[Piglit] [PATCH v2 1/4] pbo-read-argb8888: make it endian-safe

[Michel Dänzer]

On 29.03.2016 18:06, Oded Gabbay wrote:
> In this test we use GL_BGRA + GL_UNSIGNED_BYTE. However, the probe
> function receives two 4-byte values to compare, expected and
> observed. This is wrong as the correct way to compare
> array_of_bytes (GL_UNSIGNED_BYTE) in an endian-safe way is by comparing
> memory (and not values).
> 
> This patch fixes this bug by changing the function to receive two
> pointers instead of values. It also corrects the way the expected values
> are constructed to be in endian-safe way for array-of-bytes
> 
> This fixes the test in llvmpipe, softpipe and r600g in big-endian machine.
> 
> v2: Changed initialization of expected results to be more clear
> 
> Signed-off-by: Oded Gabbay <oded.gabbay at gmail.com>
> ---
>  tests/general/pbo-read-argb8888.c | 18 ++++++++++++------
>  1 file changed, 12 insertions(+), 6 deletions(-)
> 
> diff --git a/tests/general/pbo-read-argb8888.c b/tests/general/pbo-read-argb8888.c
> index 99b4b3b..eaaa6ab 100644
> --- a/tests/general/pbo-read-argb8888.c
> +++ b/tests/general/pbo-read-argb8888.c
> @@ -43,12 +43,16 @@ PIGLIT_GL_TEST_CONFIG_BEGIN
>  PIGLIT_GL_TEST_CONFIG_END
>  
>  static GLboolean
> -probe(int x, int y, uint32_t expected, uint32_t observed)
> +probe(int x, int y, uint8_t *expected, uint32_t *observed)
>  {
> -	if ((expected & 0xffffff) != (observed & 0xffffff)) {
> +	uint8_t *p_obs = (uint8_t *) observed;
> +
> +	if (expected[0] != p_obs[0] ||
> +		 expected[1] != p_obs[1] ||
> +		 expected[2] != p_obs[2]) {
>  		printf("Probe color at (%i,%i)\n", x, y);
> -		printf("  Expected: 0x%08x\n", expected);
> -		printf("  Observed: 0x%08x\n", observed);
> +		printf("  Expected: 0x%08x\n", *((uint32_t *) expected));
> +		printf("  Observed: 0x%08x\n", *observed);

For clarity and cleaner code, I'd change the observed pointer to uint8_t
as well, and not print the expected and observed values as packed 32-bit
values. E.g.

	printf("  Expected: b=0x%02x g=0x%02x r=0x%02x a=0x%02x\n",
	       expected[0], expected[1], expected[2], expected[3]);

and correspondingly for observed.


> @@ -63,6 +67,8 @@ piglit_display(void)
>  	static float red[]   = {1.0, 0.0, 0.0, 0.0};
>  	static float green[] = {0.0, 1.0, 0.0, 0.0};
>  	uint32_t *addr;

This would be uint8_t* as well then.


> @@ -84,8 +90,8 @@ piglit_display(void)
>  
>  	addr = glMapBufferARB(GL_PIXEL_PACK_BUFFER, GL_READ_ONLY_ARB);
>  
> -	pass &= probe(10, 10, 0x0000ff00, addr[0]);
> -	pass &= probe(10, 10, 0x00ff0000, addr[1]);
> +	pass &= probe(10, 10, exp_green, &addr[0]);
> +	pass &= probe(10, 10, exp_red, &addr[1]);

And this would be

	pass &= probe(10, 10, exp_green, addr);
	pass &= probe(10, 10, exp_red, addr + 4);


-- 
Earthling Michel Dänzer               |               http://www.amd.com
Libre software enthusiast             |             Mesa and X developer