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
Problem with the Update command used with a sqldataadapter
I'm connected to a database on an SQL Server and I'm using a sqldataadapter, sqlconnection, sqldatas
Request for tunning the below query
Hi,
Can any one help me on the below query while improving the performance,
IMAGE - SERVER SIDE scripting help...
How to receive pixel data of an image and buid a bitmap file on the server using the HTTP POST metho
PHP SUBMIT
Code: <input name="doLogin" type="image" src="images/loginsubmit.jpg
I need help on this PHP code
Hi everybody, I made some kind of mistake while editing the code below. As you see, at the 3 row my
Displaying data from MySql a different way
Hi all,
I'm pretty new to php and MySql and have hit a problem.
I am able to display data
Image DPI
Hi.
I allow users to upload images, the user then is able to adjust several settings for the
Access website from only 1 computer...?
One of my customers wants his website to only be accessed by people in which they bought the website
UL and LI Add Form
The idea I want here is when the user click on a character name from the drop down select bar at the
Amatuer requiring assistance
Beginner and amateur in need of assistance
My Site - (Spare Parts for Domestic Appliances)