[gtk+/wip/otte/rendernode: 27/100] gsk: Remove world matrix support

[Benjamin Otte <otte src gnome org>]

commit 3783652dab71d31eabfd5d7cb1519c5776901de9
Author: Benjamin Otte <otte redhat com>
Date:   Mon Dec 12 16:52:55 2016 +0100

    gsk: Remove world matrix support
    
    Use the real transform and compute it manually.

 gsk/gskcairorenderer.c     |    9 ++---
 gsk/gskglrenderer.c        |   14 +++++--
 gsk/gskrendernode.c        |   83 --------------------------------------------
 gsk/gskrendernodeprivate.h |   11 ------
 gsk/gskvulkanrenderpass.c  |    8 ++--
 5 files changed, 17 insertions(+), 108 deletions(-)
---
diff --git a/gsk/gskcairorenderer.c b/gsk/gskcairorenderer.c
index 3aebb41..185d976 100644
--- a/gsk/gskcairorenderer.c
+++ b/gsk/gskcairorenderer.c
@@ -53,14 +53,14 @@ gsk_cairo_renderer_render_node (GskCairoRenderer *self,
 {
   GskRenderNode *child;
   gboolean pop_group = FALSE;
-  graphene_matrix_t mvp;
+  graphene_matrix_t mat;
   cairo_matrix_t ctm;
   graphene_rect_t frame;
 
   cairo_save (cr);
 
-  gsk_render_node_get_world_matrix (node, &mvp);
-  if (graphene_matrix_to_2d (&mvp, &ctm.xx, &ctm.yx, &ctm.xy, &ctm.yy, &ctm.x0, &ctm.y0))
+  gsk_render_node_get_transform (node, &mat);
+  if (graphene_matrix_to_2d (&mat, &ctm.xx, &ctm.yx, &ctm.xy, &ctm.yy, &ctm.x0, &ctm.y0))
     {
       GSK_NOTE (CAIRO, g_print ("CTM = { .xx = %g, .yx = %g, .xy = %g, .yy = %g, .x0 = %g, .y0 = %g }\n",
                                 ctm.xx, ctm.yx,
@@ -105,9 +105,6 @@ gsk_cairo_renderer_render_node (GskCairoRenderer *self,
     case GSK_CONTAINER_NODE:
       if (gsk_render_node_get_n_children (node) != 0)
         {
-          cairo_matrix_invert (&ctm);
-          cairo_transform (cr, &ctm);
-
           GSK_NOTE (CAIRO, g_print ("Drawing %d children of node [%p]\n",
                                     gsk_render_node_get_n_children (node),
                                     node));
diff --git a/gsk/gskglrenderer.c b/gsk/gskglrenderer.c
index f7d9eb9..654e5d1 100644
--- a/gsk/gskglrenderer.c
+++ b/gsk/gskglrenderer.c
@@ -617,12 +617,13 @@ render_node_needs_render_target (GskRenderNode *node)
 static void
 gsk_gl_renderer_add_render_item (GskGLRenderer           *self,
                                  const graphene_matrix_t *projection,
+                                 const graphene_matrix_t *parent_modelview,
                                  GArray                  *render_items,
                                  GskRenderNode           *node,
                                  RenderItem              *parent)
 {
   graphene_rect_t viewport;
-  graphene_matrix_t mv;
+  graphene_matrix_t mv, transform;
   graphene_rect_t bounds;
   GskRenderNode *child;
   RenderItem item;
@@ -659,7 +660,8 @@ gsk_gl_renderer_add_render_item (GskGLRenderer           *self,
   item.max.z = 0.f;
 
   /* The location of the item, in normalized world coordinates */
-  gsk_render_node_get_world_matrix (node, &mv);
+  gsk_render_node_get_transform (node, &transform);
+  graphene_matrix_multiply (&transform, parent_modelview, &mv);
   graphene_matrix_multiply (&mv, &self->mvp, &item.mvp);
   item.z = project_item (projection, &mv);
 
@@ -791,7 +793,7 @@ out:
        child != NULL;
        child = gsk_render_node_get_next_sibling (child))
     {
-      gsk_gl_renderer_add_render_item (self, projection, render_items, child, ritem);
+      gsk_gl_renderer_add_render_item (self, projection, &mv, render_items, child, ritem);
     }
 }
 
