Mosaic cartograms

CMakeLists.txt

@@ -47,6 +47,7 @@ find_package(Qt5Widgets REQUIRED)
 set(CMAKE_AUTOMOC ON)
 find_package(glog REQUIRED)
 find_package(Ipelib REQUIRED)
+find_package(Eigen3 3.4 REQUIRED NO_MODULE)
 
 # ## SOURCES ###
 

README.md

@@ -7,7 +7,7 @@
 
 CartoCrow is a framework that simplifies the implementation of algorithms in cartographic visualization. It allows researchers to experiment with these algorithms and use them to generate maps. The framework behind CartoCrow can be used to run other cartography algorithms online. CartoCrow consists of a C++ library (this repository) which provides a set of command-line applications, and a web interface (see [cartocrow-web](https://github.com/tue-alga/cartocrow-web)) which allows end users to generate maps in a user-friendly way.
 
-> [!WARNING]  
+> [!WARNING]
 > CartoCrow is still a **work in progress**  and should not be considered stable yet.
 
 This repository consists of the following subdirectories:
@@ -115,7 +115,7 @@ The remaining dependencies need to be built manually.
     * in `src/ipelib/ipeplatform.cpp` and `src/ipelib/ipebitmap_win.cpp`, add an `#include <string>`;
     * in `src/ipelib/ipeplatform.cpp`, in `Platform::runLatex()`, replace `wcmd.data()` by `&wcmd[0]`;
     * in `src/ipelib/ipeplatform.cpp`, in `String::w()`, replace `result.data()` by `&result[0]`.
-  
+
   Then, to compile:
   ```sh
   cd src
@@ -135,6 +135,15 @@ On Ubuntu, most dependencies can be obtained from the repository:
 ```sh
 sudo apt install build-essential cmake
 sudo apt install libcgal-dev nlohmann-json3-dev qtbase5-dev
+sudo apt install libeigen3-dev
+```
+
+If Eigen [cannot be found](https://stackoverflow.com/q/23284473) during compilation, you might need to run:
+
+```sh
+cd /usr/include
+sudo ln -s eigen3/Eigen Eigen
+
 ```
 
 The remaining dependencies need to be built manually.

cartocrow/CMakeLists.txt

@@ -15,6 +15,7 @@ add_subdirectory(renderer)
 add_subdirectory(necklace_map)
 add_subdirectory(simplification)
 add_subdirectory(flow_map)
+add_subdirectory(mosaic_cartogram)
 add_subdirectory(isoline_simplification)
 
 add_library(cartocrow_lib INTERFACE)
@@ -25,14 +26,10 @@ target_link_libraries(
     necklace_map
     flow_map
     simplification
+    mosaic_cartogram
 )
 
-install(
-    TARGETS cartocrow_lib
-    EXPORT ${CARTOCROW_EXPORT_TARGETS}
-    LIBRARY DESTINATION ${CMAKE_INSTALL_LIBRARY_DIR}
-    INCLUDES DESTINATION ${CMAKE_INSTALL_SOURCE_DIR}
-)
+cartocrow_install_module(cartocrow_lib)
 install(
     EXPORT ${CARTOCROW_EXPORT_TARGETS}
     FILE "${CARTOCROW_EXPORT_TARGETS}.cmake"

cartocrow/core/CMakeLists.txt

@@ -1,5 +1,6 @@
 set(SOURCES
 	core.cpp
+	ellipse.cpp
 	ipe_reader.cpp
 	region_arrangement.cpp
 	region_map.cpp
@@ -9,6 +10,7 @@ set(SOURCES
 set(HEADERS
 	centroid.h
 	core.h
+	ellipse.h
 	ipe_reader.h
 	region_arrangement.h
 	region_map.h
@@ -18,7 +20,7 @@ set(HEADERS
 
 add_library(core ${SOURCES})
 target_link_libraries(core
-	PUBLIC Ipe::ipelib
+	PUBLIC Eigen3::Eigen Ipe::ipelib
 	PRIVATE glog::glog
 )
 

cartocrow/core/centroid.h

@@ -23,6 +23,7 @@ Created by tvl (t.vanlankveld@esciencecenter.nl) on 05-12-2019
 #define CARTOCROW_CORE_POLYGON_H
 
 #include "core.h"
+#include "region_arrangement.h"
 
 #include <CGAL/Kernel/global_functions_2.h>
 #include <CGAL/Origin.h>
@@ -89,6 +90,17 @@ template <class K> Point<K> centroid(const PolygonSet<K>& polygon) {
 	return CGAL::ORIGIN + sum / areaSum;
 }
 
+/// Computes the centroid of the given face.
+inline Point<Exact> centroid(RegionArrangement::Face_const_handle f) {
+	Polygon<Exact> polygon;
+	auto circ = f->outer_ccb();
+	auto curr = circ;
+	do {
+		polygon.push_back(curr->target()->point());
+	} while (++curr != circ);
+	return centroid(polygon);
+}
+
 } // namespace cartocrow
 
 #endif //CARTOCROW_CORE_POLYGON_H

cartocrow/core/core.cpp

@@ -20,10 +20,32 @@ Created by tvl (t.vanlankveld@esciencecenter.nl) on 05-12-2019
 */
 
 #include "core.h"
+#include <algorithm>
+#include <cmath>
 #include <CGAL/number_utils_classes.h>
 
 namespace cartocrow {
 
+Color Color::shaded(double f) const {
+	f = std::clamp(f, 0.0, 2.0);
+	if (f < 1) {
+		// darken (shade)
+		return {
+			(int) std::round(r * f),
+			(int) std::round(g * f),
+			(int) std::round(b * f)
+		};
+	} else {
+		// lighten (tint)
+		f -= 1;
+		return {
+			(int) std::round(r + (255 - r) * f),
+			(int) std::round(g + (255 - g) * f),
+			(int) std::round(b + (255 - b) * f),
+		};
+	}
+}
+
 Number<Inexact> wrapAngle(Number<Inexact> alpha, Number<Inexact> beta) {
 	return wrap<Inexact>(alpha, beta, beta + M_2xPI);
 }

cartocrow/core/core.h

@@ -162,6 +162,14 @@ Polyline<Inexact> approximate(const Polyline<K>& p) {
 	return result;
 }
 
+/// Returns the area of a polygon with holes.
+/// TODO: move to more logical place
+template <class K> Number<K> area(PolygonWithHoles<K> polygon) {
+	Number<K> a = polygon.outer_boundary().area();
+	for (const auto &h : polygon.holes()) a -= h.area();
+	return a;  // = outer area minus area of each hole
+}
+
 /// An RGB color. Used for storing the color of elements to be drawn.
 struct Color {
 	/// Red component (integer 0-255).
@@ -170,6 +178,10 @@ struct Color {
 	int g;
 	/// Blue component (integer 0-255).
 	int b;
+
+	/// Returns a new color that is darker (\f$0 \le f < 1\f$) or lighter
+	/// (\f$1 < f \le 2\f$).
+	Color shaded(double f) const;
 };
 
 /// Wraps the given number \f$n\f$ to the interval \f$[a, b)\f$.