WIP: Add code to generalize data using different strategies

.github/actions/ubuntu-prerequisites/action.yml

@@ -16,10 +16,12 @@ runs:
     - name: Install software
       run: |
         sudo apt-get install -yq --no-install-suggests --no-install-recommends \
+          cimg-dev \
           libboost-filesystem-dev \
           libboost-system-dev \
           libbz2-dev \
           libexpat1-dev \
+          libpotrace-dev \
           libpq-dev \
           libproj-dev \
           pandoc \

.github/actions/win-install/action.yml

@@ -5,9 +5,8 @@ runs:
 
   steps:
     - name: Install packages
-      run: vcpkg install bzip2:x64-windows expat:x64-windows zlib:x64-windows proj4:x64-windows boost-geometry:x64-windows boost-system:x64-windows boost-filesystem:x64-windows boost-property-tree:x64-windows lua:x64-windows libpq:x64-windows
+      run: vcpkg install cimg:x64-windows bzip2:x64-windows expat:x64-windows zlib:x64-windows proj4:x64-windows boost-geometry:x64-windows boost-system:x64-windows boost-filesystem:x64-windows boost-property-tree:x64-windows lua:x64-windows libpq:x64-windows
       shell: bash
-
     - name: Install psycopg2 and beahve
       run: python -m pip install psycopg2 behave
       shell: bash

.github/workflows/ci.yml

@@ -14,7 +14,7 @@ jobs:
 
       - name: Install prerequisites
         run: |
-          brew install lua boost postgis pandoc
+          brew install lua boost postgis pandoc cimg potrace
           pip3 install psycopg2 behave
           pg_ctl -D /usr/local/var/postgres init
           pg_ctl -D /usr/local/var/postgres start
@@ -45,6 +45,7 @@ jobs:
     env:
       CC: gcc-10
       CXX: g++-10
+      EXTRA_FLAGS: -Wno-unused-but-set-parameter # workaround for GCC bug
       LUA_VERSION: 5.3
       LUAJIT_OPTION: ON
       POSTGRESQL_VERSION: 9.6
@@ -79,6 +80,7 @@ jobs:
     env:
       CC: gcc-10
       CXX: g++-10
+      EXTRA_FLAGS: -Wno-unused-but-set-parameter # workaround for GCC bug
       LUA_VERSION: 5.3
       LUAJIT_OPTION: OFF
       POSTGRESQL_VERSION: 10

.github/workflows/test-install.yml

@@ -37,12 +37,14 @@ jobs:
         run: |
           sudo apt-get purge -yq postgresql*
           sudo apt-get install -yq --no-install-suggests --no-install-recommends \
+            cimg-dev \
             libboost-filesystem-dev \
             libboost-system-dev \
             libbz2-dev \
             libexpat1-dev \
             liblua${LUA_VERSION}-dev \
             libluajit-5.1-dev \
+            libpotrace-dev \
             libpq-dev \
             libproj-dev \
             lua${LUA_VERSION} \

CMakeLists.txt

@@ -205,6 +205,11 @@ include_directories(SYSTEM ${PostgreSQL_INCLUDE_DIRS})
 
 find_package(Threads)
 
+find_path(POTRACE_INCLUDE_DIR potracelib.h)
+find_library(POTRACE_LIBRARY NAMES potrace)
+
+find_path(CIMG_INCLUDE_DIR CImg.h)
+
 ############### Libraries are found now ########################
 
 set(LIBS ${Boost_LIBRARIES} ${PostgreSQL_LIBRARY} ${OSMIUM_LIBRARIES})
@@ -276,6 +281,32 @@ add_subdirectory(src)
 add_executable(osm2pgsql src/osm2pgsql.cpp)
 target_link_libraries(osm2pgsql osm2pgsql_lib ${LIBS})
 
+if (${POTRACE_LIBRARY} STREQUAL "POTRACE_LIBRARY-NOTFOUND" OR ${CIMG_INCLUDE_DIR} STREQUAL "CIMG_INCLUDE_DIR-NOTFOUND")
+    message(STATUS "Did not find cimg and/or potrace library. Not building osm2pgsql-gen.")
+else()
+    if (WITH_LUA)
+        message(STATUS "Found cimg and potrace library. Building osm2pgsql-gen.")
+        include_directories(SYSTEM ${CIMG_INCLUDE_DIR})
+        include_directories(SYSTEM ${POTRACE_INCLUDE_DIR})
+        add_executable(osm2pgsql-gen src/gen/osm2pgsql-gen.cpp
+                    src/gen/canvas.cpp
+                    src/gen/gen-base.cpp
+                    src/gen/gen-create.cpp
+                    src/gen/gen-discrete-isolation.cpp
+                    src/gen/gen-rivers.cpp
+                    src/gen/gen-tile-builtup.cpp
+                    src/gen/gen-tile-raster.cpp
+                    src/gen/gen-tile-vector.cpp
+                    src/gen/gen-tile.cpp
+                    src/gen/params.cpp
+                    src/gen/raster.cpp
+                    src/gen/tracer.cpp)
+        target_link_libraries(osm2pgsql-gen osm2pgsql_lib ${LIBS} ${POTRACE_LIBRARY})
+    else()
+        message(STATUS "No Lua. Not building osm2pgsql-gen.")
+    endif()
+endif()
+
 #############################################################
 # Optional "clang-tidy" target
 #############################################################
@@ -287,7 +318,7 @@ find_program(CLANG_TIDY
 if (CLANG_TIDY)
     message(STATUS "Looking for clang-tidy - found ${CLANG_TIDY}")
 
