osgchips: Main Page

A single osgchips::Stacks object (derived from osg::Geode) can contain multiple osgchips::Stack objects (derived from osg::Geometry). Picking is enabled on the bounding box of the osgchips::Stacks object and not on a per osgchips::Stack basis to save CPU time. The various type of chips are stored in the osgchips::ChipBank singleton.

Usage

The osgchips::Stacks and osgchips::Stack derive publicly from OpenSceneGraph classes (osg::Geode and osg::Geometry respectively) so that specific application needs may be addressed. For instance, the application may want to set state attributes on a osgchips::Stack using the osg::StateSet pointer returned by getStateSet().

The API is designed for simplicity, as demonstrated in the osgchips.cpp example.

  osgchips::Stacks* stacks = dynamic_cast<osgchips::Stacks*>(osgDB::readNodeFile("default.osgchips"));

Example

XML configuration element

   
#include <osgDB/ReadFile>
osgchips::Stacks* stacks = dynamic_cast<osgchips::Stacks*>(osgDB::readNodeFile("default.osgchips"));

Each element of the configuration file and its use are described in the comments of the sample file shown below. This file is available from the source distribution in data/default.osgchips or in /usr/share/osgchips/default.osgchips if installed on GNU/Linux. It is used by the osgchips example.

<?xml version='1.0' encoding='iso-8859-1' ?> <!-- -*- nxml -*- -->

<!--

osgchips configuration file. The order of the elements is important: material, chip and stacks.

-->

<!--

osgchips element

Defines chips that are stored in the osgchips::ChipBank singleton and/or create a osgchips::Stacks
object.

mesh = mesh file that can be read by osgDB::readNodeFile to create a osg::Geode (mandatory)
-->

<osgchips xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	  xsi:noNamespaceSchemaLocation="http://download.gna.org/osgchips/osgchips.xsd"
	  mesh="chip.osg" >

  <!--
      material element

      Defines a material that can be referenced in the material attribute of the chip element.
      name = symbolic name of the material (mandatory)
      red = [0-255] integer (optional, default 0)
      green = [0-255] integer (optional, default 0)
      blue = [0-255] integer (optional, default 0)
      alpha = [0-1] float (optional, default 1)

      Example: <material name="colored" red="100" green="255" blue="255" alpha="1.0" />

  -->
  <material name="transparent" red="255" green="100" blue="255" alpha="0.5" />
  <material name="colored" red="100" green="255" blue="255" alpha="1.0" />
  
  <!--
      chip element
      
      Defines a chip that can be referenced in the chip attribute of the stack element.
      The material and/or the texture attributes must be specified for the stacks to
      be visible. If two chips have the same value, only the last one will be returned
      by the osgchips::ChipBank::getChip(unsigned int value) method. The same apply for
      two chips with the same name and osgchips::ChipBank::getChip(const std::string& name).

      name = symbolic name of the chip (mandatory)
      value = [1-N] integer numerical value of the chip (mandatory)
      texture = URI of the image used as a texture for the mesh /osgchips@mesh. (optional, no default)
		See the README or osgchips HTML documentation for more information.
      material = reference to the material element defined earlier in this file (optional, no default)
      
      Example: <chip name="1" texture="white-1.png" value="1" />

  -->
  <chip name="1" texture="white-1.png" value="1" />
  <chip name="2" texture="yellow-2.png" value="2" />
  <chip name="5" texture="red-5.png" value="5" />
  <chip name="10" texture="blue-10.png" value="10" />
  <chip name="20" texture="grey-20.png" value="20" />
  <chip name="25" texture="green-25.png" value="25" />
  <chip name="50" texture="orange-50.png" value="50" />
  <chip name="100" texture="black-100.png" value="100" />
  <chip name="250" texture="pink-250.png" value="250" />
  <chip name="500" texture="purple-500.png" value="500" />
  <chip name="1000" texture="burgundy-1000.png" value="1000" />
  <chip name="2000" texture="lightblue-2000.png" value="2000" />
  <chip name="5000" texture="brown-5000.png" value="5000" />

  <chip name="transparent-100" material="transparent" value="100" />
  <chip name="tinted-250" material="transparent" texture="pink-250.png" value="250" />
  <chip name="colored-100" material="colored" texture="black-100.png" value="100" />

  <!-- 
       stacks element 
       
       Defines an osgchip::Stacks object
  -->
  <stacks>
    <!--
	stack element
	
	Defines a chip stack and its position. The chip mesh is translated so that its
	bottom center is on the specified position.
	
	chip = reference to the chip element defined in the osg::ChipBank singleton, either
	       because it was read in this file or because it was previously read from another
	       file.
	count = number of chips in the stack (optional, default 1)
	x = [0-N] float, position on the x axis (optional, default 0)
	y = [0-N] float, position on the y axis (optional, default 0)
	z = [0-N] float, position on the z axis (optional, default 0)
    -->
    <stack chip="50" count="5" x="0" y="0" z="0" />
    <stack chip="25" count="0" x="20" y="0" z="0" />
    <stack chip="100" count="2"  x="0" y="0" z="10" />
    <stack chip="transparent-100" count="20"  x="0" y="0" z="-10" />
    <stack chip="100" count="5"  x="0" y="0" z="-15" />
    <stack chip="transparent-100" count="20"  x="0" y="0" z="-20" />
    <stack chip="tinted-250" count="10"  x="10" y="0" z="0" />
    <stack chip="colored-100" count="13" x="-10" y="0" z="0" />

    <stack chip="1" count="5" x="0" y="0" z="-50" />
    <stack chip="2" count="5" x="5" y="0" z="-50" />
    <stack chip="5" count="5" x="10" y="0" z="-50" />
    <stack chip="10" count="5" x="15" y="0" z="-50" />
    <stack chip="20" count="5" x="20" y="0" z="-50" />
    <stack chip="25" count="5" x="25" y="0" z="-50" />
    <stack chip="50" count="5" x="30" y="0" z="-50" />
    <stack chip="100" count="5" x="35" y="0" z="-50" />
    <stack chip="250" count="5" x="40" y="0" z="-50" />
    <stack chip="500" count="5" x="45" y="0" z="-50" />
    <stack chip="1000" count="5" x="50" y="0" z="-50" />
    <stack chip="2000" count="5" x="55" y="0" z="-50" />
    <stack chip="5000" count="5" x="60" y="0" z="-50" />
  </stacks>
  
</osgchips>

Error handling policy

Debug

Resources usage

Memory

The osgchips::ChipBank instance stores a single copy of the vertexes, normals, texture coordinates and primitive sets (osg::PrimitiveSet) that define the cylinder for a chip stack. The vertexes and texture coordinates are duplicated for each osg::Stack instance (for resizing purposes) but the normals and primitive sets are shared.

CPU <=> GPU

Using osgchips in your code

The source code itself is designed to be self contained so that copying the .cpp and .h files in another application is an alternative that does not require any modification.