LCD display emulation updated to keep aspect ratio.

Signed-off-by: Pavel Pisa <pisa@cmp.felk.cvut.cz>

4 files changed, 117 insertions, 13 deletions

diff --git a/qtmips_gui/lcddisplaydock.cpp b/qtmips_gui/lcddisplaydock.cpp
index 6517f4a..1109efd 100644
--- a/qtmips_gui/lcddisplaydock.cpp
+++ b/qtmips_gui/lcddisplaydock.cpp
@@ -40,9 +40,17 @@
 #include "lcddisplaydock.h"
 #include "lcddisplayview.h"
 
-LcdDisplayDock::LcdDisplayDock(QWidget *parent, QSettings *settings) : QDockWidget(parent) {
+LcdDisplayDock::LcdDisplayDock(QWidget *parent, QSettings *settings) : Super(parent) {
     lcd_display_widget = new LcdDisplayView(this);
-    setWidget(lcd_display_widget);
+    QWidget *fill_widget = new QWidget(this);
+
+    layout = new QBoxLayout(QBoxLayout::LeftToRight, fill_widget);
+    // add spacer, then your widget, then spacer
+    layout->addItem(new QSpacerItem(0, 0));
+    layout->addWidget(lcd_display_widget);
+    layout->addItem(new QSpacerItem(0, 0));
+    fill_widget->setLayout(layout);
+    setWidget(fill_widget);
 
     setObjectName("LCD Display");
     setWindowTitle("LCD Display");
@@ -54,4 +62,41 @@ LcdDisplayDock::~LcdDisplayDock() {
 
 void LcdDisplayDock::setup(machine::LcdDisplay *lcd_display) {
     lcd_display_widget->setup(lcd_display);
+    update_layout(width(), height());
+}
+
+void LcdDisplayDock::update_layout(int w, int h) {
+    // Keeping aspect ratio based on
+    // https://stackoverflow.com/questions/30005540/keeping-the-aspect-ratio-of-a-sub-classed-qwidget-during-resize
+
+    float thisAspectRatio = (float)w / h;
+    int widgetStretch, outerStretch;
+    float arWidth = lcd_display_widget->fb_width(); // aspect ratio width
+    float arHeight = lcd_display_widget->fb_height(); // aspect ratio height
+
+    if ((arWidth == 0) || (arHeight == 0)) {
+        outerStretch = 0;
+        widgetStretch = 1;
+    }  else if (thisAspectRatio > (arWidth/arHeight)) { // too wide
+        layout->setDirection(QBoxLayout::LeftToRight);
+        widgetStretch = height() * (arWidth/arHeight); // i.e., my width
+        outerStretch = (width() - widgetStretch) / 2 + 0.5;
+    } else { // too tall
+        layout->setDirection(QBoxLayout::TopToBottom);
+        widgetStretch = width() * (arHeight/arWidth); // i.e., my height
+        outerStretch = (height() - widgetStretch) / 2 + 0.5;
+    }
+
+    layout->setStretch(0, outerStretch);
+    layout->setStretch(1, widgetStretch);
+    layout->setStretch(2, outerStretch);
+}
+
+void LcdDisplayDock::resizeEvent(QResizeEvent *event) {
+    // Keeping aspect ratio based on
+    // https://stackoverflow.com/questions/30005540/keeping-the-aspect-ratio-of-a-sub-classed-qwidget-during-resize
+
+    update_layout(event->size().width(), event->size().height());
+
+    Super::resizeEvent(event);
 }
diff --git a/qtmips_gui/lcddisplaydock.h b/qtmips_gui/lcddisplaydock.h
index 9a4f866..4659fa5 100644
--- a/qtmips_gui/lcddisplaydock.h
+++ b/qtmips_gui/lcddisplaydock.h
@@ -37,20 +37,28 @@
 #define LCDDISPLAYDOCK_H
 
 #include <QDockWidget>
+#include <QBoxLayout>
 #include "lcddisplayview.h"
 #include "qtmipsmachine.h"
 
 class LcdDisplayDock : public QDockWidget {
     Q_OBJECT
+
+    using Super = QDockWidget;
+
 public:
     LcdDisplayDock(QWidget *parent, QSettings *settings);
     ~LcdDisplayDock();
+    virtual void resizeEvent(QResizeEvent *event) override;
 
     void setup(machine::LcdDisplay *lcd_display);
 
