Qt实现3D照片墙代码项目

以下是一个简单的Qt实现3D照片墙的代码项目，供参考：

main.cpp:

#include <QApplication>
#include "mainwindow.h"

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    MainWindow w;
    w.show();

    return a.exec();
}

mainwindow.h:

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>
#include <QOpenGLWidget>
#include <QOpenGLFunctions>
#include <QOpenGLTexture>

class MainWindow : public QMainWindow, protected QOpenGLFunctions
{
    Q_OBJECT

public:
    explicit MainWindow(QWidget *parent = nullptr);
    ~MainWindow();

protected:
    void initializeGL();
    void resizeGL(int w, int h);
    void paintGL();
    void mousePressEvent(QMouseEvent *event);
    void mouseMoveEvent(QMouseEvent *event);
    void wheelEvent(QWheelEvent *event);

private:
    QOpenGLWidget *m_widget;
    QOpenGLTexture *m_texture;
    GLuint m_program;
    GLuint m_vbo;
    GLuint m_ibo;
    GLfloat m_angleX;
    GLfloat m_angleY;
    QPoint m_lastPos;
};

#endif // MAINWINDOW_H

mainwindow.cpp:

#include "mainwindow.h"
#include <QMouseEvent>
#include <QOpenGLShaderProgram>
#include <QOpenGLBuffer>

const char *vertexShaderSource =
    "attribute vec3 a_position;\n"
    "attribute vec2 a_texCoord;\n"
    "uniform mat4 u_modelViewProjectionMatrix;\n"
    "varying vec2 v_texCoord;\n"
    "void main()\n"
    "{\n"
    "    gl_Position = u_modelViewProjectionMatrix * vec4(a_position, 1.0);\n"
    "    v_texCoord = a_texCoord;\n"
    "}\n";

const char *fragmentShaderSource =
    "varying vec2 v_texCoord;\n"
    "uniform sampler2D u_texture;\n"
    "void main()\n"
    "{\n"
    "    gl_FragColor = texture2D(u_texture, v_texCoord);\n"
    "}\n";

MainWindow::MainWindow(QWidget *parent)
    : QMainWindow(parent), m_widget(nullptr), m_texture(nullptr), m_program(0), m_vbo(0), m_ibo(0), m_angleX(0.0f), m_angleY(0.0f)
{
    m_widget = new QOpenGLWidget(this);
    setCentralWidget(m_widget);
}

MainWindow::~MainWindow()
{
    makeCurrent();

    glDeleteProgram(m_program);
    glDeleteBuffers(1, &m_vbo);
    glDeleteBuffers(1, &m_ibo);
    delete m_texture;

    doneCurrent();
}

void MainWindow::initializeGL()
{
    initializeOpenGLFunctions();

    // load texture
    m_texture = new QOpenGLTexture(QImage(":/images/image.png").mirrored());

    // shader program
    QOpenGLShaderProgram program;
    program.addShaderFromSourceCode(QOpenGLShader::Vertex, vertexShaderSource);
    program.addShaderFromSourceCode(QOpenGLShader::Fragment, fragmentShaderSource);
    program.link();
    m_program = program.programId();

    // vertex data
    GLfloat vertices[] = {
        -1.0f,  1.0f, -1.0f, 0.0f, 1.0f,
         1.0f,  1.0f, -1.0f, 1.0f, 1.0f,
         1.0f, -1.0f, -1.0f, 1.0f, 0.0f,
        -1.0f, -1.0f, -1.0f, 0.0f, 0.0f,
        -1.0f,  1.0f,  1.0f, 0.0f, 1.0f,
         1.0f,  1.0f,  1.0f, 1.0f, 1.0f,
         1.0f, -1.0f,  1.0f, 1.0f, 0.0f,
        -1.0f, -1.0f,  1.0f, 0.0f, 0.0f,
    };

    // index data
    GLuint indices[] = {
        0, 1, 2, 0, 2, 3,
        1, 5, 6, 1, 6, 2,
        5, 4, 7, 5, 7, 6,
        4, 0, 3, 4, 3, 7,
        4, 5, 1, 4, 1, 0,
        3, 2, 6, 3, 6, 7,
    };

    // vertex buffer object
    glGenBuffers(1, &m_vbo);
    glBindBuffer(GL_ARRAY_BUFFER, m_vbo);
    glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);

