linux-kernel - Re: [PATCH v7 2/4] drm/rect: Add drm_rect

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Message-ID: <4b5c6ba2-e16c-4884-a067-8d9ab7ad35f8@suse.de>
Date: Thu, 22 Aug 2024 14:58:07 +0200
From: Thomas Zimmermann <tzimmermann@...e.de>
To: Jocelyn Falempe <jfalempe@...hat.com>,
 Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>,
 Maxime Ripard <mripard@...nel.org>, David Airlie <airlied@...il.com>,
 Daniel Vetter <daniel@...ll.ch>, Miguel Ojeda <ojeda@...nel.org>,
 Alex Gaynor <alex.gaynor@...il.com>,
 Wedson Almeida Filho <wedsonaf@...il.com>, Boqun Feng
 <boqun.feng@...il.com>, Gary Guo <gary@...yguo.net>,
 Bjorn Roy Baron <bjorn3_gh@...tonmail.com>,
 Benno Lossin <benno.lossin@...ton.me>,
 Andreas Hindborg <a.hindborg@...sung.com>, Alice Ryhl
 <aliceryhl@...gle.com>, linux-kernel@...r.kernel.org,
 dri-devel@...ts.freedesktop.org, rust-for-linux@...r.kernel.org,
 Danilo Krummrich <dakr@...hat.com>
Subject: Re: [PATCH v7 2/4] drm/rect: Add drm_rect_overlap()



Am 22.08.24 um 09:33 schrieb Jocelyn Falempe:
> Check if two rectangles overlap.
> It's a bit similar to drm_rect_intersect() but this won't modify
> the rectangle.
> Simplifies a bit drm_panic.
>
> Signed-off-by: Jocelyn Falempe <jfalempe@...hat.com>

Reviewed-by: Thomas Zimmermann <tzimmermann@...e.de>

There's an optional comment further below.

> ---
>
> v7:
>   * rename r1/r2 to a/b in drm_rect_overlap() (Jani Nikula)
>
>   drivers/gpu/drm/drm_panic.c |  3 +--
>   include/drm/drm_rect.h      | 15 +++++++++++++++
>   2 files changed, 16 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_panic.c b/drivers/gpu/drm/drm_panic.c
> index 0a047152f88b8..59fba23e5fd7a 100644
> --- a/drivers/gpu/drm/drm_panic.c
> +++ b/drivers/gpu/drm/drm_panic.c
> @@ -529,8 +529,7 @@ static void draw_panic_static_user(struct drm_scanout_buffer *sb)
>   	/* Fill with the background color, and draw text on top */
>   	drm_panic_fill(sb, &r_screen, bg_color);
>   
> -	if ((r_msg.x1 >= logo_width || r_msg.y1 >= logo_height) &&
> -	    logo_width <= sb->width && logo_height <= sb->height) {
> +	if (!drm_rect_overlap(&r_logo, &r_msg)) {
>   		if (logo_mono)
>   			drm_panic_blit(sb, &r_logo, logo_mono->data, DIV_ROUND_UP(logo_width, 8),
>   				       fg_color);
> diff --git a/include/drm/drm_rect.h b/include/drm/drm_rect.h
> index 73fcb899a01da..46f09cf68458c 100644
> --- a/include/drm/drm_rect.h
> +++ b/include/drm/drm_rect.h
> @@ -238,6 +238,21 @@ static inline void drm_rect_fp_to_int(struct drm_rect *dst,
>   		      drm_rect_height(src) >> 16);
>   }
>   
> +/**
> + * drm_rect_overlap - Check if two rectangles overlap
> + * @a: first rectangle
> + * @b: second rectangle
> + *
> + * RETURNS:
> + * %true if the rectangles overlap, %false otherwise.
> + */
> +static inline bool drm_rect_overlap(const struct drm_rect *a,
> +				    const struct drm_rect *b)
> +{
> +	return (a->x2 > b->x1 && b->x2 > a->x1 &&
> +		a->y2 > b->y1 && b->y2 > a->y1);

I found this hard to understand. You may want to use the existing 
_intersect helper

bool overlap(a, b)
{
   struct drm_rect tmp = *a

   return intersect(tmp, b);
}

Up to you.

Best regards
Thomas

> +}
> +
>   bool drm_rect_intersect(struct drm_rect *r, const struct drm_rect *clip);
>   bool drm_rect_clip_scaled(struct drm_rect *src, struct drm_rect *dst,
>   			  const struct drm_rect *clip);

-- 
--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Frankenstrasse 146, 90461 Nuernberg, Germany
GF: Ivo Totev, Andrew Myers, Andrew McDonald, Boudien Moerman
HRB 36809 (AG Nuernberg)