Zeichnen eines Arrays von Objekten in Open GL Glut

Question

Ich habe versucht, mehrere Bälle für ein Spiel, das ich mache, zu zeichnen, ich habe versucht, dies funktioniert, aber es gibt Probleme in meiner init-Klasse und Display-Methode-Klasse, ich habe es kommentiert, wo die Fehler sind.

Ball.h:

#pragma once
#include "Vector2f.h"
#include "Vector3f.h"

class Ball
{
private:
    Vector3f position;
    Vector3f velocity;

public:
    Ball(void);
    ~Ball(void);

    void Draw();
    void SetPos(Vector3f New_position);
    void SetVel(Vector3f New_velocity);
    Vector3f GetPos();
};

Ball.cpp

#include "Ball.h"
#include "Vector2f.h"
#include "Vector3f.h"
#include "Glut/glut.h"
#include "GL/gl.h"
#include "GL/glu.h"

Ball::Ball(void)
{
    Vector3f Temp_position;
    position = Temp_position;
    Vector3f Temp_velocity;
    velocity = Temp_velocity;
}

Ball::~Ball(void)
{
}

void Ball::SetPos(Vector3f New_position)
{
    position = New_position;
}

void Ball::Draw()
{
    glPushMatrix();
    glTranslatef(position.X(), position.Y(), position.Z());
    glColor3d(1, 0, 0);
    glutSolidSphere(0.3, 50, 50);
    glPopMatrix();
}

void Ball::SetVel(Vector3f New_velocity)
{
    velocity = New_velocity;
}

Vector3f Ball::GetPos()
{
    Vector3f temp;
    temp = position;
    return temp;
}

Ich möchte in der Lage sein, ein Array der Bälle in Main.cpp zu zeichnen

Main.cpp 

#include "Display.h"
#include "Vector3f.h"
#include "Ball.h"
#include "Glut/glut.h"
#include "GL/gl.h"
#include "GL/glu.h"
#include <math.h>

static float TableWidth = 4;  // Z axis normal = 4
float Display::eyeX = -7.5; //-7.5
float Display::eyeY = 3; //3
float Display::eyeZ = 5; //5
float Display::Position[4] = { 1.0f, 0.0f, -3.5, 1.0f };
float Display::translateZ = -3.5;
float Display::translateX = 0.0;
//Timer Display::m_Timer = Timer();
float Display::lightX = 5.0; //5 2.5
float Display::lightY = 5.0;
float Display::lightZ = 2.5;

float m_TableX = -5.0f;
float m_TableZ = -2.5f;
float m_TableWidth = 2.5f;
float m_TableLength = 5.0f;

float ballx = 0.7;
float bally = 0.1;
float ballz = -0.7;

Ball Redball;
float BALL_RED_START = 0;
float RADIUS_OF_BALL = 0.3;
float BALL_RED_END = 8;
float m_ball;

void Display::Init(int argc, char ** argv)
{
    glutInit(&argc, argv); // initializes glut
    // sets display mode. These parameter set RGB colour model
    // and double buffering.
    glutInitWindowSize(500,500);
    glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE);
    glutCreateWindow("Pool Version 1.0");

    // Set glut callback functions
    glutDisplayFunc(Display::DisplayScene);
    glutIdleFunc(Display::Idle);
    glutReshapeFunc(Display::Resize);
    glutKeyboardFunc(Display::KeyboardInput);
    //m_Timer.getSeconds();
    glEnable(GL_DEPTH_TEST);
    glPointSize(5);

        glEnable(GL_NORMALIZE);
        glEnable(GL_LIGHTING);
        glClearColor(0,0,0,1);
        glEnable(GL_COLOR_MATERIAL);

float white[] = { 1.0f, 1.0f, 1.0f, 1.0f };
glLightfv(GL_LIGHT0, GL_DIFFUSE, white);

glEnable(GL_LIGHT0);
Redball.SetPos(Vector3f(0.0,0.3,0.0));

for(int i = BALL_RED_START; i < BALL_RED_START; i++)
{
  glColor3f(1,0,0);
  Redball[i]->SetPos(Vector3f (i+128,RADIUS_OF_BALL,45));  //I tried this but it doesn't work Error C2227
}

