I have been having problems with OpenGL in XCode (written in C++). The following code yields different results in Visual Studio and XCode and I cannot figure out why, somehow the z-depth is screwed up so the cube looks weird in XCode.
Any suggestion is appreciated! Happy holidays everyone!
Following is the source code (main.cpp):
#include <iostream>
#include <GLUT/glut.h>
/* Define color vectors */
GLfloat RED[3] = {1.0f, 0.0f, 0.0f};
GLfloat GREEN[3] = {0.0f, 1.0f, 0.0f};
GLfloat BLUE[3] = {0.0f, 0.0f, 1.0f};
GLfloat ORANGE[3] = {1.0f, 0.5f, 0.0f};
GLfloat YELLOW[3] = {1.0f, 1.0f, 0.0f};
GLfloat VIOLET[3] = {1.0f, 0.0f, 1.0f};
GLfloat CYAN[3] = {0.0f, 1.0f, 1.0f};
static GLfloat spin = 0.0;
void init() {
glShadeModel(GL_SMOOTH);
glClearColor(0.0f, 0.0f, 0.0f, 0.5f);
glClearDepth(1.0f);
glEnable(GL_DEPTH_TEST);
glDepthFunc(GL_LEQUAL);
glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST);
}
void display() {
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glLoadIdentity();
glTranslatef(0.0f, -1.0f, -10.0f);
glRotatef(spin, 1.0f, 1.0f, 1.0f);
glBegin(GL_QUADS);
glColor3fv(GREEN); // Set The Color To Green
glVertex3f( 1.0f, 1.0f,-1.0f); // Top Right Of The Quad (Top)
//glColor3fv(BLUE);
glVertex3f(-1.0f, 1.0f,-1.0f); // Top Left Of The Quad (Top)
//glColor3fv(RED);
glVertex3f(-1.0f, 1.0f, 1.0f); // Bottom Left Of The Quad (Top)
//glColor3fv(VIOLET);
glVertex3f( 1.0f, 1.0f, 1.0f); // Bottom Right Of The Quad (Top)
glColor3fv(BLUE); // Set The Color To Orange
glVertex3f( 1.0f,-1.0f, 1.0f); // Top Right Of The Quad (Bottom)
//glColor3fv(YELLOW);
glVertex3f(-1.0f,-1.0f, 1.0f); // Top Left Of The Quad (Bottom)
//glColor3fv(ORANGE);
glVertex3f(-1.0f,-1.0f,-1.0f); // Bottom Left Of The Quad (Bottom)
//glColor3fv(CYAN);
glVertex3f( 1.0f,-1.0f,-1.0f); // Bottom Right Of The Quad (Bottom)
glColor3fv(VIOLET);
glVertex3f( 1.0f, 1.0f, 1.0f); // Top Right Of The Quad (Front)
//glColor3fv(RED);
glVertex3f(-1.0f, 1.0f, 1.0f); // Top Left Of The Quad (Front)
//glColor3fv(YELLOW);
glVertex3f(-1.0f,-1.0f, 1.0f); // Bottom Left Of The Quad (Front)
//glColor3fv(BLUE);
glVertex3f( 1.0f,-1.0f, 1.0f); // Bottom Right Of The Quad (Front)
glColor3fv(CYAN);
glVertex3f( 1.0f,-1.0f,-1.0f); // Top Right Of The Quad (Back)
//glColor3fv(ORANGE);
glVertex3f(-1.0f,-1.0f,-1.0f); // Top Left Of The Quad (Back)
//glColor3fv(BLUE);
glVertex3f(-1.0f, 1.0f,-1.0f); // Bottom Left Of The Quad (Back)
//glColor3fv(GREEN);
glVertex3f( 1.0f, 1.0f,-1.0f); // Bottom Right Of The Quad (Back)
#if 0
glColor3fv(RED);
glVertex3f(-1.0f, 1.0f, 1.0f); // Top Right Of The Quad (Left)
//glColor3fv(BLUE);
glVertex3f(-1.0f, 1.0f,-1.0f); // Top Left Of The Quad (Left)
//glColor3fv(ORANGE);
glVertex3f(-1.0f,-1.0f,-1.0f); // Bottom Left Of The Quad (Left)
//glColor3fv(YELLOW);
glVertex3f(-1.0f,-1.0f, 1.0f); // Bottom Right Of The Quad (Left)
glColor3fv(GREEN);
glVertex3f( 1.0f, 1.0f,-1.0f); // Top Right Of The Quad (Right)
//glColor3fv(VIOLET);
glVertex3f( 1.0f, 1.0f, 1.0f); // Top Left Of The Quad (Right)
//glColor3fv(BLUE);
glVertex3f( 1.0f,-1.0f, 1.0f); // Bottom Left Of The Quad (Right)
//glColor3fv(CYAN);
glVertex3f( 1.0f,-1.0f,-1.0f); // Bottom Right Of The Quad (Right)
#endif
glEnd();
glutSwapBuffers();
}
void spinDisplay() {
spin += 0.5;
spin > 360.0? (spin - 360.0) : spin;
glutPostRedisplay();
}
void reshape(int width, int height)
{
height == 0? 1 : height;
glViewport(0, 0, width, height);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
gluPerspective(45.0f,(GLfloat)width/(GLfloat)height,0.1f,100.0f);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
}
void mouse(int button, int state, int x, int y) {
switch(button) {
case GLUT_LEFT_BUTTON:
if (state == GLUT_DOWN)
glutIdleFunc(spinDisplay);
break;
case GLUT_RIGHT_BUTTON:
if (state == GLUT_DOWN)
glutIdleFunc(NULL);
break;
default:
break;
}
}
int main(int argc, char** argv) {
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB);
glutInitWindowSize(640, 480);
glutInitWindowPosition(100, 100);
glutCreateWindow(“Rotating Cube”);
init();
glutDisplayFunc(display);
glutReshapeFunc(reshape);
glutMouseFunc(mouse);
glutMainLoop();
return 0;
}
