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Help => Graphics => Topic started by: tntexplosivesltd on February 13, 2011, 09:40:10 am

Title: Smaller images from a larger image
Post by: tntexplosivesltd on February 13, 2011, 09:40:10 am

Hi.
I am wondering how to load an image of ASCII characters and create many smaller images (one for each letter) from that large image.
Thank you in advance,
tntexplosivesltd.

Title: Smaller images from a larger image
Post by: devlin on February 13, 2011, 09:50:12 am

http://www.sfml-dev.org/documentation/2.0/classsf_1_1Image.htm

http://www.sfml-dev.org/documentation/2.0/classsf_1_1Image.htm (in particular SetSubRect)

It's all in the documentation ;)

Title: Smaller images from a larger image
Post by: tntexplosivesltd on February 13, 2011, 10:00:31 am

I want to use the images to draw text in openGL. SetSubRect looks to be going the wrong way about it. Found a link myself anyway:
http://www.sfml-dev.org/forum/viewtopic.php?t=2790

Title: Smaller images from a larger image
Post by: tntexplosivesltd on February 13, 2011, 10:14:52 am

Hmm... this shows image --> C++ STL vector --> image.
Can I just do image --> image?

Title: Smaller images from a larger image
Post by: Laurent on February 13, 2011, 10:34:42 am

You can use Image::Copy.

But why do you want to break your big image into individual smaller images? Rendering them will be much more efficient if they are all in the same texture.

Title: Smaller images from a larger image
Post by: tntexplosivesltd on February 13, 2011, 10:36:37 am

So how can I pass the letters to OpenGL individually?

Title: Smaller images from a larger image
Post by: Laurent on February 13, 2011, 10:47:33 am

With texture coordinates (Image::GetTexCoords).