Beginner question about vertex arrays in OpenGL

Posted by MrDatabase on Game Development See other posts from Game Development or by MrDatabase
Published on 2011-01-12T17:19:52Z Indexed on 2011/01/12 17:59 UTC
Read the original article Hit count: 292

Filed under:
|
|

Is there a special order in which vertices are entered into a vertex array? Currently I'm drawing single textures like this:

glBindTexture(GL_TEXTURE_2D, texName);
glVertexPointer(2, GL_FLOAT, 0, vertices);
glTexCoordPointer(2, GL_FLOAT, 0, coordinates);
glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);

where vertices has four "xy pairs". This is working fine.

As a test I doubled the sizes of the vertices and coordinates arrays and changed the last line above to:

glDrawArrays(GL_TRIANGLE_STRIP, 0, 8);

since vertices now contains eight "xy pairs". I do see two textures (the second is intentionally offset from the first). However the textures are now distorted. I've tried passing GL_TRIANGLES to glDrawArrays instead of GL_TRIANGLE_STRIP but this doesn't work either. I'm so new to OpenGL that I thought it's best to just ask here :-)

Cheers!

© Game Development or respective owner

Related posts about opengl

Related posts about iphone