Framebuffer API

[thejpster]

Need a device we can open to send 2D drawing commands to:

• move graphics cursor
• set Foreground/background colour
• draw line of given thickness
• read back area
• draw outline rectangle
• draw filled rectangle
• draw bitmap to area, with colour masking

Low level API can work in screen-format data and high level APIs can convert that into pixel colour iterators for embedded-graphics.

See the BBC Micro's VDU API for inspiration. Also look at Windows GDI perhaps.

[thejpster]

The BBC Micro user guide has a polygon drawing demo we can port over.

Need to decide if screen always has a 'fixed' resolution (e.g. 1280x960) or if commands a relative to the actual screen dimensions. I think I prefer the latter.