qt5base-lts/examples/opengl/qopenglwidget/glwidget.cpp
Marc Mutz aa37e67ef7 Port from qAsConst() to std::as_const()
We've been requiring C++17 since Qt 6.0, and our qAsConst use finally
starts to bother us (QTBUG-99313), so time to port away from it
now.

Since qAsConst has exactly the same semantics as std::as_const (down
to rvalue treatment, constexpr'ness and noexcept'ness), there's really
nothing more to it than a global search-and-replace, with manual
unstaging of the actual definition and documentation in dist/,
src/corelib/doc/ and src/corelib/global/.

Task-number: QTBUG-99313
Change-Id: I4c7114444a325ad4e62d0fcbfd347d2bbfb21541
Reviewed-by: Ivan Solovev <ivan.solovev@qt.io>
2022-10-11 23:17:18 +02:00

541 lines
16 KiB
C++

// Copyright (C) 2016 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 <qmath.h>
#include "mainwindow.h"
#include "bubble.h"
const int bubbleNum = 8;
#ifndef GL_SRGB8_ALPHA8
#define GL_SRGB8_ALPHA8 0x8C43
#endif
GLWidget::GLWidget(MainWindow *maybeMainWindow, const QColor &background)
: m_mainWindow(maybeMainWindow),
m_background(background)
{
setMinimumSize(300, 250);
if (QCoreApplication::arguments().contains(QStringLiteral("--srgb")))
setTextureFormat(GL_SRGB8_ALPHA8);
}
GLWidget::~GLWidget()
{
reset();
}
void GLWidget::reset()
{
qDeleteAll(m_bubbles);
// Leave everything in a state suitable for a subsequent call to
// initialize(). This matters when coming from the context's
// aboutToBeDestroyed signal, would not matter when invoked from the
// destructor.
m_bubbles.clear();
// And now release all OpenGL resources.
makeCurrent();
delete m_texture;
m_texture = nullptr;
delete m_program1;
m_program1 = nullptr;
delete m_program2;
m_program2 = nullptr;
delete m_vshader1;
m_vshader1 = nullptr;
delete m_fshader1;
m_fshader1 = nullptr;
delete m_vshader2;
m_vshader2 = nullptr;
delete m_fshader2;
m_fshader2 = nullptr;
m_vbo1.destroy();
m_vbo2.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::setScaling(int scale)
{
if (scale > 30)
m_fScale = 1 + qreal(scale - 30) / 30 * 0.25;
else if (scale < 30)
m_fScale = 1 - (qreal(30 - scale) / 30 * 0.25);
else
m_fScale = 1;
}
void GLWidget::setLogo()
{
m_qtLogo = true;
}
void GLWidget::setTexture()
{
m_qtLogo = false;
}
void GLWidget::setShowBubbles(bool bubbles)
{
m_showBubbles = bubbles;
}
void GLWidget::paintQtLogo()
{
m_program1->enableAttributeArray(m_vertexAttr1);
m_program1->enableAttributeArray(m_normalAttr1);
m_vbo1.bind();
// The data in the buffer is placed like this:
// vertex1.x, vertex1.y, vertex1.z, normal1.x, normal1.y, normal1.z, vertex2.x, ...
