Haskell Language Graphics with Gloss Getting something on the screen
Example
In Gloss, one can use the display function to create very simple static graphics.
To use this one needs to first import Graphics.Gloss. Then in the code there should the following:
main :: IO ()
main = display window background drawing
window is of type Display which can be constructed in two ways:
-- Defines window as an actual window with a given name and size
window = InWindow name (width, height) (0,0)
-- Defines window as a fullscreen window
window = FullScreen
Here the last argument (0,0) in InWindow marks the location of the top left corner.
For versions older than 1.11: In older versions of Gloss FullScreen takes another argument which is meant to be the size of the frame that gets drawn on which in turn gets stretched to fullscreen-size, for example: FullScreen (1024,768)
background is of type Color. It defines the background color, so it's as simple as:
background = white
Then we get to the drawing itself. Drawings can be very complex. How to specify these will be covered elsewhere ([one can refer to this for the moment][1]), but it can be as simple as the following circle with a radius of 80:
drawing = Circle 80
Summarizing example
As more or less stated in the documentation on Hackage, getting something on the screen is as easy as:
import Graphics.Gloss
main :: IO ()
main = display window background drawing
where
window = InWindow "Nice Window" (200, 200) (0, 0)
background = white
drawing = Circle 80
