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Type: Posts; User: Tron

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1. ## Thread: indexed vertexarrays slow, very slow ?

by Tron
Replies
13
Views
1,290

### Re: indexed vertexarrays slow, very slow ?

you don't have to specify the vertex/color/texture/index pointers every frame.
just call glDrawElements.
if your indexes are in consecutive order (0, 1, 2, 3, 4, 5, ...) like for tri-strips or...
2. ## Thread: Mipmapping a single level

by Tron
Replies
6
Views
313

### Re: Mipmapping a single level

according to the opengl standard you either must generate no mipmaps or all down to 1x1.
everything else may cause 'undefined beahvior' (;
3. ## Thread: x,y,z, and w?

by Tron
Replies
4
Views
579

### Re: x,y,z, and w?

this is not completly true, in fact w IS a fourth dimension (but no one - at least no human - is able to imagine a fourth spatial dimension)
by dividing x, y and z by w you actually project this 4d...
4. ## Thread: What is the max value for FOV ?

by Tron
Replies
6
Views
713

### Re: What is the max value for FOV ?

this is a simple perspective projection matrix:
A 0 0 0
0 B 0 0
0 0 C D
0 0 1 0

A = 1.0 / Aspect
B = 1.0
C = (Far + Near) / (Far - Near)
D = -2.0 * Far * Near / (Far - Near)
5. ## Thread: Why I can't get through the simplest code??

by Tron
Replies
6
Views
214

### Re: Why I can't get through the simplest code??

did you initialize a valid render context and made it current?
6. ## Thread: What is the max value for FOV ?

by Tron
Replies
6
Views
713

### Re: What is the max value for FOV ?

@Bob:
normal FOV is 90 degree, so 60 degree is pretty distorted and zoomed

@transnept:
the limit is < 180, cause the matrix is generated with tan(FOV / 2) and tan(90) is undefiend
7. ## Thread: unresolved external simbol main

by Tron
Replies
2
Views
109

### Re: unresolved external simbol main

this is absolutely NO openGL related question... next time post in a general coding forum or better read a FAQ

every (console) program must have a main() function, it's the entry point of the...
8. ## Thread: rounding GLfloat values??

by Tron
Replies
1
Views
161

### Re: rounding GLfloat values??

(int)(FloatNumber + 0.5f)
9. ## Thread: Perspective view in flight simulators.

by Tron
Replies
1
Views
127

### Re: Perspective view in flight simulators.

this is exactly the what fov does: zooming (ever played quake? try 'fov' in the console)

the normal value for fov is 90 degree
smaller values zoom in, larger values zoom out

i tested this in...

by Tron
Replies
13
Views
1,112

### Re: Error Reading File BMP File Size ?

in fact it is not a string ("MB"), it's a a 2 byte charachter literal ('MB')

but this is NOT portable! e.g. try it with MinGW and it will fail, because MinGW compiles this the other way round, so...

by Tron
Replies
13
Views
1,112

### Re: Error Reading File BMP File Size ?

jup, it's an alignment problem, you read th bytes 4 till 7 instead of 2 till 5
the bytes are:
xx xx 07 00 00 00
the first 4 are the size (the 07 00 result from the about 465k file size) the...
12. ## Thread: Zooming and clipping

by Tron
Replies
3
Views
225

### Re: Zooming and clipping

eh? zomming has nothing to do with the clipping planes!

this is the matrix: (perspective, lefthanded, postmultiplied)
A 0 0 0
0 B 0 0
0 0 C D
0 0 1 0

A = 1.0 / tan(Angle / 2.0 / 180.0 *...
13. ## Thread: int, float VS. GLint, GLfloat

by Tron
Replies
12
Views
11,043

### Re: int, float VS. GLint, GLfloat

it's the same, they're just typedefs

by Tron
Replies
2
Views
115

### Re: OpenGL Matrices

per definition it's
0 4 8 12
1 5 9 13
2 6 10 14
3 7 11 15
post-multiplied
15. ## Thread: Windows Programming with Visual C++

by Tron
Replies
10
Views
394

### Re: Windows Programming with Visual C++

not really an OpenGL question...

you selected the wrong type of project, try 'win32 application' or something like that(not console)
16. ## Thread: Problems with Object-Oriented OpenGL programming

by Tron
Replies
18
Views
759

### Re: Problems with Object-Oriented OpenGL programming

include the windows.h BEFORE GL/gl.h
17. ## Thread: Full Screen Question

by Tron
Replies
14
Views
1,151

### Re: Full Screen Question

the CDS_FULLSCREEN flag is used to remove the taskbar (otherwise it would be displayed over your 'fullscreen' window)
18. ## Thread: Why the display list doesn't work?

by Tron
Replies
3
Views
205

### Re: Why the display list doesn't work?

[This message has been edited by Tron (edited 11-21-2001).]

[This message has been edited by Tron (edited 11-22-2001).]
19. ## Thread: glLineWidth - doesn't work !

by Tron
Replies
10
Views
2,517

### Re: glLineWidth - doesn't work !

the only width which is guaranteed is 1.0
support for other is implemantation depedent
20. ## Thread: how do i edit opengl.dll?

by Tron
Replies
10
Views
568

### Re: how do i edit opengl.dll?

ROFLNSC

you have absolutely NO idea what you're trying to do...

by Tron
Replies
2
Views
155

### Re: screenshot routine

do you set glPixelStorei(GL_PACK_ALIGNMENT, 1)? if not every line is word-aligned!

for comparison check out my screenshot code, which just generates a 24bit RGB raw-file

[This message has...
22. ## Thread: construct rotation matrix

by Tron
Replies
2
Views
201

### Re: construct rotation matrix

@chowe6685:

@huangzl99:
is that the whole code?
you MUST have an active OpenGL rendering context to issue ANY OpenGL commands (even glGetString)
23. ## Thread: OpenGL in VB ???

by Tron
Replies
9
Views
590

### Re: OpenGL in VB ???

programming OpenGL in VB is like placing a 40hp engine into a Ferrari chassis :D
24. ## Thread: avoiding double includes while using opengl libraries in object oriented environment?

by Tron
Replies
13
Views
916

### Re: avoiding double includes while using opengl libraries in object oriented environment?

if you have a header file you can prevent it from beeing included multiple times (and generating multiple-declaration errors) by using a sentry.

checks if this token is defined, if not processes...
25. ## Thread: avoiding double includes while using opengl libraries in object oriented environment?

by Tron
Replies
13
Views
916

### Re: avoiding double includes while using opengl libraries in object oriented environment?

btw: this is technique called: sentry