c++ - OpenGL 代码适用于 Windows 但不适用于 Mac

Question

我的学校使用 windows 计算机，但我家里只有一台 mac。 该代码在 Windows 中运行良好，但由于某种原因，我在 xCode 中运行它时出错。 我不确定要包含哪些框架，所以我添加了 GLKit、Cocoa、GLUT 和 OpenGL。 我错过了什么吗？ 我想获得 Xcode 设置，这样我就可以使用在 Windows 上运行的相同代码来完成家庭作业。 这是代码

#include <stdio.h>
#include <stdarg.h>
#include <math.h>
#define GL_GLEXT_PROTOTYPES
#ifdef __APPLE__
    #include <GLUT/glut.h>
#else
    #include <GL/glut.h>
#endif

#define GLUT_KEY_ESCAPE 27

const GLsizei windowWidth = 500;
const GLsizei windowHeight = 500;

GLfloat cubeRotateX = 45.0f;
GLfloat cubeRotateY = 45.0f;
bool keys[255];

GLvoid establishProjectionMatrix(GLsizei width, GLsizei height)
{
    glViewport(0, 0, width, height);

    glMatrixMode(GL_PROJECTION);

    glLoadIdentity();

    gluPerspective(45.0f, (GLfloat)width / (GLfloat)height, 0.1f, 200.0f);
}

GLvoid initGL(GLsizei width, GLsizei height)
{
    establishProjectionMatrix(width, height);

    glShadeModel(GL_SMOOTH);

    glClearColor(0.0f, 0.0f, 0.0f, 1.0f);

    glEnable(GL_DEPTH_TEST);
    glDepthFunc(GL_LEQUAL);

    glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST);
    glEnable(GL_PERSPECTIVE_CORRECTION_HINT);
}

GLvoid displayFPS(GLvoid)
{
    static long lastTime = glutGet(GLUT_ELAPSED_TIME);
    static int loops = 0;
    static GLfloat fps = 0.0f;

    int newTime = glutGet(GLUT_ELAPSED_TIME);

    if (newTime - lastTime > 100)
    {
        float newFPS = (float)loops / float(newTime - lastTime) * 1000.0f;
        fps = (fps + newFPS) / 2.0f;

        char title[80];
        sprintf_s(title, "OpenGL Demo - %.2f", fps);
        glutSetWindowTitle(title);

        lastTime = newTime;
        loops = 0;
    }
    loops++;
}

GLvoid drawScene(GLvoid)
{
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();

    glTranslatef(0, 0, -5.0f);
    glRotatef(cubeRotateX, 1.0, 0.0, 0.0);
    glRotatef(cubeRotateY, 0.0, 1.0, 0.0);

    glBegin(GL_QUADS);
    glColor3f(0.0f, 1.0f, 1.0f);
    glVertex3f( 1.0f,  1.0f, -1.0f);
    glVertex3f(-1.0f,  1.0f, -1.0f);
    glVertex3f(-1.0f,  1.0f,  1.0f);
    glVertex3f( 1.0f,  1.0f,  1.0f);

    glColor3f(0.0f, 1.0f, 0.0f);
    glVertex3f( 1.0f, -1.0f, -1.0f);
    glVertex3f(-1.0f, -1.0f, -1.0f);
    glVertex3f(-1.0f, -1.0f,  1.0f);
    glVertex3f( 1.0f, -1.0f,  1.0f);

    glColor3f(1.0f, 0.0f, 0.0f);
    glVertex3f( 1.0f,  1.0f, 1.0f);
    glVertex3f(-1.0f,  1.0f, 1.0f);
    glVertex3f(-1.0f, -1.0f, 1.0f);
    glVertex3f( 1.0f, -1.0f, 1.0f);

    glColor3f(1.0f, 1.0f, 0.0f);
    glVertex3f( 1.0f,  1.0f, -1.0f);
    glVertex3f(-1.0f,  1.0f, -1.0f);
    glVertex3f(-1.0f, -1.0f, -1.0f);
    glVertex3f( 1.0f, -1.0f, -1.0f);

    glColor3f(0.0f, 0.0f, 1.0f);
    glVertex3f(-1.0f,  1.0f,  1.0f);
    glVertex3f(-1.0f,  1.0f, -1.0f);
    glVertex3f(-1.0f, -1.0f, -1.0f);
    glVertex3f(-1.0f, -1.0f,  1.0f);

    glColor3f(1.0f, 0.0f, 1.0f);
    glVertex3f( 1.0f,  1.0f,  1.0f);
    glVertex3f( 1.0f,  1.0f, -1.0f);
    glVertex3f( 1.0f, -1.0f, -1.0f);
    glVertex3f( 1.0f, -1.0f,  1.0f);
    glEnd();

    glFlush();

    glutSwapBuffers();

    displayFPS();
}
GLboolean checkKeys(GLvoid)
{
    const GLfloat speed = 1.0f;

    if ( keys[GLUT_KEY_ESCAPE] )
        return true;

    if (keys[GLUT_KEY_LEFT])
        cubeRotateY -= speed;
    if (keys[GLUT_KEY_RIGHT])
        cubeRotateY += speed;
    if (keys[GLUT_KEY_UP])
        cubeRotateX -= speed;
    if (keys[GLUT_KEY_DOWN])
        cubeRotateX += speed;

    return false;
}
GLvoid timerLoop(int value)
{
    if (checkKeys())
        exit(0);
    glutPostRedisplay();

    glutTimerFunc(1, timerLoop, 0);
}



GLvoid keyboardCB(unsigned char key, int x, int y)
{
    keys[key] = true;
}
GLvoid keyboardUpCB(unsigned char key, int x, int y)
{
    keys[key] = false;
}
GLvoid keyboardSpecialCB(int key, int x, int y)
{
    keys[key] = true;
}
GLvoid keyboardSpecialUpCB(int key, int x, int y)
{
    keys[key] = false;
}




int main(int argc, char** argv)
{
    glutInit(&argc, argv);

    glutInitDisplayMode(GLUT_DOUBLE);

    int windowID = glutCreateWindow("OpenGL Cube Demo");
    glutReshapeWindow(windowWidth, windowHeight);

    initGL(windowWidth, windowHeight);

    glutDisplayFunc(drawScene);

    glutKeyboardFunc(keyboardCB);
    glutKeyboardUpFunc(keyboardUpCB);
    glutSpecialFunc(keyboardSpecialCB);
    glutSpecialUpFunc(keyboardSpecialUpCB);

    glutTimerFunc(1, timerLoop, 0);

    glutMainLoop();
    return 0;

}

为什么它在 visual studio 中工作而不在 Xcode 中工作？？

Answer 1

编译器的错误看起来很清楚。它不起作用的表面原因是因为此代码包含不可移植的 Windows 主义。

• C++ 不允许 void 的类型定义表示一个空的参数列表。你必须使用 void本身。所以，只是改变了那些 GLvoid s 至 void

• sprintf_s()是 Windows 特定的函数。您可以将其替换为 snprintf() , 但你必须在缓冲区后添加一个参数，即缓冲区的大小。所以，替换这个:

  sprintf_s(title, ...);
  

  与:

  snprintf(title, sizeof(title), ...);
  

• exit()功能可跨平台使用，但您必须包含正确的标题。添加#include <stdlib.h>靠近文件顶部。