Qt Openglwidget 显示图片纹理贴图

#include "cameraglwidget.h" #include <QOpenGLShaderProgram> #include <QOpenGLTexture> #include <QPainter> #include<QImageReader.h> struct VertexData { QVector2D position; QVector2D texCoord; }; CameraGLWidget::CameraGLWidget(QWidget *parent) : QOpenGLWidget(parent) { } CameraGLWidget::~CameraGLWidget() { arrayBuf.destroy(); } void CameraGLWidget::resizeGL(int w, int h) { glViewport(0,0,w,h); } void CameraGLWidget::paintGL() { // Clear color and depth buffer glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); m_texture->bind(); // Use texture unit 0 which contains cube.png m_program->setUniformValue(m_textureUniform, 0); // Draw cube geometry using indices from VBO 1 glDrawArrays(GL_TRIANGLE_STRIP, 0, 4); } void CameraGLWidget::initializeGL() { initializeOpenGLFunctions(); initShaders(); initTextures(); initBuffArray(); } void CameraGLWidget::initShaders() { //Create QOpenGLShaderProgram m_program = new QOpenGLShaderProgram; // Compile vertex shader m_program->addShaderFromSourceFile(QOpenGLShader::Vertex,"GLSL/vshader.glsl"); // Compile fragment shader m_program->addShaderFromSourceFile(QOpenGLShader::Fragment,"GLSL/fshader.glsl"); // Link shader pipeline m_program->link(); // Bind shader pipeline for use m_program->bind(); //Get identifer of Attribute or uniform value in vshader.glsl and fshader.glsl m_vertexAttr = m_program->attributeLocation("vertexIn"); m_textureAttr = m_program->attributeLocation("textureIn"); m_textureUniform = m_program->uniformLocation("texture"); } void CameraGLWidget::initTextures() { // Load image m_texture = new QOpenGLTexture(QImage("./S40_duplicate.png").mirrored()); // Set nearest filtering mode for texture minification m_texture->setMinificationFilter(QOpenGLTexture::Nearest); // Set bilinear filtering mode for texture magnification m_texture->setMagnificationFilter(QOpenGLTexture::Linear); // Wrap texture coordinates by repeating // f.ex. texture coordinate (1.1, 1.2) is same as (0.1, 0.2) m_texture->setWrapMode(QOpenGLTexture::Repeat); } void CameraGLWidget:: initBuffArray() { // Vertex data and texture data VertexData vertices[] = { {QVector2D(-1.0f, -1.0f), QVector2D(0.0f, 0.0f)}, // v0 {QVector2D( 1.0f, -1.0f), QVector2D(1.0f, 0.0f)}, // v1 {QVector2D(-1.0f, 1.0f), QVector2D(0.0f, 1.0f)}, //v2 {QVector2D( 1.0f, 1.0f), QVector2D(1.0f, 1.0f)} // v3 }; arrayBuf.create(); arrayBuf.bind(); arrayBuf.allocate(vertices, 4 * sizeof(VertexData)); // Offset for position quintptr offset = 0; // Tell OpenGL programmable pipeline how to locate vertex position data m_program->enableAttributeArray(m_vertexAttr); m_program->setAttributeBuffer(m_vertexAttr, GL_FLOAT, offset, 2, sizeof(VertexData)); // Offset for texture coordinate offset += sizeof(QVector2D); // Tell OpenGL programmable pipeline how to locate vertex texture coordinate data m_program->enableAttributeArray(m_textureAttr); m_program->setAttributeBuffer(m_textureAttr, GL_FLOAT, offset, 2, sizeof(VertexData)); }