wayland/screencopy: add screencopy

src/wayland/buffer/shm.cpp

@@ -0,0 +1,91 @@
+#include "shm.hpp"
+#include <algorithm>
+#include <memory>
+
+#include <private/qwaylanddisplay_p.h>
+#include <private/qwaylandintegration_p.h>
+#include <private/qwaylandshm_p.h>
+#include <private/qwaylandshmbackingstore_p.h>
+#include <qdebug.h>
+#include <qlogging.h>
+#include <qloggingcategory.h>
+#include <qquickwindow.h>
+#include <qsize.h>
+#include <wayland-client-protocol.h>
+
+#include "manager.hpp"
+
+namespace qs::wayland::buffer::shm {
+
+Q_LOGGING_CATEGORY(logShm, "quickshell.wayland.buffer.shm", QtWarningMsg);
+
+bool WlShmBuffer::isCompatible(const WlBufferRequest& request) const {
+	if (QSize(static_cast<int>(request.width), static_cast<int>(request.height)) != this->size()) {
+		return false;
+	}
+
+	auto matchingFormat = std::ranges::find(request.shm.formats, this->format);
+	return matchingFormat != request.shm.formats.end();
+}
+
+QDebug& operator<<(QDebug& debug, const WlShmBuffer* buffer) {
+	auto saver = QDebugStateSaver(debug);
+	debug.nospace();
+
+	if (buffer) {
+		auto fmt = QtWaylandClient::QWaylandShm::formatFrom(
+		    static_cast<::wl_shm_format>(buffer->format) // NOLINT
+		);
+
+		debug << "WlShmBuffer(" << static_cast<const void*>(buffer) << ", size=" << buffer->size()
+		      << ", format=" << fmt << ')';
+	} else {
+		debug << "WlShmBuffer(0x0)";
+	}
+
+	return debug;
+}
+
+WlShmBuffer::~WlShmBuffer() { qCDebug(logShm) << "Destroyed" << this; }
+
+WlBufferQSGTexture* WlShmBuffer::createQsgTexture(QQuickWindow* window) const {
+	auto* texture = new WlShmBufferQSGTexture();
+
+	// If the QWaylandShmBuffer is destroyed before the QSGTexture, we'll hit a UAF
+	// in the render thread.
+	texture->shmBuffer = this->shmBuffer;
+
+	texture->qsgTexture.reset(window->createTextureFromImage(*this->shmBuffer->image()));
+	texture->sync(this, window);
+	return texture;
+}
+
+void WlShmBufferQSGTexture::sync(const WlBuffer* /*unused*/, QQuickWindow* window) {
+	// This is both dumb and expensive. We should use an RHI texture and render images into
+	// it more intelligently, but shm buffers are already a horribly slow fallback path,
+	// to the point where it barely matters.
+	this->qsgTexture.reset(window->createTextureFromImage(*this->shmBuffer->image()));
+}
+
+WlBuffer* ShmbufManager::createShmbuf(const WlBufferRequest& request) {
+	if (request.shm.formats.isEmpty()) return nullptr;
+
+	static const auto* waylandIntegration = QtWaylandClient::QWaylandIntegration::instance();
+	auto* display = waylandIntegration->display();
+
+	// Its probably fine...
+	auto format = request.shm.formats[0];
+
+	auto* buffer = new WlShmBuffer(
+	    new QtWaylandClient::QWaylandShmBuffer(
+	        display,
+	        QSize(static_cast<int>(request.width), static_cast<int>(request.height)),
+	        QtWaylandClient::QWaylandShm::formatFrom(static_cast<::wl_shm_format>(format)) // NOLINT
+	    ),
+	    format
+	);
+
+	qCDebug(logShm) << "Created shmbuf" << buffer;
+	return buffer;
+}
+} // namespace qs::wayland::buffer::shm