Implement initial structure and core functionality for Duck Preview application

duck_preview/rendering/overlay.py

@@ -0,0 +1,49 @@
+from __future__ import annotations
+
+from PySide6.QtCore import Qt
+from PySide6.QtGui import QColor, QFont, QFontMetrics, QPainter
+from PySide6.QtWidgets import QWidget
+
+
+class OverlayWidget(QWidget):
+    def __init__(self, parent: QWidget | None = None) -> None:
+        super().__init__(parent)
+        self.setAttribute(Qt.WA_TransparentForMouseEvents)
+        self.setAttribute(Qt.WA_NoSystemBackground)
+        self._visible = True
+        self._metrics: dict[str, float | int] = {}
+
+    def set_visible(self, visible: bool) -> None:
+        self._visible = visible
+        self.update()
+
+    def set_metrics(self, metrics: dict[str, float | int]) -> None:
+        self._metrics = metrics
+        self.update()
+
+    def paintEvent(self, event) -> None:  # noqa: N802
+        if not self._visible or not self._metrics:
+            return
+
+        lines = [
+            f"FPS:     {self._metrics.get('fps', 0):>7}",
+            f"Frame:   {self._metrics.get('frame_time_ms', 0):>7.1f} ms",
+            f"Frames:  {self._metrics.get('frame_count', 0):>7}",
+        ]
+
+        painter = QPainter(self)
+        painter.setRenderHint(QPainter.TextAntialiasing)
+
+        font = QFont("Consolas", 11)
+        painter.setFont(font)
+        fm = QFontMetrics(font)
+
+        text_width = max(fm.horizontalAdvance(line) for line in lines) + 24
+        text_height = len(lines) * (fm.height() + 6) + 12
+
+        painter.fillRect(8, 8, text_width, text_height, QColor(0, 0, 0, 160))
+
+        painter.setPen(QColor(0, 255, 0))
+        for i, line in enumerate(lines):
+            y = 22 + i * (fm.height() + 6)
+            painter.drawText(16, y, line)

duck_preview/rendering/video_widget.py

@@ -0,0 +1,39 @@
+from __future__ import annotations
+
+from PySide6.QtCore import Qt
+from PySide6.QtGui import QColor, QImage, QPainter
+from PySide6.QtMultimedia import QVideoFrame
+from PySide6.QtWidgets import QWidget
+
+
+class VideoWidget(QWidget):
+    def __init__(self, parent: QWidget | None = None) -> None:
+        super().__init__(parent)
+        self._frame: QImage | None = None
+        self.setAttribute(Qt.WA_OpaquePaintEvent)
+        self.setMinimumSize(320, 240)
+
+    def on_frame(self, frame: QVideoFrame) -> None:
+        image = frame.toImage()
+        if not image.isNull():
+            self._frame = image
+            self.update()
+
+    def paintEvent(self, event) -> None:  # noqa: N802
+        painter = QPainter(self)
+        painter.setRenderHint(QPainter.SmoothPixmapTransform)
+
+        if self._frame is not None:
+            painter.fillRect(self.rect(), QColor(0, 0, 0))
+            scaled = self._frame.scaled(
+                self.size(),
+                Qt.KeepAspectRatio,
+                Qt.SmoothTransformation,
+            )
+            x = (self.width() - scaled.width()) // 2
+            y = (self.height() - scaled.height()) // 2
+            painter.drawImage(x, y, scaled)
+        else:
+            painter.fillRect(self.rect(), QColor(20, 20, 20))
+            painter.setPen(QColor(100, 100, 100))
+            painter.drawText(self.rect(), Qt.AlignCenter, "No camera feed")