Re: [igt-dev] [PATCH v4 10/13] chamelium: Change our pattern for a custom one

Eric Anholt
2018-08-09T21:31:52Z

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Maxime Ripard <maxime.ripard@bootlin.com> writes:

> The current pattern being used is the one generated through the
> igt_create_color_pattern_fb.
>
> However, in order to deal with multiple formats and the upsampling /
> downsampling issues that might arise from converting back and forth between
> formats, we will need to have a pattern with quite precise color values,
> and without any shades or gradient of colors.

64x64 blocks of color seem pretty limited, and might miss tiling issues
for people -- would the previous pattern be worth using for 1:1,
possibly non-format-converted cases?

> The easiest way to do that will be to only use values that would have the
> same part on the common most significant bits (5, to deal with the most
> formats) and have the same bit repeated on the least significant bits that
> are going to be dropped and / or padded when converting between formats.
>
> Pixman will fill the lowest bits with 1, and our hardware is able to

Let's specify which hardware here :)

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