    // index buffer object
    glGenBuffers(1, &m_ibo);
    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, m_ibo);
    glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(indices), indices, GL_STATIC_DRAW);

    // attribute location
    GLuint positionLocation = glGetAttribLocation(m_program, "a_position");
    GLuint texCoordLocation = glGetAttribLocation(m_program, "a_texCoord");

    // vertex array object
    GLuint vao;
    glGenVertexArrays(1, &vao);
    glBindVertexArray(vao);
    glBindBuffer(GL_ARRAY_BUFFER, m_vbo);
    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, m_ibo);
    glEnableVertexAttribArray(positionLocation);
    glEnableVertexAttribArray(texCoordLocation);
    glVertexAttribPointer(positionLocation, 3, GL_FLOAT, GL_FALSE, 5 * sizeof(GLfloat), nullptr);
    glVertexAttribPointer(texCoordLocation, 2, GL_FLOAT, GL_FALSE, 5 * sizeof(GLfloat), (const void *)(3 * sizeof(GLfloat)));
    glBindVertexArray(0);

    glEnable(GL_DEPTH_TEST);
    glEnable(GL_TEXTURE_2D);
    glEnable(GL_BLEND);
    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
}

void MainWindow::resizeGL(int w, int h)
{
    glViewport(0, 0, w, h);
}

void MainWindow::paintGL()
{
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

    // model view projection matrix
    GLfloat aspectRatio = (GLfloat)m_widget->width() / (GLfloat)m_widget->height();
    QMatrix4x4 projectionMatrix;
    projectionMatrix.perspective(45.0f, aspectRatio, 0.1f, 100.0f);
    QMatrix4x4 modelViewMatrix;
    modelViewMatrix.translate(0.0f, 0.0f, -5.0f);
    modelViewMatrix.rotate(m_angleX, 0.0f, 1.0f, 0.0f);
    modelViewMatrix.rotate(m_angleY, 1.0f, 0.0f, 0.0f);
    QMatrix4x4 modelViewProjectionMatrix = projectionMatrix * modelViewMatrix;

    // shader program
    glUseProgram(m_program);
    glUniformMatrix4fv(glGetUniformLocation(m_program, "u_modelViewProjectionMatrix"), 1, GL_FALSE, modelViewProjectionMatrix.constData());

    // texture
    m_texture->bind();
    glUniform1i(glGetUniformLocation(m_program, "u_texture"), 0);

    // draw
    glBindVertexArray(0);
    glBindVertexArray(m_vao);
    glDrawElements(GL_TRIANGLES, 36, GL_UNSIGNED_INT, nullptr);
    glBindVertexArray(0);

    // release resources
    glUseProgram(0);
    m_texture->release();
}

void MainWindow::mousePressEvent(QMouseEvent *event)
{
    m_lastPos = event->pos();
}

void MainWindow::mouseMoveEvent(QMouseEvent *event)
{
    GLfloat dx = (GLfloat)(event->x() - m_lastPos.x()) / (GLfloat)m_widget->width();
    GLfloat dy = (GLfloat)(event->y() - m_lastPos.y()) / (GLfloat)m_widget->height();
    m_angleX += 180.0f * dx;
    m_angleY += 180.0f * dy;
    m_lastPos = event->pos();
    update();
}

void MainWindow::wheelEvent(QWheelEvent *event)
{
    GLfloat delta = (GLfloat)event->delta() / (GLfloat)120.0f;
    GLfloat distance = 0.1f * delta;
    QMatrix4x4 modelViewMatrix;
    modelViewMatrix.translate(0.0f, 0.0f, distance);
    QMatrix4x4 rotationMatrix;
    rotationMatrix.rotate(m_angleX, 0.0f, 1.0f, 0.0f);
    rotationMatrix.rotate(m_angleY, 1.0f, 0.0f, 0.0f);
    modelViewMatrix = rotationMatrix * modelViewMatrix;
    GLfloat z = modelViewMatrix.column(3).z();
    if (z > -1.0f && z < -0.3f)
    {
        m_angleX /= 2.0f;
        m_angleY /= 2.0f;
        modelViewMatrix.setToIdentity();
        modelViewMatrix.translate(0.0f, 0.0f, distance);
        modelViewMatrix = rotationMatrix * modelViewMatrix;
    }
    update();
}

在工程中添加资源文件image.png，代码中用到了这张图片作为纹理。