Hey @T1001,
yes, you are on the right track there, to initialize an image as RGBA F32, you would do something like this:
static const Int32 size = 1024;
const ImageRef image = ImageClasses::IMAGE().Create() iferr_return;
const maxon::ColorProfile profile = ColorSpaces::RGBspace().GetDefaultNonlinearColorProfile();
const PixelFormat format = PixelFormats::RGBA::F32();
const Int32 channelCount = format.GetChannelCount();
// Init the bitmap with its size, storage convention, and pixel format. Whe choose here the
// "normal", i.e., consecutive layout. An alternative would be a planar layout.
image.Init(size, size, ImagePixelStorageClasses::Normal(), format) iferr_return;
image.Set(IMAGEPROPERTIES::IMAGE::COLORPROFILE, profile) iferr_return;
Regarding the rest, I roughly cover this in my example. A little GeUserArea which wraps around some render buffer data. I rather not yet share it here, as it "misbehaves" still in one aspect, and I am not sure if that is my or the API's fault (will have to catch one of the Image API devs for that).
You can also have a look at the Color Management and OCIO manual as I covered there quite a bit of pixel format and buffer handling subjects. Last but not least regarding hardware acceleration: The Image API does not have much drawing functions, that is primarily done in the semi-public Drawport API. It depends a bit on what you want to accelerate, filling a buffer cannot be accelerated, you either fill things row by row, or just wrap around some existing memory.
When you need hardware accelerated drawing functions like drawing a circle, etc., then you indeed must use the Drawport API. To get access to it as an external, you would have to apply for Maxon Registered Developer membership, as this would also grant access to the semi-public Drawport API. As its name implies, the Drawport API is the API with wich viewports are drawn in Cinema 4D. You might be familar with BaseDraw, the Cinema API type which is used to draw into view ports. Similar to how you can get an ImageRef from a BaseBitmap, you can get a DrawPortRef from a BaseDraw. Under the hood, draw ports are also used to draw into bitmaps, and there is also a mechanism with which one can attach a draw port to a dialog (a draw port user area).
But not all parts of the Drawport API are semi-public, some are fully private. I would first have to check, if the bitmap drawing part is semi-public and I know for a fact that the user area is not semi-public (but we wanted to expose it at some point but I think it never happend).
So, long story short, when you think you need all that, I would recommend reaching out via our contact form or directly apply for registered developer membership.
Cheers,
Ferdinand
