sna: Clip the fbcon to the frontbuffer

...both to correct the placement of the fbcon into the smaller scanout and
to ensure that we correctly clip the boxes to be copied.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

1 files changed, 18 insertions, 6 deletions

diff --git a/src/sna/sna_display.c b/src/sna/sna_display.c
index cb1beba7..f92a1dbf 100644
--- a/src/sna/sna_display.c
+++ b/src/sna/sna_display.c
@@ -502,6 +502,8 @@ void sna_copy_fbcon(struct sna *sna)
 	struct kgem_bo *bo;
 	BoxRec box;
 	bool ok;
+	int sx, sy;
+	int dx, dy;
 	int i;
 
 	if (sna->kgem.wedged)
@@ -527,8 +529,8 @@ void sna_copy_fbcon(struct sna *sna)
 		goto cleanup_fbcon;
 
 	box.x1 = box.y1 = 0;
-	box.x2 = fbcon->width;
-	box.y2 = fbcon->height;
+	box.x2 = min(fbcon->width, sna->front->drawable.width);
+	box.y2 = min(fbcon->height, sna->front->drawable.height);
 
 	bo = sna_create_bo_for_fbcon(sna, fbcon);
 	if (bo == NULL)
@@ -537,11 +539,21 @@ void sna_copy_fbcon(struct sna *sna)
 	priv = sna_pixmap(sna->front);
 	assert(priv && priv->gpu_bo);
 
+	sx = dx = 0;
+	if (box.x2 < fbcon->width)
+		sx = (fbcon->width - box.x2) / 2.;
+	if (box.x2 < sna->front->drawable.width)
+		dx = (sna->front->drawable.width - box.x2) / 2.;
+
+	sy = dy = 0;
+	if (box.y2 < fbcon->height)
+		sy = (fbcon->height - box.y2) / 2.;
+	if (box.y2 < sna->front->drawable.height)
+		dy = (sna->front->drawable.height - box.y2) / 2.;
+
 	ok = sna->render.copy_boxes(sna, GXcopy,
-				    sna->front, bo, 0, 0,
-				    sna->front, priv->gpu_bo,
-				    (sna->front->drawable.width - fbcon->width)/2,
-				    (sna->front->drawable.height - fbcon->height)/2,
+				    sna->front, bo, sx, sy,
+				    sna->front, priv->gpu_bo, dx, dy,
 				    &box, 1);
 	sna_damage_add_box(&priv->gpu_damage, &box);