QOpenGLWidget绘制对象

Question

我已经在这里问了一个关于QOpenglWidget的问题。在我的上一道题中，我只是用错误的方式来称呼shaderid。现在我正在尝试从一个对象加载顶点。我已经编写了一个加载程序，它加载顶点、纹理坐标、法线和索引。我已经在本机openGL中编写了这段代码，并检查了输出。顶点等与我的Qt代码中的顶点匹配。

唯一的问题是，我无法让方法paintGL（）绘制我的对象，它应该是一个简单的立方体。

--主要.cpp

    #include <QApplication>
#include <QLabel>
#include <QSurfaceFormat>
#ifndef QT_NO_OPENGL
#include "mainwidget.h"
#endif
int main(int argc, char *argv[])
{
    QApplication app(argc, argv);
    QSurfaceFormat format;
    format.setDepthBufferSize(24);
    QSurfaceFormat::setDefaultFormat(format);
    app.setApplicationName("MainWidget");
#ifndef QT_NO_OPENGL
    MainWidget widget;
    widget.resize(800, 600);
    widget.show();
#else
    QLabel note("OpenGL Support required");
    note.show();
#endif
    return app.exec();
}

--MainWidget.h

#ifndef MAINWIDGET_H
#define MAINWIDGET_H
#include <QOpenGLWidget>
#include <QOpenGLFunctions>
#include <QVector2D>
#include <QOpenGLShaderProgram>
#include <QOpenGLBuffer>
#include <QVector3D>
#include <QOpenGLVertexArrayObject>
#include <QVector>
#include "geometryengine.h"

class GeometryEngine;
class MainWidget : public QOpenGLWidget, protected QOpenGLFunctions
{
    Q_OBJECT
public:
    MainWidget(QWidget *parent = 0);
    ~MainWidget();
protected:
    void initializeGL()Q_DECL_OVERRIDE;
    void resizeGL(int w, int h)Q_DECL_OVERRIDE;
    void paintGL()Q_DECL_OVERRIDE;
    void initShaders();
private:
    QOpenGLShaderProgram program;
    GeometryEngine *geometries;
};
#endif // MAINWIDGET_H

--主部件.cpp

#include "mainwidget.h"
#include <iostream>

extern QVector<QVector3D> m_vertices;
extern QVector<QVector2D> m_uvs;
extern QVector<QVector3D> m_normals;
extern QVector<QVector3D> m_indexed_vertices;
extern QVector<QVector2D> m_indexed_uvs;
extern QVector<QVector3D> m_indexed_normals;
extern QVector<unsigned short> m_indices;
MainWidget::MainWidget(QWidget *parent):QOpenGLWidget(parent), geometries(0){
}
MainWidget::~MainWidget(){
    makeCurrent();
    delete geometries;
    doneCurrent();
}
void MainWidget::initializeGL(){
    initializeOpenGLFunctions();
    glClearColor(0, 0, 0.4f, 0);
    glEnable(GL_DEPTH_TEST);
    initShaders();
    geometries = new GeometryEngine;
    for(auto i : m_indexed_vertices){
            std::cout<<i.x()<<" "<<i.y()<<" "<<i.z()<<std::endl;
            //std::cout << i << " " << std::endl;
        }
}
void MainWidget::resizeGL(int w, int h){
}
void MainWidget::paintGL(){
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
    /*for(auto i : m_indices){
            //std::cout<<i.x()<<" "<<i.y()<<" "<<i.z()<<std::endl;
            std::cout << i << " " << std::endl;
        }*/
    geometries->drawGeometry(&program, m_indices);
}

void MainWidget::initShaders(){
    // Compile vertex shader
    if (!program.addShaderFromSourceFile(QOpenGLShader::Vertex, "vertex.vert"))
        close();
    // Compile fragment shader
    if (!program.addShaderFromSourceFile(QOpenGLShader::Fragment, "fragment.frag"))
        close();
    // Link shader pipeline
    if (!program.link())
        close();
    // Bind shader pipeline for use
    if (!program.bind())
        close();
}

