Revision control
++ // Copyright (C) 2022 The Qt Company Ltd.
++ // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
++
++ #include "glwidget.h"
++ #include <QPainter>
++ #include <QPaintEngine>
++ #include <QOpenGLShaderProgram>
++ #include <QOpenGLTexture>
++ #include <QRandomGenerator>
++ #include <QCoreApplication>
++ #include <QFileDialog>
++ #include <qmath.h>
++
++ GLWidget::GLWidget(const QColor &background)
++ : m_background(background)
++ {
++ setMinimumSize(300, 250);
++ }
++
++ GLWidget::~GLWidget()
++ {
++ reset();
++ }
++
++ void GLWidget::saveImage(TargetBuffer targetBuffer)
++ {
++ QImage img = grabFramebuffer(targetBuffer);
++ if (img.isNull()) {
++ qFatal("Failed to grab framebuffer");
++ }
++
++ const char *fn =
++ targetBuffer == TargetBuffer::LeftBuffer
++ ? "leftBuffer.png" : "rightBuffer.png";
++
++ QFileDialog fd(this);
++ fd.setAcceptMode(QFileDialog::AcceptSave);
++ fd.setDefaultSuffix("png");
++ fd.selectFile(fn);
++ if (fd.exec() == QDialog::Accepted)
++ img.save(fd.selectedFiles().first());
++ }
++
++ void GLWidget::reset()
++ {
++ // And now release all OpenGL resources.
++ makeCurrent();
++ delete m_program;
++ m_program = nullptr;
++ delete m_vshader;
++ m_vshader = nullptr;
++ delete m_fshader;
++ m_fshader = nullptr;
++ m_vbo.destroy();
++ doneCurrent();
++
++ // We are done with the current QOpenGLContext, forget it. If there is a
++ // subsequent initialize(), that will then connect to the new context.
++ QObject::disconnect(m_contextWatchConnection);
++ }
++ void GLWidget::initializeGL()
++ {
++ initializeOpenGLFunctions();
++
++ m_vshader = new QOpenGLShader(QOpenGLShader::Vertex);
++ const char *vsrc1 =
++ "attribute highp vec4 vertex;\n"
++ "attribute mediump vec3 normal;\n"
++ "uniform mediump mat4 matrix;\n"
++ "varying mediump vec4 color;\n"
++ "void main(void)\n"
++ "{\n"
++ " vec3 toLight = normalize(vec3(0.0, 0.3, 1.0));\n"
++ " float angle = max(dot(normal, toLight), 0.0);\n"
++ " vec3 col = vec3(0.40, 1.0, 0.0);\n"
++ " color = vec4(col * 0.2 + col * 0.8 * angle, 1.0);\n"
++ " color = clamp(color, 0.0, 1.0);\n"
++ " gl_Position = matrix * vertex;\n"
++ "}\n";
++ m_vshader->compileSourceCode(vsrc1);
++
++ m_fshader = new QOpenGLShader(QOpenGLShader::Fragment);
++ const char *fsrc1 =
++ "varying mediump vec4 color;\n"
++ "void main(void)\n"
++ "{\n"
++ " gl_FragColor = color;\n"
++ "}\n";
++ m_fshader->compileSourceCode(fsrc1);
++
++ m_program = new QOpenGLShaderProgram;
++ m_program->addShader(m_vshader);
++ m_program->addShader(m_fshader);
++ m_program->link();
++
++
++ m_vertexAttr = m_program->attributeLocation("vertex");
++ m_normalAttr = m_program->attributeLocation("normal");
++ m_matrixUniform = m_program->uniformLocation("matrix");
++
++ createGeometry();
++
++ m_vbo.create();
++ m_vbo.bind();
++ const int vertexCount = m_vertices.count();
++ QList<GLfloat> buf;
++ buf.resize(vertexCount * 3 * 2);
++ GLfloat *p = buf.data();
++ for (int i = 0; i < vertexCount; ++i) {
++ *p++ = m_vertices[i].x();
++ *p++ = m_vertices[i].y();
++ *p++ = m_vertices[i].z();
++ *p++ = m_normals[i].x();
++ *p++ = m_normals[i].y();
++ *p++ = m_normals[i].z();
++ }
++ m_vbo.allocate(buf.constData(), (int)buf.count() * sizeof(GLfloat));
++ m_vbo.release();
++
++ m_contextWatchConnection = QObject::connect(context(), &QOpenGLContext::aboutToBeDestroyed, context(), [this] { reset(); });
++
++ glFrontFace(GL_CW);
++ glCullFace(GL_FRONT);
++ glEnable(GL_CULL_FACE);
++ glEnable(GL_DEPTH_TEST);
++ }
++
++ void GLWidget::paintGL()
++ {
++ // When QSurfaceFormat::StereoBuffers is enabled, this function is called twice.
++ // Once where currentTargetBuffer() == QOpenGLWidget::LeftBuffer,
++ // and once where currentTargetBuffer() == QOpenGLWidget::RightBuffer.
++
++ glClearColor(m_background.redF(), m_background.greenF(), m_background.blueF(), 1.0f);
++
++ glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
++
++ //! [1]
++ // Slightly translate the model, so that there's a visible difference in each buffer.