-    file(GLOB CT_CHECK_FILES src/*.cpp tests/*cpp)
+    file(GLOB CT_CHECK_FILES src/*.cpp src/*/*.cpp tests/*cpp)
 
     add_custom_target(clang-tidy
         ${CLANG_TIDY}

README.md

@@ -49,6 +49,8 @@ Required libraries are
 * [zlib](https://www.zlib.net/)
 * [Boost libraries](https://www.boost.org/), including geometry, system and
   filesystem
+* [CImg](https://cimg.eu/) (Optional, see README-gen.md)
+* [potrace](https://potrace.sourceforge.net/) (Optional, see README-gen.md)
 * [PostgreSQL](https://www.postgresql.org/) client libraries
 * [Lua](https://www.lua.org/) (Optional, used for Lua tag transforms
   and the flex output)
@@ -80,14 +82,15 @@ On a Debian or Ubuntu system, this can be done with:
 
 ```sh
 sudo apt-get install make cmake g++ libboost-dev libboost-system-dev \
-  libboost-filesystem-dev libexpat1-dev zlib1g-dev \
+  libboost-filesystem-dev libexpat1-dev zlib1g-dev libpotrace-dev cimg-dev \
   libbz2-dev libpq-dev libproj-dev lua5.3 liblua5.3-dev pandoc
 ```
 
 On a Fedora system, use
 
 ```sh
 sudo dnf install cmake make gcc-c++ boost-devel expat-devel zlib-devel \
+  potrace-devel cimg-devel \
   bzip2-devel postgresql-devel proj-devel proj-epsg lua-devel pandoc
 ```
 

src/gen/canvas.cpp

@@ -0,0 +1,130 @@
+/**
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ *
+ * This file is part of osm2pgsql (https://osm2pgsql.org/).
+ *
+ * Copyright (C) 2006-2023 by the osm2pgsql developer community.
+ * For a full list of authors see the git log.
+ */
+
+#include "canvas.hpp"
+#include "raster.hpp"
+
+cimg_library::CImg<int> canvas_t::create_pointlist(geom::point_list_t const &pl,
+                                                   tile_t const &tile) const
+{
+    cimg_library::CImg<int> points{static_cast<unsigned int>(pl.size()), 2};
+
+    int n = 0;
+    for (auto const point : pl) {
+        auto const tp = tile.to_tile_coords(point, m_extent);
+        points(n, 0) = static_cast<int>(static_cast<double>(m_buffer) + tp.x());
+        points(n, 1) =
+            static_cast<int>(static_cast<double>(m_buffer + m_extent) - tp.y());
+        ++n;
+    }
+
+    return points;
+}
+
+std::size_t canvas_t::draw_polygon(geom::polygon_t const &polygon,
+                                   tile_t const &tile)
+{
+    if (polygon.inners().empty()) {
+        m_rast.draw_polygon(create_pointlist(polygon.outer(), tile), &White);
+        return polygon.outer().size();
+    }
+
+    std::size_t num_points = polygon.outer().size();
+    m_temp.draw_polygon(create_pointlist(polygon.outer(), tile), &White);
+    for (auto const &inner : polygon.inners()) {
+        num_points += inner.size();
+        m_temp.draw_polygon(create_pointlist(inner, tile), &Black);
+    }
+    m_rast |= m_temp;
+
+    return num_points;
+}
+
+std::size_t canvas_t::draw_linestring(geom::linestring_t const &linestring,
+                                      tile_t const &tile)
+{
+    m_rast.draw_line(create_pointlist(linestring, tile), &White);
+    return linestring.size();
+}
+
+std::size_t canvas_t::draw(geom::geometry_t const &geometry, tile_t const &tile)
+{
+    if (geometry.is_linestring()) {
+        auto const &linestring = geometry.get<geom::linestring_t>();
+        return draw_linestring(linestring, tile);
+    }
+
+    if (geometry.is_polygon()) {
+        auto const &polygon = geometry.get<geom::polygon_t>();
+        return draw_polygon(polygon, tile);
+    }
+
+    if (geometry.is_multipolygon()) {
+        auto const &mp = geometry.get<geom::multipolygon_t>();
+        std::size_t num_points = 0;
+        for (auto const &p : mp) {
+            num_points += draw_polygon(p, tile);
+        }
+        return num_points;
+    }
+
+    // XXX other geometry types?
+
+    return 0;
+}
+
+void canvas_t::save(std::string const &filename) const
+{
+    m_rast.save(filename.c_str());
+}
+
+std::string canvas_t::to_wkb(tile_t const &tile, double margin) const
+{
+    std::string wkb;
+    wkb.reserve(61 + 2 + m_rast.size());
+
+    // header
+    wkb_raster_header header{};
+    header.nBands = 1;
+    header.scaleX = tile.extent() / static_cast<double>(m_extent);
+    header.scaleY = -header.scaleX;
+    header.ipX = tile.xmin(margin);
+    header.ipY = tile.ymax(margin);
+    header.width = m_extent + 2 * m_buffer;
+    header.height = header.width;
+    add_raster_header(&wkb, header);
+
+    // band
+    wkb_raster_band band{};
+    band.bits = 4;
+    add_raster_band(&wkb, band);
+
+    // rasterdata
+    wkb.append(reinterpret_cast<char const *>(m_rast.data()), m_rast.size());
+
+    assert(wkb.size() == 61 + 2 + m_rast.size());
+
+    return wkb;
+}
+
+void canvas_t::merge(canvas_t const &other) { m_rast |= other.m_rast; }
+
+std::string to_hex(std::string const &in)
+{
+    std::string result;
+    char const *const lookup_hex = "0123456789ABCDEF";
+
+    for (const auto c : in) {
+        unsigned int const num = static_cast<unsigned char>(c);
+        result += lookup_hex[(num >> 4U) & 0xfU];
+        result += lookup_hex[num & 0xfU];
+    }
+
+    return result;
+}