    // Begin glut main loop
    glutMainLoop();
}

void BallMovement()
{
    //Vector3f position(0.0,0.3,0.0);
    /*Redball.SetPos(Vector3f(0.0,0.3,0.0));*/
    Vector3f New_velocity(0.01,0,0);
    Redball.SetVel(New_velocity);

    Vector3f New_position;
    Vector3f Old_position;

    Old_position = Redball.GetPos();

    //New_position = Old_position + New_velocity;

    New_position.SetX(Old_position.X() + New_velocity.X());
    New_position.SetY(Old_position.Y() + New_velocity.Y());
    New_position.SetZ(Old_position.Z() + New_velocity.Z());

    Redball.SetPos(New_position);
}

void Display::DisplayScene()
{
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); // Clear the back buffer

    glPushMatrix();
    glLoadIdentity();
    glNormal3f(0,1,0);
    Vector3f didums = Redball.GetPos();
    gluLookAt(eyeX, eyeY, eyeZ,     // eye position
            0, 0, 0,        // what I'm looking at
            0.0, 1.0, 0); // Up direction

    float Position[] = {lightX, lightY, lightZ, 1.0f};
glLightfv(GL_LIGHT0, GL_POSITION, Position);
DrawLight(0, Position);

    /* Rendering code goes here */

for (int i = BALL_RED_START; i<BALL_RED_END;i++)
{
glColor3f(1,0,0);
Redball[i]->Draw();     //I tried this but it doesn't work Error C2227
}

drawTable();
drawTableLegFrontLeft();
drawTableLegFrontRight();
drawTableLegBackLeft();
drawTableLegBackRight();
drawCushions();
//drawCircle();
//drawHCircle();
Table(-2,-4.5,2,4.5); // Draws the table top in trianglestrip       -4.5, 0.5, -0.5, 9.5

    glPopMatrix();
    glutSwapBuffers(); // Swap the front and back buffers
}

void Display::Resize(int w, int h)
{
    /* Resize is called when window is resized */
    glMatrixMode(GL_PROJECTION); // set matrix mode to profection
    // this dictates how the 3d scene is "squashed" onto the 2d screen
    glLoadIdentity();
    glViewport(0, 0, w, h);  // Set the part of the window to use.
    gluPerspective(45,              // field of view
                (float)w/(float)h,  // ration of window
                1,                  // front clipping plane
                1000                // back clipping plane
                );          // set the area in the 3d scene to draw

    glMatrixMode(GL_MODELVIEW); // Setthe matrix mode to model view
        // the matrix specifies how the 3d scene is viewed
    /*glLoadIdentity();
    gluLookAt(-3.5, 2, eyeZ,        // eye position
            1, 1, 0,        // what I'm looking at
            0.0, 1.0, 0); // Up direction*/
}

void Display::Idle()
{
    /* When nothing else is happening, idle is called.
     * Simulation should be done here and then
     * the display method should be called
     */

    BallMovement();

    glutPostRedisplay();
}

Answer 1

Ich sehe, Sie haben erklärt Ball als Ball Redball; was einen einzelnen Ball auf dem Stapel erzeugt.

Dann versuchen Sie, es als eine Sammlung von Ball s mit Redball[i]->SetPos(...) y Redball[i]->Draw() . Es scheint, dass Sie versuchen, mit 8 von ihnen zu arbeiten.

Sie möchten ein Array von Ball s, mit einer maximalen Größe von 8 (gemäß BALL_RED_END ). Der Einfachheit halber könnten Sie Folgendes tun

Ball RedBall[8];
for( //some conditions here )
{
    RedBall[i].Draw();
}

als Ihre Erklärung und Verwendung.

Denken Sie daran, dass Sie bei jeder Verwendung von Redball.SetPos(...) nicht mehr gültig sein wird.