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.
Did you know?Explore Trending and Topic pages for more stories like this.
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 
53 
Other forums
Email Form Syntax Issue
I need the TO: in email to display To: CEO instead of To: abc@mail.com
How to alter the scri
Best way to read this text file.
Hi.I am planning to make a small application in C# to convert the players from Football manager 2010
array empty
Hiya peeps,
Ok here is the codes.
order.php
Code:
limitations on array_unique()
Does any one know what/how imitations are applied to array_unique? I have an issue where no matter h
Binding 2 UDP sockets on same port, connected to different destinations, 1 receives
Hello,
My application wants to send/recv data to 2 different UDP ports on a remote computer, us
bit of help needed
Im about to sort out my registration page for my website by customising a "registration" s
Form submissing with PHP and JQuery/Ajax
I have searched everywhere, but cannot find a solution for this... I have worked all day trying to g
Display data returned from Ajaxservices!!
I have a question about displaying results using ajax. I have part of the code below.
$.ajax({
Need Help with a query
Hello,
For some reason I am just not getting the right answer when I do this query and not quite
Deleting Partners on the Customer Master.
Does SAP handle removing the Partner from Open Sales Orders when a Partner is deleted in the Custome
