/*****************************************************************
  ivdraw0.cpp
  by Dave Pape
  21 March 2003

*****************************************************************/
#include <stdlib.h>
#include <math.h>
#include <unistd.h>
#include <stdio.h>
#include <GL/glut.h>
#include <GL/gl.h>
#include <Inventor/SoInteraction.h>
#include <Inventor/SoDB.h>
#include <Inventor/nodes/SoNodes.h>
#include <Inventor/actions/SoGLRenderAction.h>
#include <dms/dms.h>


using namespace dms;

void createScene(char *file);
void drawEverything(void);

void key(unsigned char k, int x, int y);
void specialkey(int k, int x, int y);
void idle(void);


PerspCamera camera;
Light light;
SoSeparator * ivRoot;
SoGLRenderAction * ivRender;
SbViewportRegion * ivViewport;

int main(int argc, char *argv[])
    {
    if (argc < 2)
        {
        cerr << "Usage: ivdraw0 file.iv" << endl;
        exit(1);
        }
    glutInit(&argc, argv);
    glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH);
    glutInitWindowSize(512,512);
    glutCreateWindow(argv[0]);
    
    glutDisplayFunc(drawEverything);
    glutKeyboardFunc(key);
    glutSpecialFunc(specialkey);
    glutIdleFunc(idle);
    
    camera.setPosition(0, 0, 10);
    light.setInfinitePosition(-5, 4, 1);
    createScene(argv[1]);
    
    glutMainLoop();
    return 0;
    }


void createScene(char *file)
    {
    SoInteraction::init();
    ivViewport = new SbViewportRegion(glutGet(GLUT_WINDOW_WIDTH),
                                       glutGet(GLUT_WINDOW_HEIGHT));
    ivRender = new SoGLRenderAction(*ivViewport);

    ivRoot = new SoSeparator;
    ivRoot->ref();
    SoInput in;
    if (!in.openFile(file))
        return;
    while (1)
        {
        SoNode *node;
        if (!SoDB::read(&in, node))
            break;
        if (node)
            ivRoot->addChild(node);
        else
            break;
        }
    in.closeFile();
    }


void drawEverything(void)
    {
    glClearColor(0.5, 0.7, 1.0, 0.0);
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
    glEnable(GL_DEPTH_TEST);
    
    camera.apply();
    light.apply();
    ivRender->apply(ivRoot);
    
    glutSwapBuffers();

    checkGLError("end-of-frame");
    }


void key(unsigned char k, int x, int y)
    {
    if (k == 27)
        exit(0);
    }


void specialkey(int k, int x, int y)
    {
    if (k == GLUT_KEY_LEFT)
        camera.turn(3);
    else if (k == GLUT_KEY_RIGHT)
        camera.turn(-3);
    else if (k == GLUT_KEY_UP)
        camera.pitch(2);
    else if (k == GLUT_KEY_DOWN)
        camera.pitch(-2);
    else if (k == GLUT_KEY_HOME)
        camera.moveForward(0.25);
    else if (k == GLUT_KEY_END)
        camera.moveForward(-0.25);
    else if (k == GLUT_KEY_PAGE_UP)
        camera.zoom(-1);
    else if (k == GLUT_KEY_PAGE_DOWN)
        camera.zoom(1);
    }


void idle(void)
    {
    glutPostRedisplay();
    }