Can someone explain pitch to me? From the documentation I assumed that

the pitch of a surface would be equal to the width of the surface times

the bits per pixel. This doesn’t seem to be correct, what is the pitch?

Thanks,

Buck

Can someone explain pitch to me? From the documentation I assumed that

the pitch of a surface would be equal to the width of the surface times

the bits per pixel. This doesn’t seem to be correct, what is the pitch?

Thanks,

Buck

‘Pitch’ is the physical width of the surface, as opposed to the logical

width of the surface. It mainly comes into play where your surfaces are

of an unusual width. Since graphics cards are often optimised to send

and store data in blocks with widths of a power of 2, it is common for

them to pad out your graphic’s width to the nearest larger power of 2

(or some other ‘round’ number in binary terms) to keep them aligned.

This means you have to keep track of where the actual image starts and

where the padding begins so that you don’t end up blitting the padding.–

Kylotan

Bytes, not bits.

256 horizontal pixels

256 X 1 for 8bit 256pitch

256 X 2 for 16bit 512pitch

256 X 3 for 24bit 768pitch

256 X 4 for 32bit 1024pitch> ----- Original Message -----

From: sdl-admin@libsdl.org [mailto:sdl-admin at libsdl.org] On Behalf Of

Wesley (Buck) Lemke

Sent: Wednesday, February 20, 2002 6:19 PM

To: sdl at libsdl.org

Subject: [SDL] Pitch QuestionCan someone explain pitch to me? From the documentation I assumed that

the pitch of a surface would be equal to the width of the surface times

the bits per pixel. This doesn’t seem to be correct, what is the pitch?