Show stickers or sticker thumbnails as inline images

client-utils.cpp

@@ -8,6 +8,7 @@
 
 #include "buildopt.h"
 #ifndef NoWebp
+#include <png.h>
 #include <webp/decode.h>
 #endif
 
@@ -868,26 +869,168 @@ std::string makeNoticeWithSender(const td::td_api::chat &chat, const TgMessageIn
     return prefix + noticeText;
 }
 
-void showGenericFile(int64_t chatId, const TgMessageInfo &message,
-                    const std::string &filePath, const std::string &fileDescription,
-                    TdAccountData &account)
+void showGenericFile(const td::td_api::chat &chat, const TgMessageInfo &message,
+                     const std::string &filePath, const std::string &fileDescription,
+                     TdAccountData &account)
 {
-    const td::td_api::chat *chat = account.getChat(chatId);
-    if (chat) {
-        if (filePath.find('"') != std::string::npos) {
-            std::string notice = makeNoticeWithSender(*chat, message, "Cannot show file: path contains quotes",
-                                                      account.purpleAccount);
-            showMessageText(account, *chat, message, NULL, notice.c_str());
-        } else {
-            std::string text = "<a href=\"file://" + filePath + "\">" + fileDescription + "</a>";
-            showMessageText(account, *chat, message, text.c_str(), NULL);
-        }
+    if (filePath.find('"') != std::string::npos) {
+        std::string notice = makeNoticeWithSender(chat, message, "Cannot show file: path contains quotes",
+                                                    account.purpleAccount);
+        showMessageText(account, chat, message, NULL, notice.c_str());
+    } else {
+        std::string text = "<a href=\"file://" + filePath + "\">" + fileDescription + "</a>";
+        showMessageText(account, chat, message, text.c_str(), NULL);
     }
 }
 