m_program1->setAttributeBuffer(m_vertexAttr1, GL_FLOAT, 0, 3, 6 * sizeof(GLfloat));
m_program1->setAttributeBuffer(m_normalAttr1, GL_FLOAT, 3 * sizeof(GLfloat), 3, 6 * sizeof(GLfloat));
m_vbo1.release();
glDrawArrays(GL_TRIANGLES, 0, m_vertices.size());
m_program1->disableAttributeArray(m_normalAttr1);
m_program1->disableAttributeArray(m_vertexAttr1);
}
void GLWidget::paintTexturedCube()
{
m_texture->bind();
if (!m_vbo2.isCreated()) {
static GLfloat afVertices[] = {
-0.5, 0.5, 0.5, 0.5,-0.5,0.5,-0.5,-0.5,0.5,
0.5, -0.5, 0.5, -0.5,0.5,0.5,0.5,0.5,0.5,
-0.5, -0.5, -0.5, 0.5,-0.5,-0.5,-0.5,0.5,-0.5,
0.5, 0.5, -0.5, -0.5,0.5,-0.5,0.5,-0.5,-0.5,
0.5, -0.5, -0.5, 0.5,-0.5,0.5,0.5,0.5,-0.5,
0.5, 0.5, 0.5, 0.5,0.5,-0.5,0.5,-0.5,0.5,
-0.5, 0.5, -0.5, -0.5,-0.5,0.5,-0.5,-0.5,-0.5,
-0.5, -0.5, 0.5, -0.5,0.5,-0.5,-0.5,0.5,0.5,
0.5, 0.5, -0.5, -0.5, 0.5, 0.5, -0.5, 0.5, -0.5,
-0.5, 0.5, 0.5, 0.5, 0.5, -0.5, 0.5, 0.5, 0.5,
-0.5, -0.5, -0.5, -0.5, -0.5, 0.5, 0.5, -0.5, -0.5,
0.5, -0.5, 0.5, 0.5, -0.5, -0.5, -0.5, -0.5, 0.5
};
static GLfloat afTexCoord[] = {
0.0f,0.0f, 1.0f,1.0f, 1.0f,0.0f,
1.0f,1.0f, 0.0f,0.0f, 0.0f,1.0f,
1.0f,1.0f, 1.0f,0.0f, 0.0f,1.0f,
0.0f,0.0f, 0.0f,1.0f, 1.0f,0.0f,
1.0f,1.0f, 1.0f,0.0f, 0.0f,1.0f,
0.0f,0.0f, 0.0f,1.0f, 1.0f,0.0f,
0.0f,0.0f, 1.0f,1.0f, 1.0f,0.0f,
1.0f,1.0f, 0.0f,0.0f, 0.0f,1.0f,
0.0f,1.0f, 1.0f,0.0f, 1.0f,1.0f,
1.0f,0.0f, 0.0f,1.0f, 0.0f,0.0f,
1.0f,0.0f, 1.0f,1.0f, 0.0f,0.0f,
0.0f,1.0f, 0.0f,0.0f, 1.0f,1.0f
};
GLfloat afNormals[] = {
0,0,-1, 0,0,-1, 0,0,-1,
0,0,-1, 0,0,-1, 0,0,-1,
0,0,1, 0,0,1, 0,0,1,
0,0,1, 0,0,1, 0,0,1,
-1,0,0, -1,0,0, -1,0,0,
-1,0,0, -1,0,0, -1,0,0,
1,0,0, 1,0,0, 1,0,0,
1,0,0, 1,0,0, 1,0,0,
0,-1,0, 0,-1,0, 0,-1,0,
0,-1,0, 0,-1,0, 0,-1,0,
0,1,0, 0,1,0, 0,1,0,
0,1,0, 0,1,0, 0,1,0
};
m_vbo2.create();
m_vbo2.bind();
m_vbo2.allocate(36 * 8 * sizeof(GLfloat));
m_vbo2.write(0, afVertices, sizeof(afVertices));
m_vbo2.write(sizeof(afVertices), afTexCoord, sizeof(afTexCoord));
m_vbo2.write(sizeof(afVertices) + sizeof(afTexCoord), afNormals, sizeof(afNormals));
m_vbo2.release();
}
m_program2->setUniformValue(m_textureUniform2, 0); // use texture unit 0
m_program2->enableAttributeArray(m_vertexAttr2);
m_program2->enableAttributeArray(m_normalAttr2);
m_program2->enableAttributeArray(m_texCoordAttr2);
m_vbo2.bind();
// In the buffer we first have 36 vertices (3 floats for each), then 36 texture
// coordinates (2 floats for each), then 36 normals (3 floats for each).
