Layers: use IDProperty and override collection properties system

First this replace a custom data struct with IDProperty, and use
IDProperty group merge and copying functions. Which means that a collection
property setting is only created if necessary.

This implements the "Layer Collection settings" override system, as
suggested in the "Override Manifesto" document.

The core is working, with Scene, LayerCollection and Object using a
single IDProperty to store all the render settings data. Next step is to
migrate this to depsgraph.

Note: Clay engine "ssao_samples" was hardcoded to 32 for now. It will come
back as part of "Workspace Settings" later.

Many thanks for Bastien Montagne for the help with the UI template
nightmare ;)

Differential Revision: https://developer.blender.org/D2563

3 files changed, 165 insertions, 0 deletions

diff --git a/source/blender/editors/include/UI_interface.h b/source/blender/editors/include/UI_interface.h
index 625a5887bef..bd3e56b39a0 100644
--- a/source/blender/editors/include/UI_interface.h
+++ b/source/blender/editors/include/UI_interface.h
@@ -948,6 +948,7 @@ void uiTemplateHeader3D(uiLayout *layout, struct bContext *C);
 void uiTemplateEditModeSelection(uiLayout *layout, struct bContext *C);
 void uiTemplateReportsBanner(uiLayout *layout, struct bContext *C);
 void uiTemplateKeymapItemProperties(uiLayout *layout, struct PointerRNA *ptr);
+void uiTemplateOverrideProperty(uiLayout *layout, struct PointerRNA *collection_props_ptr, struct PointerRNA *scene_props_ptr, const char *name, const char *custom_template);
 void uiTemplateComponentMenu(uiLayout *layout, struct PointerRNA *ptr, const char *propname, const char *name);
 void uiTemplateNodeSocket(uiLayout *layout, struct bContext *C, float *color);
 void uiTemplateCacheFile(uiLayout *layout, struct bContext *C, struct PointerRNA *ptr, const char *propname);
diff --git a/source/blender/editors/interface/interface_ops.c b/source/blender/editors/interface/interface_ops.c
index fb95cdf389b..de226e74c65 100644
--- a/source/blender/editors/interface/interface_ops.c
+++ b/source/blender/editors/interface/interface_ops.c
@@ -42,6 +42,8 @@
 #include "BLT_lang.h"
 
 #include "BKE_context.h"
+#include "BKE_idprop.h"
+#include "BKE_layer.h"
 #include "BKE_screen.h"
 #include "BKE_global.h"
 #include "BKE_node.h"
@@ -50,6 +52,7 @@
 
 #include "RNA_access.h"
 #include "RNA_define.h"
+#include "RNA_types.h"
 
 #include "UI_interface.h"
 
@@ -328,6 +331,109 @@ static void UI_OT_unset_property_button(wmOperatorType *ot)
 	ot->flag = OPTYPE_UNDO;
 }
 
+/* Use/Unuse Property Button Operator ------------------------ */
+
+static int use_property_button_exec(bContext *C, wmOperator *UNUSED(op))
+{
+	PointerRNA ptr, scene_props_ptr;
+	PropertyRNA *prop;
+	IDProperty *props;
+
+	uiBut *but = UI_context_active_but_get(C);
+
+	prop = but->rnaprop;
+	ptr = but->rnapoin;
+	props = (IDProperty *)ptr.data;
+	/* XXX Using existing data struct to pass another RNAPointer */
+	scene_props_ptr = but->rnasearchpoin;
+
+	const char *identifier = RNA_property_identifier(prop);
+	if (IDP_GetPropertyFromGroup(props, identifier)) {
+		return OPERATOR_CANCELLED;
+	}
+
+	switch (RNA_property_type(prop)) {
+		case PROP_FLOAT:
+		{
+			float value = RNA_property_float_get(&scene_props_ptr, prop);
+			BKE_collection_engine_property_add_float(props, identifier, value);
+			break;
+		}
+		case PROP_ENUM:
+		{
+			int value = RNA_enum_get(&scene_props_ptr, identifier);
+			BKE_collection_engine_property_add_int(props, identifier, value);
+			break;
+		}
+		case PROP_INT:
+		{
+			int value = RNA_int_get(&scene_props_ptr, identifier);
+			BKE_collection_engine_property_add_int(props, identifier, value);
+			break;
+		}
+		case PROP_BOOLEAN:
+		{
+			int value = RNA_boolean_get(&scene_props_ptr, identifier);
+			BKE_collection_engine_property_add_bool(props, identifier, value);
+			break;
+		}
+		case PROP_STRING:
+		case PROP_POINTER:
+		case PROP_COLLECTION:
+		default:
+			break;
+	}
+
+	return OPERATOR_FINISHED;
+}
+
+static void UI_OT_use_property_button(wmOperatorType *ot)
+{
+	/* identifiers */
+	ot->name = "Use property";
+	ot->idname = "UI_OT_use_property_button";
+	ot->description = "Create a property";
+
+	/* callbacks */
+	ot->poll = ED_operator_regionactive;
+	ot->exec = use_property_button_exec;
+
+	/* flags */
+	ot->flag = OPTYPE_UNDO;
+}
+
+static int unuse_property_button_exec(bContext *C, wmOperator *UNUSED(op))
+{
+	PointerRNA ptr;
+	PropertyRNA *prop;
+	int index;
+
+	/* try to unset the nominated property */
+	UI_context_active_but_prop_get(C, &ptr, &prop, &index);
+	const char *identifier = RNA_property_identifier(prop);
+
+	IDProperty *props = (IDProperty *)ptr.data;
+	IDProperty *prop_to_remove = IDP_GetPropertyFromGroup(props, identifier);
+	IDP_FreeFromGroup(props, prop_to_remove);
+
+	return OPERATOR_FINISHED;
+}
+
+static void UI_OT_unuse_property_button(wmOperatorType *ot)
+{
+	/* identifiers */
+	ot->name = "Unuse property";
+	ot->idname = "UI_OT_unuse_property_button";
+	ot->description = "Remove a property";
+
+	/* callbacks */
+	ot->poll = ED_operator_regionactive;
+	ot->exec = unuse_property_button_exec;
+
+	/* flags */
+	ot->flag = OPTYPE_UNDO;
+}
+
 /* Copy To Selected Operator ------------------------ */
 
