update

2026-05-14 13:30:06 +08:00
parent 974946cee4
commit e43171521d
91 changed files with 10485 additions and 3254 deletions
@@ -0,0 +1,271 @@
+// 必须在任何 Qt 头（会定义宏 signals）之前包含 vips/glib
+#ifdef LT_HAVE_VIPS
+#  include <vips/vips.h>
+#endif
+
+#include "large_image/VipsBackend.h"
+
+#include <QByteArray>
+#include <QFile>
+#include <QFileInfo>
+
+#include <algorithm>
+#include <cmath>
+#include <cstdlib>
+
+namespace core {
+
+#ifdef LT_HAVE_VIPS
+
+namespace {
+
+bool gReady = false;
+
+QByteArray encodedPath(const QString& path) {
+    return QFile::encodeName(path);
+}
+
+bool saveVipsImageToPngFile(VipsImage* img, const QString& destPath) {
+    if (!img) {
+        return false;
+    }
+    const QByteArray dest = encodedPath(destPath);
+    if (vips_pngsave(img, dest.constData(), "compression", 3, nullptr) != 0) {
+        return false;
+    }
+    return true;
+}
+
+}  // namespace
+
+bool VipsBackend::init(const char* argv0) {
+    if (gReady) {
+        return true;
+    }
+    if (vips_init(argv0) != 0) {
+        return false;
+    }
+    gReady = true;
+    return true;
+}
+
+void VipsBackend::shutdown() {
+    if (!gReady) {
+        return;
+    }
+    vips_shutdown();
+    gReady = false;
+}
+
+bool VipsBackend::isAvailable() {
+    return gReady;
+}
+
+bool VipsBackend::probeSize(const QString& path, QSize* out) {
+    if (!gReady || !out) {
+        return false;
+    }
+    const QByteArray enc = encodedPath(path);
+    if (enc.isEmpty()) {
+        return false;
+    }
+    VipsImage* in = vips_image_new_from_file(enc.constData(), "access", VIPS_ACCESS_SEQUENTIAL, nullptr);
+    if (!in) {
+        return false;
+    }
+    const int w = vips_image_get_width(in);
+    const int h = vips_image_get_height(in);
+    g_object_unref(in);
+    if (w <= 0 || h <= 0) {
+        return false;
+    }
+    *out = QSize(w, h);
+    return true;
+}
+
+bool VipsBackend::loadThumbnailQImage(const QString& path, qint64 maxPixels, QImage* out) {
+    if (!gReady || !out || maxPixels < 1024) {
+        return false;
+    }
+    const QByteArray enc = encodedPath(path);
+    if (enc.isEmpty()) {
+        return false;
+    }
+
+    QSize sz;
+    if (!probeSize(path, &sz)) {
+        return false;
+    }
+    const qint64 pixels = qint64(sz.width()) * qint64(sz.height());
+    if (pixels <= 0) {
+        return false;
+    }
+
+    VipsImage* thumb = nullptr;
+    if (pixels <= maxPixels) {
+        thumb = vips_image_new_from_file(enc.constData(), "access", VIPS_ACCESS_SEQUENTIAL, nullptr);
+        if (!thumb) {
+            return false;
+        }
+    } else {
+        const int targetW =
+            std::max(1, int(std::floor(std::sqrt(double(maxPixels) * double(sz.width()) / double(sz.height())))));
+        if (vips_thumbnail(enc.constData(), &thumb, targetW, nullptr) != 0) {
+            return false;
+        }
+    }
+
+    void* buf = nullptr;
+    size_t len = 0;
+    if (vips_pngsave_buffer(thumb, &buf, &len, "compression", 3, nullptr) != 0) {
+        g_object_unref(thumb);
+        return false;
+    }
+    g_object_unref(thumb);
+
+    const bool ok = out->loadFromData(static_cast<const uchar*>(buf), static_cast<int>(len), "PNG");
+    g_free(buf);
+    return ok && !out->isNull();
+}
+
+bool VipsBackend::loadRegionToQImage(const QString& sourcePath, const QRect& rectInSource, int maxOutputWidth,
+                                     int maxOutputHeight, QImage* out) {
+    if (!gReady || !out || maxOutputWidth < 32 || maxOutputHeight < 32) {
+        return false;
+    }
+    out->detach();
+    *out = QImage();
+
+    const QByteArray src = encodedPath(sourcePath);
+    if (src.isEmpty()) {
+        return false;
+    }
+
+    VipsImage* in = vips_image_new_from_file(src.constData(), "access", VIPS_ACCESS_RANDOM, nullptr);
+    if (!in) {
+        return false;
+    }
+
+    const int iw = vips_image_get_width(in);
+    const int ih = vips_image_get_height(in);
+    const QRect bounds(0, 0, iw, ih);
+    QRect r = rectInSource.normalized().intersected(bounds);
+    if (r.width() <= 0 || r.height() <= 0) {
+        g_object_unref(in);
+        return false;
+    }
+
+    VipsImage* cropped = nullptr;
+    if (vips_crop(in, &cropped, r.left(), r.top(), r.width(), r.height(), nullptr) != 0) {
