Utility.cpp

#include "Utility.h"

void Utility::DrawQuad (const Point& p1, const Point& p2, const Point& p3, const Point& p4)
{
        Point midpoint;

        // calculate midpoint
        midpoint.x = (p1.x + p2.x + p3.x + p4.x) / 4;
        midpoint.y = (p1.y + p2.y + p3.y + p4.y) / 4;
        midpoint.z = (p1.z + p2.z + p3.z + p4.z) / 4;

        // do not fill the quad
        glPolygonMode (GL_FRONT_AND_BACK, GL_LINE);

        glColor4fv (color);

        glBegin (GL_QUADS);

                glVertex3f (p1.x, p1.y, p1.z);
                glVertex3f (p2.x, p2.y, p2.z);
                glVertex3f (p3.x, p3.y, p3.z);
                glVertex3f (p4.x, p4.y, p4.z);

        glEnd ();

        // reset fill mode
        glPolygonMode (GL_FRONT_AND_BACK, GL_FILL);
}

void Utility::DrawBoundingBox (BoundingBox bounding_box)
{
        // do not fill the quads
        glPolygonMode (GL_FRONT_AND_BACK, GL_LINE);

        glColor4fv (color);

        glBegin (GL_QUADS);

                // top
                glVertex3f (bounding_box.xmax, bounding_box.ymax, bounding_box.zmax);
                glVertex3f (bounding_box.xmax, bounding_box.ymin, bounding_box.zmax);
                glVertex3f (bounding_box.xmin, bounding_box.ymin, bounding_box.zmax);
                glVertex3f (bounding_box.xmin, bounding_box.ymax, bounding_box.zmax);

                // bottom
                glVertex3f (bounding_box.xmax, bounding_box.ymax, bounding_box.zmin);
                glVertex3f (bounding_box.xmax, bounding_box.ymin, bounding_box.zmin);
                glVertex3f (bounding_box.xmin, bounding_box.ymin, bounding_box.zmin);
                glVertex3f (bounding_box.xmin, bounding_box.ymax, bounding_box.zmin);

                // left
                glVertex3f (bounding_box.xmax, bounding_box.ymin, bounding_box.zmin);
                glVertex3f (bounding_box.xmax, bounding_box.ymin, bounding_box.zmax);
                glVertex3f (bounding_box.xmin, bounding_box.ymin, bounding_box.zmax);
                glVertex3f (bounding_box.xmin, bounding_box.ymin, bounding_box.zmin);

                // right
                glVertex3f (bounding_box.xmax, bounding_box.ymax, bounding_box.zmin);
                glVertex3f (bounding_box.xmax, bounding_box.ymax, bounding_box.zmax);
                glVertex3f (bounding_box.xmin, bounding_box.ymax, bounding_box.zmax);
                glVertex3f (bounding_box.xmin, bounding_box.ymax, bounding_box.zmin);

                // front
                glVertex3f (bounding_box.xmax, bounding_box.ymax, bounding_box.zmin);
                glVertex3f (bounding_box.xmax, bounding_box.ymax, bounding_box.zmax);
                glVertex3f (bounding_box.xmax, bounding_box.ymin, bounding_box.zmax);
                glVertex3f (bounding_box.xmax, bounding_box.ymin, bounding_box.zmin);

                // back
                glVertex3f (bounding_box.xmin, bounding_box.ymax, bounding_box.zmin);
                glVertex3f (bounding_box.xmin, bounding_box.ymax, bounding_box.zmax);
                glVertex3f (bounding_box.xmin, bounding_box.ymin, bounding_box.zmax);
                glVertex3f (bounding_box.xmin, bounding_box.ymin, bounding_box.zmin);

        glEnd ();

        // reset fill mode
        glPolygonMode (GL_FRONT_AND_BACK, GL_FILL);
}

void Utility::SetColor (float red, float green, float blue, float alpha)
{
        color[0] = red;
        color[1] = green;
        color[2] = blue;
        color[3] = alpha;
}

float Utility::color[4] = {1.0f, 1.0f, 1.0f, 0.0f};

Point Utility::GetPointFromBox (const BoundingBox & box, int index)
{
        Point result;
        switch (index)
        {
                case 0:         result.x = box.xmax;
                                        result.y = box.ymax;
                                        result.z = box.zmax;
                                        break;
                case 1:         result.x = box.xmax;
                                        result.y = box.ymax;
                                        result.z = box.zmin;
                                        break;
                case 2:         result.x = box.xmax;
                                        result.y = box.ymin;
                                        result.z = box.zmax;
                                        break;
                case 3:         result.x = box.xmax;
                                        result.y = box.ymin;
                                        result.z = box.zmin;
                                        break;
                case 4:         result.x = box.xmin;
                                        result.y = box.ymax;
                                        result.z = box.zmax;
                                        break;
                case 5:         result.x = box.xmin;
                                        result.y = box.ymax;
                                        result.z = box.zmin;
                                        break;
                case 6:         result.x = box.xmin;
                                        result.y = box.ymin;
                                        result.z = box.zmax;
                                        break;
                case 7:         result.x = box.xmin;
                                        result.y = box.ymin;
                                        result.z = box.zmin;
                                        break;
                default:        result.x = 0.0f;
                                        result.y = 0.0f;
                                        result.z = 0.0f;
        }

        return result;
}

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