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CLK/OSBindings/Qt/scantargetwidget.cpp

229 lines
6.6 KiB
C++

#include "scantargetwidget.h"
#include <QApplication>
#include <QCursor>
#include <QDebug>
#include <QDesktopWidget>
#include <QGuiApplication>
#include <QKeyEvent>
#include <QMouseEvent>
#include <QOpenGLContext>
#include <QScreen>
#include <QTimer>
#include "../../ClockReceiver/TimeTypes.hpp"
ScanTargetWidget::ScanTargetWidget(QWidget *parent) : QOpenGLWidget(parent) {}
ScanTargetWidget::~ScanTargetWidget() {}
void ScanTargetWidget::initializeGL() {
setDefaultClearColour();
// Follow each swapped frame with an additional update.
connect(this, &QOpenGLWidget::frameSwapped, this, &ScanTargetWidget::vsync);
}
void ScanTargetWidget::paintGL() {
if(requestedRedrawTime) {
const auto now = Time::nanos_now();
vsyncPredictor.add_timer_jitter(now - requestedRedrawTime);
requestedRedrawTime = 0;
}
// TODO: if Qt 5.14 can be guaranteed, just use window()->screen().
const auto screenNumber = QApplication::desktop()->screenNumber(this);
QScreen *const screen = QGuiApplication::screens()[screenNumber];
const float newOutputScale = float(screen->devicePixelRatio());
if(outputScale != newOutputScale) {
outputScale = newOutputScale;
resize();
}
vsyncPredictor.set_frame_rate(float(screen->refreshRate()));
glClear(GL_COLOR_BUFFER_BIT);
// Gmynastics ahoy: if a producer has been specified or previously connected then:
//
// (i) if it's a new producer, generate a new scan target and pass it on;
// (ii) in any case, check whether the underlyiung framebuffer has changed; and
// (iii) draw.
//
// The slightly convoluted scan target forwarding arrangement works around an issue
// with QOpenGLWidget under macOS, which I did not fully diagnose, in which creating
// a scan target in ::initializeGL did not work (and no other arrangement really works
// with regard to starting up).
if(isConnected || producer) {
if(producer) {
isConnected = true;
framebuffer = defaultFramebufferObject();
scanTarget = std::make_unique<Outputs::Display::OpenGL::ScanTarget>(framebuffer);
producer->set_scan_target(scanTarget.get());
producer = nullptr;
}
// Qt reserves the right to change the framebuffer object due to window resizes or if setParent is called;
// therefore check whether it has changed.
const auto newFramebuffer = defaultFramebufferObject();
if(framebuffer != newFramebuffer) {
framebuffer = newFramebuffer;
scanTarget->set_target_framebuffer(framebuffer);
}
vsyncPredictor.begin_redraw();
scanTarget->update(scaledWidth, scaledHeight);
scanTarget->draw(scaledWidth, scaledHeight);
glFinish(); // Make sure all costs are properly accounted for in the vsync predictor.
vsyncPredictor.end_redraw();
}
}
void ScanTargetWidget::vsync() {
if(!isConnected) return;
vsyncPredictor.announce_vsync();
const auto time_now = Time::nanos_now();
requestedRedrawTime = vsyncPredictor.suggested_draw_time();
const auto delay_time = (requestedRedrawTime - time_now) / 1'000'000;
if(delay_time > 0 && delay_time < vsyncPredictor.frame_duration()) {
QTimer::singleShot(delay_time, this, SLOT(repaint()));
} else {
requestedRedrawTime = 0;
repaint();
}
}
void ScanTargetWidget::resizeGL(int w, int h) {
if(rawWidth != w || rawHeight != h) {
rawWidth = w;
rawHeight = h;
resize();
}
}
void ScanTargetWidget::resize() {
const int newScaledWidth = int(float(rawWidth) * outputScale);
const int newScaledHeight = int(float(rawHeight) * outputScale);
if(newScaledWidth != scaledWidth || newScaledHeight != scaledHeight) {
scaledWidth = newScaledWidth;
scaledHeight = newScaledHeight;
glViewport(0, 0, scaledWidth, scaledHeight);
}
}
void ScanTargetWidget::setScanProducer(MachineTypes::ScanProducer *producer) {
this->producer = producer;
repaint();
}
void ScanTargetWidget::stop() {
makeCurrent();
scanTarget.reset();
isConnected = false;
setDefaultClearColour();
vsyncPredictor.pause();
requestedRedrawTime = 0;
repaint();
}
void ScanTargetWidget::setDefaultClearColour() {
// Retain the default background colour.
