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path: root/drivers/gpu/drm/drm_rect.c
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Diffstat (limited to 'drivers/gpu/drm/drm_rect.c')
-rw-r--r--drivers/gpu/drm/drm_rect.c42
1 files changed, 26 insertions, 16 deletions
diff --git a/drivers/gpu/drm/drm_rect.c b/drivers/gpu/drm/drm_rect.c
index b8363aaa9032..0460e874896e 100644
--- a/drivers/gpu/drm/drm_rect.c
+++ b/drivers/gpu/drm/drm_rect.c
@@ -52,9 +52,17 @@ 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)
+static u32 clip_scaled(int src, int dst, int *clip)
{
- u64 tmp = mul_u32_u32(src, dst - clip);
+ u64 tmp;
+
+ if (dst == 0)
+ return 0;
+
+ /* Only clip what we have. Keeps the result bounded. */
+ *clip = min(*clip, dst);
+
+ tmp = mul_u32_u32(src, dst - *clip);
/*
* Round toward 1.0 when clipping so that we don't accidentally
@@ -73,11 +81,13 @@ static u32 clip_scaled(u32 src, u32 dst, u32 clip)
* @clip: clip rectangle
*
* Clip rectangle @dst by rectangle @clip. Clip rectangle @src by the
- * same amounts multiplied by @hscale and @vscale.
+ * the corresponding amounts, retaining the vertical and horizontal scaling
+ * factors from @src to @dst.
*
* RETURNS:
+ *
* %true if rectangle @dst is still visible after being clipped,
- * %false otherwise
+ * %false otherwise.
*/
bool drm_rect_clip_scaled(struct drm_rect *src, struct drm_rect *dst,
const struct drm_rect *clip)
@@ -87,34 +97,34 @@ bool drm_rect_clip_scaled(struct drm_rect *src, struct drm_rect *dst,
diff = clip->x1 - dst->x1;
if (diff > 0) {
u32 new_src_w = clip_scaled(drm_rect_width(src),
- drm_rect_width(dst), diff);
+ drm_rect_width(dst), &diff);
- src->x1 = clamp_t(int64_t, src->x2 - new_src_w, INT_MIN, INT_MAX);
- dst->x1 = clip->x1;
+ src->x1 = src->x2 - new_src_w;
+ dst->x1 += diff;
}
diff = clip->y1 - dst->y1;
if (diff > 0) {
u32 new_src_h = clip_scaled(drm_rect_height(src),
- drm_rect_height(dst), diff);
+ drm_rect_height(dst), &diff);
- src->y1 = clamp_t(int64_t, src->y2 - new_src_h, INT_MIN, INT_MAX);
- dst->y1 = clip->y1;
+ src->y1 = src->y2 - new_src_h;
+ dst->y1 += diff;
}
diff = dst->x2 - clip->x2;
if (diff > 0) {
u32 new_src_w = clip_scaled(drm_rect_width(src),
- drm_rect_width(dst), diff);
+ drm_rect_width(dst), &diff);
- src->x2 = clamp_t(int64_t, src->x1 + new_src_w, INT_MIN, INT_MAX);
- dst->x2 = clip->x2;
+ src->x2 = src->x1 + new_src_w;
+ dst->x2 -= diff;
}
diff = dst->y2 - clip->y2;
if (diff > 0) {
u32 new_src_h = clip_scaled(drm_rect_height(src),
- drm_rect_height(dst), diff);
+ drm_rect_height(dst), &diff);
- src->y2 = clamp_t(int64_t, src->y1 + new_src_h, INT_MIN, INT_MAX);
- dst->y2 = clip->y2;
+ src->y2 = src->y1 + new_src_h;
+ dst->y2 -= diff;
}
return drm_rect_visible(dst);