ios, quartz2d, fastest way of drawing bitmap context into window context?
hallo, sorry for my weak english,
I am looking hardly for fastest possible way of redrawing bitmap
context (which holds pointer to may raw bitmap data) onto iphone
view window context
in the examples i have found in the net people are doing this by
making CGImage from such bitmap context then making UIImage
from this and drawing it onto the view
i am thinking if it is a fastest way of doing it? do i need to create
then release CGImage – in documentation there is info that
making CGImage copy data – is it possible to send my bitmap context
data straight to window context without allocating/ copying then
releasing it in CGImage? (which seem physically not necessary)
parade
I think I see what you are getting at. You have a pointer to the bitmap data and you just want the window to display that. On the old Mac OS (9 and previous) you could write draw directly to video memory, but you can’t do that anymore. Back then video memory was part of RAM and now it’s all on the OpenGL card.
At some level the bitmap data will have to be copied at least once. You can either do it directly by creating an OpenGL texture from the data and drawing that in an OpenGL context or you can use the UIImage approach. The UIImage approach will be slower and may contain two or more copies of the bitmap data, once to the UIImage and once when rendering the UIImage.
In either case, you need to create and release the CGImage.