Java-Gaming.org Hi !
 Featured games (88) games approved by the League of Dukes Games in Showcase (681) Games in Android Showcase (196) games submitted by our members Games in WIP (745) games currently in development
 News: Read the Java Gaming Resources, or peek at the official Java tutorials
Pages: [1]
 ignore  |  Print
 A bug in Wiki-LWJGL tutorial?  (Read 3129 times) 0 Members and 1 Guest are viewing this topic.
preshel

Senior Newbie

 « Posted 2007-02-26 22:52:16 »

Hi,

I've checked out the speedy VBO in
http://lwjgl.org/wiki/doku.php/lwjgl/tutorials/opengl/speedyvbo#interleaving_a_vbo

and I've notived that:

 1  2 `// texture coordinates offset = (3 + 3 + 2) * 4;GL11.glTexCoordPointer(2, GL_FLOAT, stride, offset);`

Looks a little bit strange... shouldn't it be offset = (3 + 3 + 4) * 4 instead?

Anyway, i've solved my bug problems... it was all due to an unupdated driver of my laptop, and apperantly, now i DO have VBO supported... yey!
darkprophet

Senior Devvie

 « Reply #1 - Posted 2007-02-26 23:49:11 »

I wrote that tutorial, im glad it helped.

Lets regard each "component" as a unit. So the x component of the vertex is 1 unit. That means each vertex has 3 units, each normal has 3 units and 2d texture coordinates have 2 units (remember its just ST coordinates). Thats the reason behind the 3 + 3 + 2 offset. The * 4 is to change that to be in terms of bytes.

DP

Friends don't let friends make MMORPGs.

Blog | Volatile-Engine
preshel

Senior Newbie

 « Reply #2 - Posted 2007-02-27 11:03:05 »

yes, i understand what the x4 means, but if u decided that the interleaved structure is like this:
V[xyz]N[xyz]C[rgba]T1[st]

then the offset for the starting of the texture should be (3+3+4)*4 and not (3+3+2)*4, since the color have rgba channels = 4 channel..., and it comes before the texture channels...

btw - i already implemented it, and its 3+3+4.
please check ur tutorial again (it really helped me, though !).
darkprophet

Senior Devvie

 « Reply #3 - Posted 2007-02-27 11:51:43 »

no, since the offset for vertices is 0 not 3

And Ive implemented the 3+3+2 successfully in a game engine a very long while back

DP

Friends don't let friends make MMORPGs.

Blog | Volatile-Engine
preshel

Senior Newbie

 « Reply #4 - Posted 2007-03-01 11:20:05 »

sorry, but i insist

the structure should be
V[3*4byte]N[3*4byte]C[4*4byte]T1[2*byte]

so if i need the texture (s,t) , i need to do :
 1  2 `intlvdarr[4*(3+3+4)+0] = texture_s;intlvdarr[4*(3+3+4)+1] = texture_t;`

the texture offset WOULD be 3+3+2 for the following structure:
V[3*4byte]N[3*4byte]T1[2*byte]C[4*4byte]

preshel

Senior Newbie

 « Reply #5 - Posted 2007-03-01 11:20:59 »

sorry, it would be 4*(3+3).

in any case it should not be (3+3+2) ....
Pages: [1]
 ignore  |  Print

You cannot reply to this message, because it is very, very old.

 CopyableCougar4 (61 views) 2016-06-25 16:56:52 Hydroque (93 views) 2016-06-22 02:17:53 SwampChicken (96 views) 2016-06-20 13:22:57 SwampChicken (99 views) 2016-06-20 13:22:49 SwampChicken (91 views) 2016-06-20 13:22:26 Hydroque (136 views) 2016-06-15 08:22:50 Hydroque (131 views) 2016-06-13 06:40:55 DarkCart (245 views) 2016-05-29 02:30:33 Hydroque (212 views) 2016-05-26 14:45:46 Mac70 (196 views) 2016-05-24 21:16:33
 Spasi 49x theagentd 43x NegativeZero 39x KaiHH 29x LiquidNitrogen 23x princec 21x DavidBVal 16x CoDi^R 16x ra4king 13x TritonDreyja 10x ags1 10x Opiop 10x purenickery 9x Hydroque 8x Archive 8x Ecumene 7x
 Making a Dynamic Plugin Systemby Hydroque2016-06-25 00:13:25Java Data structures2016-06-13 21:22:09Java Data structures2016-06-13 21:20:42FPS Camera Tutorialby Hydroque2016-05-22 05:40:58Website offering 3D Models specifically for games for freeby vusman2016-05-18 17:23:09Website offering 3D Models specifically for games for freeby vusman2016-05-09 08:50:56Website offering 3D Models specifically for games for freeby vusman2016-05-06 11:10:21Website offering 3D Models specifically for games for freeby vusman2016-04-29 12:56:17
 java-gaming.org 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‑gaming.org