star-2d

Contour structuring for efficient 2D geometric queries
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README.md (3896B)

      1 # Star 2D
      2 
      3 Star-2D is a C library that manages *2D geometries* and implements
      4 operators to access them efficiently such as uniform sampling, ray
      5 tracing or a closest point query.
      6 
      7 The main concept exposed in Star-2D is the *shape*. A shape is a set of
      8 segments representing the outline of a 2D geometry. Shape data is
      9 user-defined and can be updated at any time. The shapes are then
     10 attached to a *scene* where they can be queried using a *view* of the
     11 scene. When it is created, the view internally builds the accelerating
     12 structures necessary for the access operators. These data structures are
     13 constructed from the scene geometry as defined at the time of view
     14 creation; a view is thus insensitive to updates of the scene following
     15 its creation. This means that multiple views can be used to save
     16 different states of the same scene, giving the caller great flexibility
     17 in managing scene data.
     18 
     19 ## Requirements
     20 
     21 - C compiler (C99)
     22 - POSIX make
     23 - pkg-config
     24 - [Embree](https://github.com/embree/embree)
     25 - [RSys](https://gitlab.com/vaplv/rsys)
     26 
     27 ## Installation
     28 
     29 Edit config.mk as needed, then run:
     30 
     31     make clean install
     32 
     33 ## Release notes
     34 
     35 ### Version 0.7
     36 
     37 - Replace CMake by Makefile as build system.
     38 - Update compiler and linker flags to increase the security and
     39   robustness of generated binaries.
     40 - Provide a pkg-config file to link the library as an external
     41   dependency.
     42 
     43 ### Version 0.6
     44 
     45 - Upgrading the ray-tracing backend from Embree3 to Embree4
     46 
     47 ### Version 0.5.1
     48 
     49 - Corrects an invalid memory read.
     50 - Fix compilation warnings detected by gcc 11.
     51 
     52 ### Version 0.5
     53 
     54 Update the API of the filtering function: add the range of the ray as
     55 input argument. For closest point queries, this range is from 0 to query
     56 radius.
     57 
     58 ### Vesion 0.4.1
     59 
     60 - Improve the accuracy of the closest point query.
     61 - Fix the closest point query: the returned hit was wrong.
     62 - Fix the barycentric coordinates of the intersection of the ray onto
     63   the segment: the coordinates could lie outside the segment.
     64 
     65 ### Version 0.4
     66 
     67 - Add the `s2d_scene_view_closest_point` function. This function
     68   retrieves the closest point into the scene to a query position in a
     69   radius from ]0, INF].  This closest point is returned as a regular hit
     70   which means that the function returns to the caller not only the
     71   distance to the query position, but also the geometric primitive onto
     72   which the point lies and its location onto this primitive. If no
     73   segment lies around the query position in a distance lesser than the
     74   one defined by the query radius, the returned hit is invalid which can
     75   be checked with the regular `S2D_HIT_NONE` macro. Finally, this
     76   function supports the filter functions so that the caller can choose
     77   to discard closest hits according to its own criteria.
     78 
     79 ### Version 0.3.1
     80 
     81 - Fix the `s2d_segment_get_vertex_attrib` function: it could fail and
     82   return an error while it shouldn't.
     83 
     84 ### Version 0.3
     85 
     86 - Migrate the ray-tracing backend from Embree2 to Embree3.
     87 
     88 ### Version 0.2
     89 
     90 - Add the `s2d_segment_get_vertex_attrib` function that returns the
     91   vertex attributes of a given segment.
     92 
     93 ### Version 0.1.1
     94 
     95 - Fix the `s2d_primitive_get_function`. The function failed when the
     96   submitted parametric coordinate was equal to 1.
     97 
     98 ### Version 0.1
     99 
    100 - Implement the `s2d_scene_view` API; it replaces the
    101   `s2d_scene_<begin|end>_session` functions that were removed. A view
    102   registers the state of the scene from which it is created. It is used
    103   to retrieve the scene data through ray-tracing, sampling or indexing.
    104   Several views can be created on the same scene.
    105 - Add the possibility to attach a same shape to several scenes.
    106 
    107 ## License
    108 
    109 Copyright (C) 2016-2021, 2023 |Méso|Star> (contact@meso-star.com)
    110 
    111 Star-2D is free software released under GPL v3+ license: GNU GPL version
    112 3 or later. You are welcome to redistribute it under certain conditions;
    113 refer to the COPYING file for details.