 //public slots:
 
 private:
+    void update_layout(int w, int h);
+
+    QBoxLayout *layout;
     LcdDisplayView *lcd_display_widget;
 };
 
diff --git a/qtmips_gui/lcddisplayview.cpp b/qtmips_gui/lcddisplayview.cpp
index 450e7d4..b186610 100644
--- a/qtmips_gui/lcddisplayview.cpp
+++ b/qtmips_gui/lcddisplayview.cpp
@@ -1,4 +1,5 @@
 #include <QPainter>
+#include <QPaintEvent>
 #include <QStyle>
 #include "lcddisplay.h"
 #include "lcddisplayview.h"
@@ -6,6 +7,8 @@
 LcdDisplayView::LcdDisplayView(QWidget *parent) : Super(parent) {
     setMinimumSize(100, 100);
     fb_pixels = nullptr;
+    scale_x = 1.0;
+    scale_y = 1.0;
 }
 
 LcdDisplayView::~LcdDisplayView() {
@@ -21,19 +24,45 @@ void LcdDisplayView::setup(machine::LcdDisplay *lcd_display) {
     if (fb_pixels != nullptr)
         delete fb_pixels;
     fb_pixels = nullptr;
-    fb_pixels = new QImage(lcd_display->height(),
-                           lcd_display->width(), QImage::Format_RGB32);
+    fb_pixels = new QImage(lcd_display->width(),
+                           lcd_display->height(), QImage::Format_RGB32);
     fb_pixels->fill(qRgb(0, 0, 0));
+    update_scale();
     update();
 }
 
 void LcdDisplayView::pixel_update(uint x, uint y, uint r, uint g, uint b) {
+    int x1, y1, x2, y2;
     if (fb_pixels != nullptr) {
         fb_pixels->setPixel(x, y, qRgb(r, g, b));
-        update();
+        x1 = x * scale_x - 2;
+        if (x1 < 0)
+            x1 = 0;
+        x2 = x * scale_x + 2;
+        if (x2 > width())
+            x2 = width();
+        y1 = y * scale_y - 2;
+        if (y1 < 0)
+            y1 = 0;
+        y2 = y * scale_y + 2;
+        if (y2 > height())
+            y2 = height();
+        update(x1, y1, x2 - x1, y2 - y1);
     }
 }
 
+void LcdDisplayView::update_scale() {
+    if (fb_pixels != nullptr) {
+        if ((fb_pixels->width() != 0) && (fb_pixels->height() != 0)) {
+            scale_x = (float)width() / fb_pixels->width();
+            scale_y = (float)height() / fb_pixels->height();
+            return;
+        }
+    }
+    scale_x = 1.0;
+    scale_y = 1.0;
+}
+
 void LcdDisplayView::paintEvent(QPaintEvent *event) {
     if (fb_pixels == nullptr)
         return Super::paintEvent(event);
@@ -41,12 +70,28 @@ void LcdDisplayView::paintEvent(QPaintEvent *event) {
         return Super::paintEvent(event);
 
     QPainter painter(this);
-    QSize widgetSize = rect().size();
-    const auto newHeight = widgetSize.width() * fb_pixels->height() / fb_pixels->width();
-    if(newHeight <= widgetSize.height())
-        widgetSize.setHeight(newHeight);
-    else
-       widgetSize.setWidth(widgetSize.height() * fb_pixels->width() / fb_pixels->height());
-    painter.drawImage(rect(), fb_pixels->scaled(widgetSize));
+    painter.drawImage(rect(), *fb_pixels);
+#if 0
+    painter.setPen(QPen(QColor(255, 255, 0)));
+    painter.drawLine(event->rect().topLeft(),event->rect().topRight());
+    painter.drawLine(event->rect().topLeft(),event->rect().bottomLeft());
+    painter.drawLine(event->rect().topLeft(),event->rect().bottomRight());
+#endif
+}
+
+void LcdDisplayView::resizeEvent(QResizeEvent *event) {
+    Super::resizeEvent(event);
+    update_scale();
 }
 
+uint LcdDisplayView::fb_width() {
+    if (fb_pixels == nullptr)
+        return 0;
+    return fb_pixels->width();
+}
+
+uint LcdDisplayView::fb_height() {
+    if (fb_pixels == nullptr)
+        return 0;
+    return fb_pixels->height();
+}
diff --git a/qtmips_gui/lcddisplayview.h b/qtmips_gui/lcddisplayview.h
index 010a106..461bffc 100644
--- a/qtmips_gui/lcddisplayview.h
+++ b/qtmips_gui/lcddisplayview.h
@@ -17,15 +17,21 @@ public:
     ~LcdDisplayView();
 
     void setup(machine::LcdDisplay *lcd_display);
+    uint fb_width();
+    uint fb_height();
 
 public slots:
     void pixel_update(uint x, uint y, uint r, uint g, uint b);
 
 protected:
     virtual void paintEvent(QPaintEvent *event)  override;
+    virtual void resizeEvent(QResizeEvent *event) override;
 
 private:
-     QImage *fb_pixels;
+    void update_scale();
+    float scale_x;
+    float scale_y;
+    QImage *fb_pixels;
 };
 
 #endif // LCDDISPLAYVIEW_H