diff options
author | Maarten Lankhorst <maarten.lankhorst@linux.intel.com> | 2018-05-03 13:22:14 +0200 |
---|---|---|
committer | Maarten Lankhorst <maarten.lankhorst@linux.intel.com> | 2018-05-04 11:09:54 +0200 |
commit | f96bdf564f3e7511aecdd4c35cc18ac5e0750a2f (patch) | |
tree | e0b610aaad29b30bf9af55abbb72821b43c0307f /drivers/gpu/drm | |
parent | 6f96f2000ac27b0f5f769b0bc2f0440ebfa1c3a3 (diff) |
drm/rect: Handle rounding errors in drm_rect_clip_scaled, v3.
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 <maarten.lankhorst@linux.intel.com>
[mlankhorst: Add Villes comment, and rename newsrc to tmp. (Ville)]
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180503112217.37292-3-maarten.lankhorst@linux.intel.com
Diffstat (limited to 'drivers/gpu/drm')
-rw-r--r-- | drivers/gpu/drm/drm_atomic_helper.c | 2 | ||||
-rw-r--r-- | drivers/gpu/drm/drm_rect.c | 49 | ||||
-rw-r--r-- | drivers/gpu/drm/i915/intel_sprite.c | 2 |
3 files changed, 38 insertions, 15 deletions
diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c index 9cb2209f6fc8..130da5195f3b 100644 --- a/drivers/gpu/drm/drm_atomic_helper.c +++ b/drivers/gpu/drm/drm_atomic_helper.c @@ -766,7 +766,7 @@ int drm_atomic_helper_check_plane_state(struct drm_plane_state *plane_state, if (crtc_state->enable) drm_mode_get_hv_timing(&crtc_state->mode, &clip.x2, &clip.y2); - plane_state->visible = drm_rect_clip_scaled(src, dst, &clip, hscale, vscale); + plane_state->visible = drm_rect_clip_scaled(src, dst, &clip); drm_rect_rotate_inv(src, fb->width << 16, fb->height << 16, rotation); diff --git a/drivers/gpu/drm/drm_rect.c b/drivers/gpu/drm/drm_rect.c index a8e934795c7d..8c057829b804 100644 --- a/drivers/gpu/drm/drm_rect.c +++ b/drivers/gpu/drm/drm_rect.c @@ -50,13 +50,25 @@ bool drm_rect_intersect(struct drm_rect *r1, const struct drm_rect *r2) } EXPORT_SYMBOL(drm_rect_intersect); +static u32 clip_scaled(u32 src, u32 dst, u32 clip) +{ + u64 tmp = mul_u32_u32(src, dst - clip); + + /* + * Round toward 1.0 when clipping so that we don't accidentally + * change upscaling to downscaling or vice versa. + */ + if (src < (dst << 16)) + return DIV_ROUND_UP_ULL(tmp, dst); + else + return DIV_ROUND_DOWN_ULL(tmp, dst); +} + /** * drm_rect_clip_scaled - perform a scaled clip operation * @src: source window rectangle * @dst: destination window rectangle * @clip: clip rectangle - * @hscale: horizontal scaling factor - * @vscale: vertical scaling factor * * Clip rectangle @dst by rectangle @clip. Clip rectangle @src by the * same amounts multiplied by @hscale and @vscale. @@ -66,33 +78,44 @@ EXPORT_SYMBOL(drm_rect_intersect); * %false otherwise */ 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 diff; diff = clip->x1 - dst->x1; if (diff > 0) { - int64_t tmp = src->x1 + (int64_t) diff * hscale; - src->x1 = clamp_t(int64_t, tmp, INT_MIN, INT_MAX); + u32 new_src_w = clip_scaled(drm_rect_width(src), + drm_rect_width(dst), diff); + + src->x1 = clamp_t(int64_t, src->x2 - new_src_w, INT_MIN, INT_MAX); + dst->x1 = clip->x1; } diff = clip->y1 - dst->y1; if (diff > 0) { - int64_t tmp = src->y1 + (int64_t) diff * vscale; - src->y1 = clamp_t(int64_t, tmp, INT_MIN, INT_MAX); + u32 new_src_h = clip_scaled(drm_rect_height(src), + drm_rect_height(dst), diff); + + src->y1 = clamp_t(int64_t, src->y2 - new_src_h, INT_MIN, INT_MAX); + dst->y1 = clip->y1; } diff = dst->x2 - clip->x2; if (diff > 0) { - int64_t tmp = src->x2 - (int64_t) diff * hscale; - src->x2 = clamp_t(int64_t, tmp, INT_MIN, INT_MAX); + u32 new_src_w = clip_scaled(drm_rect_width(src), + drm_rect_width(dst), diff); + + src->x2 = clamp_t(int64_t, src->x1 + new_src_w, INT_MIN, INT_MAX); + dst->x2 = clip->x2; } diff = dst->y2 - clip->y2; if (diff > 0) { - int64_t tmp = src->y2 - (int64_t) diff * vscale; - src->y2 = clamp_t(int64_t, tmp, INT_MIN, INT_MAX); + u32 new_src_h = clip_scaled(drm_rect_height(src), + drm_rect_height(dst), diff); + + src->y2 = clamp_t(int64_t, src->y1 + new_src_h, INT_MIN, INT_MAX); + dst->y2 = clip->y2; } - return drm_rect_intersect(dst, clip); + return drm_rect_visible(dst); } EXPORT_SYMBOL(drm_rect_clip_scaled); diff --git a/drivers/gpu/drm/i915/intel_sprite.c b/drivers/gpu/drm/i915/intel_sprite.c index dbdcf85032df..e17c26a1cff1 100644 --- a/drivers/gpu/drm/i915/intel_sprite.c +++ b/drivers/gpu/drm/i915/intel_sprite.c @@ -1003,7 +1003,7 @@ intel_check_sprite_plane(struct intel_plane *plane, drm_mode_get_hv_timing(&crtc_state->base.mode, &clip.x2, &clip.y2); - state->base.visible = drm_rect_clip_scaled(src, dst, &clip, hscale, vscale); + state->base.visible = drm_rect_clip_scaled(src, dst, &clip); crtc_x = dst->x1; crtc_y = dst->y1; |