[PATCH 5/5] d3d9/tests: D3DCMP_GREATER is broken on r500.

[Stefan Dösinger]

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Am 2013-09-12 12:44, schrieb Henri Verbeet:
> On 12 September 2013 12:23, Stefan Dösinger
> <stefan at codeweavers.com> wrote:
>> +     * On the r500 driver on Windows D3DCMP_GREATER and
>> D3DCMP_GREATEREQUAL are broken for depth +     * values > 0.5.
>> The range appears to be distored, apparently an incoming value of
>> ~0.875 is
> "distorted"?
Sorry, I wasn't able to find out what the driver is doing exactly.
Everything seems ok when the value in the Z buffer and the incoming
fragment's Z are 0.5 or smaller. At first I thought D3DCMP_GREATER is
broken in general and behaves like D3DCMP_NEVER - that was when I
investigated the failure in the d3d8 version of this test. On closer
inspection it turned out that 0.5000001 is roughly equal to 0.0877,
and 0.95 roughly matches the 0.75 we write into the buffer with the
clear call. (The numbers are from my memory, they may be a bit off.)

D3DCMP_LESS works correctly. I think D3DCMP_GREATER also produces
expected results when just comparing geometry Z vs geometry Z, so a
game that uses it and doesn't depend on a match with the clear value
should still work, maybe with reduced precision.

D3DCMP_GREATEREQUAL has the same bug as D3DCMP_GREATER.
D3DCMP_LESSEQUAL works ok as well.

After two hours of trying to find out what the driver does I decided
it's not worth the time and marked the tests broken. It is after all a
no longer maintained Windows driver.

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