This is a simple hardware test I wrote to validate that WashingtonDC is correctly implementing the PowerVR2's backface culling. It presents a triangle strip of two polygons which can moved and rotated in three dimensions using the dreamcast controller. The translation of the polygons as well as the determinant used for determining the facing of both polygons are displayed on-screen.


Pressing the x-button shows a separate status screeen with the screen-coordinates of all four vertices, as well as the rotation angles along all three axes in degrees, and the determinants that were also shown on the 3d view screen. The cull function can be changed here, and the bias value (register 0x5f8078) can be adjusted in increments of 100.




#culltest_3d_screen.png #culltest_info_screen.png