Markus Mayer

//##########################################################################################################################
// OrientationHelperSceneNode.h file
//##########################################################################################################################

/**
 * Orientation Helper Scene Node for Irrlicht
 * (c) 2010, Markus Mayer <https://launchpad.net/~sunside>
 */

/* This program is free software. It comes without any warranty, to
 * the extent permitted by applicable law. You can redistribute it
 * and/or modify it under the terms of the Creative Commons
 * Attribution 3.0 Unported license.
 * See http://creativecommons.org/licenses/by/3.0/ for more details. */

#include <Irrlicht.h>
using namespace irr;

class OrientationHelperSceneNode : public scene::ISceneNode
{
public:
    OrientationHelperSceneNode(f32 size, scene::ISceneNode* parent, scene::ISceneManager* mgr, s32 id);
    virtual ~OrientationHelperSceneNode(void) {}
    virtual void render();
    inline virtual const core::aabbox3d<f32>& getBoundingBox() const { return boundingBox; }

    inline virtual void OnRegisterSceneNode() {
        if (!isVisible()) return;

        SceneManager->registerNodeForRendering(this);
        ISceneNode::OnRegisterSceneNode();
    }

    //! Rotates the node, so that it's Z direction matches the given vector
    /**
    * @direction        The direction vector
    * @worldUp      The world up vector
    */
    void rotateZToDirection(const core::vector3df &direction, const core::vector3df &worldUp);

    //! Rotates the node, so that it's Z direction matches the given vector
    /**
    * @direction        The camera to take the target direction vector from
    * @worldUp      The world up vector
    */
    inline void rotateZToDirection(const scene::ICameraSceneNode *camera, const core::vector3df &worldUp) {
        core::vector3df direction = (camera->getTarget() - camera->getPosition()).normalize();
        rotateZToDirection(direction, worldUp);
    }

    //! Rotates the node, so that it's Z direction matches the given vector
    /**
    * @direction        The camera to take the target direction and world up vector from
    */
    inline void rotateZToDirection(const scene::ICameraSceneNode *camera) {
        core::vector3df worldUp = camera->getUpVector();
        rotateZToDirection(camera, worldUp);
    }

private:

    core::aabbox3d<f32> boundingBox;
    f32 size;
    video::SMaterial boxMaterial;
};

//##########################################################################################################################
// OrientationHelperSceneNode.c file
//##########################################################################################################################


/**
 * Orientation Helper Scene Node for Irrlicht
 * (c) 2010, Markus Mayer <https://launchpad.net/~sunside>
 */

/* This program is free software. It comes without any warranty, to
 * the extent permitted by applicable law. You can redistribute it
 * and/or modify it under the terms of the Creative Commons
 * Attribution 3.0 Unported license.
 * See http://creativecommons.org/licenses/by/3.0/ for more details. */

#include "OrientationHelperSceneNode.h"

OrientationHelperSceneNode::OrientationHelperSceneNode(f32 helperSize, scene::ISceneNode* parent, scene::ISceneManager* mgr, s32 id)
    : scene::ISceneNode(parent, mgr, id), size(helperSize)
{
    boundingBox = core::aabbox3d<f32>(-size*0.5f, -size*0.5f, -size*0.5f, size*1.5f, size*1.5f, size*1.5f);

    // Materialien erzeugen
    boxMaterial.Lighting = false;
    boxMaterial.Thickness = 2.0f;
    boxMaterial.Wireframe = true;
    boxMaterial.FrontfaceCulling = false;
    boxMaterial.BackfaceCulling = false;
}

//! Renders the node
void OrientationHelperSceneNode::render() {

    // Prepare rendering
    video::IVideoDriver* driver = SceneManager->getVideoDriver();
    driver->setMaterial(boxMaterial);
    driver->setTransform(video::ETS_WORLD, AbsoluteTransformation);

    // Calculate lengths
    f32 halfSize = size*0.5f;
    f32 lineLength = 1.5f*size;
    f32 arrowOffset = -0.125f*size;
    f32 offsetLine = lineLength - 0.25f*size;

    // Create and draw box
    core::vector3df zero = vector3df(0, 0, 0);
    core::aabbox3d<f32> box(-halfSize, -halfSize, -halfSize, halfSize, halfSize, halfSize);
    driver->draw3DBox(box);

    // X arrow (red)
    video::SColor color = video::SColor(255, 255, 0, 0);
    driver->draw3DLine(zero, vector3df(lineLength, 0, 0), color);

    core::triangle3df triangle(
        core::vector3df(offsetLine, -arrowOffset, 0),
        core::vector3df(offsetLine, arrowOffset, 0),
        core::vector3df(lineLength, 0, 0));
    driver->draw3DTriangle(triangle, color);

    triangle = core::triangle3df(
        core::vector3df(offsetLine, 0, -arrowOffset),
        core::vector3df(offsetLine, 0, arrowOffset),
        core::vector3df(lineLength, 0, 0));
    driver->draw3DTriangle(triangle, color);

    // Y arrow (green)
    color = video::SColor(255, 0, 255, 0);
    driver->draw3DLine(zero, vector3df(0, lineLength, 0), color);

    triangle = core::triangle3df(
        core::vector3df(-arrowOffset, offsetLine, 0),
        core::vector3df(arrowOffset, offsetLine, 0),
        core::vector3df(0, lineLength, 0));
    driver->draw3DTriangle(triangle, color);

    triangle = core::triangle3df(
        core::vector3df(0, offsetLine, -arrowOffset),
        core::vector3df(0, offsetLine, arrowOffset),
        core::vector3df(0, lineLength, 0));
    driver->draw3DTriangle(triangle, color);

    // Z arrow (blue)
    color = video::SColor(255, 0, 0, 255);
    driver->draw3DLine(zero, vector3df(0, 0, lineLength), color);

    triangle = core::triangle3df(
        core::vector3df(-arrowOffset, 0, offsetLine),
        core::vector3df(arrowOffset, 0, offsetLine),
        core::vector3df(0, 0, lineLength));
    driver->draw3DTriangle(triangle, color);

    triangle = core::triangle3df(
        core::vector3df(0, -arrowOffset, offsetLine),
        core::vector3df(0, arrowOffset, offsetLine),
        core::vector3df(0, 0, lineLength));
    driver->draw3DTriangle(triangle, color);
}

//! Rotates the element
void OrientationHelperSceneNode::rotateZToDirection(const core::vector3df &direction, const core::vector3df &worldUp) {
    core::vector3df right = worldUp.crossProduct(direction).normalize();
    core::vector3df up = direction.crossProduct(right).normalize();

    // Create aim-at matrix from look-at matrix
    core::matrix4 mLookAt, m;
    mLookAt.buildCameraLookAtMatrixLH(core::vector3df(), direction, worldUp);
    mLookAt.getInverse(m);

    // Set the rotation
    core::vector3df rotation = m.getRotationDegrees();
    setRotation(rotation);
}