@@ -800,12 +802,16 @@ gsk_gl_renderer_validate_tree (GskGLRenderer           *self,
                                GskRenderNode           *root,
                                const graphene_matrix_t *projection)
 {
+  graphene_matrix_t identity;
+
   if (self->gl_context == NULL)
     {
       GSK_NOTE (OPENGL, g_print ("No valid GL context associated to the renderer"));
       return FALSE;
     }
 
+  graphene_matrix_init_identity (&identity);
+
   gdk_gl_context_make_current (self->gl_context);
 
   self->render_items = g_array_new (FALSE, FALSE, sizeof (RenderItem));
@@ -813,7 +819,7 @@ gsk_gl_renderer_validate_tree (GskGLRenderer           *self,
   gsk_gl_driver_begin_frame (self->gl_driver);
 
   GSK_NOTE (OPENGL, g_print ("RenderNode -> RenderItem\n"));
-  gsk_gl_renderer_add_render_item (self, projection, self->render_items, root, NULL);
+  gsk_gl_renderer_add_render_item (self, projection, &identity, self->render_items, root, NULL);
 
   GSK_NOTE (OPENGL, g_print ("Total render items: %d\n",
                              self->render_items->len));
diff --git a/gsk/gskrendernode.c b/gsk/gskrendernode.c
index 888fca6..e5d6c2d 100644
--- a/gsk/gskrendernode.c
+++ b/gsk/gskrendernode.c
@@ -112,7 +112,6 @@ gsk_render_node_new (const GskRenderNodeClass *node_class)
   self->mag_filter = GSK_SCALING_FILTER_NEAREST;
 
   self->is_mutable = TRUE;
-  self->needs_world_matrix_update = TRUE;
 
   return self;
 }
@@ -304,11 +303,9 @@ gsk_render_node_insert_child_internal (GskRenderNode   *node,
 
   child->parent = node;
   child->age = 0;
-  child->needs_world_matrix_update = TRUE;
 
   node->n_children += 1;
   node->age += 1;
-  node->needs_world_matrix_update = TRUE;
 
   if (child->prev_sibling == NULL)
     node->first_child = child;
@@ -517,8 +514,6 @@ gsk_render_node_set_transform (GskRenderNode           *node,
     graphene_matrix_init_identity (&node->transform);
   else
     graphene_matrix_init_from_matrix (&node->transform, transform);
-
-  node->transform_set = !graphene_matrix_is_identity (&node->transform);
 }
 
 /**
@@ -634,57 +629,6 @@ gsk_render_node_get_toplevel (GskRenderNode *node)
   return NULL;
 }
 
-/*< private >
- * gsk_render_node_update_world_matrix:
- * @node: a #GskRenderNode
- * @force: %TRUE if the update should be forced
- *
- * Updates the cached world matrix of @node and its children, if needed.
- */
-void
-gsk_render_node_update_world_matrix (GskRenderNode *node,
-                                     gboolean       force)
-{
-  GskRenderNode *child;
-
-  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]\n",
-                                      node,
-                                      node->parent != NULL ? node->parent : 0,
-                                      node->transform_set ? "y" : "n"));
-
-      if (node->parent == NULL)
-        {
-          if (node->transform_set)
-            graphene_matrix_init_from_matrix (&node->world_matrix, &node->transform);
-          else
-            graphene_matrix_init_identity (&node->world_matrix);
-        }
-      else
-        {
-          GskRenderNode *parent = node->parent;
-          graphene_matrix_t tmp;
-
-          graphene_matrix_init_identity (&tmp);
-
-          if (node->transform_set)
-            graphene_matrix_multiply (&tmp, &node->transform, &tmp);
-
-          graphene_matrix_multiply (&tmp, &parent->world_matrix, &node->world_matrix);
-        }
-
-      node->needs_world_matrix_update = FALSE;
-    }
-
-  for (child = gsk_render_node_get_first_child (node);
-       child != NULL;
-       child = gsk_render_node_get_next_sibling (child))
-    {
-      gsk_render_node_update_world_matrix (child, TRUE);
-    }
-}
-
 void
 gsk_render_node_set_scaling_filters (GskRenderNode    *node,
                                      GskScalingFilter  min_filter,
@@ -698,33 +642,6 @@ gsk_render_node_set_scaling_filters (GskRenderNode    *node,
     node->mag_filter = mag_filter;
 }
 
