glTraslate, glRotate, a cube and some steps

[tirengarfio]

Hello,

the code below gives 12 positions and 12 angle rotations on the Y axis to a cube.

The positions and the angles are inside of two matrices.

When you push the key 'b' you go to next position and angle.

My problem is at the 7th step: the window doesnt show the view it should and I cannot understand why.

 
 
#include <stdafx.h>
#include <glut.h>
#include <math.h>
 
#include <iostream>
using namespace std;
 
 
double m=5;
double n=6;
double o=10;
double b=m/n;
double c=2*b;
double f=3*b;
int i=0;
double p=2;
double q=12;
double d1=(m*sqrt(p))/q;
 
 
double array[12][3]={   0,   0,  0, //posicion0 
                        0,   0,  0, //1
			0,   0,  b, //2
		        0,   0,  c, //3
		        0,   0,  c, //4
		      -d1,   0,  c+d1, //5
	            -2*d1,   0,  c+d1*2, //6
                    -2*d1,   0,  c+d1*2, //7 -> //THIS IS THE STEP I CANT UNDERStand
                      -d1,   0,  c+d1*3, //8 
			0,   0,  c+d1*4, //9
                        0,   0,  c+d1*4, //10
			0,   0,  f+d1*4}; //11
 
 
 
float xpos = 0, ypos = 0, zpos = 0, xrot = 0, yrot = 0, angle=0.0;
 
 
double array2[12]={    0,  //posicion inicial
					0,   //1
					0,
					0,
				  -45,   //4
				  -45,
				  -45,
				   45,   //7 -> THIS IS THE STEP I CANT NOT UNDERSTAND
				   45,   //8
				   45,
					0,
					0,   //11
};
 
 
 
 
void init (void) {
 
}
 
void enable (void) {
	glEnable (GL_DEPTH_TEST); //enable the depth testing
	//dglEnable (GL_LIGHTING); //enable the lighting
	glEnable (GL_LIGHT0); //enable LIGHT0, our Diffuse Light
	glShadeModel (GL_SMOOTH); //set the shader to smooth shader
}
 
void camera (void) {
 
	glTranslated(-array[i][0],-array[i][1],-array[i][2]);
 
	glRotatef(array2[i], 0.0, 1.0, 0.0);
 
 
}
 
void display (void) {
	glClearColor (0.0,0.0,0.0,1.0); //clear the screen to black
    glClear (GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); //clear the color buffer and the depth buffer
    glLoadIdentity();  
	gluLookAt (0.0, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0, 1.0, 0.0); //camera position, x,y,z, looking at x,y,z, Up Positions of the camera
	camera();
	enable();
 
 
 
	glBegin(GL_QUADS);           // Draw The Cube Using quads
		glColor3f(0.0f,1.0f,0.0f);     // Color Blue
		glVertex3f( 2.5f, 2.5f, 0.0f);    // Top Right Of The Quad (Top)
		glVertex3f(-2.5f, 2.5f, 0.0f);    // Top Left Of The Quad (Top)
		glVertex3f(-2.5f, 2.5f, 5.0f);    // Bottom Left Of The Quad (Top)
		glVertex3f( 2.5f, 2.5f, 5.0f);    // Bottom Right Of The Quad (Top)
 
		glColor3f(1.0f,0.5f,0.0f);     // Color Orange
		glVertex3f( 2.5f,-2.5f, 5.0f);    // Top Right Of The Quad (Bottom)
		glVertex3f(-2.5f,-2.5f, 5.0f);    // Top Left Of The Quad (Bottom)
		glVertex3f(-2.5f,-2.5f, 0.0f);    // Bottom Left Of The Quad (Bottom)
		glVertex3f( 2.5f,-2.5f, 0.0f);    // Bottom Right Of The Quad (Bottom)
 
