Confusion about using cache write to fill polygons

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hstubbs3
Posts: 72
Joined: Thu Oct 26, 2023 12:14 pm

Confusion about using cache write to fill polygons

Post by hstubbs3 »

The VERA FX tutorial and doc both indicate that the cache write is always to 4-byte aligned address...
And using it with the linear bitmap buffers, each line would always start at 4-byte aligned point..
Would be _nice_ to have more options for bitmap width, but anyways...

The polygon helper sets the initial x for addr1 for you, which is not guaranteed to be 4-byte aligned at all... so what's the expected / optimal strategy to use with the polygon helper when drawing arbitrary polygons using cache writes?

Is the doc wrong and the cache write isn't always 4-byte aligned? can you read the calculated addr1 back from the vera without causing some weird side effect??
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