OpenGL rotating a 2D texture - c++

Question

UPDATE
See bottom for update.
I've been looking alot around the internet and I have found a few tutorials that explain what I'm trying to achieve but I can't get it to work, either the tutorial is incomplete or not applicable on my code.
I'm trying something as simple as rotating a 2D image around its origin (center).
I use xStart, xEnd, yStart and yEnd to flip the texture which are either 0 or 1.
This is what the code looks like
GameRectangle dest = destination;
Vector2 position = dest.getPosition();
glEnable(GL_TEXTURE_2D);
glBindTexture(GL_TEXTURE_2D, this->image);
//If the rotation isn't 0 we'll rotate it
if (rotation != 0)
{
glMatrixMode(GL_TEXTURE);
glLoadIdentity();
glTranslatef(0.5, 0.5, 0);
glRotatef(rotation, 0, 0, 1);
glMatrixMode(GL_PROJECTION);
}
glBegin(GL_QUADS);
glTexCoord2d(xStart,yStart);
glVertex2f(position.x, position.y);
glTexCoord2d(xEnd,yStart);
glVertex2f(position.x + this->bounds.getWidth(), position.y);
glTexCoord2d(xEnd,yEnd);
glVertex2f(position.x + this->bounds.getWidth(), position.y + this->bounds.getHeight());
glTexCoord2d(xStart,yEnd);
glVertex2f(position.x, position.y + this->bounds.getHeight());
glEnd();
glDisable(GL_TEXTURE_2D);
//Reset the rotation so next object won't be rotated
glMatrixMode(GL_TEXTURE);
glLoadIdentity();
glRotatef(0, 0, 0, 1);
glMatrixMode(GL_PROJECTION);
This code will draw the image in it's original size and it will rotate it, but it will rotate it from the top left corner which crops the image a lot. By calling GameRectangle.getOrigin() I can easily get the center of the rectangle, but I don't know where to use it.
Bit if put:
glTranslatef(-0.5, -0.5, 0);
After I call the:
glRotatef(0.5, 0.5, 0);
It will rotate from the center, but it will strech the image if it's not a perfect 90 degrees rotation.
UPDATE
After trying pretty much everything possible, I got the result I was looking for.
But I'm not sure if this is the best approach. Please tell me if there's something wrong with my code.
As I mentioned in a comment above, I use the same image multiple times and draw it with different values, so I can't save anything to the actual image. So I must reset the values everytime after I have rendered it.
I changed my code to this:
//Store the position temporary
GameRectangle dest = destination;
Vector2 position = dest.getPosition();
glEnable(GL_TEXTURE_2D);
glBindTexture(GL_TEXTURE_2D, this->image);
glTranslatef(dest.getOrigin().x, dest.getOrigin().y, 0);
glRotatef(rotation, 0, 0, 1);
glBegin(GL_QUADS);
glTexCoord2d(xStart,yStart);
glVertex2f(-dest.getWidth()/2, -dest.getHeight()/2);
glTexCoord2d(xEnd,yStart);
glVertex2f(dest.getWidth()/2, -dest.getHeight()/2);
glTexCoord2d(xEnd,yEnd);
glVertex2f(dest.getWidth()/2, dest.getHeight()/2);
glTexCoord2d(xStart,yEnd);
glVertex2f(-dest.getWidth()/2, dest.getHeight()/2);
glEnd();
//Reset the rotation and translation
glRotatef(-rotation,0,0,1);
glTranslatef(-dest.getOrigin().x, -dest.getOrigin().y, 0);
glDisable(GL_TEXTURE_2D);
This rotates the texture together with the quad it's drawn in, it doesn't strech or crop. However the edges are a bit jagged if the image is filled square but I guess I can't avoid that with out antialiasing.

Answer 1

What you want is this:
glPushMatrix(); //Save the current matrix.
//Change the current matrix.
glTranslatef(dest.getOrigin().x, dest.getOrigin().y, 0);
glRotatef(rotation, 0, 0, 1);
glBegin(GL_QUADS);
glTexCoord2d(xStart,yStart);
glVertex2f(-dest.getWidth()/2, -dest.getHeight()/2);
glTexCoord2d(xEnd,yStart);
glVertex2f(dest.getWidth()/2, -dest.getHeight()/2);
glTexCoord2d(xEnd,yEnd);
glVertex2f(dest.getWidth()/2, dest.getHeight()/2);
glTexCoord2d(xStart,yEnd);
glVertex2f(-dest.getWidth()/2, dest.getHeight()/2);
glEnd();
//Reset the current matrix to the one that was saved.
glPopMatrix();