src/gen/canvas.hpp

@@ -0,0 +1,88 @@
+#ifndef OSM2PGSQL_CANVAS_HPP
+#define OSM2PGSQL_CANVAS_HPP
+
+/**
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ *
+ * This file is part of osm2pgsql (https://osm2pgsql.org/).
+ *
+ * Copyright (C) 2006-2023 by the osm2pgsql developer community.
+ * For a full list of authors see the git log.
+ */
+
+#include "geom.hpp"
+#include "tile.hpp"
+
+#define cimg_display 0 // NOLINT(cppcoreguidelines-macro-usage)
+#include "CImg.h"
+
+#include <cstddef>
+
+/**
+ * This class wraps the image class from the CImg library.
+ */
+class canvas_t
+{
+public:
+    static void info() { cimg_library::cimg::info(); }
+
+    /**
+     * Create a new image canvas. It will be quadratic and have the width and
+     * height extent + 2*buffer.
+     */
+    canvas_t(std::size_t extent, std::size_t buffer)
+    : m_extent(extent),
+      m_buffer(buffer), m_rast{size(), size(), 1, 1, 0}, m_temp{size(), size(),
+                                                                1, 1, 0}
+    {}
+
+    unsigned int size() const noexcept
+    {
+        return static_cast<unsigned int>(m_extent + 2 * m_buffer);
+    }
+
+    unsigned char const *begin() const noexcept { return m_rast.begin(); }
+    unsigned char const *end() const noexcept { return m_rast.end(); }
+
+    std::size_t draw(geom::geometry_t const &geometry, tile_t const &tile);
+
+    unsigned char operator()(int x, int y) const noexcept
+    {
+        return m_rast(x, y, 0, 0);
+    }
+
+    void open_close(unsigned int buffer_size)
+    {
+        m_rast.dilate(buffer_size).erode(buffer_size * 2).dilate(buffer_size);
+    }
+
+    void save(std::string const &filename) const;
+
+    std::string to_wkb(tile_t const &tile, double margin) const;
+
+    void merge(canvas_t const &other);
+
+private:
+    constexpr static unsigned char const Black = 0;
+    constexpr static unsigned char const White = 255;
+
+    using image_type = cimg_library::CImg<unsigned char>;
+
+    cimg_library::CImg<int> create_pointlist(geom::point_list_t const &pl,
+                                             tile_t const &tile) const;
+
+    std::size_t draw_polygon(geom::polygon_t const &polygon,
+                             tile_t const &tile);
+
+    std::size_t draw_linestring(geom::linestring_t const &linestring,
+                                tile_t const &tile);
+
+    std::size_t m_extent;
+    std::size_t m_buffer;
+    image_type m_rast;
+    image_type m_temp;
+}; // class canvas_t
+
+std::string to_hex(std::string const &in);
+
+#endif // OSM2PGSQL_CANVAS_HPP