OpenGL绘制球体

于(0,0,0) 绘制一个半径R=1 的球体函数：
sphere_entry

void sphere_entry(int du, int dv){

	float gu = 3.1415926535 / du , gv = 2.0*3.1415926535 / (dv-1);

	float x, y, z ,r ;

	glPushMatrix();
#define MAKE_R(z2) sqrt(1.0 - (z2))
#define MAKE_Z(z_step) cos((z_step) *gu)
#define MAKE_Y(x_step,r) (r)*sin((x_step)* gv)
#define MAKE_X(x_step,r) (r)*cos((x_step)* gv)
	// 球体
	glBegin(GL_QUADS);
	for (int z_step = 0 ; z_step < du; ++z_step) {
		for (int x_step = 0; x_step < dv; ++x_step) {

			z = MAKE_Z(z_step);
			r = MAKE_R(z*z);
			x = MAKE_X(x_step, r);
			y = MAKE_Y(x_step, r);
			glVertex3f(x, y, z);

			z = MAKE_Z(z_step+1);
			r = MAKE_R(z*z);
			x = MAKE_X(x_step, r);
			y = MAKE_Y(x_step, r);
			glVertex3f(x, y, z);

			z = MAKE_Z(z_step + 1);
			r = MAKE_R(z*z);
			x = MAKE_X(x_step + 1,r);
			y = MAKE_Y(x_step+1, r);
			glVertex3f(x, y, z);

			z = MAKE_Z(z_step);
			r = MAKE_R(z*z);
			x = MAKE_X(x_step + 1,r);
			y = MAKE_Y(x_step + 1, r);
			glVertex3f(x, y, z);
		}

	}

	glEnd();
#undef MAKE_Y
#undef MAKE_Z
#undef MAKE_X
#undef MAKE_R
	glPopMatrix();
}

显示效果：

所有代码：
main.cpp

#include "pch.h"
#include 

#include 
#include 

#ifdef _WIN32
#define FREEGLUT_STATIC
#include 
#endif

#include "sphere.h"

float angle;

void changed_size(int w, int h) {
	// 修改视窗size
	glViewport(0, 0, w, h);

	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();

	gluPerspective(45.0f, double(w) / double(h), 1.0f, 1000.0f);

	glMatrixMode(GL_MODELVIEW);
	glLoadIdentity();
	
	gluLookAt(0.0f, 0.0f, 5.0f,
		0.0f, 0.0f, 0.0f,
		0.0f, 1.0f, 0.0f);
}

// 初始化渲染环境
void setup_rc() {

	// 蓝色背景
	glClearColor(0.f, 0.f, .3f, 1.f);

	angle = 0.0f;

	glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);

}

// 渲染
void render(void) {

	// 清除颜色缓冲、深度缓冲、模板缓冲
	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);

	glLoadIdentity();
	glTranslatef(0.0f, 0.0f, -5.0f);
	glRotatef(angle, 0.0f, 1.0f, 1.0f);
	glColor3f(.6f, .05f, .95f);

	sphere_entry(32,32);

	angle += .02f;
	angle = angle > 360.0f ? 0.0f : angle;

	// 交换缓冲区
	glutSwapBuffers();
}

int main(int argc, char**argv) {

	gltSetWorkingDirectory(*argv);

	glutInit(&argc, argv);
	glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGBA | GLUT_DEPTH | GLUT_STENCIL);
	glutInitWindowSize(800, 600);
	glutCreateWindow("OpenGL App");
	glutReshapeFunc(changed_size);
	glutDisplayFunc(render);
	glutIdleFunc(render);

	GLenum err = glewInit();
	if (GLEW_OK != err) {
		std::cerr << "GLEW Error : " << glewGetErrorString(err) << std::endl;
		return 1;
	}

	setup_rc();

	glutMainLoop();

	return 0;
}