From eaffd0b00551c7eb286d7d3dd12ada73bcbe095f Mon Sep 17 00:00:00 2001
From: tastytea <tastytea@tastytea.de>
Date: Wed, 26 Dec 2018 22:16:11 +0100
Subject: [PATCH] libravatar/sigil algorithm, first try

---
 example.cpp         | 28 ++++++++++++++--------------
 src/identiconpp.cpp |  8 ++++----
 src/identiconpp.hpp |  6 ++++++
 src/libravatar.cpp  | 21 ++++++++++++++++++++-
 src/simple.cpp      |  2 --
 5 files changed, 44 insertions(+), 21 deletions(-)

diff --git a/example.cpp b/example.cpp
index ad4ca50..3ca8e3f 100644
--- a/example.cpp
+++ b/example.cpp
@@ -34,20 +34,20 @@ int main(int argc, char *argv[])
         img.write("identicon_example_simple.png");
     }
 
-    // {
-    //     Identiconpp identicon(10, 10, Identiconpp::identicon_type::libravatar,
-    //         "ffffffff",
-    //         {
-    //             "000000ff",
-    //             "ff0000ff",
-    //             "ffff00ff",
-    //             "00ff00ff",
-    //             "00ffffff",
-    //             "0000ffff"
-    //         });
-    //     img = identicon.generate(digest, 500);
-    //     img.write("identicon_example_libravatar.png");
-    // }
+    {
+        Identiconpp identicon(5, 5, Identiconpp::identicon_type::libravatar,
+            "ffffffff",
+            {
+                "000000ff",
+                "ff0000ff",
+                "ffff00ff",
+                "00ff00ff",
+                "00ffffff",
+                "0000ffff"
+            });
+        img = identicon.generate("5a105e8b9d40e1329780d62ea2265d8a", 500);
+        img.write("identicon_example_libravatar.png");
+    }
 
     return 0;
 }
diff --git a/src/identiconpp.cpp b/src/identiconpp.cpp
index 5920546..dcf8219 100644
--- a/src/identiconpp.cpp
+++ b/src/identiconpp.cpp
@@ -101,12 +101,12 @@ Magick::Color Identiconpp::get_color(const uint16_t firstbit,
     // Get rid of excess bits
     bits = bits & (1 << colorbits) - 1;
 
-    if (bits > _foreground.size())
+    if (bits > (_foreground.size() - 1))
     {
-        bits -= _foreground.size();
+        bits -= (_foreground.size() - 1);
     }
 
     // Lookup und set color
-    ttdebug << "Color: #" << _foreground[bits - 1] << '\n';
-    return Magick::Color("#" + _foreground[bits - 1]);
+    ttdebug << "Color: #" << _foreground[bits] << '\n';
+    return Magick::Color("#" + _foreground[bits]);
 }
diff --git a/src/identiconpp.hpp b/src/identiconpp.hpp
index c972cba..b349e4c 100644
--- a/src/identiconpp.hpp
+++ b/src/identiconpp.hpp
@@ -83,6 +83,9 @@ private:
     /*!
      *  @brief  Generate simple identicon.
      *
+     *          Use bits 0 to (columns / 2 + columns % 2) * _rows, use the
+     *          following bits to determine foreground color.
+     *
      *  @param  digest  The pre-computed digest
      *  @param  width   The width of the image
      *  @param  height  The height of the image
@@ -96,6 +99,9 @@ private:
     /*!
      *  @brief  Generate libravatar-style / sigil identicon.
      *
+     *          Use bits 9 to (columns / 2 + columns % 2) * _rows, use the first
+     *          8 bits to determine foreground color.
+     *
      *  @param  digest  The pre-computed digest
      *  @param  width   The width of the image
      *  @param  height  The height of the image
diff --git a/src/libravatar.cpp b/src/libravatar.cpp
index 1e07911..95fbfec 100644
--- a/src/libravatar.cpp
+++ b/src/libravatar.cpp
@@ -21,8 +21,27 @@ Magick::Image Identiconpp::generate_libravatar(const string &digest,
                                                const uint16_t width,
                                                const uint16_t height)
 {
-    throw "Not implemented.";
+    // throw "Not implemented.";
     Magick::Image img(Magick::Geometry(_columns, _rows),
                       Magick::Color("#" + _background));
+    Magick::Color dotcolor = get_color(0, digest);
+
+    uint8_t used_columns = _columns / 2 + _columns % 2;
+    uint8_t cells = _rows * used_columns;
+    for (uint8_t cur_cell = 0; cur_cell < cells; ++cur_cell)
+    {
+        if (get_bit(8 + cur_cell, digest))
+        {
+            const uint8_t column = cur_cell / _columns;
+            const uint8_t row = cur_cell % _rows;
+            ttdebug << "col=" << std::to_string(column)
+                    << ", row=" << std::to_string(row) << '\n';
+            img.pixelColor(column, row, dotcolor);
+            img.pixelColor(_columns - column - 1, row, dotcolor);
+        }
+    }
+
+    img.scale(Magick::Geometry(width, height));
+    img.magick("png");
     return img;
 }
diff --git a/src/simple.cpp b/src/simple.cpp
index 98bcf26..5b7367a 100644
--- a/src/simple.cpp
+++ b/src/simple.cpp
@@ -34,8 +34,6 @@ Magick::Image Identiconpp::generate_simple(const string &digest,
             {
                 ttdebug << "col=" << std::to_string(column)
                         << ", row=" << std::to_string(row) << '\n';
-                ttdebug << "col=" << std::to_string(used_columns - 1 + column)
-                        << ", row=" << std::to_string(_rows - 1 - row) << '\n';
                 img.pixelColor(column, row, dotcolor);
                 img.pixelColor(_columns - 1 - column, row, dotcolor);
             }