Physical Simulation Language: PSL

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Physical Simulation LanguagePSL

• John Hamer John Rodriguez Danian Martinez
  Taino Ortiz
• hamer jr534
  djm188 tjo22

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Background Info

• PSL is a language intended for the convenient
  analysis of motion and objects in a 2D space.
• Other languages, such as Direct X, make even the
  simplest simulation a bother.
• Window management issues
• Efficient memory handling, message queueing

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Purpose

• PSL was created for two reasons
• To facilitate the creation of simple polygonal
  shapes using a simple language.
• To feature interaction among these objects for
  the demonstration of physical principles.

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Key Features

• Key Features of PSL
• Graphical Display
• Immediate response to what he programmed in PSL
• Collision Detection and Reaction
• Attempts to simulate how real world objects
  handle collisions in the environment
• Slightly costly
• O(n2) algorithm

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PSL Data Flow
This diagram shows the process a .PSL file is put
through to become an executable
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Compiler

• ANTLR v2.7.2 was used to develop PslParser and
  PslLexer via our language-specific CFG
• We decided to implement our own treewalker, which
  assisted ANTLR in performing semantic analysis of
  the resultant ASTs

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PSL Objects

• Possible objects in PSL
• Circle
• Circle(double center_x, double center_y, double
  radius)
• Rectangle
• Rectangle(double x, double y, double length,
  double width)
• Square
• Square(double x, double y, double length)
• Polygon convex AND concave
• Poly(double x1, double y1, double x2, double y2)
• Line
• Line(double x1, double y1, double x2, double y2)

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Abstract Syntax Tree

• Each statement is composed of a subtree known as
  a child with the first token as the root and all
  proceeding tokens its children
• Value list become children of the Object that is
  being created of altered.
• The AST that ANTLR generates is read as a list
  and using the API provided by their AST files
  they are processed one child at a time.

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Intermediate Code Generator

• Takes in
• One vector of all objects
• All global variables defined
• Abides by PSL-specific C template to generate
  appropriate environment and object specifications
• Writes the corresponding C source file
• PSL bytecode ?

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Backend

• Graphics programming already has a commonly-used
  API OpenGL!
• Often complicated and error prone
• Complicates the simplest demo
• Not for rookies
• PSL implements its powerful capabilities while
  eliminating the learning curve

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Backend (continued)

• The backend of the PSL language implemented a
  carefully structured OO environment using
  C/OpenGL
• PslEnvironment the rendering environment
• PslPolygon, PslSquare, etc
• For windowing, the GLUT toolkit was used on
  Windows XP, Mesa on Redhat Linux.
• Set using PSL Global setter methods

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Design of Backend
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Simple.psl
def circle1 Circle(3, 3, 3)//Creates a
circle circle1.color(255, 0, 0)//Sets color to
red circle1.points(20) def poly1 Polygon(-5,
-5, 3, -5)//Creats a square Poly1.addpoint(-2.5,
-2.5) poly.color(0, 0, 255)//Sets color to
blue Global.zoom(15)//Set the camera zoom /
Sets window size / Global.windowSize(300, 300)
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Simple.psx
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Testing Plan

• Modular Testing
• Tested each module before integrating
• Regression Testing
• Tested new modules to verify that they worked
  with the other modules
• Integration Testing
• Integration of front and Backend
• This Test verified that the language worked
• Error Testing
• Used to verify that the compiler threw errors for
  incorrect syntax and/or semantics

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Conclusion

• PSL is a valuable asset
• To the graphics designer, executive, or engineer
  who must incorporate graphical displays into
  their everyday assignments.
• A lecture given by a high school physics
  professor will be much more effective with
  PSL-designed presentations in his or her arsenal.

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Lessons

• Three very important properties of a good team
• Trust
• Communication
• Commitment