初学opengl,绕了很多弯路,继承于QOpenGLWindow,描画出来。新建类myopengl,头文件如下:
#ifndef MYOPENGL_H
#define MYOPENGL_H
#include <QWidget>
#include <QOpenGLWidget>
#include <QOpenGLWindow>
#include <QGLWidget>
#include <QGLFunctions>
#include <QOpenGLFunctions>
#include <QtOpenGL>
#include <QOpenGLBuffer>
#include <QOpenGLShaderProgram>
#include <QMatrix4x4>
#include <GL/glu.h>
class myopenGL:public QOpenGLWindow, protected QOpenGLFunctions
{
Q_OBJECT
public:
explicit myopenGL(QWindow *parent = 0);
~myopenGL();
protected:
void initializeGL() override;
void paintGL() override;
void resizeGL(int width, int height) override;
void loadGLTextures();
protected:
GLfloat rTri;
GLfloat rQuad;
GLfloat xRot, yRot, zRot;
GLuint texture[1];
private:
};
#endif // MYOPENGL_H
myopengl.cpp 代码如下:
#include "myopengl.h"
#include <QImage>
#include <QDebug>
myopenGL::myopenGL(QWindow *parent)
{
rTri = 0.0;
rQuad = 0.0;
xRot = yRot = zRot = 0.0;
}
myopenGL::~myopenGL()
{
}
void myopenGL::loadGLTextures()
{
QImage tex, buf;
if ( !buf.load( "./msbg_blue.png" ) )
{
qWarning( "Could not read image file, using single-color instead." );
QImage dummy( 128, 128, QImage::Format_RGB32 );
dummy.fill( Qt::green );
buf = dummy;
}
tex = QGLWidget::convertToGLFormat( buf );
glGenTextures( 1, &texture[0] );
glBindTexture( GL_TEXTURE_2D, texture[0] );
glTexImage2D( GL_TEXTURE_2D, 0, 3, tex.width(), tex.height(), 0,
GL_RGBA, GL_UNSIGNED_BYTE, tex.bits() );
glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR );
glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR );
}
//初始化opengl窗口部件
void myopenGL::initializeGL()
{
initializeOpenGLFunctions();
glClearColor(0.0,0.0,0.0,1.0);
glShadeModel(GL_SMOOTH);
glClearDepth(1.0);
glEnable(GL_DEPTH_TEST);
glDepthFunc(GL_LEQUAL);
glHint(GL_PERSPECTIVE_CORRECTION_HINT,GL_NICEST);
}
//绘制opengl窗口
void myopenGL::paintGL()
{
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glLoadIdentity();
glTranslatef(-1.5f,0.0f,-6.0f);
glRotatef( rTri, 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, 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, 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, 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 );
glEnd();
glTranslatef(3.0f,0.0f,-7.0f);
glRotatef( rQuad, 0.0, 0.0, 1.0 );
glRotatef( rTri, 0.0, 1.0, 0.0 );
glRotatef( rQuad, 0.0, 0.0, 1.0 );
glBegin(GL_QUADS);
glColor3f( 0.0, 1.0, 0.0 );
glVertex3f( 1.0, 1.0, -1.0 );
glVertex3f( -1.0, 1.0, -1.0 );
glVertex3f( -1.0, 1.0, 1.0 );
glVertex3f( 1.0, 1.0, 1.0 );
glColor3f( 1.0, 0.5, 0.0 );
glVertex3f( 1.0, -1.0, 1.0 );
glVertex3f( -1.0, -1.0, 1.0 );
glVertex3f( -1.0, -1.0, -1.0 );
glVertex3f( 1.0, -1.0, -1.0 );
glColor3f( 1.0, 0.0, 0.0 );
glVertex3f( 1.0, 1.0, 1.0 );
glVertex3f( -1.0, 1.0, 1.0 );
glVertex3f( -1.0, -1.0, 1.0 );
glVertex3f( 1.0, -1.0, 1.0 );
glColor3f( 1.0, 1.0, 0.0 );
glVertex3f( 1.0, -1.0, -1.0 );
glVertex3f( -1.0, -1.0, -1.0 );
glVertex3f( -1.0, 1.0, -1.0 );
glVertex3f( 1.0, 1.0, -1.0 );
glColor3f( 0.0, 0.0, 1.0 );
glVertex3f( -1.0, 1.0, 1.0 );
glVertex3f( -1.0, 1.0, -1.0 );
glVertex3f( -1.0, -1.0, -1.0 );
glVertex3f( -1.0, -1.0, 1.0 );
glColor3f( 1.0, 0.0, 1.0 );
glVertex3f( 1.0, 1.0, -1.0 );
glVertex3f( 1.0, 1.0, 1.0 );
glVertex3f( 1.0, -1.0, 1.0 );
glVertex3f( 1.0, -1.0, -1.0 );
glEnd();
rTri += 0.2;
rQuad -= 0.15;
}
//处理窗口大小
void myopenGL::resizeGL(int width, int height)
{
glViewport(0,0,(GLint)width,(GLint)height);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
gluPerspective(45.0,(GLfloat)width/(GLfloat)height,0.1,100.0);
glMatrixMode(GL_MODELVIEW); //选择模型观察矩阵
glLoadIdentity(); //重置模型观察矩阵
}
main.cpp修改代码如下:
#include "myopengl.h"
#include <QGuiApplication>
#include <QPushButton>
int main(int argc, char *argv[])
{
QCoreApplication::setAttribute(Qt::AA_UseDesktopOpenGL);
QGuiApplication a(argc, argv);
myopenGL w;
w.resize(QSize(1280,720));
//QPushButton ptn(&w);
w.show();
return a.exec();
}
效果图:
这么简单的效果用了就走了好多弯路。跟QT的版本有关系。有的人用的是QOpenGLWindow,有的人用的是QOpenGLWidget。听说推荐用的是QOpenGLWidget。