Two parallel line segments intersection

Posted by Judarkness on Stack Overflow See other posts from Stack Overflow or by Judarkness
Published on 2010-05-11T02:49:13Z Indexed on 2010/05/11 2:54 UTC
Read the original article Hit count: 192

Filed under:

geometry

I know there are many algorithms to verify whether two line segments are intersected.

But once they encountered parallel condition, they just tell the user a big "No" and
pretend there is no overlap, share end point, or end point collusion.

I know I can can calculate the distance between 2 lines segments.
If the distance is 0, check the end points located in the other line segments or not.
And this means I have to use a lot of if else and && || conditions.

This is not difficult, but my question is

"Is there a trick( or mathematics) method to calculate this special parallel case?"

Related posts about geometry

GLSL check if fragment is on geometry

as seen on Stack Overflow - Search for 'Stack Overflow'
I am currently writing the positions of my geometry to the RGB channels of gl_FragColor and I would like to write 1.0 to the alpha channel if the fragment is part of geometry, and 0.0 if its empty. Is there a simple way to tell if a fragment is geometry or not? Maybe through gl_FragCoord.z? thanks >>> More
In JTS, when I do geometry.buffer(1).buffer(-1), will the resulting geometry be equivalent to the or

as seen on Stack Overflow - Search for 'Stack Overflow'
I was having problems while intersecting two geometries, getting a TopologyException probably due to a rounding error during the operation, then I read this fix and tried a buffer(0) on both input geometries, but still without success. Then I tried geo.buffer(1).buffer(-1) and it worked. Will these… >>> More
Multiple mesh with one geometry and diferent textures. Error

as seen on Stack Overflow - Search for 'Stack Overflow'
I have a loop where I create a multiple Mesh with different geometry, because each mesh has one texture: .... var geoCube = new THREE.CubeGeometry(voxelSize, voxelSize, voxelSize); var geometry = new THREE.Geometry(); for( var i = 0; i < voxels.length; i++ ){ var voxel = voxels[i]; var object; … >>> More
How to read verbose VC++ linker output

as seen on Stack Overflow - Search for 'Stack Overflow'
Trying to debug some linker errors, I turned on /VERBOSE and I'm trying to make sense of the output. It occurs to me that I really don't know how to read it. For example: 1>Compiling version info 1>Linking... 1>Starting pass 1 1>Processed /DEFAULTLIB:mfc80.lib 1>Processed /DEFAULTLIB:mfcs80… >>> More
Drawing a rectangular prism using opengl

as seen on Game Development - Search for 'Game Development'
I'm trying to learn opengl. I did some code for building a rectangular prism. I don't want to draw back faces so I used glCullFace(GL_BACK), glEnable(GL_CULL_FACE);. But I keep getting back faces also when viewing from front and also sometimes when rotating sides are vanishing. Can someone point me… >>> More

Developer IT