type PointPair fixes + minor

Author: skramm

README.md

@@ -46,7 +46,7 @@ Try the above snippet
 [online here](https://godbolt.org/z/d9oqYs34f),
 or on your own Debian-style Linux box:
 ```
-$ sudo apt install build-essentials
+$ sudo apt install build-essential
 $ wget https://raw.githubusercontent.com/skramm/homog2d/master/homog2d.hpp
 $ wget https://raw.githubusercontent.com/skramm/homog2d/master/misc/tryme.cpp
 $ g++ tryme.cpp

docs/homog2d_qa.md

@@ -29,7 +29,7 @@ It can be used to statically make sure that a call to a function meets some requ
 so it can be used to get the nature of an object, either with the free function
 (`auto t = type(obj);`)
 or with the corresponding member function.
-(`auto t = obj.type();`).  
+(`auto t = obj.type();`).
 You can get is as text with the free function `getString(Type)`.
 * `Dtype` is an enum that is used to identify the numerical datatype of an object,
 [see manual here](homog2d_manual.md#numtype).
@@ -114,7 +114,6 @@ Thus, the need for the class `rtp::Root`
 </dd>
 
 
-
 <dt>
 Q: `Circle_::center()` and `FRect_::getCenter()`?
 Why not the same identifier?
@@ -126,7 +125,16 @@ Thus, the intent is clearer.
 </dd>
 
 
-
+<dt>
+Q: What is the difference between types `PointPair` and `Segment`?
+Don't these two types just hold two points?
+</dt>
+<dd>
+A: They both indeed hold two points, but they dont have the same semantic.
+The latter represents a real geometrical object, thus cannot have a null length
+(two identical points).
+The first one just hold two arbitrary points.
+</dd>
 
 
 <dt>

homog2d.hpp

@@ -384,11 +384,11 @@ using Segment_ = base::SegVec<typ::IsSegment,T>;
 template<typename T>
 using OSegment_  = base::SegVec<typ::IsOSeg,T>;
 
-/// \todo 20250127: remove the first one and replace with `PointPair_`
-template<typename T>
-using PointPair1_ = std::pair<Point2d_<T>,Point2d_<T>>;
+
 template<typename T1,typename T2>
 using PointPair2_ = std::pair<Point2d_<T1>,Point2d_<T2>>;
+template<typename T>
+using PointPair_  = std::pair<Point2d_<T>,Point2d_<T>>;
 
 template<typename T>
 using CPolyline_ = base::PolylineBase<typ::IsClosed,T>;
@@ -1281,7 +1281,7 @@ shareCommonCoord( const std::pair<Point2d_<FPT1>,Point2d_<FPT2>>& ppts )
 /// Private free function, get top-left and bottom-right points from two arbitrary points
 /** Throws if one of the coordinates is equal to the other (x1=x2 or y1=y2)*/
 template<typename FPT>
-PointPair1_<FPT>
+PointPair_<FPT>
 getCorrectPoints( const Point2d_<FPT>& p0, const Point2d_<FPT>& p1 )
 {
 #ifndef HOMOG2D_NOCHECKS
@@ -2487,7 +2487,7 @@ class Intersect<Inters_2,FPT>: public IntersectCommon
 		}
 		size_t size() const { return _doesIntersect?2:0; }
 
-		PointPair1_<FPT>
+		PointPair_<FPT>
 		get() const
 		{
 			if( !_doesIntersect )
@@ -2629,7 +2629,7 @@ class FRect_: public detail::Common<FPT>
 
 /// Constructor from pair of points
 	template<typename FPT2>
-	FRect_( const PointPair1_<FPT2>& ppts )
+	FRect_( const PointPair_<FPT2>& ppts )
 	{
 		set( ppts.first, ppts.second );
 	}
@@ -2730,7 +2730,7 @@ class FRect_: public detail::Common<FPT>
 
 /// Returns the 2 major points of the rectangle
 /// \sa getPts( const FRect_<FPT>& )
-	PointPair1_<FPT>
+	PointPair_<FPT>
 	getPts() const
 	{
 		return std::make_pair( _ptR1, _ptR2 );
@@ -3445,7 +3445,7 @@ Use of Sfinae so it can be selected only for arithmetic types
 
 private:
 	template<typename FPT2>
-	bool implC_isInside( const PointPair1_<FPT2>& ppts ) const
+	bool implC_isInside( const PointPair_<FPT2>& ppts ) const
 	{
 		const auto& p1 = ppts.first;
 		const auto& p2 = ppts.second;
@@ -4098,15 +4098,15 @@ Thus, we need the second one.
