From 84c5472752d9fba936c389fae4f1dd6f66e8bd44 Mon Sep 17 00:00:00 2001
From: Emmanuele Bassi <ebassi@gnome.org>
Date: Mon, 8 Aug 2016 19:34:03 +0100
Subject: [PATCH] gsk: Remove child-transform from render nodes

The child-transform is useful only if we also provide clipping to the
parent nodes, otherwise children will just be drawn outside of the
parent's bounds.

We'll introduce child transforms either at a higher layer, or once we
add clipping support to GskRenderNode.
---
 docs/reference/gsk/gsk3-sections.txt |  1 -
 gsk/gskrendernode.c                  | 36 +++-------------------------
 gsk/gskrendernode.h                  |  3 ---
 gsk/gskrendernodeprivate.h           |  4 ----
 4 files changed, 3 insertions(+), 41 deletions(-)

diff --git a/docs/reference/gsk/gsk3-sections.txt b/docs/reference/gsk/gsk3-sections.txt
index 36160daca9..c412444fb6 100644
--- a/docs/reference/gsk/gsk3-sections.txt
+++ b/docs/reference/gsk/gsk3-sections.txt
@@ -55,7 +55,6 @@ gsk_render_node_contains
 gsk_render_node_set_bounds
 gsk_render_node_set_transform
 gsk_render_node_set_anchor_point
-gsk_render_node_set_child_transform
 gsk_render_node_set_opacity
 gsk_render_node_set_hidden
 gsk_render_node_is_hidden
diff --git a/gsk/gskrendernode.c b/gsk/gskrendernode.c
index 716ecfae00..1ec296e6f3 100644
--- a/gsk/gskrendernode.c
+++ b/gsk/gskrendernode.c
@@ -177,7 +177,6 @@ gsk_render_node_init (GskRenderNode *self)
   graphene_rect_init_from_rect (&self->bounds, graphene_rect_zero ());
 
   graphene_matrix_init_identity (&self->transform);
-  graphene_matrix_init_identity (&self->child_transform);
 
   graphene_point3d_init (&self->anchor_point, 0.f, 0.f, 0.f);
 
@@ -961,31 +960,6 @@ gsk_render_node_set_anchor_point (GskRenderNode            *node,
   graphene_point3d_init_from_point (&node->anchor_point, offset);
 }
 
-/**
- * gsk_render_node_set_child_transform:
- * @node: a #GskRenderNode
- * @transform: (nullable): a transformation matrix
- *
- * Sets the transformation matrix used when rendering the children
- * of @node.
- *
- * Since: 3.22
- */
-void
-gsk_render_node_set_child_transform (GskRenderNode           *node,
-                                     const graphene_matrix_t *transform)
-{
-  g_return_if_fail (GSK_IS_RENDER_NODE (node));
-  g_return_if_fail (node->is_mutable);
-
-  if (transform == NULL)
-    graphene_matrix_init_identity (&node->child_transform);
-  else
-    graphene_matrix_init_from_matrix (&node->child_transform, transform);
-
-  node->child_transform_set = !graphene_matrix_is_identity (&node->child_transform);
-}
-
 /**
  * gsk_render_node_set_opacity:
  * @node: a #GskRenderNode
@@ -1177,11 +1151,10 @@ gsk_render_node_update_world_matrix (GskRenderNode *node,
 
   if (force || node->needs_world_matrix_update)
     {
-      GSK_NOTE (RENDER_NODE, g_print ("Updating cached world matrix on node %p [parent=%p, t_set=%s, ct_set=%s]\n",
+      GSK_NOTE (RENDER_NODE, g_print ("Updating cached world matrix on node %p [parent=%p, t_set=%s]\n",
                                       node,
                                       node->parent != NULL ? node->parent : 0,
-                                      node->transform_set ? "y" : "n",
-                                      node->parent != NULL && node->parent->child_transform_set ? "y" : "n"));
+                                      node->transform_set ? "y" : "n"));
 
       if (node->parent == NULL)
         {
@@ -1195,10 +1168,7 @@ gsk_render_node_update_world_matrix (GskRenderNode *node,
           GskRenderNode *parent = node->parent;
           graphene_matrix_t tmp;
 
-          if (parent->child_transform_set)
-            graphene_matrix_init_from_matrix (&tmp, &parent->child_transform);
-          else
-            graphene_matrix_init_identity (&tmp);
+          graphene_matrix_init_identity (&tmp);
 
           if (node->transform_set)
             graphene_matrix_multiply (&tmp, &node->transform, &tmp);
diff --git a/gsk/gskrendernode.h b/gsk/gskrendernode.h
index ced2630872..afeab20219 100644
--- a/gsk/gskrendernode.h
+++ b/gsk/gskrendernode.h
@@ -98,9 +98,6 @@ GDK_AVAILABLE_IN_3_22
 void                    gsk_render_node_set_anchor_point        (GskRenderNode            *node,
                                                                  const graphene_point3d_t *offset);
 GDK_AVAILABLE_IN_3_22
-void                    gsk_render_node_set_child_transform     (GskRenderNode            *node,
-                                                                 const graphene_matrix_t  *transform);
-GDK_AVAILABLE_IN_3_22
 void                    gsk_render_node_set_opacity             (GskRenderNode *node,
                                                                  double         opacity);
 GDK_AVAILABLE_IN_3_22
diff --git a/gsk/gskrendernodeprivate.h b/gsk/gskrendernodeprivate.h
index 0dce747026..85cb2b839e 100644
--- a/gsk/gskrendernodeprivate.h
+++ b/gsk/gskrendernodeprivate.h
@@ -55,15 +55,11 @@ struct _GskRenderNode
 
   graphene_point3d_t anchor_point;
 
-  /* Transformations applied to the children of the node */
-  graphene_matrix_t child_transform;
-
   /* Bit fields; leave at the end */
   gboolean is_mutable : 1;
   gboolean hidden : 1;
   gboolean opaque : 1;
   gboolean transform_set : 1;
-  gboolean child_transform_set : 1;
   gboolean needs_world_matrix_update : 1;
 };