/* isosurf.c */

/*
 * Display an isosurface of 3-D wind speed volume.  Use arrow keys to
 * rotate, S toggles smooth shading, L toggles lighting
 * Brian Paul
 */




#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <math.h>
#include "gltk.h"


GLboolean speed_test = GL_FALSE;

GLenum doubleBuffer;

GLenum smooth = GL_TRUE;
GLenum lighting = GL_TRUE;
GLenum depth = GL_TRUE;


#define MAXVERTS 10000

static GLfloat verts[MAXVERTS][4];
static GLfloat norms[MAXVERTS][3];
static GLint numverts;

static GLfloat xrot;
static GLfloat yrot;



static void read_surface( char *filename )
{
   FILE *f;

   f = fopen(filename,"r");
   if (!f) {
      printf("couldn't read %s\n", filename);
      exit(1);
   }

   numverts = 0;
   while (!feof(f) && numverts<MAXVERTS) {
      fscanf( f, "%f %f %f  %f %f %f",
	      &verts[numverts][0], &verts[numverts][1], &verts[numverts][2],
	      &norms[numverts][0], &norms[numverts][1], &norms[numverts][2] );
      verts[numverts][3] = 1.0;
      numverts++;
   }
   numverts--;

   printf("%d vertices, %d triangles\n", numverts, numverts-2);
   fclose(f);
}



static void draw_surface( void )
{
   GLuint i;

   glBegin( GL_TRIANGLE_STRIP );
   for (i=0;i<numverts;i++) {
      glNormal3fv( norms[i] );
      glVertex4fv( verts[i] );
   }
   glEnd();
}



static void draw1(void)
{
    glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
    glPushMatrix();
    glRotatef( yrot, 0.0, 1.0, 0.0 );
    glRotatef( xrot, 1.0, 0.0, 0.0 );

    draw_surface();

    glPopMatrix();

    glFlush();
    if (doubleBuffer) {
	tkSwapBuffers();
    }
}


static void draw(void)
{
   if (speed_test) {
      for (xrot=0.0;xrot<=90.0;xrot+=10.0) {
	 yrot++;
	 draw1();
      }
      tkQuit();
   }
   else {
      draw1();
   }
}



static void InitMaterials(void)
{
    static float ambient[] = {0.1, 0.1, 0.1, 1.0};
    static float diffuse[] = {0.5, 1.0, 1.0, 1.0};
    static float position0[] = {0.0, 0.0, 20.0, 0.0};
    static float position1[] = {0.0, 0.0, -20.0, 0.0};
    static float front_mat_shininess[] = {60.0};
    static float front_mat_specular[] = {0.2, 0.2, 0.2, 1.0};
    static float front_mat_diffuse[] = {0.5, 0.28, 0.38, 1.0};
    static float back_mat_shininess[] = {60.0};
    static float back_mat_specular[] = {0.5, 0.5, 0.2, 1.0};
    static float back_mat_diffuse[] = {1.0, 1.0, 0.2, 1.0};
    static float lmodel_ambient[] = {1.0, 1.0, 1.0, 1.0};
    static float lmodel_twoside[] = {GL_TRUE};

    glLightfv(GL_LIGHT0, GL_AMBIENT, ambient);
    glLightfv(GL_LIGHT0, GL_DIFFUSE, diffuse);
    glLightfv(GL_LIGHT0, GL_POSITION, position0);
    glEnable(GL_LIGHT0);
    
    glLightfv(GL_LIGHT1, GL_AMBIENT, ambient);
    glLightfv(GL_LIGHT1, GL_DIFFUSE, diffuse);
    glLightfv(GL_LIGHT1, GL_POSITION, position1);
    glEnable(GL_LIGHT1);
    
    glLightModelfv(GL_LIGHT_MODEL_AMBIENT, lmodel_ambient);
    glLightModelfv(GL_LIGHT_MODEL_TWO_SIDE, lmodel_twoside);
    glEnable(GL_LIGHTING);

    glMaterialfv(GL_FRONT_AND_BACK, GL_SHININESS, front_mat_shininess);
    glMaterialfv(GL_FRONT_AND_BACK, GL_SPECULAR, front_mat_specular);
    glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, front_mat_diffuse);
/*
    glMaterialfv(GL_BACK, GL_SHININESS, back_mat_shininess);
    glMaterialfv(GL_BACK, GL_SPECULAR, back_mat_specular);
    glMaterialfv(GL_BACK, GL_DIFFUSE, back_mat_diffuse);
*/

