OmaPhoto 1.0.0: the Linux port of Compositor

A layered image editor for Linux and Omarchy, ported from Compositor
(github.com/robbietilton/Compositor), whose Swift source is its
specification. It reads and writes Compositor's .comp projects.

Packages for Ubuntu, Fedora and Arch come from the release workflow;
scripts/install/ holds one install script per distribution family,
and flake.nix serves NixOS.

Co-Authored-By: Claude <noreply@anthropic.com>

src/Document/ContentFill.cpp

@@ -0,0 +1,33 @@
+#include "Document/ContentFill.h"
+#include "Document/BrushStroke.h"
+#include "Document/PixelAdjust.h"
+#include "IO/ImageExporter.h"
+
+// The kernel shares this file's name: angle brackets skip here.
+extern "C" {
+#include <ContentFill.h>
+}
+
+ContentFillError::ContentFillError(Kind kind)
+    : std::runtime_error("Not enough unselected, opaque image pixels to synthesize a fill. Use a smaller selection with some surrounding image."), kind(kind)
+{
+}
+
+QImage ContentFill::run(const FilterJob &job)
+{
+    if (!job.selection)
+        throw ContentFillError(ContentFillError::Kind::noSource);
+    const int width = job.image.width(), height = job.image.height();
+    QImage pixels = BrushRaster::context(width, height, false);
+    QPainter painter(&pixels);
+    BrushRaster::draw(job.image, QRectF(0, 0, width, height), painter);
+    painter.end();
+    // White through the selection: the pixels to make.
+    const QImage mask = PixelAdjust::coverage(*job.selection, width, height, job.mapping);
+    const int result = content_fill(pixels.bits(), size_t(pixels.bytesPerLine()), mask.constBits(), size_t(mask.bytesPerLine()), width, height);
+    if (result == 0)
+        throw ContentFillError(ContentFillError::Kind::noSource);
+    if (result != 1)
+        throw ExportError(ExportError::Kind::render);
+    return pixels;
+}