		glColor3f(1.0f,0.0f,0.0f);     // Color Red      
		glVertex3f( 2.5f, 2.5f, 5.0f);    // Top Right Of The Quad (Front)
		glVertex3f(-2.5f, 2.5f, 5.0f);    // Top Left Of The Quad (Front)
		glVertex3f(-2.5f,-2.5f, 5.0f);    // Bottom Left Of The Quad (Front)
		glVertex3f( 2.5f,-2.5f, 5.0f);    // Bottom Right Of The Quad (Front)
 
		glColor3f(1.0f,1.0f,0.0f);     // Color Yellow
		glVertex3f( 2.5f,-2.5f, 0.0f);    // Top Right Of The Quad (Back)
		glVertex3f(-2.5f,-2.5f, 0.0f);    // Top Left Of The Quad (Back)
		glVertex3f(-2.5f, 2.5f, 0.0f);    // Bottom Left Of The Quad (Back)
		glVertex3f( 2.5f, 2.5f, 0.0f);    // Bottom Right Of The Quad (Back)
 
		glColor3f(0.0f,0.0f,1.0f);     // Color Blue
		glVertex3f(-2.5f, 2.5f, 5.0f);    // Top Right Of The Quad (Left)
		glVertex3f(-2.5f, 2.5f, 0.0f);    // Top Left Of The Quad (Left)
		glVertex3f(-2.5f,-2.5f, 0.0f);    // Bottom Left Of The Quad (Left)
		glVertex3f(-2.5f,-2.5f, 5.0f);    // Bottom Right Of The Quad (Left)
 
		glColor3f(1.0f,0.0f,1.0f);     // Color Violet
		glVertex3f( 2.5f, 2.5f, 0.0f);    // Top Right Of The Quad (Right)
		glVertex3f( 2.5f, 2.5f, 5.0f);    // Top Left Of The Quad (Right)
		glVertex3f( 2.5f,-2.5f, 5.0f);    // Bottom Left Of The Quad (Right)
		glVertex3f( 2.5f,-2.5f, 0.0f);    // Bottom Right Of The Quad (Right)
 
    glEnd();
 
 
 
	glutSwapBuffers(); //swap the buffers
	angle++; //increase the angle
}
 
void reshape (int w, int h) {
	glViewport (0, 0, (GLsizei)w, (GLsizei)h); //set the viewport to the current window specifications
	glMatrixMode (GL_PROJECTION); //set the matrix to projection
	glLoadIdentity ();
	gluPerspective (60, (GLfloat)w / (GLfloat)h, 0.1, 1000.0); //set the perspective (angle of sight, width, height, , depth)
	glMatrixMode (GL_MODELVIEW); //set the matrix back to model
}
 
void keyboard (unsigned char key, int x, int y) {
 
 
	if (key=='b')
	{		
 
		cout << "Posicion" << i+1 << endl;
		cout << array[i+1][0] << endl << array[i+1][1] << endl << array[i+1][2] << endl;
		cout << array2[i+1] << endl << endl;
		i++;
	}
 
 
 
}
 
int main (int argc, char **argv) {
    glutInit (&amp;argc, argv);
	glutInitDisplayMode (GLUT_DOUBLE | GLUT_DEPTH); //set the display to Double buffer, with depth
	glutInitWindowSize (500, 500); //set the window size
	glutInitWindowPosition (100, 100); //set the position of the window
    glutCreateWindow ("A basic OpenGL Window"); //the caption of the window
	init (); //call the init function
    glutDisplayFunc (display); //use the display function to draw everything
	glutIdleFunc (display); //update any variables in display, display can be changed to anyhing, as long as you move the variables to be updated, in this case, angle++;
	glutReshapeFunc (reshape); //reshape the window accordingly
	glutKeyboardFunc (keyboard); //check the keyboard
    glutMainLoop (); //call the main loop
    return 0;
}

[dorbie]

You don't describe what you see or what you expect to see.

You may want to interpolate the positions and rotations for a few frames just so you know what is going on.

An alternative would be to place the same transformation on the modelview (inverse or transpose) draw an arrow and view it all from a birdseye vantage point.