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Globe


Description

This program will render a globe, which can be scaled, rotated and translated. The program uses a Bitmap file of width:height ratio 2:1 which is a plate carrée projection. This is a particular type of cylindrical projection. It is possible to load in any Bitmap with a width:height ratio of 2:1, which will be projected onto a sphere by the program. Loading in Bitmaps of tessellations produces some interesting results; Click the link below to download various 2:1 JPEG images which can be used with this program (note that in order to load these images into the program it will be necessary to convert them to Bitmap file format).

Globe screenshot


How it works


Each pixel p on the screen is checked to determine if it is mapped to a point on the surface of the 3D sphere by the 3D projection. If it is mapped to a point on the sphere then this point b is transformed by the inverse of the current 3D rotation of the sphere to the point c. Point c is then projected to a pixel d on the bitmap by the plate carrée method. The pixel p is then set to the same colour as pixel d.

Compatability

Windows 98 or later, Linux with WINE.

Downloads

Cryptography application

Source code (C++ Borland Builder5.0 project)


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