 
 	/// Returns a pair of points that are lying on line at distance \c dist from a point defined by one of its coordinates.
 	template<typename FPT2>
-	PointPair1_<FPT>
+	PointPair_<FPT>
 	getPoints( GivenCoord gc, FPT coord, FPT2 dist ) const
 	{
 		return impl_getPoints_A( gc, coord, dist, detail::BaseHelper<LP>() );
 	}
 
 	/// Returns a pair of points that are lying on line at distance \c dist from point \c pt, assuming that one is lying on the line.
 	template<typename FPT2>
-	PointPair1_<FPT>
+	PointPair_<FPT>
 	getPoints( const Point2d_<FPT>& pt, FPT2 dist ) const
 	{
 		return impl_getPoints_B( pt, dist, detail::BaseHelper<LP>() );
@@ -4384,13 +4384,13 @@ Please check out warning described in impl_getAngle()
 	constexpr Point2d_<FPT> impl_getPoint( GivenCoord gc, FPT other, const detail::BaseHelper<typename typ::IsPoint>& ) const;
 
 	template<typename FPT2>
-	PointPair2_<FPT,FPT>           impl_getPoints_A( GivenCoord, FPT, FPT2, const detail::BaseHelper<typename typ::IsLine>& ) const;
+	PointPair_<FPT>           impl_getPoints_A( GivenCoord, FPT, FPT2, const detail::BaseHelper<typename typ::IsLine>& ) const;
 	template<typename FPT2>
-	constexpr PointPair2_<FPT,FPT> impl_getPoints_A( GivenCoord, FPT, FPT2, const detail::BaseHelper<typename typ::IsPoint>& ) const;
+	constexpr PointPair_<FPT> impl_getPoints_A( GivenCoord, FPT, FPT2, const detail::BaseHelper<typename typ::IsPoint>& ) const;
 	template<typename FPT2>
-	PointPair2_<FPT,FPT>           impl_getPoints_B( const Point2d_<FPT>&, FPT2, const detail::BaseHelper<typename typ::IsLine>& ) const;
+	PointPair_<FPT>           impl_getPoints_B( const Point2d_<FPT>&, FPT2, const detail::BaseHelper<typename typ::IsLine>& ) const;
 	template<typename FPT2>
-	constexpr PointPair2_<FPT,FPT> impl_getPoints_B( const Point2d_<FPT>&, FPT2, const detail::BaseHelper<typename typ::IsPoint>& ) const;
+	constexpr PointPair_<FPT> impl_getPoints_B( const Point2d_<FPT>&, FPT2, const detail::BaseHelper<typename typ::IsPoint>& ) const;
 
 	void impl_op_stream( std::ostream&, const Point2d_<FPT>& ) const;
 	void impl_op_stream( std::ostream&, const Line2d_<FPT>&  ) const;
@@ -5270,7 +5270,7 @@ Requires both points inside AND no intersections
 If x-coordinate are equal, then
 the one with smallest y-coordinate will be returned first
 */
-	PointPair1_<FPT>
+	PointPair_<FPT>
 	getPts() const
 	{
 		return std::make_pair( _ptS1, _ptS2 );
@@ -5879,7 +5879,7 @@ template<
 		T
 	>::type* = nullptr
 >
-PointPair1_<typename T::value_type::FType>
+PointPair_<typename T::value_type::FType>
 getBB_Points( const T& vpts )
 {
 	HOMOG2D_START;
@@ -8843,14 +8843,14 @@ LPBase<LP,FPT>::impl_getPoint( GivenCoord gc, FPT other, const detail::BaseHelpe
 /// ILLEGAL INSTANCIATION
 template<typename LP,typename FPT>
 template<typename FPT2>
-constexpr PointPair1_<FPT>
+constexpr PointPair_<FPT>
 LPBase<LP,FPT>::impl_getPoints_A( GivenCoord, FPT, FPT2, const detail::BaseHelper<typename typ::IsPoint>& ) const
 {
 	static_assert( detail::AlwaysFalse<LP>::value, "Invalid: you cannot call getPoints() on a point" );
 }
 template<typename LP,typename FPT>
 template<typename FPT2>
-constexpr PointPair1_<FPT>
+constexpr PointPair_<FPT>
 LPBase<LP,FPT>::impl_getPoints_B( const Point2d_<FPT>&, FPT2, const detail::BaseHelper<typename typ::IsPoint>& ) const
 {
 	static_assert( detail::AlwaysFalse<LP>::value, "Invalid: you cannot call getPoints() on a point" );
@@ -8859,7 +8859,7 @@ LPBase<LP,FPT>::impl_getPoints_B( const Point2d_<FPT>&, FPT2, const detail::Base
 /// Returns pair of points on line at distance \c dist from point on line at coord \c coord. Implementation for lines
 template<typename LP,typename FPT>
 template<typename FPT2>
-PointPair2_<FPT,FPT>
+PointPair_<FPT>
 LPBase<LP,FPT>::impl_getPoints_A( GivenCoord gc, FPT coord, FPT2 dist, const detail::BaseHelper<typename typ::IsLine>& ) const
