[cairo] A couple of questions about Cairo

[Øyvind Kolås]

On Tue, Sep 1, 2020 at 9:23 AM Petr Kobalíček <kobalicek.petr at gmail.com> wrote:
>
> Totally unsuitable, you are looking for some embedded rasterizer.
>
> BTW How much RAM the device has, have you thought about the size of cairo itself including all its dependencies?
>
> On Tue, Sep 1, 2020 at 4:48 AM Andrew Stuart <andrew.stuart at supercoders.com.au> wrote:
>>
>> Hello Cairo community,
>>
>> I’m looking for a way to render 2d graphics on a highly memory constrained embedded 8 bit CPU without a framebuffer - so it must be possible to render scanline by scanline.
>>
>> How suitable or unsuitable would Cairo be for such requirements?  I can see mention of scanline rendering on the Internet in relation Cairo but it is not clear if this is fully implemented.

Over the last year I have been experimenting with a rasterizer
designed with the constraint of potentially tiny code/RAM size, that
can be suitable, it provides an API inspired by cairo/HTML5 canvas 2d
context, and can be found at http://ctx.graphics/ . I would recommend
using wider horizontal strips than single scanlines; since there is a
constant overhead for each replay of the deferred display list. If at
all possible these chunks should also be computed in RGBA8 instead of
(in ctx) slower formats like RGB565; like the microcontroller demos at
http://ctx.graphics/mcu/ currently are using.

When rendering graphics in this manner the size of the display list
becomes the new big graphics related in-memory thing, rather than the
framebuffer, the limit one runs into is no longer resolution but
complexity.

/pippin