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kieranhj / pop-beeb

Prince of Persia port to BBC Master
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Could speed up half-vres sprite plot for player... #141

Closed kieranhj closed 6 years ago

kieranhj commented 6 years ago

At the moment plotting half-vres sprites (for the player) is done by a hack that causes the plot function to reuse the same data for odd numbered lines. This means the same data is being unpacked twice before plotting to the screen.

It would be more efficient if the hack just / also skipped the decode part for the second line - this should be possible in theory as the data is already stored on the stack.

kieranhj commented 6 years ago

This has been done on a branch plot-half-res. Pleasingly the game now runs at a solid 25Hz when the player is standing still.

kieranhj commented 6 years ago

Implemented.