画圆

• void drawCricle(float r, int x, int y)
• {
• for (float i = 0; i < 360; i += 0.01)
• {
• glColor3f(rand() % 200 + 40, rand() % 254, rand() % 200 + 40);//随机颜色
• glVertex2f(r*cos(i*3.14159 / 180.0), r*sin(i*3.14159 / 180.0));//计算xy坐标
• }
• }
• void Render(void)
• {
• int a = clock();
• glClear(GL_COLOR_BUFFER_BIT);
• glPointSize(1);
• glColor3f(0, 1.0, 0);
• glBegin(GL_POINTS);
• drawCricle(0.9, 0, 0);
• glEnd();
• glFlush();
• cout << "FPS:" << 1000.0 / (clock() - a) << endl;
• }
• int main(int argc, char *argv[])
• {
• glutInit(&argc, argv);
• glutInitDisplayMode(GLUT_RGB | GLUT_SINGLE | GLUT_DEPTH);
• glutInitWindowSize(640, 640);
• glutCreateWindow("OpenGL");
• glutDisplayFunc(Render);
• glutMainLoop();
• return 0;
• }

void drawCricle(float r, int x, int y)
{
	for (float i = 0; i < 360; i += 0.01)
	{
		glColor3f(rand() % 200 + 40, rand() % 254, rand() % 200 + 40);//随机颜色
		glVertex2f(r*cos(i*3.14159 / 180.0), r*sin(i*3.14159 / 180.0));//计算xy坐标
	}
}


void Render(void)
{
	int a = clock();
	glClear(GL_COLOR_BUFFER_BIT);
	glPointSize(1);
	glColor3f(0, 1.0, 0);
	
	glBegin(GL_POINTS);

	drawCricle(0.9, 0, 0);

	glEnd();
	
	glFlush();
	cout << "FPS:" << 1000.0 / (clock() - a) << endl;

}


int main(int argc, char *argv[])
{
	glutInit(&argc, argv);
	glutInitDisplayMode(GLUT_RGB | GLUT_SINGLE | GLUT_DEPTH);
	glutInitWindowSize(640, 640);
	glutCreateWindow("OpenGL");
	glutDisplayFunc(Render);

	glutMainLoop();

	return 0;
}