Archived

This topic is now archived and is closed to further replies.

bohrjl11

Texturing Question

Recommended Posts

Hi all, I was wondering if anybody knows how the glTexCoord2f() function works. I have a texture with some text on it and the text appears as a mirrow image of it. I didn''t use the same classes to load textures (I have a jpg loader), but I copied the code between glBegin and glEnd in tutorial six or seven. I tried to modify them to get the image right but can''t seem to get it. Wondering if anybody can help??? Thanks

Share this post


Link to post
Share on other sites
just a guess, but maybe the texture is being specified left to right, while the drawn quad is right to left?

i.e. for a tri-strip

Tex poly
a-c c-a
| | | |
b-d d-b


I've had my texture swapped vertically (my bad, it was in my BMP loader function) but never horizontally.

Can you post some code?

lonesock

Piranha are people too.

[edited by - lonesock on April 3, 2004 9:08:40 PM]

Share this post


Link to post
Share on other sites
Yea, that could be...I thought I tried that option, but maybe not Here is my original code for the quad before I made everything worse:

// Front Face
glNormal3f( 0.0f, 0.0f, 1.0f); // Normal Pointing Towards Viewer
glTexCoord2f(0.0f, 0.0f); glVertex3f(-1.0f, -1.0f, 1.0f); // Point 1 (Front)
glTexCoord2f(1.0f, 0.0f); glVertex3f( 1.0f, -1.0f, 1.0f); // Point 2 (Front)
glTexCoord2f(1.0f, 1.0f); glVertex3f( 1.0f, 1.0f, 1.0f); // Point 3 (Front)
glTexCoord2f(0.0f, 1.0f); glVertex3f(-1.0f, 1.0f, 1.0f); // Point 4 (Front)
// Back Face
glNormal3f( 0.0f, 0.0f,-1.0f); // Normal Pointing Away From Viewer
glTexCoord2f(1.0f, 0.0f); glVertex3f(-1.0f, -1.0f, -1.0f); // Point 1 (Back)
glTexCoord2f(1.0f, 1.0f); glVertex3f(-1.0f, 1.0f, -1.0f); // Point 2 (Back)
glTexCoord2f(0.0f, 1.0f); glVertex3f( 1.0f, 1.0f, -1.0f); // Point 3 (Back)
glTexCoord2f(0.0f, 0.0f); glVertex3f( 1.0f, -1.0f, -1.0f); // Point 4 (Back)
// Top Face
glNormal3f( 0.0f, 1.0f, 0.0f); // Normal Pointing Up
glTexCoord2f(0.0f, 1.0f); glVertex3f(-1.0f,1.0f,-1.0f); // Point 1 (Top)
glTexCoord2f(0.0f, 0.0f); glVertex3f(-1.0f, 1.0f, 1.0f); // Point 2 (Top)
glTexCoord2f(1.0f, 0.0f); glVertex3f( 1.0f, 1.0f, 1.0f); // Point 3 (Top)
glTexCoord2f(1.0f, 1.0f); glVertex3f( 1.0f, 1.0f, -1.0f); // Point 4 (Top)
// Bottom Face
glNormal3f( 0.0f,-1.0f, 0.0f); // Normal Pointing Down
glTexCoord2f(1.0f, 1.0f); glVertex3f(-1.0f, -1.0f, -1.0f); // Point 1 (Bottom)
glTexCoord2f(0.0f, 1.0f); glVertex3f( 1.0f, -1.0f, -1.0f); // Point 2 (Bottom)
glTexCoord2f(0.0f, 0.0f); glVertex3f( 1.0f, -1.0f, 1.0f); // Point 3 (Bottom)
glTexCoord2f(1.0f, 0.0f); glVertex3f(-1.0f, -1.0f, 1.0f); // Point 4 (Bottom)
// Right face
glNormal3f( 1.0f, 0.0f, 0.0f); // Normal Pointing Right
glTexCoord2f(1.0f, 0.0f); glVertex3f( 1.0f, -1.0f, -1.0f); // Point 1 (Right)
glTexCoord2f(1.0f, 1.0f); glVertex3f( 1.0f, 1.0f, -1.0f); // Point 2 (Right)
glTexCoord2f(0.0f, 1.0f); glVertex3f( 1.0f, 1.0f, 1.0f); // Point 3 (Right)
glTexCoord2f(0.0f, 0.0f); glVertex3f( 1.0f, -1.0f, 1.0f); // Point 4 (Right)
// Left Face
glNormal3f(-1.0f, 0.0f, 0.0f); // Normal Pointing Left
glTexCoord2f(0.0f, 0.0f); glVertex3f(-1.0f, -1.0f, -1.0f); // Point 1 (Left)
glTexCoord2f(1.0f, 0.0f); glVertex3f(-1.0f, -1.0f, 1.0f); // Point 2 (Left)
glTexCoord2f(1.0f, 1.0f); glVertex3f(-1.0f, 1.0f, 1.0f); // Point 3 (Left)
glTexCoord2f(0.0f, 1.0f); glVertex3f(-1.0f, 1.0f, -1.0f); // Point 4 (Left)

Sorry...kinda long and boring!! Anything else you need let me know. I appreciate the help!!
Thanks

Share this post


Link to post
Share on other sites
well, everything looks right out of tut6, so no errors there. In terms of weirdness, is it possible that glDepthFunc is GL_GREATER, so you''re actually seeing the back side of the cube? Or, in the same spirit, backface culling might be set to the wrong order (if I remember correctly, it is still the point order of the poly that OpenGL uses to bfc, not the normal vector that you are graciously providing).

Other than that, you might want to try dumping the loaded jpg to a bmp using a different library or code, just to make sure there is nothing funky with the jpg load code. I don''t really think this is the issue, though.

lonesock

Piranha are people too.

Share this post


Link to post
Share on other sites