From f96bdf564f3e7511aecdd4c35cc18ac5e0750a2f Mon Sep 17 00:00:00 2001 From: Maarten Lankhorst Date: Thu, 3 May 2018 13:22:14 +0200 Subject: drm/rect: Handle rounding errors in drm_rect_clip_scaled, v3. MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Instead of relying on a scale which may increase rounding errors, clip src by doing: src * (dst - clip) / dst and rounding the result away from 1, so the new coordinates get closer to 1. We won't need to fix up with a magic macro afterwards, because our scaling factor will never go to the other side of 1. Changes since v1: - Adjust dst immediately, else drm_rect_width/height on dst gives bogus results. Change since v2: - Get rid of macros and use 64-bits math. Signed-off-by: Maarten Lankhorst [mlankhorst: Add Villes comment, and rename newsrc to tmp. (Ville)] Reviewed-by: Ville Syrjälä Link: https://patchwork.freedesktop.org/patch/msgid/20180503112217.37292-3-maarten.lankhorst@linux.intel.com --- include/drm/drm_rect.h | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) (limited to 'include/drm/drm_rect.h') diff --git a/include/drm/drm_rect.h b/include/drm/drm_rect.h index 44bc122b9ee0..6c54544a4be7 100644 --- a/include/drm/drm_rect.h +++ b/include/drm/drm_rect.h @@ -175,8 +175,7 @@ static inline bool drm_rect_equals(const struct drm_rect *r1, 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, - int hscale, int vscale); + const struct drm_rect *clip); int drm_rect_calc_hscale(const struct drm_rect *src, const struct drm_rect *dst, int min_hscale, int max_hscale); -- cgit v1.2.3