From 14dbe81deb8c9d583c8c56e4ede45a46880c2a76 Mon Sep 17 00:00:00 2001 From: Robert Bragg Date: Thu, 23 Sep 2010 22:18:42 +0100 Subject: [PATCH] material: Don't prune ancestry if it owns some layers Each time a material property changes we look to see if any of its ancestry has become redundant and if so we prune that redundant ancestry. There was a problem with the logic that handles this though because we weren't considering that a material which is a layer state authority may still defer to ancestors to define the state of individual layers. For example a material that derives from a parent with 5 layers can become a STATE_LAYERS authority by simply changing it's ->n_layers count to 4 and in that case it can still defer to its ancestors to define the state of those 4 layers. This patch checks first if a material is a layer state authority and if so only tries to prune its ancestry if it also *owns* all the individual layers it depends on. (I.e. if g_list_length (material->layer_differences) != material->n_layers then it's not safe to try pruning its ancestry!) http://bugzilla-attachments.gnome.org/attachment.cgi?id=170907 --- cogl/cogl-material.c | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) diff --git a/cogl/cogl-material.c b/cogl/cogl-material.c index 216914e28..985ebe2db 100644 --- a/cogl/cogl-material.c +++ b/cogl/cogl-material.c @@ -3537,6 +3537,27 @@ _cogl_material_prune_redundant_ancestry (CoglMaterial *material) { CoglMaterial *new_parent = _cogl_material_get_parent (material); + /* Before considering pruning redundant ancestry we check if this + * material is an authority for layer state and if so only consider + * reparenting if it *owns* all the layers it depends on. NB: A + * material can be be a STATE_LAYERS authority but it may still + * defer to its ancestors to define the state for some of its + * layers. + * + * For example a material that derives from a parent with 5 layers + * can become a STATE_LAYERS authority by simply changing it's + * ->n_layers count to 4 and in that case it can still defer to its + * ancestors to define the state of those 4 layers. + * + * If a material depends on any ancestors for layer state then we + * immediatly bail out. + */ + if (material->differences & COGL_MATERIAL_STATE_LAYERS) + { + if (material->n_layers != g_list_length (material->layer_differences)) + return; + } + /* walk up past ancestors that are now redundant and potentially * reparent the material. */ while (_cogl_material_get_parent (new_parent) &&