1 files changed, 102 insertions, 0 deletions
diff --git a/src/yuzu/util/util.cpp b/src/yuzu/util/util.cpp
index 5c3e4589e..f2854c8ec 100644
--- a/src/yuzu/util/util.cpp
+++ b/src/yuzu/util/util.cpp
@@ -5,6 +5,10 @@
 #include <cmath>
 #include <QPainter>
 #include "yuzu/util/util.h"
+#ifdef _WIN32
+#include <windows.h>
+#include "common/fs/file.h"
+#endif
 
 QFont GetMonospaceFont() {
     QFont font(QStringLiteral("monospace"));
@@ -37,3 +41,101 @@ QPixmap CreateCirclePixmapFromColor(const QColor& color) {
     painter.drawEllipse({circle_pixmap.width() / 2.0, circle_pixmap.height() / 2.0}, 7.0, 7.0);
     return circle_pixmap;
 }
+
+bool SaveIconToFile(const std::string_view path, const QImage& image) {
+#if defined(WIN32)
+#pragma pack(push, 2)
+    struct IconDir {
+        WORD id_reserved;
+        WORD id_type;
+        WORD id_count;
+    };
+
+    struct IconDirEntry {
+        BYTE width;
+        BYTE height;
+        BYTE color_count;
+        BYTE reserved;
+        WORD planes;
+        WORD bit_count;
+        DWORD bytes_in_res;
+        DWORD image_offset;
+    };
+#pragma pack(pop)
+
+    const QImage source_image = image.convertToFormat(QImage::Format_RGB32);
+    constexpr std::array<int, 7> scale_sizes{256, 128, 64, 48, 32, 24, 16};
+    constexpr int bytes_per_pixel = 4;
+
+    const IconDir icon_dir{
+        .id_reserved = 0,
+        .id_type = 1,
+        .id_count = static_cast<WORD>(scale_sizes.size()),
+    };
+
+    Common::FS::IOFile icon_file(path, Common::FS::FileAccessMode::Write,
+                                 Common::FS::FileType::BinaryFile);
+    if (!icon_file.IsOpen()) {
+        return false;
+    }
+
+    if (!icon_file.Write(icon_dir)) {
+        return false;
+    }
+
+    std::size_t image_offset = sizeof(IconDir) + (sizeof(IconDirEntry) * scale_sizes.size());
+    for (std::size_t i = 0; i < scale_sizes.size(); i++) {
+        const int image_size = scale_sizes[i] * scale_sizes[i] * bytes_per_pixel;
+        const IconDirEntry icon_entry{
+            .width = static_cast<BYTE>(scale_sizes[i]),
+            .height = static_cast<BYTE>(scale_sizes[i]),
+            .color_count = 0,
+            .reserved = 0,
+            .planes = 1,
+            .bit_count = bytes_per_pixel * 8,
+            .bytes_in_res = static_cast<DWORD>(sizeof(BITMAPINFOHEADER) + image_size),
+            .image_offset = static_cast<DWORD>(image_offset),
+        };
+        image_offset += icon_entry.bytes_in_res;
+        if (!icon_file.Write(icon_entry)) {
+            return false;
+        }
+    }
+
+    for (std::size_t i = 0; i < scale_sizes.size(); i++) {
+        const QImage scaled_image = source_image.scaled(
+            scale_sizes[i], scale_sizes[i], Qt::IgnoreAspectRatio, Qt::SmoothTransformation);
+        const BITMAPINFOHEADER info_header{
+            .biSize = sizeof(BITMAPINFOHEADER),
+            .biWidth = scaled_image.width(),
+            .biHeight = scaled_image.height() * 2,
+            .biPlanes = 1,
+            .biBitCount = bytes_per_pixel * 8,
+            .biCompression = BI_RGB,
+            .biSizeImage{},
+            .biXPelsPerMeter{},
+            .biYPelsPerMeter{},
+            .biClrUsed{},
+            .biClrImportant{},
+        };
+
+        if (!icon_file.Write(info_header)) {
+            return false;
+        }
+
+        for (int y = 0; y < scaled_image.height(); y++) {
+            const auto* line = scaled_image.scanLine(scaled_image.height() - 1 - y);
+            std::vector<u8> line_data(scaled_image.width() * bytes_per_pixel);
+            std::memcpy(line_data.data(), line, line_data.size());
+            if (!icon_file.Write(line_data)) {
+                return false;
+            }
+        }
+    }
+    icon_file.Close();
+
+    return true;
+#else
+    return false;
+#endif
+}