Allow taking screenshots in main menu (#16749)

Co-authored-by: sfan5 <sfan5@live.de>
Co-authored-by: siliconsniffer <siliconsniffer@users.noreply.github.com>

src/util/CMakeLists.txt

@@ -17,6 +17,7 @@ set(util_SRCS
 	${CMAKE_CURRENT_SOURCE_DIR}/pointabilities.cpp
 	${CMAKE_CURRENT_SOURCE_DIR}/quicktune.cpp
 	${CMAKE_CURRENT_SOURCE_DIR}/serialize.cpp
+	${CMAKE_CURRENT_SOURCE_DIR}/screenshot.cpp
 	${CMAKE_CURRENT_SOURCE_DIR}/sha1.cpp
 	${CMAKE_CURRENT_SOURCE_DIR}/string.cpp
 	${CMAKE_CURRENT_SOURCE_DIR}/srp.cpp

src/util/screenshot.cpp

@@ -0,0 +1,96 @@
+// Luanti
+// SPDX-License-Identifier: LGPL-2.1-or-later
+// Copyright (C) 2013 celeron55, Perttu Ahola <celeron55@gmail.com>
+
+#include "screenshot.h"
+#include "filesys.h"
+#include "gettime.h"
+#include "porting.h"
+#include "settings.h"
+#include "util/string.h"
+#include "util/numeric.h"
+#include "gettext.h"
+#include "log.h"
+#include "debug.h"
+#include <IVideoDriver.h>
+#include <ctime>
+
+#define SCREENSHOT_MAX_SERIAL_TRIES 1000
+
+bool takeScreenshot(video::IVideoDriver *driver, std::string &filename_out)
+{
+	sanity_check(driver);
+
+	video::IImage* const raw_image = driver->createScreenShot();
+
+	if (!raw_image) {
+		errorstream << "Could not take screenshot" << std::endl;
+		return false;
+	}
+
+	const struct tm tm = mt_localtime();
+
+	char timestamp_c[64];
+	strftime(timestamp_c, sizeof(timestamp_c), "%Y%m%d_%H%M%S", &tm);
+
+	std::string screenshot_dir = g_settings->get("screenshot_path");
+	if (!fs::IsPathAbsolute(screenshot_dir))
+		screenshot_dir = porting::path_user + DIR_DELIM + screenshot_dir;
+
+	std::string filename_base = screenshot_dir
+			+ DIR_DELIM
+			+ std::string("screenshot_")
+			+ timestamp_c;
+	std::string filename_ext = "." + g_settings->get("screenshot_format");
+
+	// Create the directory if it doesn't already exist.
+	// Otherwise, saving the screenshot would fail.
+	fs::CreateAllDirs(screenshot_dir);
+
+	u32 quality = (u32)g_settings->getS32("screenshot_quality");
+	quality = rangelim(quality, 0, 100) / 100.0f * 255;
+
+	// Try to find a unique filename
+	std::string filename;
+	unsigned serial = 0;
+
+	while (serial < SCREENSHOT_MAX_SERIAL_TRIES) {
+		filename = filename_base + (serial > 0 ? ("_" + itos(serial)) : "").append(filename_ext);
+		if (!fs::PathExists(filename))
+			break;	// File did not apparently exist, we'll go with it
+		serial++;
+	}
+
+	if (serial == SCREENSHOT_MAX_SERIAL_TRIES) {
+		errorstream << "Could not find suitable filename for screenshot" << std::endl;
+		raw_image->drop();
+		return false;
+	}
+
+	video::IImage* const image =
+			driver->createImage(video::ECF_R8G8B8, raw_image->getDimension());
+
+	if (!image) {
+		errorstream << "Could not create image for screenshot" << std::endl;
+		raw_image->drop();
+		return false;
+	}
+
+	raw_image->copyTo(image);
+
+	bool success = driver->writeImageToFile(image, filename.c_str(), quality);
+
+	if (success) {
+		filename_out = filename;
+		std::string msg = fmtgettext("Saved screenshot to \"%s\"", filename.c_str());
+		infostream << msg << std::endl;
+	} else {
+		std::string msg = fmtgettext("Failed to save screenshot to \"%s\"", filename.c_str());
+		errorstream << msg << std::endl;
+	}
+
+	image->drop();
+	raw_image->drop();
+	return success;
+}
+

src/util/screenshot.h

@@ -0,0 +1,20 @@
+// Luanti
+// SPDX-License-Identifier: LGPL-2.1-or-later
+// Copyright (C) 2013 celeron55, Perttu Ahola <celeron55@gmail.com>
+
+#pragma once
+
+#include <string>
+
+namespace video {
+	class IVideoDriver;
+}
+
+/**
+ * Take a screenshot and save it to disk
+ * @param driver Video driver to use for the screenshot
+ * @param filename_out Output parameter that receives the path to the saved screenshot
+ * @return true if the screenshot was saved successfully, false otherwise
+ */
+bool takeScreenshot(video::IVideoDriver *driver, std::string &filename_out);
+