fix: use integers for message layout bounds (#6254)

CHANGELOG.md

@@ -34,7 +34,7 @@
 - Bugfix: Fixed a crash that could occur an eventsub connection's keepalive timer would run after the connection was dead, causing the keepalive timer to use-itself-after-free. (#6204)
 - Bugfix: Fixed a crash that could occur when an image started loading mid app shutdown. (#6213)
 - Bugfix: Fixed some minor typos. (#6196)
-- Bugfix: Fixed inconsistent spaces in messages when using fractional scaling. (#6231)
+- Bugfix: Fixed inconsistent spaces in messages when using fractional scaling. (#6231, #6254)
 - Dev: Mini refactor of Split. (#6148)
 - Dev: Conan will no longer generate a `CMakeUserPresets.json` file. (#6117)
 - Dev: Pass `--force-openssl` when installing from CMake in Qt 6.8+. (#6129)

src/messages/layouts/MessageLayout.cpp

@@ -56,14 +56,14 @@ const MessagePtr &MessageLayout::getMessagePtr() const
 }
 
 // Height
-qreal MessageLayout::getHeight() const
+int MessageLayout::getHeight() const
 {
-    return this->container_.getHeight();
+    return static_cast<int>(this->container_.getHeight());
 }
 
-qreal MessageLayout::getWidth() const
+int MessageLayout::getWidth() const
 {
-    return this->container_.getWidth();
+    return static_cast<int>(this->container_.getWidth());
 }
 
 // Layout
@@ -236,7 +236,7 @@ MessagePaintResult MessageLayout::paint(const MessagePaintContext &ctx)
     }
 
     // draw on buffer
-    ctx.painter.drawPixmap(QPointF{0, ctx.y}, *pixmap);
+    ctx.painter.drawPixmap(QPoint{0, ctx.y}, *pixmap);
 
     // draw gif emotes
     result.hasAnimatedElements =
@@ -246,11 +246,11 @@ MessagePaintResult MessageLayout::paint(const MessagePaintContext &ctx)
     if (this->message_->flags.has(MessageFlag::Disabled))
     {
         ctx.painter.fillRect(
-            QRectF{
+            QRect{
                 0,
                 ctx.y,
-                static_cast<qreal>(pixmap->width()),
-                static_cast<qreal>(pixmap->height()),
+                pixmap->width(),
+                pixmap->height(),
             },
             ctx.messageColors.disabled);
     }
@@ -259,11 +259,11 @@ MessagePaintResult MessageLayout::paint(const MessagePaintContext &ctx)
         ctx.preferences.fadeMessageHistory)
     {
         ctx.painter.fillRect(
-            QRectF{
+            QRect{
                 0,
                 ctx.y,
-                static_cast<qreal>(pixmap->width()),
-                static_cast<qreal>(pixmap->height()),
+                pixmap->width(),
+                pixmap->height(),
             },
             ctx.messageColors.disabled);
     }
@@ -274,11 +274,11 @@ MessagePaintResult MessageLayout::paint(const MessagePaintContext &ctx)
         ctx.preferences.enableRedeemedHighlight)
     {
         ctx.painter.fillRect(
-            QRectF{
+            QRect{
                 0,
                 ctx.y,
-                this->scale_ * 4,
-                static_cast<qreal>(pixmap->height()),
+                static_cast<int>(this->scale_ * 4),
+                pixmap->height(),
             },
             *ColorProvider::instance().color(ColorType::RedeemedHighlight));
     }

src/messages/layouts/MessageLayout.hpp

@@ -52,8 +52,10 @@ public:
     const Message *getMessage();
     const MessagePtr &getMessagePtr() const;
 
-    qreal getHeight() const;
-    qreal getWidth() const;
+    /// In contrast to other metrics, the height and width are integers because
+    /// this is how the backing pixmap is measured - it needs whole integers.
+    int getHeight() const;
+    int getWidth() const;
 
     MessageLayoutFlags flags;
 

src/messages/layouts/MessageLayoutContext.hpp

@@ -76,7 +76,7 @@ struct MessagePaintContext {
     const bool isMentions{};
 
     // y coordinate we're currently painting at
-    qreal y{};
+    int y{};
 
     // Index of the message that is currently being painted
     // This index refers to the snapshot being used in the painting

src/widgets/helper/ChannelView.cpp

@@ -764,7 +764,7 @@ void ChannelView::updateScrollbar(
         {
             this->scrollBar_->setPageSize(
                 static_cast<qreal>(messages.size() - i) +
-                (h / std::max(1.0, message->getHeight())));
+                (h / std::max(1, message->getHeight())));
 
             showScrollbar = true;
             break;
@@ -1608,8 +1608,9 @@ void ChannelView::drawMessages(QPainter &painter, const QRect &area)
         .isMentions = this->underlyingChannel_ ==
                       getApp()->getTwitch()->getMentionsChannel(),
 
-        .y = -(messagesSnapshot[start]->getHeight() *
-               (fmod(this->scrollBar_->getRelativeCurrentValue(), 1))),
+        .y = -static_cast<int>(
+            messagesSnapshot[start]->getHeight() *
+            (fmod(this->scrollBar_->getRelativeCurrentValue(), 1))),
         .messageIndex = start,
         .isLastReadMessage = false,
 
@@ -1646,25 +1647,23 @@ void ChannelView::drawMessages(QPainter &painter, const QRect &area)
                 {
                     animationArea = QRect{
                         0,
-                        static_cast<int>(ctx.y),
-                        static_cast<int>(layout->getWidth()),
-                        static_cast<int>(layout->getHeight()),
+                        ctx.y,
+                        layout->getWidth(),
+                        layout->getHeight(),
                     };
                 }
                 else
                 {
-                    animationArea.setBottom(
-                        static_cast<int>(ctx.y + layout->getHeight()));
+                    animationArea.setBottom((ctx.y + layout->getHeight()));
                     animationArea.setWidth(
-                        std::max(static_cast<int>(layout->getWidth()),
-                                 animationArea.width()));
+                        std::max(layout->getWidth(), animationArea.width()));
                 }
             }
 
             if (this->highlightedMessage_ == layout)
             {
                 painter.fillRect(
-                    QRectF{
+                    QRect{
                         0,
                         ctx.y,
                         layout->getWidth(),