Digital differential analyzer (graphics algorithm): Difference between revisions

Revision as of 08:46, 8 July 2008

Revision as of 08:47, 8 July 2008

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==Performance==

The DDA method can be implemented using [[floating-point]] or [[integer]] arithmetic. The naïve floating-point implementation requires one addition and one roundrounding operation per interpolated value (e.g. coordinate x, y, depth, color component etc.) and output result. This process is only efficient when a [[FPU]] with fast add and roundrounding operation is available.

The [[fixed-point]] integer operation requires two additions per output cycle, and in case of fractional part overflow one additional increment and subtraction. The probability of fractional part overflows is proportional to the ratio ''m'' of the interpolated start/end values.