Hi !
Featured games (91)
games approved by the League of Dukes
Games in Showcase (757)
Games in Android Showcase (229)
games submitted by our members
Games in WIP (844)
games currently in development
News: Read the Java Gaming Resources, or peek at the official Java tutorials
    Home     Help   Search   Login   Register   
Pages: [1]
  ignore  |  Print  
  Basic proof of PO2 size  (Read 1230 times)
0 Members and 1 Guest are viewing this topic.
Offline K.I.L.E.R

Senior Devvie

Java games rock!

« Posted 2006-11-10 11:46:22 »

I know the solution is simple to calculate, I just dislike the current solution because of lack of proof behind it(who gives a damn if it works? It has to be proven in the realm of mathematics before it's useful).
I had to revisit this issue because I have to make a 3D networked game for my assignment and wanted to re-invent the wheel, with solid proof.

If you don't care about this then don't read it. I only did this as a proof for my assignment and thought maybe someone might benefit from my proof.

lambda = texture dimension size (either width or height)
alpha = some unknown integer value that is the power

This statement is assuming that the current dimension is PO2 but since I don't know this, I thought I'd try and find the power while converting the base from PO2 into something more common (base e).
lambda = 2^alpha

Convert base 2 to base e.

ln(lambda) = ln(2^alpha)
ln(lambda) = alpha*ln(2)

alpha = ln(lambda) / ln(2)

How to get this to work?

private static boolean isPowerOf2(final int width, final int height) {
   currentImageScaledWidth = (int) Math.pow(2, Math.ceil(Math.log(width) / Math.log(2)));
   currentImageScaledHeight = (int) Math.pow(2, Math.ceil(Math.log(height) / Math.log(2)));
   return ((width == currentImageScaledWidth) && (height == currentImageScaledHeight));

If it's already a PO2 texture then nothing happens. If a dimension isn't PO2, then it converts to the nearest higher PO2 dimension.

Texture tex = TextureLoader.load("C:\\Documents and Settings\\Kruno\\Desktop\\newOOP2Ass\\res\\Title.BMP");
double curTexBaseX = Math.log(tex.width) / Math.log(2);
double curTexBaseY = Math.log(tex.height) / Math.log(2);
System.out.print("PO2 Width: " + Math.pow(2, Math.ceil(curTexBaseX)));
System.out.print("\t PO2 Height: " + Math.pow(2, Math.ceil(curTexBaseY)));

BPP: 3     Width: 453     Height: 239     Scaled Width: 512     Scaled Height: 256
PO2 Width: 512.0    PO2 Height: 256.0

Is there a name for a "redneck" programmer?

Unemployed. Wink
Pages: [1]
  ignore  |  Print  

EgonOlsen (79 views)
2018-06-10 19:43:48

EgonOlsen (59 views)
2018-06-10 19:43:44

EgonOlsen (78 views)
2018-06-10 19:43:20

DesertCoockie (261 views)
2018-05-13 18:23:11

nelsongames (160 views)
2018-04-24 18:15:36

nelsongames (158 views)
2018-04-24 18:14:32

ivj94 (902 views)
2018-03-24 14:47:39

ivj94 (162 views)
2018-03-24 14:46:31

ivj94 (813 views)
2018-03-24 14:43:53

Solater (177 views)
2018-03-17 05:04:08
Java Gaming Resources
by philfrei
2017-12-05 19:38:37

Java Gaming Resources
by philfrei
2017-12-05 19:37:39

Java Gaming Resources
by philfrei
2017-12-05 19:36:10

Java Gaming Resources
by philfrei
2017-12-05 19:33:10

List of Learning Resources
by elect
2017-03-13 14:05:44

List of Learning Resources
by elect
2017-03-13 14:04:45

SF/X Libraries
by philfrei
2017-03-02 08:45:19

SF/X Libraries
by philfrei
2017-03-02 08:44:05 is not responsible for the content posted by its members, including references to external websites, and other references that may or may not have a relation with our primarily gaming and game production oriented community. inquiries and complaints can be sent via email to the info‑account of the company managing the website of java‑
Powered by MySQL Powered by PHP Powered by SMF 1.1.18 | SMF © 2013, Simple Machines | Managed by Enhanced Four Valid XHTML 1.0! Valid CSS!