source: projectionDesigner/trunk/projdesignerplugins/defaultplugin/DefaultProjectorData.cpp @ 37

#include "DefaultProjectorData.h"
#include <stdlib.h>
#include <GL/glut.h>
#include <math.h>

#ifndef M_PI
#define M_PI 3.1415926535897932384626433832795
#endif // M_PI
#define RAD(angle) ((angle)*M_PI/180.f)


const QString DefaultPluginData::g_projector_name=QObject::tr("Standard Frustum");


/**
 * Default constructor fot the DefaultPluginData.
 *
 */
DefaultPluginData::DefaultPluginData(ProjectorInterface* plugin, float fov, float aspectRatio, float nearDist, float farDist, float offaxisX, float offaxisY):
    ProjectorData(plugin),
    m_fov(fov),
    m_aspectRatio(aspectRatio),
    m_nearDist(nearDist),
    m_farDist(farDist),
    m_offaxisX(offaxisX),
    m_offaxisY(offaxisY),
    m_visibleFar(1.2f)
{
}


/**
 * Destructor fot the DefaultPluginData.
 *
 */
DefaultPluginData::~DefaultPluginData()
{
}


/**
 * Implements the copy from other datas.
 *
 * This method is used by the copy constructor.
 *
 * @param data The source data.
 *
 * @return true if the copy is ok, false otherwise. The copy can fail if
 *         ProjectorData is not a DefaultPluginData.
 *
 * @seealso is_equal_to
 *
 */
bool DefaultPluginData::copy_from(const ProjectorData& data) 
{
    if (!ProjectorData::copy_from(data)) return false;
    Q_ASSERT(NULL!=plugin());
    Q_ASSERT(NULL!=data.plugin());
    const DefaultPluginData& _data = static_cast<const DefaultPluginData&>(data);
    m_fov = _data.m_fov;
    m_aspectRatio = _data.m_aspectRatio;
    m_nearDist = _data.m_nearDist;
    m_farDist = _data.m_farDist;
    m_offaxisX = _data.m_offaxisX;
    m_offaxisY = _data.m_offaxisY;
    m_visibleFar = _data.m_visibleFar;
    return true;
}


/**
 * Implements the egality-test with other datas.
 *
 * This could be an operator==.
 *
 * @param data The data to test with.
 *
 * @return true if the data are equal, false otherwise. The test can fail if
 *         the data have different parameters, but also it ProjectorData is
 *         not a DefaultPluginData.
 *
 * @seealso copy_from
 *
 */
bool DefaultPluginData::is_equal_to(const ProjectorData& data) const
{
    if (!ProjectorData::is_equal_to(data)) return false;
    const DefaultPluginData& _data = static_cast<const DefaultPluginData&>(data);
    return m_fov==_data.m_fov&&
        m_aspectRatio==_data.m_aspectRatio&&
        m_nearDist==_data.m_nearDist&&
        m_farDist==_data.m_farDist&&
        m_offaxisX==_data.m_offaxisX&&
        m_offaxisY==_data.m_offaxisY&&
        m_visibleFar==_data.m_visibleFar;
}


/**
 * Draws the frustum (a truncated pyramid).
 *
 * This method draws the frustum from outside. If the frustum is selected,
 * the lines are a little bigger.
 *
 * @param bSelected true if the frustum is selected.
 *
 * @seealso copy_from
 *
 */
void DefaultPluginData::draw(bool bSelected)
{
    QColor m_color(0,0,255);

    if (m_bShow)
    {
        glPushMatrix();
        glPushAttrib(GL_ENABLE_BIT | GL_CURRENT_BIT | GL_LINE_BIT);

        if (bSelected)
            glLineWidth(3.0f);