--GeometryEngine.h

#ifndef GEOMETRYENGINE_H
#define GEOMETRYENGINE_H
#include <QOpenGLFunctions>
#include <QOpenGLShaderProgram>
#include <QOpenGLBuffer>
#include <QOpenGLVertexArrayObject>
#include "mainwidget.h"

class GeometryEngine : protected QOpenGLFunctions
{
public:
    GeometryEngine();
    virtual ~GeometryEngine();
    void drawGeometry(QOpenGLShaderProgram *program, QVector<unsigned short> indices);

private:
    void initGeometry(const char *path, QVector<QVector3D> &vert, QVector<QVector2D> &uv, QVector<QVector3D> &norm,QVector<unsigned short> &indices, QVector<QVector3D> &indexed_vertices,
    QVector<QVector2D> &indexed_uvs,
    QVector<QVector3D> &indexed_normals);
    QOpenGLBuffer arrayBuf;
    QOpenGLBuffer indexBuf;
    QOpenGLVertexArrayObject vertexArrayID;
};
#endif // GEOMETRYENGINE_H

--GeometryEngine.cpp

#include "geometryengine.h"
#include "mainwidget.h"
#include "loadobj.h"
#include <QVector>
#include <QVector2D>
#include <QVector3D>
#include <string>
#include <iostream>

QVector<QVector3D> m_vertices;
QVector<QVector2D> m_uvs;
QVector<QVector3D> m_normals;
QVector<QVector3D> m_indexed_vertices;
QVector<QVector2D> m_indexed_uvs;
QVector<QVector3D> m_indexed_normals;
QVector<unsigned short> m_indices;
GeometryEngine::GeometryEngine() : indexBuf(QOpenGLBuffer::IndexBuffer)
{

    initializeOpenGLFunctions();
    vertexArrayID.create();
    vertexArrayID.bind();
    //generate vbos
    arrayBuf.create();
    indexBuf.create();

    initGeometry("cube.obj", m_vertices, m_uvs, m_normals, m_indices, m_indexed_vertices, m_indexed_uvs, m_indexed_normals);
}
GeometryEngine::~GeometryEngine(){
    arrayBuf.destroy();
    indexBuf.destroy();
    vertexArrayID.destroy();
}
void GeometryEngine::initGeometry(const char *path,QVector<QVector3D> &vertices, QVector<QVector2D> &uvs, QVector<QVector3D> &normals, QVector<unsigned short> &indices,  QVector<QVector3D> &indexed_vertices, QVector<QVector2D> &indexed_uvs, QVector<QVector3D> &indexed_normals ){
    bool res = loadObj(path, vertices, uvs, normals);
    vboIndexer(vertices, uvs, normals, indices, indexed_vertices, indexed_uvs, indexed_normals );
    /*for(auto i : indices){
            //std::cout<<i.x()<<" "<<i.y()<<" "<<i.z()<<std::endl;
            std::cout << i << " " << std::endl;
        }*/
    arrayBuf.bind();
    arrayBuf.allocate(&indexed_vertices, indexed_vertices.size() * sizeof(QVector3D));
    indexBuf.bind();
    indexBuf.allocate(&indices, indices.size() * sizeof(unsigned short));
}
void GeometryEngine::drawGeometry(QOpenGLShaderProgram *program, QVector<unsigned short> indices){
    arrayBuf.bind();
    indexBuf.bind();
    int vertexLocation = program->attributeLocation("vertex");
    program->enableAttributeArray(vertexLocation);
    program->setAttributeBuffer(vertexLocation, GL_FLOAT, 0, 3, sizeof(GLfloat));
    //glDrawElements(GL_TRIANGLE_STRIP, indices.size(), GL_UNSIGNED_SHORT, 0);
    glDrawArrays(GL_TRIANGLES, 0, 3);
    glDisableVertexAttribArray(0);
}

--vertex.vert

#version 330
layout(location = 0) in vec3 vertex;
void main(){
    gl_Position = vec4(vertex, 1.0);
}

--碎片.frag

#version 330
out vec3 color;
void main(){
    color = vec3(1,0,0);
}

我不知道是我把QOpenGL代码搞砸了，还是因为我把顶点存储在QVector中，而不是数组中。作为引导，我使用了Qt中的立方体示例，正如您在代码相似性中看到的那样。

Answer 1

ok问题已解决。

原生openGL能够绘制Vectors中的数据，而QopenGLWidget只有在数据存储在数组中时才能绘制。即使阵列包含Qvector3D数据。

如果我错了，请纠正我。。因为这在我看来有点可疑。