 bool UI_context_copy_to_selected_list(
@@ -1114,6 +1220,8 @@ void ED_operatortypes_ui(void)
 	WM_operatortype_append(UI_OT_copy_python_command_button);
 	WM_operatortype_append(UI_OT_reset_default_button);
 	WM_operatortype_append(UI_OT_unset_property_button);
+	WM_operatortype_append(UI_OT_use_property_button);
+	WM_operatortype_append(UI_OT_unuse_property_button);
 	WM_operatortype_append(UI_OT_copy_to_selected_button);
 	WM_operatortype_append(UI_OT_reports_to_textblock);  /* XXX: temp? */
 	WM_operatortype_append(UI_OT_drop_color);
diff --git a/source/blender/editors/interface/interface_templates.c b/source/blender/editors/interface/interface_templates.c
index a31ce55ca5f..e3a71feb1a9 100644
--- a/source/blender/editors/interface/interface_templates.c
+++ b/source/blender/editors/interface/interface_templates.c
@@ -58,6 +58,8 @@
 #include "BKE_depsgraph.h"
 #include "BKE_global.h"
 #include "BKE_idcode.h"
+#include "BKE_idprop.h"
+#include "BKE_layer.h"
 #include "BKE_library.h"
 #include "BKE_linestyle.h"
 #include "BKE_main.h"
@@ -3751,6 +3753,60 @@ void uiTemplateKeymapItemProperties(uiLayout *layout, PointerRNA *ptr)
 	}
 }
 
+/********************************* Overrides *************************************/
+
+void uiTemplateOverrideProperty(uiLayout *layout, struct PointerRNA *collection_props_ptr, struct PointerRNA *scene_props_ptr, const char *name, const char *custom_template)
+{
+	bool is_set = false;
+	uiLayout *row, *col;
+
+	PointerRNA *ptr;
+	PropertyRNA *prop;
+
+	IDProperty *collection_props = collection_props_ptr->data;
+
+	if (IDP_GetPropertyFromGroup(collection_props, name)) {
+		prop = RNA_struct_find_property(collection_props_ptr, name);
+		ptr = collection_props_ptr;
+		is_set = RNA_property_is_set(ptr, prop);
+	}
+	else {
+		/* property doesn't exist yet */
+		prop = RNA_struct_find_property(scene_props_ptr, name);
+		ptr = scene_props_ptr;
+	}
+
+	row = uiLayoutRow(layout, false);
+	col = uiLayoutColumn(row, false);
+
+	uiLayoutSetEnabled(col, is_set);
+
+	if (custom_template && STREQ(custom_template, "icon_view")) {
+		uiTemplateIconView(col, ptr, name, false, 5.0f);
+	}
+	else {
+		uiItemFullR(col, ptr, prop, -1, 0, 0, NULL, ICON_NONE);
+	}
+
+	col = uiLayoutColumn(row, false);
+	uiBut *but;
+	uiBlock *block = uiLayoutGetBlock(col);
+	UI_block_emboss_set(block, UI_EMBOSS_NONE);
+
+	if (is_set) {
+		but = uiDefIconButO(block, UI_BTYPE_BUT, "UI_OT_unuse_property_button", WM_OP_EXEC_DEFAULT, ICON_X, 0, 0, UI_UNIT_X, UI_UNIT_Y, NULL);
+	}
+	else {
+		but = uiDefIconButO(block, UI_BTYPE_BUT, "UI_OT_use_property_button", WM_OP_EXEC_DEFAULT, ICON_ZOOMIN, 0, 0, UI_UNIT_X, UI_UNIT_Y, NULL);
+		/* XXX - Using existing data struct to pass another RNAPointer */
+		but->rnasearchpoin = *scene_props_ptr;
+	}
+
+	but->rnapoin = *collection_props_ptr;
+	but->rnaprop = prop;
+	UI_block_emboss_set(block, UI_EMBOSS);
+}
+
 /********************************* Color management *************************************/
 
 void uiTemplateColorspaceSettings(uiLayout *layout, PointerRNA *ptr, const char *propname)