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# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
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# GNU General Public License for more details.
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# along with this program; if not, write to the Free Software Foundation,
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# <pep8 compliant> (Thanks to CodemanX on IRC)

bl_info = {
    "name": "Show Vertex Groups/Weights",
    "author": "Jason van Gumster (Fweeb), Bartius Crouch",
    "version": (0, 7, 1),
    "blender": (2, 62, 3),
    "location": "3D View > Properties Region > Show Weights",
    "description": "Finds the vertex groups of a selected vertex and displays the corresponding weights",
    "warning": "Requires bmesh",
    "wiki_url": "http://wiki.blender.org/index.php/Extensions:2.6/Py/"\
        "Scripts/Modeling/Show_Vertex_Group_Weights",
    "tracker_url": "http://projects.blender.org/tracker/index.php?"\
        "func=detail&aid=30609",
    "category": "Mesh"}

#TODO - Add button for selecting vertices with no groups


import bpy, bmesh, bgl, blf, mathutils


# Borrowed/Modified from Bart Crouch's old Index Visualizer add-on
def calc_callback(self, context):
    #polling
    if context.mode != "EDIT_MESH" or len(context.active_object.vertex_groups) == 0:
        return

    # get color info from theme
    acol = context.user_preferences.themes[0].view_3d.editmesh_active
    tcol = (acol[0] * 0.85, acol[1] * 0.85, acol[2] * 0.85)
    
    # get screen information
    mid_x = context.region.width / 2.0
    mid_y = context.region.height / 2.0
    width = context.region.width
    height = context.region.height
    
    # get matrices
    view_mat = context.space_data.region_3d.perspective_matrix
    ob_mat = context.active_object.matrix_world
    total_mat = view_mat * ob_mat
    
    # calculate location info
    texts = []
    locs = []
    weights  = []
    me = context.active_object.data
    bm = bmesh.from_edit_mesh(me)
    dvert_lay = bm.verts.layers.deform.active

    for v in bm.verts:
        if v.select: #XXX Should check v.hide here, but it doesn't work
            if bm.select_mode == {'VERT'} and bm.select_history.active is not None and bm.select_history.active.index == v.index:
                locs.append([acol[0], acol[1], acol[2], v.index, v.co.to_4d()])
            else:
                locs.append([tcol[0], tcol[1], tcol[2], v.index, v.co.to_4d()])
            dvert = v[dvert_lay]
            for vgroup in context.active_object.vertex_groups:
                if vgroup.index in dvert.keys():
                    weights += [v.index, vgroup.index, dvert[vgroup.index]]

    for loc in locs:
        vec = total_mat * loc[4] # order is important
        # dehomogenise
        vec = mathutils.Vector((vec[0] / vec[3], vec[1] / vec[3], vec[2] / vec[3]))
        x = int(mid_x + vec[0] * width / 2.0)
        y = int(mid_y + vec[1] * height / 2.0)
        texts += [loc[0], loc[1], loc[2], loc[3], x, y, 0]

    # store as ID property in mesh
    context.active_object.data["show_vgroup_verts"] = texts
    context.active_object.data["show_vgroup_weights"] = weights


# draw in 3d-view
def draw_callback(self, context):
    # polling
    if context.mode != "EDIT_MESH" or len(context.active_object.vertex_groups) == 0:
        return
    # retrieving ID property data
    try:
        texts = context.active_object.data["show_vgroup_verts"]
        weights = context.active_object.data["show_vgroup_weights"]
    except:
        return
    if not texts:
        return

    bm = bmesh.from_edit_mesh(context.active_object.data)

    if bm.select_mode == {'VERT'} and bm.select_history.active is not None:
        active_vert = bm.select_history.active
    else:
        active_vert = None

