Shapes

Description				Download
Shapes is a useful library for XNA to generate textures of simple (or not so simple) geometric forms. It is also helpful for detecting collisions in a 2D Game. With the Shapes Library comes the Sampler library (v1.0). It manages many Game1.cs like sample classes in a single project.
Version	Platforms		License	Author
v2.0	Windows PC (tested) Xbox360 (not tested) Zune (not tested)		MIT License means: free for all, but insert a copyright: © 2009 Liquid Fire Arts	Liquid Fire Arts Salomon Zwecker
Namespace		Description
LiquidFireArts.Wormhole.Geometry		In this namespace are all drawings and shapes
LiquidFireArts.Wormhole.Misc		Here are the helper classes: TextureGenerator, Brush, CollisionDetector2D, GeometryTemplates
LiquidFireArts.Sampler		This namespace is for the Sampler library. In it are SampleManager and Sample.

Class Diagramm

click to view in original size

Screenshots

The following screenshots are showing the samples coming along with the library.

Click at the images to view them in original size.

This sample shows how to create some shapes and detect collision using the CollisionDetector2D	Collision between a Shape and an animated SpriteShape	A little Editor to create a ShapeComposition with random generated shapes	Another Editor to edit LineStrips and Polygons	A small Jump'n'Run game created with shapes only

Features

• Object oriented design and easy to use

• Create geometric forms
  • Drawings (1-Dimensional)
    • Dot (a point)
    • Line (straight from one point to another)
    • LineStrip (many connected lines)

• Shapes (2-Dimensional)
  • Rect (an axis aligned rectangle)
  • Ellipse (with a horizontal and vertical radius)
  • Triangle (three points describing a trianlge - faster than a polygon)
  • Polygon (a closed LineStrip with scanline algorithm)
  • SpriteShape (a shape created from a Texture2D. Animation by changing the source rectangle is possible)
  • ShapeComposition (a shape defined by many other shapes and their compose functions

• Templates
• LineStrip
• Star (with as many rays as you want)
• NGramm (another kind of star. If it has five rays it is called "Pentagramm")
• NGon (N connected points describing a circle)
• Arrow (points from one point to another)

• ShapeComposition
• RoundedRect (a rectangle with round corners)
• YinYang (a Yin & Yang symbol)
• Smiley =)

• Generate textures from the Drawings and shapes
  • Border (the outline of the Drawing or Shape drawn with a brush of your choice)
• Filled (shapes only - the inner area inside a shape filled with a defined color)
• Filled with border (shapes only - a combination of both rendered into a single texture)

• Collision Detection
  • Rasterized intersection tests between shapes or drawings
• Manager class to check between collisions in the background
• Variable accuracy to tune performance

• Well XML-Tag documentation (with help from my wonder full englisch skulls :P)

• Many Samples
  • Collision between shapes
  • Collision with an animated SpriteShape
  • Creating a ShapeComposition
  • Editing a LineStrip and make a Polygon from it
  • Jump'n'Run game sample

Known Problems

• Some wrong DistanceToEdge() calculation
• The borders of ellipses are deformed
• Intersecting points of Shapes inside a ShapeComposition have gaps

• there are sometimes wrong pixels in textures genereated from SpriteShapes

• Sometimes the outer pixels of a generated Texture is overlapping with another generated Texture but the collision detector doesn't notice it
  • maybe the position of one of them has floating point values
  • or the accuracy of the collision detector is greater than 1
  • or the position of the texture and the position of the shape are not the same

• It is so slow
  • it takes long to generate a texture (especially borders)
    • this is because the CPU is filling the texture and not the graphics card
  • sometimes the frames per second are very low
    • this can occure if you detect collisions between big shapes. You may set the accuracy higher to increase performance.
    • maybe you generate a texture while the game is running. Avoid to do this and generate anything at loading time of the game / level / whatever.

Ideas for releases in the future

• Transform geometry
• Scale drawings and shapes
• Rotate drawings and shapes

• Shaders for the drawings and shapes

• Collision detection for special geometry to increase performance
  • Line
  • LineStrip
  • Triangle
  • Polygon

• Finding points of intersection

• Triangulated Polygons

• Bezier Curves

• Multithreading

• Editor

Sampler

Features

• Game1.cs like Sample class design

• Create as many samples as you want in a single XNA-Project to show the features of your library

• Switch between samples by pressing a key

• Description for each samples displayed on the screen

• Help text how to switch between samples and how to hide the text

• FPS Display

• Initialization and Deactivation logic
  • you may don't change anything in a sample when the user changes the sample
  • or you delete anything and initialize it next time the user is activating the sample

• Well XML-Tag documented

• Many samples for the samples - comes along with the shapes library ;)