m_program2->setAttributeBuffer(m_vertexAttr2, GL_FLOAT, 0, 3);
m_program2->setAttributeBuffer(m_texCoordAttr2, GL_FLOAT, 36 * 3 * sizeof(GLfloat), 2);
m_program2->setAttributeBuffer(m_normalAttr2, GL_FLOAT, 36 * 5 * sizeof(GLfloat), 3);
m_vbo2.release();
glDrawArrays(GL_TRIANGLES, 0, 36);
m_program2->disableAttributeArray(m_vertexAttr2);
m_program2->disableAttributeArray(m_normalAttr2);
m_program2->disableAttributeArray(m_texCoordAttr2);
}
void GLWidget::initializeGL()
{
initializeOpenGLFunctions();
m_texture = new QOpenGLTexture(QImage(":/qt.png"));
m_vshader1 = 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_vshader1->compileSourceCode(vsrc1);
m_fshader1 = new QOpenGLShader(QOpenGLShader::Fragment);
const char *fsrc1 =
"varying mediump vec4 color;\n"
"void main(void)\n"
"{\n"
" gl_FragColor = color;\n"
"}\n";
m_fshader1->compileSourceCode(fsrc1);
m_program1 = new QOpenGLShaderProgram;
m_program1->addShader(m_vshader1);
m_program1->addShader(m_fshader1);
m_program1->link();
m_vertexAttr1 = m_program1->attributeLocation("vertex");
m_normalAttr1 = m_program1->attributeLocation("normal");
m_matrixUniform1 = m_program1->uniformLocation("matrix");
m_vshader2 = new QOpenGLShader(QOpenGLShader::Vertex);
const char *vsrc2 =
"attribute highp vec4 vertex;\n"
"attribute highp vec4 texCoord;\n"
"attribute mediump vec3 normal;\n"
"uniform mediump mat4 matrix;\n"
"varying highp vec4 texc;\n"
"varying mediump float angle;\n"
"void main(void)\n"
"{\n"
" vec3 toLight = normalize(vec3(0.0, 0.3, 1.0));\n"
" angle = max(dot(normal, toLight), 0.0);\n"
" gl_Position = matrix * vertex;\n"
" texc = texCoord;\n"
"}\n";
m_vshader2->compileSourceCode(vsrc2);
m_fshader2 = new QOpenGLShader(QOpenGLShader::Fragment);
const char *fsrc2 =
"varying highp vec4 texc;\n"
"uniform sampler2D tex;\n"
"varying mediump float angle;\n"
"void main(void)\n"
"{\n"
" highp vec3 color = texture2D(tex, texc.st).rgb;\n"
" color = color * 0.2 + color * 0.8 * angle;\n"
" gl_FragColor = vec4(clamp(color, 0.0, 1.0), 1.0);\n"
"}\n";
m_fshader2->compileSourceCode(fsrc2);
m_program2 = new QOpenGLShaderProgram;
m_program2->addShader(m_vshader2);
m_program2->addShader(m_fshader2);
m_program2->link();
m_vertexAttr2 = m_program2->attributeLocation("vertex");
m_normalAttr2 = m_program2->attributeLocation("normal");
m_texCoordAttr2 = m_program2->attributeLocation("texCoord");
m_matrixUniform2 = m_program2->uniformLocation("matrix");
m_textureUniform2 = m_program2->uniformLocation("tex");
m_fAngle = 0;
m_fScale = 1;
createGeometry();
// Use a vertex buffer object. Client-side pointers are old-school and should be avoided.
m_vbo1.create();
m_vbo1.bind();
// For the cube all the data belonging to the texture coordinates and
// normals is placed separately, after the vertices. Here, for the Qt logo,
// let's do something different and potentially more efficient: create a
// properly interleaved data set.
