[PATCH v2 1/5] drm/tests: Test drm_rect_intersect()

[Maíra Canal]

Hi Arthur,

On 3/27/23 10:38, Arthur Grillo wrote:
> Insert test for the drm_rect_intersect() function, it also create a
> helper for comparing drm_rects more easily.
> 
> Signed-off-by: Arthur Grillo <arthurgrillo at riseup.net>
> ---
>   drivers/gpu/drm/tests/drm_rect_test.c | 139 ++++++++++++++++++++++++++
>   1 file changed, 139 insertions(+)
> 
> diff --git a/drivers/gpu/drm/tests/drm_rect_test.c b/drivers/gpu/drm/tests/drm_rect_test.c
> index e9809ea32696..3654c0be3d6b 100644
> --- a/drivers/gpu/drm/tests/drm_rect_test.c
> +++ b/drivers/gpu/drm/tests/drm_rect_test.c
> @@ -9,6 +9,17 @@
>   
>   #include <drm/drm_rect.h>
>   
> +#include <linux/string_helpers.h>

Is this include really needed? I was able to compile without it.

> +
> +static void drm_rect_compare(struct kunit *test, const struct drm_rect *r,
> +			     const struct drm_rect *expected)
> +{
> +	KUNIT_EXPECT_EQ(test, r->x1, expected->x1);

Maybe it would be nice to have a message here that shows the current x1
and the expected x1. Same for the other dimensions.

> +	KUNIT_EXPECT_EQ(test, r->y1, expected->y1);
> +	KUNIT_EXPECT_EQ(test, drm_rect_width(r), drm_rect_width(expected));
> +	KUNIT_EXPECT_EQ(test, drm_rect_height(r), drm_rect_height(expected));
> +}
> +
>   static void drm_test_rect_clip_scaled_div_by_zero(struct kunit *test)
>   {
>   	struct drm_rect src, dst, clip;
> @@ -196,11 +207,139 @@ static void drm_test_rect_clip_scaled_signed_vs_unsigned(struct kunit *test)
>   	KUNIT_EXPECT_FALSE_MSG(test, drm_rect_visible(&src), "Source should not be visible\n");
>   }
>   
> +struct drm_rect_intersect_case {
> +	const char *description;
> +	struct drm_rect r1, r2;
> +	bool should_be_visible;
> +	struct drm_rect expected_intersection;
> +};
> +
> +static const struct drm_rect_intersect_case drm_rect_intersect_cases[] = {
> +	{
> +		.description = "top-left X bottom-right",
> +		.r1 = DRM_RECT_INIT(1, 1, 2, 2),
> +		.r2 = DRM_RECT_INIT(0, 0, 2, 2),
> +		.should_be_visible = true,
> +		.expected_intersection = DRM_RECT_INIT(1, 1, 1, 1),
> +	},
> +	{
> +		.description = "top-right X bottom-left",
> +		.r1 = DRM_RECT_INIT(0, 0, 2, 2),
> +		.r2 = DRM_RECT_INIT(1, -1, 2, 2),
> +		.should_be_visible = true,
> +		.expected_intersection = DRM_RECT_INIT(1, 0, 1, 1),
> +	},
> +	{
> +		.description = "bottom-left X top-right",
> +		.r1 = DRM_RECT_INIT(1, -1, 2, 2),
> +		.r2 = DRM_RECT_INIT(0, 0, 2, 2),
> +		.should_be_visible = true,
> +		.expected_intersection = DRM_RECT_INIT(1, 0, 1, 1),
> +	},
> +	{
> +		.description = "bottom-right X top-left",
> +		.r1 = DRM_RECT_INIT(0, 0, 2, 2),
> +		.r2 = DRM_RECT_INIT(1, 1, 2, 2),
> +		.should_be_visible = true,
> +		.expected_intersection = DRM_RECT_INIT(1, 1, 1, 1),
> +	},
> +	{
> +		.description = "right X left",
> +		.r1 = DRM_RECT_INIT(0, 0, 2, 1),
> +		.r2 = DRM_RECT_INIT(1, 0, 3, 1),
> +		.should_be_visible = true,
> +		.expected_intersection = DRM_RECT_INIT(1, 0, 1, 1),
> +	},
> +	{
> +		.description = "left X right",
> +		.r1 = DRM_RECT_INIT(1, 0, 3, 1),
> +		.r2 = DRM_RECT_INIT(0, 0, 2, 1),
> +		.should_be_visible = true,
> +		.expected_intersection = DRM_RECT_INIT(1, 0, 1, 1),
> +	},
> +	{
> +		.description = "up X bottom",
> +		.r1 = DRM_RECT_INIT(0, 0, 1, 2),
> +		.r2 = DRM_RECT_INIT(0, -1, 1, 3),
> +		.should_be_visible = true,
> +		.expected_intersection = DRM_RECT_INIT(0, 0, 1, 2),
> +	},
> +	{
> +		.description = "bottom X up",
> +		.r1 = DRM_RECT_INIT(0, -1, 1, 3),
> +		.r2 = DRM_RECT_INIT(0, 0, 1, 2),
> +		.should_be_visible = true,
> +		.expected_intersection = DRM_RECT_INIT(0, 0, 1, 2),
> +	},
> +	{
> +		.description = "touching corner",
> +		.r1 = DRM_RECT_INIT(0, 0, 1, 1),
> +		.r2 = DRM_RECT_INIT(1, 1, 2, 2),
> +		.should_be_visible = false,
> +		.expected_intersection = DRM_RECT_INIT(1, 1, 0, 0),
> +	},
> +	{
> +		.description = "touching side",
> +		.r1 = DRM_RECT_INIT(0, 0, 1, 1),
> +		.r2 = DRM_RECT_INIT(1, 0, 1, 1),
> +		.should_be_visible = false,
> +		.expected_intersection = DRM_RECT_INIT(1, 0, 0, 1),
> +	},
> +	{
> +		.description = "equal rects",
> +		.r1 = DRM_RECT_INIT(0, 0, 2, 2),
> +		.r2 = DRM_RECT_INIT(0, 0, 2, 2),
> +		.should_be_visible = true,
> +		.expected_intersection = DRM_RECT_INIT(0, 0, 2, 2),
> +	},
> +	{
> +		.description = "inside another",
> +		.r1 = DRM_RECT_INIT(0, 0, 2, 2),
> +		.r2 = DRM_RECT_INIT(1, 1, 1, 1),
> +		.should_be_visible = true,
> +		.expected_intersection = DRM_RECT_INIT(1, 1, 1, 1),
> +	},
> +	{
> +		.description = "far away",
> +		.r1 = DRM_RECT_INIT(0, 0, 1, 1),
> +		.r2 = DRM_RECT_INIT(3, 6, 1, 1),
> +		.should_be_visible = false,
> +		.expected_intersection = DRM_RECT_INIT(3, 6, -2, -5),
> +	},
> +};

