view_map_geometry.cpp

Go to the documentation of this file.

/*
 * SPDX-FileCopyrightText: 1996-2020 Freeciv and Freeciv21 contributors
 * SPDX-FileCopyrightText: 2022-2023 Louis Moureaux <m_louis30@yahoo.com>
 *
 * SPDX-License-Identifier: GPLv3-or-later
 */
 
/*
 * This file contains tileset geometry functions to manipulate the GUI for
 * the the main map view.
 */
 
#include "views/view_map_geometry.h"
 
#include "game.h"
#include "map.h"
#include "tileset/tilespec.h"
 
namespace freeciv {
 
gui_rect_iterator::gui_rect_iterator(const struct tileset *t,
                                     const QRect &rect)
{
  const auto normalized = rect.normalized();
  if (!normalized.isValid()) {
    m_index = 0;
    m_count = 0; // Don't iterate
    return;
  }
 
  m_isometric = tileset_is_isometric(t);
 
  m_r1 = m_isometric ? 2 : 1;
  m_r2 = m_r1 * 2; // double the ratio
  m_w = tileset_tile_width(t);
  m_h = tileset_tile_height(t);
 
  // Don't divide by r2 yet, to avoid integer rounding errors.
  m_x0 = DIVIDE(normalized.left() * m_r2, m_w) - m_r1 / 2;
  m_y0 = DIVIDE(normalized.top() * m_r2, m_h) - m_r1 / 2;
  m_x1 = DIVIDE(normalized.right() * m_r2 + m_w - 1, m_w) + m_r1;
  m_y1 = DIVIDE(normalized.bottom() * m_r2 + m_h - 1, m_h) + m_r1;
 
  // Start counting
  m_index = 0;
  m_count = (m_x1 - m_x0) * (m_y1 - m_y0);
 
  log_debug("Iterating over %d-%d x %d-%d rectangle.", m_x1, m_x0, m_y1,
            m_y0);
}
 
bool gui_rect_iterator::next()
{
  if (m_index >= m_count) {
    return false;
  }
 
  m_tile = nullptr;
  m_has_corner = false;
  m_has_edge = false;
  m_has_tile = false;
 
  m_xi = m_x0 + (m_index % (m_x1 - m_x0));
  m_yi = m_y0 + (m_index / (m_x1 - m_x0));
 
  const auto si = m_xi + m_yi;
  const auto di = m_yi - m_xi;
 
  if (m_isometric) {
    if ((m_xi + m_yi) % 2 != 0) {
      m_index++;
      return next();
    }
 
    if (m_xi % 2 == 0 && m_yi % 2 == 0) {
      if ((m_xi + m_yi) % 4 == 0) {
        // Tile
        m_tile = map_pos_to_tile(&(wld.map), si / 4 - 1, di / 4);
        m_has_tile = (m_tile != nullptr);
      } else {
        // Corner
        m_has_corner = true;
        m_corner.tile[0] =
            map_pos_to_tile(&(wld.map), (si - 6) / 4, (di - 2) / 4);
        m_corner.tile[1] =
            map_pos_to_tile(&(wld.map), (si - 2) / 4, (di - 2) / 4);
        m_corner.tile[2] =
            map_pos_to_tile(&(wld.map), (si - 2) / 4, (di + 2) / 4);
        m_corner.tile[3] =
            map_pos_to_tile(&(wld.map), (si - 6) / 4, (di + 2) / 4);
        if (tileset_hex_width(tileset) > 0) {
          m_has_edge = true;
          m_edge.type = EDGE_UD;
          m_edge.tile[0] = m_corner.tile[0];
          m_edge.tile[1] = m_corner.tile[2];
        } else if (tileset_hex_height(tileset) > 0) {
          m_has_edge = true;
          m_edge.type = EDGE_LR;
          m_edge.tile[0] = m_corner.tile[1];
          m_edge.tile[1] = m_corner.tile[3];
        }
      }
    } else {
      // Edge.
      m_has_edge = true;
      if (si % 4 == 0) {
        m_edge.type = EDGE_NS;
        m_edge.tile[0] = map_pos_to_tile(&(wld.map), (si - 4) / 4,
                                         (di - 2) / 4); // N
        m_edge.tile[1] = map_pos_to_tile(&(wld.map), (si - 4) / 4,
                                         (di + 2) / 4); // S
      } else {
        m_edge.type = EDGE_WE;
        m_edge.tile[0] = map_pos_to_tile(&(wld.map), (si - 6) / 4,
                                         di / 4); // W
        m_edge.tile[1] = map_pos_to_tile(&(wld.map), (si - 2) / 4,
                                         di / 4); // E
      }
    }
  } else {
    if (si % 2 == 0) {
      if (m_xi % 2 == 0) {
        // Corner.
        m_has_corner = true;
        m_corner.tile[0] = map_pos_to_tile(&(wld.map), m_xi / 2 - 1,
                                           m_yi / 2 - 1); // NW
        m_corner.tile[1] = map_pos_to_tile(&(wld.map), m_xi / 2,
                                           m_yi / 2 - 1); // NE
        m_corner.tile[2] = map_pos_to_tile(&(wld.map), m_xi / 2,
                                           m_yi / 2); // SE
        m_corner.tile[3] = map_pos_to_tile(&(wld.map), m_xi / 2 - 1,
                                           m_yi / 2); // SW
      } else {
        // Tile.
        m_tile = map_pos_to_tile(&(wld.map), (m_xi - 1) / 2, (m_yi - 1) / 2);
        m_has_tile = (m_tile != nullptr);
      }
    } else {
      // Edge.
      m_has_edge = true;
      if (m_yi % 2 == 0) {
        m_edge.type = EDGE_NS;
        m_edge.tile[0] = map_pos_to_tile(&(wld.map), (m_xi - 1) / 2,
                                         m_yi / 2 - 1); // N
        m_edge.tile[1] = map_pos_to_tile(&(wld.map), (m_xi - 1) / 2,
                                         m_yi / 2); // S
      } else {
        m_edge.type = EDGE_WE;
        m_edge.tile[0] = map_pos_to_tile(&(wld.map), m_xi / 2 - 1,
                                         (m_yi - 1) / 2); // W
        m_edge.tile[1] = map_pos_to_tile(&(wld.map), m_xi / 2,
                                         (m_yi - 1) / 2); // E
      }
    }
  }
 
  m_index++;
  return true;
}
 
} // namespace freeciv