+        g_object_unref(in);
+        return false;
+    }
+    g_object_unref(in);
+
+    const int cw = r.width();
+    const int ch = r.height();
+    VipsImage* toEncode = cropped;
+
+    // 视口解码：输出尺寸不应超过 maxOutput*，否则后续绘制阶段再缩小会引入明显的线性滤波“发糊”。
+    // 这里始终把区域降采样到不超过 maxOutput*（保持宽高比），让 vips 在解码阶段完成高质量缩放。
+    double scale = 1.0;
+    if (cw > maxOutputWidth || ch > maxOutputHeight) {
+        const double sx = static_cast<double>(maxOutputWidth) / static_cast<double>(cw);
+        const double sy = static_cast<double>(maxOutputHeight) / static_cast<double>(ch);
+        scale = std::min({sx, sy, 1.0});
+    }
+    if (scale < 0.9999) {
+        VipsImage* resized = nullptr;
+        if (vips_resize(cropped, &resized, scale, "kernel", VIPS_KERNEL_LANCZOS3, nullptr) != 0) {
+            g_object_unref(cropped);
+            return false;
+        }
+        g_object_unref(cropped);
+        toEncode = resized;
+    }
+
+    void* buf = nullptr;
+    size_t len = 0;
+    if (vips_pngsave_buffer(toEncode, &buf, &len, "compression", 3, nullptr) != 0) {
+        g_object_unref(toEncode);
+        return false;
+    }
+    g_object_unref(toEncode);
+
+    const bool ok = out->loadFromData(static_cast<const uchar*>(buf), static_cast<int>(len), "PNG");
+    g_free(buf);
+    return ok && !out->isNull();
+}
+
+bool VipsBackend::saveRectToPng(const QString& sourcePath, const QRect& rectInSource, const QString& destPngPath) {
+    if (!gReady) {
+        return false;
+    }
+    const QByteArray src = encodedPath(sourcePath);
+    if (src.isEmpty()) {
+        return false;
+    }
+
+    VipsImage* in = vips_image_new_from_file(src.constData(), "access", VIPS_ACCESS_RANDOM, nullptr);
+    if (!in) {
+        return false;
+    }
+
+    const int iw = vips_image_get_width(in);
+    const int ih = vips_image_get_height(in);
+    const QRect bounds(0, 0, iw, ih);
+    QRect r = rectInSource.normalized().intersected(bounds);
+    if (r.width() <= 0 || r.height() <= 0) {
+        g_object_unref(in);
+        return false;
+    }
+
+    VipsImage* toSave = in;
+    VipsImage* cropped = nullptr;
+    if (r != bounds) {
+        if (vips_crop(in, &cropped, r.left(), r.top(), r.width(), r.height(), nullptr) != 0) {
+            g_object_unref(in);
+            return false;
+        }
+        toSave = cropped;
+    }
+
+    const bool ok = saveVipsImageToPngFile(toSave, destPngPath);
+    if (cropped) {
+        g_object_unref(cropped);
+    }
+    g_object_unref(in);
+    return ok;
+}
+
+#else  // !LT_HAVE_VIPS
+
+bool VipsBackend::init(const char*) {
+    return false;
+}
+
+void VipsBackend::shutdown() {}
+
+bool VipsBackend::isAvailable() {
+    return false;
+}
+
+bool VipsBackend::probeSize(const QString&, QSize*) {
+    return false;
+}
+
+bool VipsBackend::loadThumbnailQImage(const QString&, qint64, QImage*) {
+    return false;
+}
+
+bool VipsBackend::saveRectToPng(const QString&, const QRect&, const QString&) {
+    return false;
+}
+
+bool VipsBackend::loadRegionToQImage(const QString&, const QRect&, int, int, QImage*) {
+    return false;
+}
+
+#endif  // LT_HAVE_VIPS
+
+}  // namespace core
@@ -0,0 +1,39 @@
+#pragma once
+
+#include <QtGlobal>
+
+#include <QImage>
+#include <QRect>
+#include <QString>
+
+namespace core {
+
+/// 基于 libvips 的大图 I/O：随机访问裁剪、流式写 PNG、缩略预览，避免整图进内存。
+/// 未编译 libvips 时 API 返回 false，由调用方回退到 Qt。
+class VipsBackend {
+public:
+    /// 须在 QApplication 创建后调用一次，argv0 建议为 argv[0]。
+    static bool init(const char* argv0);
+    static void shutdown();
+
+    static bool isAvailable();
+
+    /// 打开文件读取宽高（轻量，不解码全图）
+    static bool probeSize(const QString& path, QSize* out);
+
+    /// 生成预览图（总像素约不超过 maxPixels），用于裁剪对话框 / 画布
+    static bool loadThumbnailQImage(const QString& path, qint64 maxPixels, QImage* out);
+
+    /// 将原图中矩形区域（像素坐标，含边界）无损写入 PNG；区域为整图时直接流式转存。
+    /// 适合 GB 级 PNG，不构建整幅 QImage。
+    static bool saveRectToPng(const QString& sourcePath, const QRect& rectInSource, const QString& destPngPath);
+
+    /// 裁剪原图矩形区域；若超过 maxOutput* 则按比例缩小（不降采样整图，只处理该区域）。
+    static bool loadRegionToQImage(const QString& sourcePath, const QRect& rectInSource, int maxOutputWidth,
+                                   int maxOutputHeight, QImage* out);
+
+private:
+    VipsBackend() = default;
+};
+
+}  // namespace core