2D-Rendering: Coordinate mapping is broken

[kimkulling]

Describe the bug
The 2D-Canvas renderer is mapping the 2D-coordinates in a wrong was:

• Only 1/2 of the place in the render screen will be used.
• The y-mapping breaks rfom 0 ... w/2
• The y-coorindate origin is at the bottom edge.

To Reproduce
Steps to reproduce the behavior:

1. Build the engine
2. Start Demo2D

Expected behavior

• Whole resolution shall be used
• Origin of y is on the top

Screenshots
NA

Desktop (please complete the following information):

• OS: All

Additional context
NA