Pixmap are ram pictures ie bitdata.
They are used if you want to modify the content of a picture dynamically as this is only possible on pixmaps. But they have their drawback compared to images: They draw slower, blend mode and several other state commands don't work and such things.
They are used if you want to modify the content of a picture dynamically as this is only possible on pixmaps. But they have their drawback compared to images: They draw slower, blend mode and several other state commands don't work and such things.