-void showWebpSticker(int64_t chatId, const TgMessageInfo &message,
-                     const std::string &filePath, const std::string &fileDescription,
-                     TdAccountData account)
+#ifndef NoWebp
+
+static void p2tgl_png_mem_write (png_structp png_ptr, png_bytep data, png_size_t length)
 {
-    showGenericFile(chatId, message, filePath, fileDescription, account);
+    GByteArray *png_mem = (GByteArray *) png_get_io_ptr(png_ptr);
+    g_byte_array_append (png_mem, data, length);
+}
+
+int p2tgl_imgstore_add_with_id_png (const unsigned char *raw_bitmap, unsigned width, unsigned height)
+{
+    GByteArray *png_mem = NULL;
+    png_structp png_ptr = NULL;
+    png_infop info_ptr = NULL;
+    png_bytepp rows = NULL;
+
+    // init png write struct
+    png_ptr = png_create_write_struct (PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
+    if (png_ptr == NULL) {
+        purple_debug_misc(config::pluginId, "error encoding png (create_write_struct failed)\n");
+        return 0;
+    }
+
+    // init png info struct
+    info_ptr = png_create_info_struct (png_ptr);
+    if (info_ptr == NULL) {
+        png_destroy_write_struct(&png_ptr, NULL);
+        purple_debug_misc(config::pluginId, "error encoding png (create_info_struct failed)\n");
+        return 0;
+    }
+
+    // Set up error handling.
+    if (setjmp(png_jmpbuf(png_ptr))) {
+        png_destroy_write_struct(&png_ptr, &info_ptr);
+        purple_debug_misc(config::pluginId, "error while writing png\n");
+        return 0;
+    }
+
+    // set img attributes
+    png_set_IHDR (png_ptr, info_ptr, width, height,
+                    8, PNG_COLOR_TYPE_RGBA, PNG_INTERLACE_NONE,
+                    PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
+
+    // alloc row pointers
+    rows = g_new0 (png_bytep, height);
+    if (rows == NULL) {
+        png_destroy_write_struct(&png_ptr, &info_ptr);
+        purple_debug_misc(config::pluginId, "error converting to png: malloc failed\n");
+        return 0;
+    }
+
+    unsigned i;
+    for (i = 0; i < height; i++)
+        rows[i] = (png_bytep)(raw_bitmap + i * width * 4);
+
+    // create array and set own png write function
+    png_mem = g_byte_array_new();
+    png_set_write_fn (png_ptr, png_mem, p2tgl_png_mem_write, NULL);
+
+    // write png
+    png_set_rows (png_ptr, info_ptr, rows);
+    png_write_png (png_ptr, info_ptr, PNG_TRANSFORM_IDENTITY, NULL);
+
+    // cleanup
+    g_free(rows);
+    png_destroy_write_struct (&png_ptr, &info_ptr);
+    unsigned png_size = png_mem->len;
+    gpointer png_data = g_byte_array_free (png_mem, FALSE);
+
+    return purple_imgstore_add_with_id (png_data, png_size, NULL);
+}
+
+int p2tgl_imgstore_add_with_id_webp (const char *filename)
+{
+    constexpr int MAX_W = 256;
+    constexpr int MAX_H = 256;
+
+    const uint8_t *data = NULL;
+    size_t len;
+    GError *err = NULL;
+    g_file_get_contents (filename, (gchar **) &data, &len, &err);
+    if (err) {
+        purple_debug_misc(config::pluginId, "cannot open file %s: %s\n", filename, err->message);
+        g_error_free(err);
+        return 0;
+    }
+
+    // downscale oversized sticker images displayed in chat, otherwise it would harm readabillity
+    WebPDecoderConfig config;
+    WebPInitDecoderConfig (&config);
+    if (WebPGetFeatures(data, len, &config.input) != VP8_STATUS_OK) {
+        purple_debug_misc(config::pluginId, "error reading webp bitstream: %s\n", filename);
+        g_free ((gchar *)data);
+        return 0;
+    }
+
+    config.options.use_scaling = 0;
+    config.options.scaled_width = config.input.width;
+    config.options.scaled_height = config.input.height;
+    if (config.options.scaled_width > MAX_W || config.options.scaled_height > MAX_H) {
+        const float max_scale_width = MAX_W * 1.0f / config.options.scaled_width;
+        const float max_scale_height = MAX_H * 1.0f / config.options.scaled_height;
+        if (max_scale_width < max_scale_height) {
+        // => the width is most limiting
+        config.options.scaled_width = MAX_W;
+        // Can't use ' *= ', because we need to do the multiplication in float
+        // (or double), and only THEN cast back to int.
+        config.options.scaled_height = (int) (config.options.scaled_height * max_scale_width);
+        } else {
+        // => the height is most limiting
+        config.options.scaled_height = MAX_H;
+        // Can't use ' *= ', because we need to do the multiplication in float
+        // (or double), and only THEN cast back to int.
+        config.options.scaled_width = (int) (config.options.scaled_width * max_scale_height);
+        }
+        config.options.use_scaling = 1;
+    }
+    config.output.colorspace = MODE_RGBA;
+    if (WebPDecode(data, len, &config) != VP8_STATUS_OK) {
+        purple_debug_misc(config::pluginId, "error decoding webp: %s\n", filename);
+        g_free ((gchar *)data);
+        return 0;
+    }
+    g_free ((gchar *)data);
+    const uint8_t *decoded = config.output.u.RGBA.rgba;
+
+    // convert and add
+    int imgStoreId = p2tgl_imgstore_add_with_id_png(decoded, config.options.scaled_width, config.options.scaled_height);
+    WebPFreeDecBuffer (&config.output);
+    return imgStoreId;
+}
+
+#else
+
+int p2tgl_imgstore_add_with_id_webp (const char *filename)
+{
+    return 0;
+}
+
+#endif
+
+void showWebpSticker(const td::td_api::chat &chat, const TgMessageInfo &message,
+                     const std::string &filePath, const std::string &fileDescription,
+                     TdAccountData &account)
+{
+    int id = p2tgl_imgstore_add_with_id_webp(filePath.c_str());
+    if (id != 0) {
+        std::string text = "\n<img id=\"" + std::to_string(id) + "\">";
+        showMessageText(account, chat, message, text.c_str(), NULL);
+    } else
+        showGenericFile(chat, message, filePath, fileDescription, account);
 }