Object become flipping

OpenGL OpenGL: Basic Coding
1

Hi everyone,

First of all this program is completely from NeHe tutorial ported to GLUT.
This program will display target that we can shoot using mouse using picking.
The original tutorial will create 30 target object that will be assign with 5 random texture.

I’ve modify it so user can shoot with the keyboard.I assign the key ‘a’ to the first object and so on.
I assign 5 object with it own texture using the original texture but not randomly as NeHe does.

So in the Function Draw i try to randomly display the object using rand() function.
But it become flipping when I run it. Is it because the rand() function or something else?
And how do I solve it?

struct objects {
	GLuint	rot;	
	.
	.			
	GLfloat	distance;									
};

static GLvoid InitObject(int num)									
{	
								
	object[num].rot=1;										
	object[num].frame=0;	
	object[num].hit=false;		
	object[num].texid=num;		
	object[num].distance=-(float(rand()%3501)/100.0f);	
	object[num].y=-1.5f+(float(rand()%401)/100.0f);		
	object[num].x=((object[num].distance-15.0f)/2.0f)-(5*level)-float(rand()%(5*level));
	object[num].dir=(rand()%2);				

	if (object[num].dir==0)					
	{
		object[num].rot=2;				
		object[num].x=-object[num].x;			
	}

	if (object[num].texid==0)				
		object[num].y=-2.0f;				

}

static void Object(GLuint texid)
{
// Draw Object Using
}

void DrawTargets(void) // Draws The Targets (Needs To Be Seperate)
{

glLoadIdentity(); // Reset The Modelview Matrix
glTranslatef(0.0f,0.0f,-10.0f); // Move Into The Screen 20 Units

for (int loop1=0; loop1<bilObject; loop1++)
{

  int loop=(rand()%30);
  glPushMatrix();								// Push The Modelview Matrix
  glTranslatef(object[loop].x,object[loop].y,object[loop].distance);	// Position The Object (x,y)
  if (object[loop].hit)							// If Object Has Been Hit
  {
  	Explosion(loop);
  	
  }
  else							// Otherwise
  {
  	glRotatef(object[loop].spin,0.0f,0.0f,1.0f);	// Rotate The Object
  	Object(loop);	// Draw The Object
  }
  glPopMatrix();						// Pop The Modelview Matrix

}

}

static void Draw(void) // Draw Our Scene
{

glClear (GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); // Clear Screen And Depth Buffer
glLoadIdentity(); // Reset The Modelview Matrix

glPushMatrix(); // Push The Modelview Matrix
glBindTexture(GL_TEXTURE_2D, textures[7].texID); // Select The Sky Texture
glBegin(GL_QUADS); // Begin Drawing Quads
.
.
.
glEnd(); // Done Drawing Quads

glBindTexture(GL_TEXTURE_2D, textures[6].texID); // Select The Ground Texture
glBegin(GL_QUADS); // Draw A Quad
.
.
.
glEnd(); // Done Drawing Quad

DrawTargets(); // Draw Our Targets
glPopMatrix();

// Pop The Modelview Matrix
glMatrixMode(GL_PROJECTION); // Select The Projection Matrix
glPushMatrix(); // Store The Projection Matrix
glLoadIdentity(); // Reset The Projection Matrix
glOrtho(0,g_width,0,g_height,-1,1); // Set Up An Ortho Screen
glMatrixMode(GL_MODELVIEW); // Select The Modelview Matrix

// Game Stats / Title
.
.
.
glMatrixMode(GL_PROJECTION); // Select The Projection Matrix
glPopMatrix(); // Restore The Old Projection Matrix
glMatrixMode(GL_MODELVIEW); // Select The Modelview Matrix

glFlush();
glutSwapBuffers();
}

[This message has been edited by dean78 (edited 01-05-2002).]