Add ability to print your Tox ID's QR code to a file

src/qr_code.c

@@ -0,0 +1,103 @@
+/*  qr_obj_code.c
+ *
+ *
+ *  Copyright (C) 2015 Toxic All Rights Reserved.
+ *
+ *  This file is part of Toxic.
+ *
+ *  Toxic is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  Toxic is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with Toxic.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include <stdlib.h>
+#include <qrencode.h>
+#include <stdbool.h>
+
+#include "toxic.h"
+#include "windows.h"
+#include "qr_code.h"
+
+#define BORDER_CHAR "|"
+#define BORDER_LEN 1
+#define CHAR_1 "\342\226\210"
+#define CHAR_2 "\342\226\204"
+#define CHAR_3 "\342\226\200"
+
+static void add_border(FILE *fp, size_t width)
+{
+    size_t i, j;
+
+    for (i = 0; i < BORDER_LEN; i += 2) {
+        fprintf(fp, BORDER_CHAR);
+
+        for (j = 0; j < BORDER_LEN + width + BORDER_LEN; ++j)
+            fprintf(fp, "%s", CHAR_1);
+
+        fprintf(fp, "%s\n", BORDER_CHAR);
+    }
+}
+
+/* Converts a tox ID string into a QRcode and prints it to the given file stream.
+ *
+ * Returns 0 on success.
+ * Returns -1 on failure.
+ */
+int ID_to_QRcode(const char *tox_id, FILE *fp)
+{
+    if (fp == NULL)
+        return -1;
+
+    QRcode *qr_obj = QRcode_encodeString(tox_id, 0, QR_ECLEVEL_L, QR_MODE_8, 0);
+
+    if (qr_obj == NULL)
+        return -1;
+
+    size_t width = qr_obj->width;
+    add_border(fp, width);
+
+    size_t i, j;
+
+    for (i = 0; i < width; i += 2) {
+        const unsigned char *row_1 = qr_obj->data + width * i;
+        const unsigned char *row_2 = row_1 + width;
+
+        fprintf(fp, BORDER_CHAR);
+
+        for (j = 0; j < BORDER_LEN; ++j)
+            fprintf(fp, "%s", CHAR_1);
+
+        for (j = 0; j < width; ++j) {
+            bool x = row_1[j] & 1;
+            bool y = (i + 1) < width ? (row_2[j] & 1) : false;
+
+            if (x && y)
+                fprintf(fp, " ");
+            else if (x)
+                fprintf(fp, "%s", CHAR_2);
+            else if (y)
+                fprintf(fp, "%s", CHAR_3);
+            else
+                fprintf(fp, "%s", CHAR_1);
+        }
+
+        for (j = 0; j < BORDER_LEN; ++j)
+            fprintf(fp, "%s", CHAR_1);
+
+        fprintf(fp, "%s\n", BORDER_CHAR);
+    }
+
+    QRcode_free(qr_obj);
+
+    return 0;
+}