++ QMatrix4x4 modelview;
++ if (currentTargetBuffer() == QOpenGLWidget::LeftBuffer)
++ modelview.translate(-0.4f, 0.0f, 0.0f);
++ else if (currentTargetBuffer() == QOpenGLWidget::RightBuffer)
++ modelview.translate(0.4f, 0.0f, 0.0f);
++ //! [1]
++
++ m_program->bind();
++ m_program->setUniformValue(m_matrixUniform, modelview);
++ m_program->enableAttributeArray(m_vertexAttr);
++ m_program->enableAttributeArray(m_normalAttr);
++
++ m_vbo.bind();
++ m_program->setAttributeBuffer(m_vertexAttr, GL_FLOAT, 0, 3, 6 * sizeof(GLfloat));
++ m_program->setAttributeBuffer(m_normalAttr, GL_FLOAT, 3 * sizeof(GLfloat), 3, 6 * sizeof(GLfloat));
++ m_vbo.release();
++
++ glDrawArrays(GL_TRIANGLES, 0, m_vertices.size());
++
++ m_program->disableAttributeArray(m_normalAttr);
++ m_program->disableAttributeArray(m_vertexAttr);
++ m_program->release();
++ update();
++ }
++
++ void GLWidget::createGeometry()
++ {
++ m_vertices.clear();
++ m_normals.clear();
++
++ qreal x1 = +0.06f;
++ qreal y1 = -0.14f;
++ qreal x2 = +0.14f;
++ qreal y2 = -0.06f;
++ qreal x3 = +0.08f;
++ qreal y3 = +0.00f;
++ qreal x4 = +0.30f;
++ qreal y4 = +0.22f;
++
++ quad(x1, y1, x2, y2, y2, x2, y1, x1);
++ quad(x3, y3, x4, y4, y4, x4, y3, x3);
++
++ extrude(x1, y1, x2, y2);
++ extrude(x2, y2, y2, x2);
++ extrude(y2, x2, y1, x1);
++ extrude(y1, x1, x1, y1);
++ extrude(x3, y3, x4, y4);
++ extrude(x4, y4, y4, x4);
++ extrude(y4, x4, y3, x3);
++
++ const int NumSectors = 100;
++ const qreal sectorAngle = 2 * qreal(M_PI) / NumSectors;
++
++ for (int i = 0; i < NumSectors; ++i) {
++ qreal angle = i * sectorAngle;
++ qreal x5 = 0.30 * sin(angle);
++ qreal y5 = 0.30 * cos(angle);
++ qreal x6 = 0.20 * sin(angle);
++ qreal y6 = 0.20 * cos(angle);
++
++ angle += sectorAngle;
++ qreal x7 = 0.20 * sin(angle);
++ qreal y7 = 0.20 * cos(angle);
++ qreal x8 = 0.30 * sin(angle);
++ qreal y8 = 0.30 * cos(angle);
++
++ quad(x5, y5, x6, y6, x7, y7, x8, y8);
++
++ extrude(x6, y6, x7, y7);
++ extrude(x8, y8, x5, y5);
++ }
++
++ for (int i = 0;i < m_vertices.size();i++)
++ m_vertices[i] *= 2.0f;
++ }
++
++ void GLWidget::quad(qreal x1, qreal y1, qreal x2, qreal y2, qreal x3, qreal y3, qreal x4, qreal y4)
++ {
++ m_vertices << QVector3D(x1, y1, -0.05f);
++ m_vertices << QVector3D(x2, y2, -0.05f);
++ m_vertices << QVector3D(x4, y4, -0.05f);
++
++ m_vertices << QVector3D(x3, y3, -0.05f);
++ m_vertices << QVector3D(x4, y4, -0.05f);
++ m_vertices << QVector3D(x2, y2, -0.05f);
++
++ QVector3D n = QVector3D::normal
++ (QVector3D(x2 - x1, y2 - y1, 0.0f), QVector3D(x4 - x1, y4 - y1, 0.0f));
++
++ m_normals << n;
++ m_normals << n;
++ m_normals << n;
++
++ m_normals << n;
++ m_normals << n;
++ m_normals << n;
++
++ m_vertices << QVector3D(x4, y4, 0.05f);
++ m_vertices << QVector3D(x2, y2, 0.05f);
++ m_vertices << QVector3D(x1, y1, 0.05f);
++
++ m_vertices << QVector3D(x2, y2, 0.05f);
++ m_vertices << QVector3D(x4, y4, 0.05f);
++ m_vertices << QVector3D(x3, y3, 0.05f);
++
++ n = QVector3D::normal
++ (QVector3D(x2 - x4, y2 - y4, 0.0f), QVector3D(x1 - x4, y1 - y4, 0.0f));
++
++ m_normals << n;
++ m_normals << n;
++ m_normals << n;
++
++ m_normals << n;
++ m_normals << n;
++ m_normals << n;
++ }
++
++ void GLWidget::extrude(qreal x1, qreal y1, qreal x2, qreal y2)
++ {
++ m_vertices << QVector3D(x1, y1, +0.05f);
++ m_vertices << QVector3D(x2, y2, +0.05f);
++ m_vertices << QVector3D(x1, y1, -0.05f);
++
++ m_vertices << QVector3D(x2, y2, -0.05f);
++ m_vertices << QVector3D(x1, y1, -0.05f);
++ m_vertices << QVector3D(x2, y2, +0.05f);
++
++ QVector3D n = QVector3D::normal
++ (QVector3D(x2 - x1, y2 - y1, 0.0f), QVector3D(0.0f, 0.0f, -0.1f));
++
++ m_normals << n;
++ m_normals << n;
++ m_normals << n;
++
++ m_normals << n;
++ m_normals << n;
++ m_normals << n;
++ }