OpenGL路（四）自制的图形功能（立方体、汽缸、圆锥）

#include <gl/glut.h>

#include <gl/GLU.h>

#include <gl/GL.h>

#pragma comment(lib, "opengl32.lib")

#pragma comment(lib, "glut32.lib")

#pragma comment(lib, "glu32.lib")

#pragma comment(lib, "glut.lib")

#include <math.h>

void Cube()

{

	glBegin(GL_QUAD_STRIP);//填充凸多边形

	glVertex3f(0.0f, 0.0f, 0.0f);

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

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

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

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

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

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

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

	glVertex3f(0.0f, 0.0f, 0.0f);

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

	glEnd();

	glBegin(GL_QUAD_STRIP);

	glVertex3f(0.0f, 0.0f, 0.0f);

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

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

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

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

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

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

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

	glEnd();

}

void Circle()

{

	glBegin(GL_TRIANGLE_FAN);//扇形连续填充三角形串

	glVertex3f(0.0f, 0.0f, 0.0f);

	int i = 0;

	for (i = 0; i <= 390; i += 15)

	{

		float p = i * 3.14 / 180;

		glVertex3f(sin(p), cos(p), 0.0f);

	}

	glEnd();

}

void Cylinder()

{

	glBegin(GL_QUAD_STRIP);//连续填充四边形串

	int i = 0;

	for (i = 0; i <= 390; i += 15)

	{

		float p = i * 3.14 / 180;

		glVertex3f(sin(p), cos(p), 1.0f);

		glVertex3f(sin(p), cos(p), 0.0f);

	}

	glEnd();

	Circle();

	glTranslatef(0, 0, 1);

	Circle();

}

void Cone()

{

	glBegin(GL_QUAD_STRIP);//连续填充四边形串

	int i = 0;

	for (i = 0; i <= 390; i += 15)

	{

		float p = i * 3.14 / 180;

		glVertex3f(0, 0, 1.0f);

		glVertex3f(sin(p), cos(p), 0.0f);

	}

	glEnd();

	Circle();

}

void renderScene(void)

{

	static float i = 0;

	i += 0.1;

	if (i > 360)

		i = 0;

	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

	glLoadIdentity();

	glPushMatrix();

	glColor3f(0, 1, 0);

	glTranslatef(-2, 2.0, -12);

	glRotatef(i, 1, 1 ,1);

	Cylinder();

	glPopMatrix();

	glPushMatrix();

	glColor3f(1, 0, 0);

	glTranslatef(2, 2, -12);

	glRotatef(i, 1, 1, 1);

	Circle();

	glPopMatrix();

	glPushMatrix();

	glColor3f(0, 1, 1);

	glTranslatef(-2, -2, -12);

	glRotatef(i, 1, 1, 1);

	Cube();

	glPopMatrix();

	glPushMatrix();

	glColor3f(1, 1, 0);

	glTranslatef(2, -2, -12);

	glRotatef(i, 1, 1, 1);

	Cone();

	glPopMatrix();

	glutSwapBuffers();

}

void changeSize(int w, int h) {

	// 防止除数即高度为0

	// (你能够设置窗体宽度为0).

	if (h == 0)

		h = 1;

	float ratio = 1.0* w / h;

	// 单位化投影矩阵。

glMatrixMode(GL_PROJECTION);

	glLoadIdentity();

	// 设置视口大小为整个窗体大小

	glViewport(0, 0, w, h);

	// 设置正确的投影矩阵

	gluPerspective(45, ratio, 1, 1000);

	//以下是设置模型视图矩阵

	glMatrixMode(GL_MODELVIEW);

	glLoadIdentity();

	gluLookAt(0.0, 0.0, 5.0, 0.0, 0.0, -1.0, 0.0f, 1.0f, 0.0f);//设置观測点

}

int main(int argc, char * argv[])

{

	glutInit(&argc, argv);

	glutInitDisplayMode(GLUT_DEPTH | GLUT_DOUBLE | GLUT_RGBA);

	glutInitWindowPosition(100, 100);

	glutInitWindowSize(320, 320);

	glutCreateWindow("Hello OpenGL");

	glutDisplayFunc(renderScene);

	glutIdleFunc(renderScene); //指定程序空暇时调用函数

	glutReshapeFunc(changeSize); //指定窗体形状变化时的回调函数

	glEnable(GL_DEPTH_TEST);

	glutMainLoop();

	return 0;

}
效果预览