    # draw
    blf.size(0, 13, 72)
    blf.enable(0, blf.SHADOW)
    blf.shadow(0, 3, 0.0, 0.0, 0.0, 1.0)
    blf.shadow_offset(0, 2, -2)
    for i in range(0, len(texts), 7):
        bgl.glColor3f(texts[i], texts[i+1], texts[i+2])
        blf.position(0, texts[i+4], texts[i+5], texts[i+6])
        blf.draw(0, "Vertex " + str(int(texts[i+3])) + ":")
        font_y = texts[i+5]
        group_name = ""
        for j in range(0, len(weights), 3):
            if int(weights[j]) == int(texts[i+3]):
                font_y -= 13
                blf.position(0, texts[i+4] + 10, font_y, texts[i+6])
                for group in context.active_object.vertex_groups:
                    if group.index == int(weights[j+1]):
                        group_name = group.name
                        break
                blf.draw(0, group_name + ": %.3f" % weights[j+2])
        if group_name == "":
            font_y -= 13
            blf.position(0, texts[i+4] + 10, font_y, texts[i+6])
            blf.draw(0, "No Groups")

    # restore defaults
    blf.disable(0, blf.SHADOW)


# operator
class ShowVGroupWeights(bpy.types.Operator):
    bl_idname = "view3d.show_vgroup_weights"
    bl_label = "Show Vertex Group Weights"
    bl_description = "Toggle the display of the vertex groups and weights for selected vertices"
    
    @classmethod
    def poll(cls, context):
        return context.mode == 'EDIT_MESH'
    
    def __del__(self):
        bpy.context.scene.display_indices = -1
        clear_properties(full=False)
    
    def modal(self, context, event):
        if context.area:
            context.area.tag_redraw()

        # removal of callbacks when operator is called again
        if context.scene.display_indices == -1:
            context.region.callback_remove(self.handle1)
            context.region.callback_remove(self.handle2)
            context.scene.display_indices = 0
            return {'CANCELLED'}
        
        return {'PASS_THROUGH'}
    
    def invoke(self, context, event):
        if context.area.type == 'VIEW_3D':
            if context.scene.display_indices < 1:
                # operator is called for the first time, start everything
                context.scene.display_indices = 1
                self.handle1 = context.region.callback_add(calc_callback,
                    (self, context), 'POST_VIEW')
                self.handle2 = context.region.callback_add(draw_callback,
                    (self, context), 'POST_PIXEL')
                context.window_manager.modal_handler_add(self)
                return {'RUNNING_MODAL'}
            else:
                # operator is called again, stop displaying
                context.scene.display_indices = -1
                clear_properties(full=False)
                return {'RUNNING_MODAL'}
        else:
            self.report({'WARNING'}, "View3D not found, can't run operator")
            return {'CANCELLED'}


# properties used by the script
class InitProperties(bpy.types.Operator):
    bl_idname = "view3d.init_find_weights"
    bl_label = "Initialize properties for vgroup weights finder"
    
    def execute(self, context):
        bpy.types.Scene.display_indices = bpy.props.IntProperty(
            name="Display indices",
            default=0)
        context.scene.display_indices = 0
        return {'FINISHED'}


# removal of ID-properties when script is disabled
def clear_properties(full=True):
    # can happen on reload
    if bpy.context.scene is None:
        return
    
    if "show_vgroup_verts" in bpy.context.active_object.data.keys():
        del bpy.context.active_object.data["show_vgroup_verts"]
    if "show_vgroup_weights" in bpy.context.active_object.data.keys():
        del bpy.context.active_object.data["show_vgroup_weights"]
    if full:
        props = ["display_indices"]
        for p in props:
            if p in bpy.types.Scene.bl_rna.properties:
                exec("del bpy.types.Scene." + p)
            if p in bpy.context.scene.keys():
                del bpy.context.scene[p]


class AssignVertexWeight(bpy.types.Operator):
    bl_idname = "mesh.vertex_group_assign"
    bl_label = "Assign Weights"
    bl_description = "Assign weights for all of the groups on a specific vertex"

    vgroup_weights = bpy.props.StringProperty(name = "Vertex Group Weights")

    @classmethod
    def poll(cls, context):
        return context.mode == 'EDIT_MESH'

    def execute(self, context):
        me = context.active_object.data
        bm = bmesh.from_edit_mesh(me)
        dvert_lay = bm.verts.layers.deform.active
        weights = eval(self.vgroup_weights) #XXX Would be nice if I didn't have to use an eval

        for v in bm.verts:
            if v.index == weights["__index__"]:
                del weights["__index__"]
                dvert = v[dvert_lay]
                for vgroup in dvert.keys():
                    dvert[vgroup] = weights[vgroup]
                break

        return {'FINISHED'}


class RemoveFromVertexGroup(bpy.types.Operator):
    bl_idname = "mesh.vertex_group_remove"
    bl_label = "Remove Vertex from Group"
    bl_description = "Remove a specific vertex from a specific vertex group"