        float left =  -tan(RAD(m_fov/2.0f)) * m_aspectRatio + m_offaxisX;
        float right =  tan(RAD(m_fov/2.0f)) * m_aspectRatio + m_offaxisX;
        float top =   -tan(RAD(m_fov/2.0f)) + m_offaxisY;
        float bottom = tan(RAD(m_fov/2.0f)) + m_offaxisY;
        float nearDist = m_nearDist;
        float farDist = m_farDist;
        if (m_visibleFar < farDist)
            farDist = m_visibleFar;

        glColor4f(1.0f, 1.0f, 1.0f, 1.0f);
        glDisable(GL_LIGHTING);

        glBegin(GL_LINE_LOOP);
        glVertex3f(nearDist*left,  nearDist*bottom, -nearDist);
        glVertex3f(nearDist*right, nearDist*bottom, -nearDist);
        glVertex3f(nearDist*right, nearDist*top,    -nearDist);
        glVertex3f(nearDist*left,  nearDist*top,    -nearDist);
        glEnd();
        glBegin(GL_LINE_LOOP);
        glVertex3f(farDist*left,  farDist*bottom, -farDist);
        glVertex3f(farDist*right, farDist*bottom, -farDist);
        glVertex3f(farDist*right, farDist*top,    -farDist);
        glVertex3f(farDist*left,  farDist*top,    -farDist);
        glEnd();
        glBegin(GL_LINES);
        glVertex3f(0.0f, 0.0f, 0.0f);
        glVertex3f(farDist*left,  farDist*bottom, -farDist);
        glVertex3f(0.0f, 0.0f, 0.0f);
        glVertex3f(farDist*right, farDist*bottom, -farDist);
        glVertex3f(0.0f, 0.0f, 0.0f);
        glVertex3f(farDist*right, farDist*top,    -farDist);
        glVertex3f(0.0f, 0.0f, 0.0f);
        glVertex3f(farDist*left,  farDist*top,    -farDist);
        glEnd();

        glColor4f((float)m_color.red()/255.0f, (float)m_color.green()/255.0f, (float)m_color.blue()/255.0f, 0.25f);
        glEnable(GL_LIGHTING);
        glEnable(GL_BLEND);
        glDepthMask(false);

        glBegin(GL_TRIANGLES);
        glNormal3f(0.0f, cos(RAD(m_fov)/2.0f), -sin(RAD(m_fov)/2.0f));
        glVertex3f(0.0f, 0.0f, 0.0f);
        glVertex3f(farDist*left,  farDist*bottom, -farDist);
        glVertex3f(farDist*right, farDist*bottom, -farDist);
        glNormal3f( cos(RAD(m_fov)*m_aspectRatio/2.0f),
                    0.0f,
                    -sin(RAD(m_fov)*m_aspectRatio/2.0f));
        glVertex3f(0.0f, 0.0f, 0.0f);
        glVertex3f(farDist*right, farDist*bottom, -farDist);
        glVertex3f(farDist*right, farDist*top,    -farDist);
        glNormal3f(0.0f, -cos(RAD(m_fov)/2.0f), -sin(RAD(m_fov)/2.0f));
        glVertex3f(0.0f, 0.0f, 0.0f);
        glVertex3f(farDist*right, farDist*top, -farDist);
        glVertex3f(farDist*left,  farDist*top, -farDist);
        glNormal3f(-cos(RAD(m_fov)*m_aspectRatio/2.0f),
                   0.0f,
                   -sin(RAD(m_fov)*m_aspectRatio/2.0f));
        glVertex3f(0.0f, 0.0f, 0.0f);
        glVertex3f(farDist*left, farDist*top,    -farDist);
        glVertex3f(farDist*left, farDist*bottom, -farDist);
        glEnd();

        glDepthMask(true);
        glPopAttrib();
        glPopMatrix();
    }
}


/**
 * Begins the draw through the frustum.
 *
 * The draw must end with a endDraw().
 *
 * This is the same than glFrustum(), with some glPush...() before.
 *
 * @seealso endDraw
 *
 */
void DefaultPluginData::beginDraw(void)
{
    // Get the previous matrix mode
    GLint previous_matrix_mode=-1;
    glGetIntegerv(GL_MATRIX_MODE, &previous_matrix_mode);