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_vbo1.allocate(buf.constData(), buf.count() * sizeof(GLfloat));
m_vbo1.release();
createBubbles(bubbleNum - m_bubbles.count());
// A well-behaved QOpenGLWidget releases OpenGL resources not only upon
// destruction, but also when the associated OpenGL context disappears. If
// the widget continues to exist, the context's destruction will be
// followed by a call to initialize(). This is not strictly mandatory in
// widgets that never change their parents.
m_contextWatchConnection = QObject::connect(context(), &QOpenGLContext::aboutToBeDestroyed, context(), [this] { reset(); });
}
void GLWidget::paintGL()
{
createBubbles(bubbleNum - m_bubbles.count());
QPainter painter;
painter.begin(this);
painter.beginNativePainting();
glClearColor(m_background.redF(), m_background.greenF(), m_background.blueF(), m_transparent ? 0.0f : 1.0f);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glFrontFace(GL_CW);
glCullFace(GL_FRONT);
glEnable(GL_CULL_FACE);
glEnable(GL_DEPTH_TEST);
QMatrix4x4 modelview;
modelview.rotate(m_fAngle, 0.0f, 1.0f, 0.0f);
modelview.rotate(m_fAngle, 1.0f, 0.0f, 0.0f);
modelview.rotate(m_fAngle, 0.0f, 0.0f, 1.0f);
modelview.scale(m_fScale);
modelview.translate(0.0f, -0.2f, 0.0f);
if (m_qtLogo) {
m_program1->bind();
m_program1->setUniformValue(m_matrixUniform1, modelview);
paintQtLogo();
m_program1->release();
} else {
m_program2->bind();
m_program2->setUniformValue(m_matrixUniform2, modelview);
paintTexturedCube();
m_program2->release();
}
glDisable(GL_DEPTH_TEST);
glDisable(GL_CULL_FACE);
painter.endNativePainting();
if (m_showBubbles) {
for (Bubble *bubble : std::as_const(m_bubbles))
bubble->drawBubble(&painter);
}
if (const int elapsed = m_time.elapsed()) {
QString framesPerSecond;
framesPerSecond.setNum(m_frames /(elapsed / 1000.0), 'f', 2);
painter.setPen(m_transparent ? Qt::black : Qt::white);
painter.drawText(20, 40, framesPerSecond + " paintGL calls / s");
}
painter.end();
for (Bubble *bubble : std::as_const(m_bubbles))
bubble->move(rect());
if (!(m_frames % 100)) {
m_time.start();
m_frames = 0;
}
m_fAngle += 1.0f;
++m_frames;
// When requested, follow the ideal way to animate: Rely on
// blocking swap and just schedule updates continuously.
if (!m_mainWindow || !m_mainWindow->timerEnabled())
update();
}
void GLWidget::createBubbles(int number)
{
for (int i = 0; i < number; ++i) {
QPointF position(width()*(0.1 + QRandomGenerator::global()->bounded(0.8)),
height()*(0.1 + QRandomGenerator::global()->bounded(0.8)));
qreal radius = qMin(width(), height())*(0.0175 + QRandomGenerator::global()->bounded(0.0875));
QPointF velocity(width()*0.0175*(-0.5 + QRandomGenerator::global()->bounded(1.0)),
height()*0.0175*(-0.5 + QRandomGenerator::global()->bounded(1.0)));
m_bubbles.append(new Bubble(position, radius, velocity));
}
}
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;
}
void GLWidget::setTransparent(bool transparent)
{
setAttribute(Qt::WA_AlwaysStackOnTop, transparent);
m_transparent = transparent;
// Call update() on the top-level window after toggling AlwayStackOnTop to make sure
// the entire backingstore is updated accordingly.
window()->update();
}
void GLWidget::resizeGL(int, int)
{
if (m_mainWindow) {
if (!m_btn) {
m_btn = new QPushButton("\nAdd widget\n", this);
connect(m_btn, &QPushButton::clicked, this, [this] { m_mainWindow->addNew(); });
}
m_btn->move(20, 80);
if (!m_btn2) {
m_btn2 = new QPushButton("\nI prefer tabbed widgets\n", this);
connect(m_btn2, &QPushButton::clicked, this, [this] { m_mainWindow->showNewWindow(); });
}
m_btn2->move(20, 160);
}
}