isoMath.cxx File Reference

#include "isoMath.hxx"
#include "Camera.hxx"
#include "Settings.hxx"
#include "Point.hxx"
#include "LOG.hxx"
#include <MapFunctions.hxx>

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Functions
Point	calculateIsoCoordinates (const SDL_Point &screenCoordinates)
	Calculates screen space coordinates to isometric space coordinates. More...
SDL_Point	convertIsoToScreenCoordinates (const Point &isoCoordinates, bool calcWithoutOffset)
	converts coordinates from isometric to screen space More...
Point	convertScreenToIsoCoordinates (const SDL_Point &screenCoordinates)
	converts screen space coordinates to isometric space coordinates. More...
bool	isPointWithinMapBoundaries (const std::vector< Point > &isoCoordinates)
	Check if given coordinates are within map boundaries. More...

Variables
bool	reverseDirection = false

Function Documentation

calculateIsoCoordinates()

Point calculateIsoCoordinates

(

const SDL_Point &

screenCoordinates

)

Calculates screen space coordinates to isometric space coordinates.

A formula is used to calculate the iso coordinates from given screen coordinates. No tile height is taken into account.

Note

This function will not work for elevated tiles

Parameters

screenCoordinates

object containing screen space coordinates

Returns

Point containing the calculated isometric coordinates of the tile that matches the screen coordinates

Definition at line 11 of file isoMath.cxx.

{
  const SDL_Point &cameraOffset = Camera::instance().cameraOffset();
  const double &zoomLevel = Camera::instance().zoomLevel();
  const SDL_Point &tileSize = Camera::instance().tileSize();
 
  const int isoX = static_cast<int>(
      (screenCoordinates.x + cameraOffset.x + 2.0 * (screenCoordinates.y + cameraOffset.y)) / (tileSize.x * zoomLevel) + 1);
  const int isoY = static_cast<int>((screenCoordinates.x + cameraOffset.x - 2.0 * (screenCoordinates.y + cameraOffset.y)) /
                                    (tileSize.x * zoomLevel));
 
  return {isoX, isoY, 0, 0};
}

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convertIsoToScreenCoordinates()

SDL_Point convertIsoToScreenCoordinates	(	const Point &	isoCoordinates,
		bool	calcWithoutOffset = false
	)

converts coordinates from isometric to screen space

The given isometric coordinates (which contain height information) are converted to the screen coordinates. The coordinates represent the x, y position of the tile where it is drawn (if tile height / width is added, the whole bounding box could be calculated) Camera Offset and current zoomLevel is taken into account

Parameters

isoCoordinates	object containing isometric coordinates
calcWithoutOffset	optional parameter to calculate screenspace coordinates without zoomLevel and cameraOffset taken into account

Returns

SDL_Point containing screen space coordinates

Definition at line 25 of file isoMath.cxx.

{
  const int heightOffset = 24;
  const SDL_Point &cameraOffset = Camera::instance().cameraOffset();
  const double &zoomLevel = Camera::instance().zoomLevel();
  const SDL_Point &tileSize = Camera::instance().tileSize();
 
  int x = static_cast<int>(std::round(static_cast<double>((isoCoordinates.x + isoCoordinates.y) * tileSize.x) * zoomLevel) / 2);
  int y = static_cast<int>(std::round(static_cast<double>((isoCoordinates.x - isoCoordinates.y) * tileSize.y) * zoomLevel) / 2);
 
  if (!calcWithoutOffset)
  {
    x -= cameraOffset.x;
    y -= cameraOffset.y;
  }
 
  if (isoCoordinates.height > 0)
  {
    y -= static_cast<int>(std::round(static_cast<double>((tileSize.x - heightOffset) * isoCoordinates.height) * zoomLevel));
  }
 
  return {x, y};
}

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convertScreenToIsoCoordinates()

Point convertScreenToIsoCoordinates

(

const SDL_Point &

screenCoordinates

)

converts screen space coordinates to isometric space coordinates.

To convert screen coordinates in to isometric coordinates, all the textures inside the nodes are checked, if the click is inside the bounding box of a texture and if so, another check ensures, that the click is not on a transparent pixel. The isometric coordinates of the map node containing the texture with the highest Z-Level (drawing order) is returned. Camera Offset and current zoomLevel is taken into account

Parameters

screenCoordinates

object containing screen space coordinates

Returns

object containing the isometric coordinates of the tile that matches the screen coordinates

Definition at line 49 of file isoMath.cxx.

{
  Point foundCoordinates = Point();
  foundCoordinates = MapFunctions::instance().findNodeInMap(screenCoordinates);
 
  // if negative coordinates are returned, this means that the point is outside of the grid
  // calculate the coordinates instead and make sure it's within grid boundaries
  if (foundCoordinates.x == -1)
  {
    foundCoordinates = calculateIsoCoordinates(screenCoordinates);
    if (foundCoordinates.x < 0)
    {
      foundCoordinates.x = 0;
    }
    else if (foundCoordinates.x >= Settings::instance().mapSize)
    {
      // map (vector) size is 128, but coordinates ranges from 0 - 127
      foundCoordinates.x = Settings::instance().mapSize - 1;
    }
    if (foundCoordinates.y < 0)
    {
      foundCoordinates.y = 0;
    }
    else if (foundCoordinates.y >= Settings::instance().mapSize)
    {
      // map (vector) size is 128, but coordinates range from 0 - 127
      foundCoordinates.y = Settings::instance().mapSize - 1;
    }
  }
  return foundCoordinates;
}

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isPointWithinMapBoundaries()

bool isPointWithinMapBoundaries

(

const std::vector< Point > &

isoCoordinates

)

Check if given coordinates are within map boundaries.

Parameters

isoCoordinates

coordinates to check

Returns

true if coordinates are inside the map bounds.

Definition at line 81 of file isoMath.cxx.

{
  for (auto p : isoCoordinates)
  {
    if (!(p.isWithinMapBoundaries()))
    {
      return false;
    }
  }
  return true;
}

Variable Documentation

reverseDirection

bool reverseDirection = false

Definition at line 9 of file isoMath.cxx.