    #XXX abusing vector props here a bit; the first element is the vert index and the second is the group index
    vert_and_group = bpy.props.IntVectorProperty(name = "Vertex and Group to remove", size = 2)

    @classmethod
    def poll(cls, context):
        return context.mode == 'EDIT_MESH'

    def execute(self, context):
        ob = context.active_object
        me = ob.data
        bm = bmesh.from_edit_mesh(me)

        # Save current selection
        selected_verts = []
        for v in bm.verts:
            if v.select is True:
                selected_verts.append(v.index)
                if v.index != self.vert_and_group[0]:
                    v.select = False

        ob.vertex_groups.active_index = self.vert_and_group[1]
        bpy.ops.object.vertex_group_remove_from()

        # Re-select vertices
        for v in bm.verts:
            if v.index in selected_verts:
                v.select = True

        #XXX Hacky, but there's no other way to update the UI panels
        bpy.ops.object.editmode_toggle()
        bpy.ops.object.editmode_toggle()
        return {'FINISHED'}


class AddToVertexGroup(bpy.types.Operator):
    bl_idname = "mesh.vertex_group_add"
    bl_label = "Add Vertex to Group"
    bl_description = "Add a specific vertex to a specific vertex group"

    def avail_vgroups(self, context):
        ob = context.active_object
        bm = bmesh.from_edit_mesh(ob.data)
        dvert_lay = bm.verts.layers.deform.active
        items = []
        self.vertex = bm.select_history.active.index

        dvert = bm.select_history.active[dvert_lay]

        items.append(("-1", "New Vertex Group", "-1", -1))

        for i in ob.vertex_groups:
            if i.index not in dvert.keys():
                items.append((i.name, i.name, str(i.index), i.index))

        return items

    vertex = bpy.props.IntProperty()
    available_vgroups = bpy.props.EnumProperty(items = avail_vgroups, name = "Available Groups")

    @classmethod
    def poll(cls, context):
        return context.mode == 'EDIT_MESH'

    def execute(self, context):
        ob = context.active_object
        me = ob.data
        bm = bmesh.from_edit_mesh(me)
        #print(self.available_vgroups)

        # Save current selection
        selected_verts = []
        for v in bm.verts:
            if v.select is True:
                selected_verts.append(v.index)
                if v.index != self.vertex:
                    v.select = False

        weight = context.tool_settings.vertex_group_weight
        context.tool_settings.vertex_group_weight = 1.0
        if self.available_vgroups == "-1":
            bpy.ops.object.vertex_group_assign(new = True) #XXX Assumes self.vertex is the active vertex
        else:
            bpy.ops.object.vertex_group_set_active(group = self.available_vgroups)
            bpy.ops.object.vertex_group_assign() #XXX Assumes self.vertex is the active vertex
        context.tool_settings.vertex_group_weight = weight

        # Re-select vertices
        for v in bm.verts:
            if v.index in selected_verts:
                v.select = True

        #XXX Hacky, but there's no other way to update the UI panels
        bpy.ops.object.editmode_toggle()
        bpy.ops.object.editmode_toggle()
        return {'FINISHED'}


class PanelShowWeights(bpy.types.Panel):
    bl_label = "Show Weights"
    bl_space_type = "VIEW_3D"
    bl_region_type = "UI"
    bl_options = {'DEFAULT_CLOSED'}