    // Push and load the new projection matrix
    glMatrixMode(GL_PROJECTION);
    glPushMatrix();
    glLoadIdentity();
    glFrustum((-tan(RAD(m_fov) / 2.0 * m_aspectRatio) - m_offaxisX) * m_nearDist, 
              ( tan(RAD(m_fov) / 2.0 * m_aspectRatio) - m_offaxisX) * m_nearDist, 
              (-tan(RAD(m_fov) / 2.0) + m_offaxisY) * m_nearDist, 
              ( tan(RAD(m_fov) / 2.0) + m_offaxisY) * m_nearDist, 
              m_nearDist, 
              m_farDist);

    // Restore the previous matrix mode
    glMatrixMode(previous_matrix_mode);
}


/**
 * Ends the draw through the frustum.
 *
 * Must be used each time a draw through the projector has begun with a
 * beginDraw().
 *
 * This is the same than some glPop...().
 *
 * @seealso beginDraw
 *
 */
void DefaultPluginData::endDraw(void)
{
    // Get the previous matrix mode
    GLint previous_matrix=-1;
    glGetIntegerv(GL_MATRIX_MODE, &previous_matrix);
    // Pop the projection matrix stack
    glMatrixMode(GL_PROJECTION);
    glPopMatrix();
    // Restore the previous matrix mode
    glMatrixMode(previous_matrix);
}


/**
 * Begins the projection.
 *
 * The projection must end with a endProjection().
 *
 * This is the same than glFrustum(), without anything else.
 * beginDraw and beginProjection are quite close and it is perhaps to merge
 * them, but for the moment, to respect the Projection Designer
 * implementation, it will be let like this.
 *
 * endProjection is not implemented here because it does nothing more than
 * the ProjectorData::endProjection().
 *
 */
void DefaultPluginData::beginProjection(void)
{
    glFrustum((-tan(RAD(m_fov) / 2.0 * m_aspectRatio) - m_offaxisX) * m_nearDist, 
              ( tan(RAD(m_fov) / 2.0 * m_aspectRatio) - m_offaxisX) * m_nearDist, 
              (-tan(RAD(m_fov) / 2.0) + m_offaxisY) * m_nearDist, 
              ( tan(RAD(m_fov) / 2.0) + m_offaxisY) * m_nearDist, 
              m_nearDist, 
              m_farDist);
}


/**
 * Loads the frustum from a QDomElement.
 *
 * @param element The QDomElement to read from.
 *
 */
void DefaultPluginData::initFromDOMElement(const QDomElement& element)
{
    if (!element.isNull())
    {
        m_fov=element.attribute("fov").toFloat();
        m_aspectRatio=element.attribute("aspectRatio").toFloat();
        m_nearDist=element.attribute("near").toFloat();
        m_farDist=element.attribute("far").toFloat();
        m_offaxisX=element.attribute("offaxisX").toFloat();
        m_offaxisY=element.attribute("offaxisY").toFloat();
        m_visibleFar=element.attribute("visibleFar").toFloat();
        ProjectorData::initFromDOMElement(element);
    }
}


/**
 * Writes the frustum in a QDomDocument.
 *
 * @param name The name of the element.
 * @param doc The document whom belongs the element.
 *
 * @return The QDomElement to add.
 *
 */
QDomElement DefaultPluginData::domElement(const QString& name, QDomDocument& doc) const
{
    QDomElement de = ProjectorData::domElement(name, doc);
    de.setAttribute("fov", m_fov);
    de.setAttribute("aspectRatio", m_aspectRatio);
    de.setAttribute("near", m_nearDist);
    de.setAttribute("far", m_farDist);
    de.setAttribute("offaxisX", m_offaxisX);
    de.setAttribute("offaxisY", m_offaxisY);
    de.setAttribute("visibleFar", m_visibleFar);
    return de;
}