SkyPic
This singleton object provides utilities for creating and manipulating images that represent views of a night sky.
Value members
Concrete methods
Given a StarMap that details what is visible in the sky, produces a Pic
that represents that information as an image. The background of the image is a
Black square of the given size. Each star and constellation in the sky appear
against that background.
Given a StarMap that details what is visible in the sky, produces a Pic
that represents that information as an image. The background of the image is a
Black square of the given size. Each star and constellation in the sky appear
against that background.
- Value parameters:
- bgSize
the width and height, in pixels, of the desired square image
- skyData
the contents of the night sky that are to be represented as an image
Given an image of the sky and a star, returns a version of the original image with a constellation drawn on top.
Given an image of the sky and a star, returns a version of the original image with a constellation drawn on top.
A constellation is depicted using a combination of red circles and yellow lines. At each star that belongs to the constellation, a red circle with a diameter of 4 pixels is added. A yellow line is then drawn between each pair of connected stars. The positions of the stars within the image are determined as in placeStar.
Given an image of the sky and a star, returns a version of the original image with
an image of the star placed on top. That is, forms an image of the star and places
it against the given (larger) image in a Pos that corresponds to the star’s
StarCoords.
Given an image of the sky and a star, returns a version of the original image with
an image of the star placed on top. That is, forms an image of the star and places
it against the given (larger) image in a Pos that corresponds to the star’s
StarCoords.
The star is depicted as a White circle whose diameter is 12.0 / (M + 2),
where M is the star’s magnitude. Its position within the resulting image is
determined by the star’s posIn method. The given star must have a magnitude
greater than -2.
For example, say the background image is 400 by 400 pixels, and the given star has the coords (0.5,0.0) and a magnitude of -0.5. The returned image will then consist of the given background image with white circle of radius 4 placed upon it at (300,200).
- Value parameters:
- skyPic
an image to place the star upon
- star
a star (of magnitude > -2) that should be depicted against the given image