 {
 	const auto pt = impl_getPoint( gc, coord, detail::BaseHelper<typ::IsLine>() );
@@ -8869,7 +8869,7 @@ LPBase<LP,FPT>::impl_getPoints_A( GivenCoord gc, FPT coord, FPT2 dist, const det
 /// Returns pair of points on line at distance \c dist from point on line at coord \c coord. Implementation for lines
 template<typename LP,typename FPT>
 template<typename FPT2>
-PointPair2_<FPT,FPT>
+PointPair_<FPT>
 LPBase<LP,FPT>::impl_getPoints_B( const Point2d_<FPT>& pt, FPT2 dist, const detail::BaseHelper<typename typ::IsLine>& ) const
 {
 #ifndef HOMOG2D_NOCHECKS
@@ -10135,7 +10135,7 @@ getPointPair( const T& elem )
 
 /// Needed because of variant
 template<typename FPT>
-PointPair2_<FPT,FPT>
+PointPair_<FPT>
 getPointPair( const Line2d_<FPT>& )
 {
 	HOMOG2D_START;
@@ -10160,7 +10160,7 @@ namespace fct {
 struct PtPairFunct
 {
 	template<typename T>
-	PointPair1_<typename T::FType>
+	PointPair_<typename T::FType>
 	operator ()(const T& a)
 	{
 		return ppair::getPointPair(a);
@@ -10285,7 +10285,7 @@ getBB_CommonType( const std::vector<CommonType_<FPT>>& v_var )
 
 	std::vector<Point2d_<FPT>> vpts;
 	vpts.reserve( v_var.size()*2 );
-	PointPair2_<FPT,FPT> ppair;
+	PointPair_<FPT> ppair;
 	for( const auto& elem: v_var )
 	{
 		try
@@ -10594,7 +10594,7 @@ class ClosestPoints
 	}
 
 public:
-	PointPair1_<HOMOG2D_INUMTYPE>
+	PointPair_<HOMOG2D_INUMTYPE>
 	getPoints() const
 	{
 		return std::make_pair(
@@ -11822,7 +11822,7 @@ Used both in the SVG and the Opencv backends
 namespace priv {
 
 template<typename FPT>
-std::array<PointPair1_<double>,3>
+std::array<PointPair_<double>,3>
 getArrowSegments(
 	const base::SegVec<typ::IsOSeg,FPT>& vec
 )
@@ -12419,6 +12419,11 @@ using OPolylineF = OPolyline_<float>;
 using OPolylineD = OPolyline_<double>;
 using OPolylineL = OPolyline_<long double>;
 
+using PointPairF = PointPair_<float>;
+using PointPairD = PointPair_<double>;
+using PointPairL = PointPair_<long double>;
+using PointPair  = PointPair_<double>;
+
 #ifdef HOMOG2D_ENABLE_VRTP
 // variant type
 using CommonType  = CommonType_<HOMOG2D_INUMTYPE>;

misc/demo_opencv.cpp

@@ -1729,8 +1729,6 @@ void demo_orthSeg( int demidx )
 }
 
 //------------------------------------------------------------------
-using PointPair = PointPair2_<double,double>;
-
 /// Parameters for points Bounding Box demo
 struct Param_BB : Data
 {

misc/test_files/demo_svg_import.cpp

@@ -25,9 +25,6 @@ or
 `$ BUILD/demo_svg_import misc/test_files/France_Normandie.svg`
 
 This will generate a svg file in current folder that is a copy of what was read in the file.
-
-\todo 20240326: once we have a function able to get the min/max points of a container holding
-primitives (see \c getBB()), automatically adjust the size of output image.
 */
 
 //#define HOMOG2D_DEBUGMODE
@@ -77,7 +74,7 @@ int main( int argc, const char** argv )
 	img::Image<img::SvgImage> out( imSize.first, imSize.second );
 	fct::DrawFunct<img::SvgImage> dfunc( out );
 
-	PointPair2_<double,double> pp_all;
+	PointPair pp_all;
 	size_t c = 0;
 	for( const auto& e: data )
 	{

misc/tryme2.cpp

@@ -1,3 +1,19 @@
+/**************************************************************************
+
+    This file is part of the C++ library "homog2d", dedicated to
+    handle 2D lines and points, see https://github.com/skramm/homog2d
+
+    Author & Copyright 2019-2025 Sebastien Kramm
+
+    Contact: firstname.lastname@univ-rouen.fr
+
+    Licence: MPL v2
+
+	This Source Code Form is subject to the terms of the Mozilla Public
+	License, v. 2.0. If a copy of the MPL was not distributed with this
+	file, You can obtain one at https://mozilla.org/MPL/2.0/.
+
+**************************************************************************/
 
 #include "homog2d.hpp"
 using namespace h2d;