1.方法:
建立三维坐标系,然后按照每个立方体的面着色,再绘制这个面上面的点,面的绘制要遵循逆时针的原则。
2.OPenGL.pro
QT += core gui opengl greaterThan(QT_MAJOR_VERSION, 4): QT += widgets TARGET = OPenGL12 TEMPLATE = app SOURCES += main.cpp\ openglwidget.cpp HEADERS += \ openglwidget.h LIBS += -lopengl32
3.OpenglWidget
OpenglWidget.h
#ifndef OPENGLWIDGET_H #define OPENGLWIDGET_H #include <QtOpenGL> class OpenglWidget : public QGLWidget { public: OpenglWidget(QWidget *parent=0); protected: void initializeGL(); void initWidget(); void paintGL(); void resizeGL(int width, int height); private: GLfloat angle; GLfloat angle1; }; #endif // OPENGLWIDGET_HOpenglWidget.cpp
#include "openglwidget.h" OpenglWidget::OpenglWidget(QWidget *parent):QGLWidget(parent) { initWidget(); initializeGL(); } void OpenglWidget::initializeGL() { //设置着色模式,平滑的 glShadeModel(GL_SMOOTH); //清除掉之前的所有颜色 glClearColor(0.0,0.0,0.0,0.0); //深度缓存,设置初始值为1.0,小于1.0的部分是可见的 glClearDepth(1.0); //启动OPenGL的相关功能,由参数决定,这里指 //(启用了之后,OpenGL在绘制的时候就会检查,当前像素前面是否有别的像素,如果别的像素挡道了它,那它就不会绘制,也就是说,OpenGL就只绘制最前面的一层) glEnable(GL_DEPTH_TEST); //制定深度缓存比较值 //这里参数指的是如果输入的深度值小于或者等于参考值则通过 glDepthFunc(GL_LEQUAL); glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST); } void OpenglWidget::initWidget() { //从屏幕上(400,400)为起始点,显示一个640*400的界面 setGeometry(400,200,640,480); setWindowTitle("My OPenGL"); } void OpenglWidget::paintGL() { //清除颜色缓冲和深度缓冲 glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT); //将当前点移置屏幕中心,相当于复位的操作 glLoadIdentity(); //平移函数,参数指的是分别从X轴,Y轴,Z轴平移 glTranslatef(-1.5,0.0,-6.0); glRotated(angle,0.0,1.0,0.0); //创建图元,是绘制什么图形的接口,参数是绘制多边形的意思 glBegin(GL_QUADS); //设置顶点值(f代表浮点),三维空间坐标 glColor3f( 1.0, 0.0, 0.0 ); glBegin( GL_QUADS ); glColor3f(1, 0, 0); glVertex3f(-1,1,1); glVertex3f(-1,1,-1); glVertex3f(-1,-1,-1); glVertex3f(-1,-1,1); glColor3f(0, 0, 1); glVertex3f(-1,1,-1); glVertex3f(-1,-1,-1); glVertex3f(1,-1,-1); glVertex3f(1,1,-1); glColor3f(0, 1, 0); glVertex3f(1,1,-1); glVertex3f(1,-1,-1); glVertex3f(1,-1,1); glVertex3f(1,1,1); glColor3f(0, 0, 1); glVertex3f(1,-1,1); glVertex3f(1,1,1); glVertex3f(-1,1,1); glVertex3f(-1,-1,1); glColor3f(0, 1, 0); glVertex3f(-1,1,1); glVertex3f(1,1,1); glVertex3f(1,1,-1); glVertex3f(-1,1,-1); glColor3f(0, 0, 1); glVertex3f(-1,-1,1); glVertex3f(-1,-1,-1); glVertex3f(1,-1,-1); glVertex3f(1,-1,1); glEnd(); glLoadIdentity(); glTranslatef(1.5,0.0,-6.0); glRotatef( angle1,0.0,1.0,0.0); glBegin( GL_TRIANGLES ); glColor3f( 1.0, 0.0, 0.0 ); glVertex3f( 0.0, 1.0, 0.0 ); glColor3f( 0.0, 0.0, 1.0 ); glVertex3f( -1.0, -1.0, -1.0 ); glColor3f( 0.0, 1.0, 0.0 ); glVertex3f( -1.0, -1.0, 1.0 ); glColor3f( 1.0, 0.0, 0.0 ); glVertex3f( 0.0, 1.0, 0.0 ); glColor3f( 0.0, 0.0, 1.0 ); glVertex3f( 1.0, -1.0, 1.0 ); glColor3f( 0.0, 1.0, 0.0 ); glVertex3f( 1.0, -1.0, -1.0 ); glColor3f( 1.0, 0.0, 0.0 ); glVertex3f( 0.0, 1.0, 0.0 ); glColor3f( 0.0, 1.0, 0.0 ); glVertex3f( -1.0, -1.0, 1.0 ); glColor3f( 0.0, 0.0, 1.0 ); glVertex3f( 1.0, -1.0, 1.0 ); glColor3f( 1.0, 0.0, 0.0 ); glVertex3f( 0.0, 1.0, 0.0 ); glColor3f( 0.0, 1.0, 0.0 ); glVertex3f( 1.0, -1.0, -1.0 ); glColor3f( 0.0, 0.0, 1.0 ); glVertex3f( -1.0, -1.0, -1.0 ); glEnd(); angle+=70; angle1+=10; } void OpenglWidget::resizeGL(int width, int height) { if(0==height) height=1; //告诉绘制到窗体的哪个位置 glViewport(0,0,width,height); // 设置矩阵模式,参数是设置为投影矩阵 glMatrixMode(GL_PROJECTION); //复位操作 glLoadIdentity(); GLdouble aspectRatio=(GLfloat)width/(GLfloat)height; GLdouble rFov=45.0*3.14159265/180.0; GLdouble zNear=0.1; GLdouble zFar=100.0; //调用glFrustum,生成矩阵与当前矩阵相乘,生成透视效果 glFrustum(-zNear*tan(rFov/2.0)*aspectRatio, zNear*tan(rFov/2.0)*aspectRatio, -zNear*tan(rFov/2.0), zNear*tan(rFov/2.0), zNear,zFar); //切回模型视图矩阵 glMatrixMode(GL_MODELVIEW); //复位 glLoadIdentity(); }
4.main
#include"openglwidget.h" #include <QApplication> int main(int argc, char *argv[]) { QApplication a(argc, argv); // Widget w; // w.show(); OpenglWidget window; window.show(); return a.exec(); }