Floating Point Precision Loss


Posted on 16th Feb 2014 07:03 pm by admin

I'm writing a program to draw a three-dimensional cube (with a corner cut off) without using any 3D graphics APIs. The only API call I make is win32's SetPixel()

Everything is going great. I've drawn lines, faces, and even the entire cube. Then rotation came along.

For some reason, when I rotate my cube, it begins to shrink. I became confused, then I realised something. Floating point numbers are truncated.

Here's some code that is fired everytime the user presses 'X' on the keyboard.

Code: p->setY( p->getY() * cos(5.0/180.0*PI) - p->getZ() * sin(5.0/180.0*PI)); p->setZ( p->getY() * sin(5.0/180.0*PI) + p->getZ() * cos(5.0/180.0*PI));

p is a Point object that I created. Here the Y value and the Z value of the Point are being set. The problem is everytime X is pressed, and this code is fired, a small amount of precision is lost. As a result, the cube shrinks.

I'm really completely stumped. I remember when studying assembler that floating point numbers can be truncated or rounded. I think rounding would solve my problem. Since 50% of the time the value would round up, and 50% of the time the value would round down.

Whereas with truncation values are always lost, and never gained.

No comments posted yet

Your Answer:

Login to answer
213 Like 53 Dislike
Previous forums Next forums
Other forums

Warning: mysql_num_rows() expects parameter 1
When i add quote at the end of this link
example:http://localhost/articlemania/category.php?cid=3

Rounding a number queried from a database
I know that to display a rounded number you just do echo "round($number)";. But how would

returning data from an ssh2_exec()
here's what i got.


$conn = ssh2_connect($this->_host);
ssh2_auth_password($c

phpMailer will not connect using SMTP
I am trying to use phpMailer with smtp:

Code: [Select]$mailer = new PHPMailer();
$mailer-&

Online Event Ticket Sales
Has anyone wrote a script for online tickets sales?

I have been googling and found lots of th

Material Master Update through BAPI - Follow up material not updated
Hi Experts,

I am updating the material master through a custom transaction using the BAPI

Transaction variant for VA02 not working
My requirement is to have transaction for user to only add the output and print a sales order.

xml
<?php

echo "<h1>XML Articles</h1>";

$home

HTML Form Server Side Validation
Hi, Im new here, im currently doing a website for a friend, and I have designed using snippets from

Bandwidth monitoring?
Hi guys,

I need a little information I have written a php app and I occurred to that I need

Sign up to write
Sign up now if you have flare of writing..
Login   |   Register
Follow Us
Indyaspeak @ Facebook Indyaspeak @ Twitter Indyaspeak @ Pinterest RSS



Play Free Quiz and Win Cash