixMode (GL_MODELVIEW);
}

void
opengl_selector::setup_opengl_transformation (const axes::properties& props)
{
  opengl_renderer::setup_opengl_transformation (props);
  apply_pick_matrix ();
}

void
opengl_selector::init_marker (const std::string& m, double sz, float width)
{
  opengl_renderer::init_marker (m, sz, width);
  apply_pick_matrix ();
}

# define BUFFER_SIZE 128

graphics_object
opengl_selector::select (const graphics_object& ax, int x, int y, int flags)
{
  glEnable (GL_DEPTH_TEST);
  glDepthFunc (GL_LEQUAL);

  xp = x;
  yp = y;

  GLuint select_buffer[BUFFER_SIZE];

  glSelectBuffer (BUFFER_SIZE, select_buffer);
  glRenderMode (GL_SELECT);
  glInitNames ();

  object_map.clear ();

  draw (ax);

  int hits = glRenderMode (GL_RENDER);
  graphics_object obj;

  if (hits > 0)
    {
      GLuint current_minZ = 0xffffffff;
      GLuint current_name = 0xffffffff;

      for (int i = 0, j = 0; i < hits && j < BUFFER_SIZE-3; i++)
        {
          GLuint n = select_buffer[j++],
                 minZ = select_buffer[j++];

          j++; // skip maxZ
          if (((flags & select_last) == 0 && (minZ <= current_minZ))
              || ((flags & select_last) != 0 && (minZ >= current_minZ)))
            {
              bool candidate = true;
              GLuint name =
                select_buffer[std::min (j + n, GLuint (BUFFER_SIZE)) - 1];

              if ((flags & select_ignore_hittest) == 0)
                {
                  graphics_object go = object_map[name];

                  if (! go.get_properties ().is_hittest ())
                    candidate = false;
                }

              if (candidate)
                {
                  current_minZ = minZ;
                  current_name = name;
                }

              j += n;
            }
          else
            j += n;
        }

      if (current_name != 0xffffffff)
        obj = object_map[current_name];
    }
  else if (hits < 0)
    warning ("opengl_selector::select: selection buffer overflow");

  object_map.clear ();

  return obj;
}

void
opengl_selector::draw (const graphics_object& go, bool toplevel)
{
  GLuint name = object_map.size ();

  object_map[name] = go;
  glPushName (name);
  opengl_renderer::draw (go, toplevel);
  glPopName ();
}

void
opengl_selector::fake_text (double x, double y, double z, const Matrix& bbox,
                            bool use_scale)
{
  ColumnVector xpos, xp1, xp2;

  xpos = get_transform ().transform (x, y, z, use_scale);

  xp1 = xp2 = xpos;
  xp1(0) += bbox(0);
  xp1(1) -= bbox(1);
  xp2(0) += (bbox(0) + bbox(2));
  xp2(1) -= (bbox(1) + bbox(3));

  ColumnVector p1, p2, p3, p4;

  p1 = get_transform ().untransform (xp1(0), xp1(1), xp1(2), false);
  p2 = get_transform ().untransform (xp2(0), xp1(1), xp1(2), false);
  p3 = get_transform ().untransform (xp2(0), xp2(1), xp1(2), false);
  p4 = get_transform ().untransform (xp1(0), xp2(1), xp1(2), false);

  glBegin (GL_QUADS);
  glVertex3dv (p1.data ());
  glVertex3dv (p2.data ());
  glVertex3dv (p3.data ());
  glVertex3dv (p4.data ());
  glEnd ();
}

void
opengl_selector::draw_text (const text::properties& props)
{
  if (props.get_string ().is_empty ())
    return;

  Matrix pos = props.get_data_position ();
  const Matrix bbox = props.get_extent_matrix ();

  fake_text (pos(0), pos(1), pos.numel () > 2 ? pos(2) : 0.0, bbox);
}

Matrix
opengl_selector::render_text (const std::string& txt,
                              double x, double y, double z,
                              int halign, int valign, double rotation)
{
#if HAVE_FREETYPE
  uint8NDArray pixels;
  Matrix bbox;

  // FIXME: probably more efficient to only compute bbox instead
  //        of doing full text rendering...
  text_to_pixels (txt, pixels, bbox, halign, valign, rotation);
  fake_text (x, y, z, bbox, false);

  return bbox;
#else
  return Matrix (1, 4, 0.0);
#endif
}

void
opengl_selector::draw_image (const image::properties& props)
{
  Matrix xd = props.get_xdata ().matrix_value ();
  octave_idx_type nc = props.get_cdata ().matrix_value ().columns ();
  double x_pix_size = (xd(1) - xd(0)) / (nc - 1);

  Matrix yd = props.get_ydata ().matrix_value ();
  octave_idx_type nr = props.get_cdata ().matrix_value ().rows ();
  double y_pix_size = (yd(1) - yd(0)) / (nr - 1);

  ColumnVector p1(3, 0.0), p2(3, 0.0), p3(3, 0.0), p4(3, 0.0);
  p1(0) = xd(0) - x_pix_size/2;
  p1(1) = yd(0) - y_pix_size/2;

  p2(0) = xd(1) + x_pix_size/2;
  p2(1) = yd(0) - y_pix_size/2;

  p3(0) = xd(1) + x_pix_size/2;
  p3(1) = yd(1) + y_pix_size/2;

  p4(0) = xd(0) - x_pix_size/2;
  p4(1) = yd(1) + y_pix_size/2;

  glBegin (GL_QUADS);
  glVertex3dv (p1.data ());
  glVertex3dv (p2.data ());
  glVertex3dv (p3.data ());
  glVertex3dv (p4.data ());
  glEnd ();
}