/*
    glColorMaterial(GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE);
    glEnable(GL_COLOR_MATERIAL);
*/
}


void foo(void)
{
    GLfloat mat_ambient[]  = { 0.0, 0,2, 0,0, 1,0 };
    GLfloat mat_diffuse[]  = { 0.0, 0.8, 0.0, 1.0 };
    GLfloat mat_specular[] = { 0.8, 0.8, 0.8, 1.0 };
    GLfloat shininess[]    = { 5.0 };
    
    GLuint l;
    l = glGenLists(1);
    
    glNewList(l, GL_COMPILE);

    glMaterialfv(GL_FRONT, GL_AMBIENT, mat_ambient);
    glMaterialfv(GL_FRONT, GL_DIFFUSE, mat_diffuse);
    glMaterialfv(GL_FRONT, GL_SPECULAR, mat_specular);
    glMaterialfv(GL_FRONT, GL_SHININESS, shininess);

    glEndList();

    glDeleteLists(l,1);   /* This line causes the error */
}



static void Init(void)
{
    glClearColor(0.0, 0.0, 0.0, 0.0);

    glShadeModel(GL_SMOOTH);
    
    glEnable(GL_DEPTH_TEST);

    InitMaterials();

    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
/*    gluPerspective(450, 1.0, 0.5, 10.0);*/
    glFrustum( -1.0, 1.0, -1.0, 1.0, 5, 25 );

    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();
    glTranslatef( 0.0, 0.0, -6.0 );

}



static void Reshape(int width, int height)
{
    glViewport(0, 0, (GLint)width, (GLint)height);
}



static GLenum Key(int key, GLenum mask)
{

    switch (key) {
      case TK_ESCAPE:
	tkQuit();
      case TK_LEFT:
	yrot -= 15.0;
	break;
      case TK_RIGHT:
	yrot += 15.0;
	break;
      case TK_UP:
	xrot += 15.0;
	break;
      case TK_DOWN:
	xrot -= 15.0;
	break;
      case TK_s:
	smooth = !smooth;
	if (smooth) {
	    glShadeModel(GL_SMOOTH);
	} else {
	    glShadeModel(GL_FLAT);
	}
	break;
      case TK_l:
	lighting = !lighting;
	if (lighting) {
	    glEnable(GL_LIGHTING);
	} else {
	    glDisable(GL_LIGHTING);
	}
	break;
      default:
	return GL_FALSE;
    }
    return GL_TRUE;
}



static GLenum Args(int argc, char **argv)
{
    GLint i;

    doubleBuffer = GL_TRUE;

    for (i = 1; i < argc; i++) {
	if (strcmp(argv[i], "-sb") == 0) {
	    doubleBuffer = GL_FALSE;
	} else if (strcmp(argv[i], "-db") == 0) {
	    doubleBuffer = GL_TRUE;
	} else if (strcmp(argv[i], "-speed") == 0) {
	    speed_test = GL_TRUE;
	    doubleBuffer = GL_TRUE;
	} else {
	    printf("%s (Bad option).\n", argv[i]);
	    return GL_FALSE;
	}
    }
    return GL_TRUE;
}



void main(int argc, char **argv)
{
    GLenum type;

    read_surface( "isosurf.dat" );

    if (Args(argc, argv) == GL_FALSE) {
	tkQuit();
    }

    tkInitPosition(0, 0, 400, 400);

    type = TK_DEPTH;
    type |= TK_RGB;
    type |= TK_DIRECT;
    type |= (doubleBuffer) ? TK_DOUBLE : TK_SINGLE;
    tkInitDisplayMode(type);

    if (tkInitWindow("Isosurface") == GL_FALSE) {
	tkQuit();
    }

    Init();

    tkExposeFunc(Reshape);
    tkReshapeFunc(Reshape);
    tkKeyDownFunc(Key);
    tkDisplayFunc( draw );
    tkExec();
}