    @classmethod
    def poll(cls, context):
        return context.mode == 'EDIT_MESH'

    def draw(self, context):
        layout = self.layout
        ob = context.active_object
        me = ob.data
        bm = bmesh.from_edit_mesh(me)
        dvert_lay = bm.verts.layers.deform.active

        if context.scene.display_indices < 1:
            layout.operator(ShowVGroupWeights.bl_idname, text = "Show Weights Overlay")
        else:
            layout.operator(ShowVGroupWeights.bl_idname, text = "Hide Weights Overlay")

        if len(ob.vertex_groups) > 0:
            # Active vertex
            active_vert = bm.select_history.active
            sub = layout.box()
            col = sub.column(align = True)
            if bm.select_mode == {'VERT'} and active_vert is not None:
                col.label(text = "Active Vertex")
                row = col.row()
                row.label(text = "Vertex " + str(active_vert.index) + ":")
                row.operator_menu_enum("mesh.vertex_group_add", "available_vgroups", text = "Add Group", icon = 'GROUP_VERTEX')
                has_groups = False
                vgroup_weights = {}

                for i in me.vertices:
                    if i.index == active_vert.index:
                        vgroup_weights["__index__"] = i.index
                        for j in range(len(i.groups)):
                            for k in ob.vertex_groups:
                                if k.index == i.groups[j].group:
                                    has_groups = True
                                    split = col.split(percentage = 0.90, align = True)
                                    vgroup_weights[k.index] = i.groups[j].weight
                                    row = split.row(align = True)
                                    row.prop(i.groups[j], "weight", text = k.name, slider = True, emboss = not k.lock_weight)
                                    row = split.row(align = True)
                                    row.operator("mesh.vertex_group_remove", text = "R").vert_and_group = (i.index, k.index)
                
                if not has_groups:
                    col.label(text = "    No Groups")
                else:
                    col.operator("mesh.vertex_group_assign").vgroup_weights = str(vgroup_weights)
                layout.separator()
            else:
                col.label(text = "No Active Vertex")
            layout.prop(context.window_manager, "show_vgroups_show_all", toggle = True)
            # All selected vertices (except for the active vertex)
            if context.window_manager.show_vgroups_show_all:
                for v in bm.verts:
                    if v.select:
                        if active_vert is not None and v.index == active_vert.index:
                            continue
                        sub = layout.box()
                        col = sub.column(align = True)
                        col.label(text = "Vertex " + str(v.index) + ":")
                        has_groups = False
                        vgroup_weights = {}
                        for i in me.vertices:
                            if i.index == v.index:
                                vgroup_weights["__index__"] = i.index
                                for j in range(len(i.groups)):
                                    for k in ob.vertex_groups:
                                        if k.index == i.groups[j].group:
                                            has_groups = True
                                            split = col.split(percentage = 0.90, align = True)
                                            vgroup_weights[k.index] = i.groups[j].weight
                                            row = split.row(align = True)
                                            row.prop(i.groups[j], "weight", text = k.name, slider = True, emboss = not k.lock_weight)
                                            row = split.row(align = True)
                                            row.operator("mesh.vertex_group_remove", text = "R").vert_and_group = (i.index, k.index)
                        if not has_groups:
                            col.label(text = "    No Groups")
                        else:
                            col.operator("mesh.vertex_group_assign").vgroup_weights = str(vgroup_weights)
        else:
            layout.label(text = "No Groups")


def register():
    bpy.types.WindowManager.show_vgroups_show_all = bpy.props.BoolProperty(
        name = "Show All Selected Vertices",
        description = "Show all vertices with vertex groups assigned to them",
        default = False)
    bpy.types.Mesh.assign_vgroup = bpy.props.StringProperty()
    bpy.utils.register_class(ShowVGroupWeights)
    bpy.utils.register_class(InitProperties)
    bpy.ops.view3d.init_find_weights()
    bpy.utils.register_class(AssignVertexWeight)
    bpy.utils.register_class(RemoveFromVertexGroup)
    bpy.utils.register_class(AddToVertexGroup)
    bpy.utils.register_class(PanelShowWeights)
    

def unregister():
    bpy.utils.unregister_class(ShowVGroupWeights)
    bpy.utils.unregister_class(InitProperties)
    clear_properties()
    bpy.utils.unregister_class(AssignVertexWeight)
    bpy.utils.unregister_class(RemoveFromVertexGroup)
    bpy.utils.unregister_class(AddToVertexGroup)
    bpy.utils.unregister_class(PanelShowWeights)
    del bpy.types.WindowManager.show_vgroups_show_all
    del bpy.types.Mesh.assign_vgroup

if __name__ == "__main__":
    register()