const QColor backgroundColour = palette().color(QWidget::backgroundRole());
glClearColor(backgroundColour.redF(), backgroundColour.greenF(), backgroundColour.blueF(), 1.0);
}
void ScanTargetWidget::setMouseDelegate(MouseDelegate *delegate) {
if(!delegate && mouseIsCaptured) {
releaseMouse();
}
mouseDelegate = delegate;
setMouseTracking(delegate);
}
void ScanTargetWidget::keyReleaseEvent(QKeyEvent *event) {
// Releasing F8 or F12 needs to be tracked but doesn't actively do anything,
// so I'm counting that as a Qt ignore.
if(event->key() == Qt::Key_F8) f8State = false;
if(event->key() == Qt::Key_F12) f12State = false;
event->ignore();
}
void ScanTargetWidget::keyPressEvent(QKeyEvent *event) {
// Use either CTRL+Escape or F8+F12 to end mouse captured mode, if currently captured;
// otherwise ignore the event.
if(event->key() == Qt::Key_F8) f8State = true;
if(event->key() == Qt::Key_F12) f12State = true;
if(mouseIsCaptured && (
(event->key() == Qt::Key_Escape && event->modifiers()&Qt::ControlModifier) ||
(f8State && f12State)
)) {
releaseMouse();
QCursor cursor;
cursor.setShape(Qt::ArrowCursor);
setCursor(cursor);
return;
}
event->ignore();
}
void ScanTargetWidget::releaseMouse() {
QOpenGLWidget::releaseMouse();
mouseIsCaptured = false;
mouseDelegate->setMouseIsCaptured(false);
}
void ScanTargetWidget::mousePressEvent(QMouseEvent *event) {
if(mouseDelegate) {
if(!mouseIsCaptured) {
mouseIsCaptured = true;
grabMouse();
QCursor cursor;
cursor.setPos(mapToGlobal(QPoint(width() / 2, height() / 2)));
cursor.setShape(Qt::BlankCursor);
setCursor(cursor);
mouseDelegate->setMouseIsCaptured(true);
} else {
setMouseButtonPressed(event->button(), true);
}
}
}
void ScanTargetWidget::mouseReleaseEvent(QMouseEvent *event) {
if(mouseDelegate && !mouseIsCaptured) {
setMouseButtonPressed(event->button(), false);
}
}
void ScanTargetWidget::setMouseButtonPressed(Qt::MouseButton button, bool isPressed) {
switch(button) {
default: break;
case Qt::LeftButton: mouseDelegate->setButtonPressed(0, isPressed); break;
case Qt::RightButton: mouseDelegate->setButtonPressed(1, isPressed); break;
case Qt::MiddleButton: mouseDelegate->setButtonPressed(2, isPressed); break;
}
}
void ScanTargetWidget::mouseMoveEvent(QMouseEvent *event) {
// Recentre the mouse cursor upon every move if it is currently captured.
if(mouseDelegate && mouseIsCaptured) {
const QPoint centre = QPoint(width() / 2, height() / 2);
const QPoint vector = event->pos() - centre;
mouseDelegate->moveMouse(vector);
QCursor::setPos(mapToGlobal(centre));
}
}
bool ScanTargetWidget::isMouseCaptured() {
return mouseIsCaptured;
}