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
I am stumped
OK. Here is what I am trying to do. I have the conditions set, and if the conditions are met, I want
How to calculate days from variable date?
This will be easy for one of you gurus. I want to fetch the date from a variable date, for example:<
php is not recognized as an internal or external command
Hello,
I am trying to bake the code in CakePHP through my console.
I have changed my Path
PHP5 - Verifying a secure mail is secure
I need to send an e-mail from a form to a external department and because it contains personal custo
Adding to the next element in a multidimensional array
Hi, I'm trying to add a value to $node->field_spaces['nid'] where x is the next available spo
Passing JS to PHP
So I have the following
Code: <?php
getdetails(?><script type="text/
How can use this array as a key?
Say I have this array for example:
print_r($array);
Prints:
Code: [Select]Array
generating all possible random letters
hi'
how can i randomize the letters a,b,c,d,e all possible ways, and i want to print the res
HTML form problem
Ive made a form to that i want to send to my email via PHP. but when it send only the name's etc sen
MS are the best!!!
Visit http://www.microsoft.com/australia/windows/default.aspx?h=watch-a-demo and click the massive '
