vector arrays - vertex arrays
April 29, 2005 08:00 PM
i have my vertices stored in vectors. i put them in vectors because its alot easier to load that way. now im looking for a way to take those vectors and put them into vertex arrays. so i have 2 questions:
1. do vertex arrays support type vector?
2. if not, whats the easiest way to copy that information into a vertex array?
btw hopefully i will be able to put a demo up soon of my engine! it will be very basic but hey, its a conglomerate of 2 years worth of learning off and on.
444
April 29, 2005 11:28 PM
1. I doubt it. the OGL interface is in C code.
2. My experience with STL Vector is limited, but I would expect the only way would be to copy element by element
Is there a particular reason for not being able to use an array?
2. My experience with STL Vector is limited, but I would expect the only way would be to copy element by element
Is there a particular reason for not being able to use an array?
Disclaimer: "I am in no way qualified to present advice on any topic concerning anything and can not be held responsible for any damages that my advice may incurr (due to neither my negligence nor yours)"
602
April 30, 2005 04:09 AM
1) Yes. Use something like &vertices[ 0 ].x for address. But use of normal arrays is sometimes perfered.
2) Create array of same size and either copy one by one or use std::copy
2) Create array of same size and either copy one by one or use std::copy
You should never let your fears become the boundaries of your dreams.
April 30, 2005 10:35 AM
Quote: Original post by falkone
Is there a particular reason for not being able to use an array?
okay, this is what works, but is impracticle
GLfloat vertArray[9] = {/*store verts here*/};i need to create a dynamic array but it never works
GLfloat *vertArray;vertArray = new GLfloat[9]; //resize accordinglyvertArray[0] = 0.0f; //and so on down the list, filling each array value...vertArray[8] = 20.0f;[Edited by - adam17 on April 30, 2005 1:35:59 PM]
567
April 30, 2005 10:01 PM
So you mean you have a vector of vertices, not a vector class for your vertex? Use vector.pointer. It's stored as an array internally anyway. Just don't hold on to that or it'll become invalid.
___________________________________________________David OlsenIf I've helped you, please vote for PigeonGrape!
514
May 02, 2005 03:04 PM
Quote: Original post by adam17Quote: Original post by falkone
Is there a particular reason for not being able to use an array?
okay, this is what works, but is impracticleGLfloat vertArray[9] = {/*store verts here*/};
Well, if you're only going to have 9 vertices (which is quite limited), there's nothing wrong with using a standard array. You're right, though, that you're going to want a dynamic array for anything useful.
Quote:
i need to create a dynamic array but it never worksGLfloat *vertArray;vertArray = new GLfloat[9]; //resize accordinglyvertArray[0] = 0.0f; //and so on down the list, filling each array value...vertArray[8] = 20.0f;
What about it doesn't work? That code looks fine to me. Is it not drawing properly? Are you sure you're making the call to gl*Pointer and the subsequent call to glDraw* properly?
Without order nothing can exist - without chaos nothing can evolve.
May 04, 2005 12:14 AM
here is how i am defining the arrays:
here is how im drawing the vertex arrays:
vertArray = new GLfloat[9]; vertArray[0] = 0.0; vertArray[1] = 0.0; vertArray[2] = 0.0; vertArray[3] =-20.0; vertArray[4] = 40.0; vertArray[5] = 0.0; vertArray[6] = 20.0; vertArray[7] = 40.0; vertArray[8] = 0.0;here is how im drawing the vertex arrays:
//i can switch between commenting either the vertex arrays, //or drawing the triangles by hand and my program crashes.//if i comment both sections, the program runs fine. //defining the array does not crash the program.//any ideas?glEnableClientState(GL_VERTEX_ARRAY); glVertexPointer(3, GL_FLOAT, 0, vertArray); glDrawArrays(GL_TRIANGLES, 0, 3); glDisableClientState(GL_VERTEX_ARRAY);glBegin(GL_TRIANGLES); glVertex3f(vertArray[0], vertArray[1], vertArray[2]); glVertex3f(vertArray[3], vertArray[4], vertArray[5]); glVertex3f(vertArray[6], vertArray[7], vertArray[8]); glEnd();
122
May 10, 2005 07:26 PM
Your code looks fine to me. My Vertex Array code looks almost exactly like that.
Where exactly is the error happening?
Where exactly is the error happening?
May 11, 2005 11:04 PM
the error is occuring when i uncomment
or when i uncomment
glEnableClientState(GL_VERTEX_ARRAY);glVertexPointer(3, GL_FLOAT, 0, vertArray);glDrawArrays(GL_TRIANGLES, 0, 3);glDisableClientState(GL_VERTEX_ARRAY);or when i uncomment
glBegin(GL_TRIANGLES);glVertex3f(vertArray[0], vertArray[1], vertArray[2]);glVertex3f(vertArray[3], vertArray[4], vertArray[5]);glVertex3f(vertArray[6], vertArray[7], vertArray[8]);glEnd();
122
May 15, 2005 11:49 PM
Have you tried it with an array of floats and not GLfloats?
I don't know why that would fix your problem, but that's the only part that differs from the code that I use.
I'm assuming the program compiles and then crashes when it gets to your uncommented code. Are you using any kind of debugger? I've been able to solve many a problem with either gdb or microsoft's debugger.
If all else fails, you can try it the old fashioned way with malloc.
[Edited by - Halibut on May 16, 2005 3:49:19 AM]
I don't know why that would fix your problem, but that's the only part that differs from the code that I use.
I'm assuming the program compiles and then crashes when it gets to your uncommented code. Are you using any kind of debugger? I've been able to solve many a problem with either gdb or microsoft's debugger.
If all else fails, you can try it the old fashioned way with malloc.
GLfloat *vertArray;//initialize withvertArray=(GLfloat*)malloc(9*sizeof(GLfloat));//free the memory withfree(vertArray);[Edited by - Halibut on May 16, 2005 3:49:19 AM]
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