OpenGL画圆

来源：互联网发布：unity3d 自学网编辑：程序博客网时间：2024/06/16 17:37

void CShape2D::drawCircle() {    static bool bDrawSemiCircle = false;    glClear(GL_LINE_BIT);    glBegin(GL_LINES);//可以改成GL_POINTS，具体含义参照gl文档    //方法1    //glPointSize(5.0f);//只对Begin的参数为GL_POINTS有用，glLineWidth：设置Line的宽度此时设置PointSize也是没有效果    //if(bDrawSemiCircle) {    //    glColor3f(0.0f, 0.0f, 1.0f);    //    if(beginPoint_.x > -radius_) {    //        for(GLfloat fVaule = radius_; fVaule >= beginPoint_.x; fVaule -= 0.0001f) {    //            glVertex2f(fVaule, -sqrt(radius_ * radius_ - fVaule * fVaule));    //        }    //        beginPoint_.x -= 0.01f;    //    }    //} else {    //    glColor3f(0.0f, 1.0f, 0.0f);    //    if(beginPoint_.x > radius_) {    //        beginPoint_.x = radius_;    //        bDrawSemiCircle = true;    //    } else {    //        for(GLfloat fVaule = -radius_; fVaule <= beginPoint_.x; fVaule += 0.0001f) {    //            glVertex2f(fVaule, sqrt(radius_ * radius_ - fVaule * fVaule));    //        }    //        beginPoint_.x += 0.01f;    //    }    //}    //方法2    glColor3f(1.0f, 0.0f, 0.0f);    if(beginPoint_.x <= 2.0f * Pi) {        for(GLfloat fVaule = 0; fVaule <= beginPoint_.x; fVaule += 0.001f) {            glVertex2f(radius_ * cos(fVaule), radius_ * sin(fVaule));         }        beginPoint_.x += 0.02f;    }    glEnd();    glFlush();    glutSwapBuffers();}

方法一还有一个bug就是首尾端点没连接到，自己接下来慢慢调试

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