What happens if width = height = 0? It would be nice to have a test
case for this scenario.

> +
> +static void drm_rect_intersect_case_desc(const struct drm_rect_intersect_case *t, char *desc)
> +{
> +	if (!t->description)
> +		snprintf(desc, KUNIT_PARAM_DESC_SIZE,
> +			 DRM_RECT_FMT " X " DRM_RECT_FMT,
> +			 DRM_RECT_ARG(&t->r1), DRM_RECT_ARG(&t->r2));

Is this conditional clause really needed? All parameters have
description.

> +	else
> +		snprintf(desc, KUNIT_PARAM_DESC_SIZE,
> +			 "%s: " DRM_RECT_FMT " X " DRM_RECT_FMT,
> +			 t->description, DRM_RECT_ARG(&t->r1), DRM_RECT_ARG(&t->r2));
> +}
> +
> +KUNIT_ARRAY_PARAM(drm_rect_intersect, drm_rect_intersect_cases, drm_rect_intersect_case_desc);
> +
> +static void drm_test_rect_intersect(struct kunit *test)
> +{
> +	const struct drm_rect_intersect_case *params = test->param_value;
> +	struct drm_rect r1_aux = params->r1;

Does this variable needs to exist? I guess you could just use params->r1.

Best Regards,
- Maíra Canal

> +	bool visible;
> +
> +	visible = drm_rect_intersect(&r1_aux, &params->r2);
> +
> +	KUNIT_EXPECT_EQ(test, visible, params->should_be_visible);
> +	drm_rect_compare(test, &r1_aux, &params->expected_intersection);
> +}
> +
>   static struct kunit_case drm_rect_tests[] = {
>   	KUNIT_CASE(drm_test_rect_clip_scaled_div_by_zero),
>   	KUNIT_CASE(drm_test_rect_clip_scaled_not_clipped),
>   	KUNIT_CASE(drm_test_rect_clip_scaled_clipped),
>   	KUNIT_CASE(drm_test_rect_clip_scaled_signed_vs_unsigned),
> +	KUNIT_CASE_PARAM(drm_test_rect_intersect, drm_rect_intersect_gen_params),
>   	{ }
>   };
>