On Thu, May 03, 2018 at 01:22:14PM +0200, Maarten Lankhorst wrote:
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
drivers/gpu/drm/drm_atomic_helper.c | 2 +- drivers/gpu/drm/drm_rect.c | 45 ++++++++++++++++++++--------- drivers/gpu/drm/i915/intel_sprite.c | 2 +- include/drm/drm_rect.h | 3 +- 4 files changed, 35 insertions(+), 17 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 4735526297aa..f477063f18ea 100644 --- a/drivers/gpu/drm/drm_rect.c +++ b/drivers/gpu/drm/drm_rect.c @@ -50,13 +50,21 @@ 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 newsrc = mul_u32_u32(src, dst - clip);
'newsrc' feels slightly misleading. It would be a decent name for the final return value of the function, but for this intermediate value 'tmp' or something equally non specific might be better.
- if (src < (dst << 16))
return DIV_ROUND_UP_ULL(newsrc, dst);- else
return DIV_ROUND_DOWN_ULL(newsrc, dst);
I think we could use a comment here to explain the choice of rounding direction. Eg.
/* * Round toward 1.0 when clipping so that we don't accidentally * change upscaling to downscaling or vice versa. */ ?
+}
/**
- 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 +74,44 @@ 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);
Could have precomputed the src/dst width/height upfront maybe.
Oh, I guess you can't since your clip_scaled() uses the dst width/height for more than the scaling factor. If it just computed diff*src/dst like the original code does then precomputing would work just fine.
Your way feels a bit more complicated to me, but looks like it should work.
Reviewed-by: Ville Syrjälä ville.syrjala@linux.intel.com
src->x1 = clamp_t(int64_t, src->x2 - new_src_w, INT_MIN, INT_MAX);dst->x1 = clip->x1;
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;
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;
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 aa1dfaa692b9..44d7aca222b0 100644 --- a/drivers/gpu/drm/i915/intel_sprite.c +++ b/drivers/gpu/drm/i915/intel_sprite.c @@ -1008,7 +1008,7 @@ 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;
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); -- 2.17.0