-/*< private >
- * gsk_render_node_get_world_matrix:
- * @node: a #GskRenderNode
- * @mv: (out caller-allocates): return location for the modelview matrix
- *   in world-relative coordinates
- *
- * Retrieves the modelview matrix in world-relative coordinates.
- */
-void
-gsk_render_node_get_world_matrix (GskRenderNode     *node,
-                                  graphene_matrix_t *mv)
-{
-  g_return_if_fail (GSK_IS_RENDER_NODE (node));
-  g_return_if_fail (mv != NULL);
-
-  if (node->needs_world_matrix_update)
-    {
-      GskRenderNode *tmp = gsk_render_node_get_toplevel (node);
-
-      gsk_render_node_update_world_matrix (tmp, TRUE);
-
-      g_assert (!node->needs_world_matrix_update);
-    }
-
-  *mv = node->world_matrix;
-}
-
 /**
  * gsk_render_node_set_name:
  * @node: a #GskRenderNode
diff --git a/gsk/gskrendernodeprivate.h b/gsk/gskrendernodeprivate.h
index 2576771..db8d16f 100644
--- a/gsk/gskrendernodeprivate.h
+++ b/gsk/gskrendernodeprivate.h
@@ -41,16 +41,11 @@ struct _GskRenderNode
   GskScalingFilter min_filter;
   GskScalingFilter mag_filter;
 
-  /* Transformations relative to the root of the scene */
-  graphene_matrix_t world_matrix;
-
   /* Transformations applied to the node */
   graphene_matrix_t transform;
 
   /* Bit fields; leave at the end */
   gboolean is_mutable : 1;
-  gboolean transform_set : 1;
-  gboolean needs_world_matrix_update : 1;
 };
 
 struct _GskRenderNodeClass
@@ -82,12 +77,6 @@ GskBlendMode gsk_render_node_get_blend_mode (GskRenderNode *node);
 
 GskRenderNode *gsk_render_node_get_toplevel (GskRenderNode *node);
 
-void gsk_render_node_update_world_matrix (GskRenderNode *node,
-                                          gboolean       force);
-
-void gsk_render_node_get_world_matrix (GskRenderNode     *node,
-                                       graphene_matrix_t *mv);
-
 G_END_DECLS
 
 #endif /* __GSK_RENDER_NODE_PRIVATE_H__ */
diff --git a/gsk/gskvulkanrenderpass.c b/gsk/gskvulkanrenderpass.c
index 22709c2..3dc3700 100644
--- a/gsk/gskvulkanrenderpass.c
+++ b/gsk/gskvulkanrenderpass.c
@@ -274,12 +274,12 @@ gsk_vulkan_render_pass_reserve_descriptor_sets (GskVulkanRenderPass *self,
 void
 gsk_vulkan_render_pass_draw (GskVulkanRenderPass     *self,
                              GskVulkanRender         *render,
-                             const graphene_matrix_t *root_mvp,
+                             const graphene_matrix_t *parent_mvp,
                              GskVulkanPipeline       *pipeline,
                              VkCommandBuffer          command_buffer)
 {
   GskVulkanRenderOp *op;
-  graphene_matrix_t world, mvp;
+  graphene_matrix_t transform, mvp;
   float float_matrix[16];
   guint i;
 
@@ -298,8 +298,8 @@ gsk_vulkan_render_pass_draw (GskVulkanRenderPass     *self,
                                0,
                                NULL);
 
-      gsk_render_node_get_world_matrix (op->node, &world);
-      graphene_matrix_multiply (&world, root_mvp, &mvp);
+      gsk_render_node_get_transform (op->node, &transform);
+      graphene_matrix_multiply (&transform, parent_mvp, &mvp);
       graphene_matrix_to_float (&mvp, float_matrix);
 
       vkCmdPushConstants (command_buffer,