fix: reset draw cam rotation

1.7.8

- fix: reset rotation in draw cam mode keep view in the same place (counter camera rotation)
- code: initial enhancement for palette linking

OP_helpers.py

@@ -1,10 +1,14 @@
 from time import ctime
 import bpy
+import mathutils
 from mathutils import Vector#, Matrix
 from pathlib import Path
+import math
 from math import radians
+
 from . import utils
 
+
 class GPTB_OT_copy_text(bpy.types.Operator):
     bl_idname = "wm.copytext"
     bl_label = "Copy to clipboard"
@@ -280,6 +284,89 @@ class GPTB_OT_set_view_as_cam(bpy.types.Operator):
         return {"FINISHED"}
 
 
+class GPTB_OT_reset_cam_rot(bpy.types.Operator):
+    bl_idname = "gp.reset_cam_rot"
+    bl_label = "Reset rotation"
+    bl_description = "Reset rotation of the draw manipulation camera"
+    bl_options = {"REGISTER"}
+
+    @classmethod
+    def poll(cls, context):
+        return context.scene.camera and not context.scene.camera.name.startswith('Cam')
+        # return context.region_data.view_perspective == 'CAMERA'# check if in camera
+
+    def get_center_view(self, context, cam):
+        from bpy_extras.view3d_utils import location_3d_to_region_2d
+        frame = cam.data.view_frame()
+        mat = cam.matrix_world
+        frame = [mat @ v for v in frame]
+        frame_px = [location_3d_to_region_2d(context.region, context.space_data.region_3d, v) for v in frame]
+        center_x = frame_px[2].x + (frame_px[0].x - frame_px[2].x)/2
+        center_y = frame_px[1].y + (frame_px[0].y - frame_px[1].y)/2
+        return mathutils.Vector((center_x, center_y))
+
+    def get_ui_ratio(self, context):
+        '''correct ui overlap from header/toolbars'''
+        regs = context.area.regions
+        if context.preferences.system.use_region_overlap:
+            w = context.area.width 
+            # minus tool header
+            h = context.area.height - regs[0].height
+        else:
+            # minus tool leftbar + sidebar right
+            w = context.area.width - regs[2].width - regs[3].width
+            # minus tool header + header
+            h = context.area.height - regs[0].height - regs[1].height
+        
+        self.ratio = h / w
+        self.ratio_inv = w / h    
+
+    def execute(self, context):
+        cam = context.scene.camera
+
+        # self.cam_init_euler = self.cam.rotation_euler.copy()
+        if not cam.parent or cam.parent.type != 'CAMERA':
+            self.report({'ERROR'}, "No parents to refer to for rotation reset")
+            return {"CANCELLED"}
+
+        # store original rotation mode
+        org_rotation_mode = cam.rotation_mode
+        
+        # set to euler to works with quaternions, restored at finish
+        cam.rotation_mode = 'XYZ'
+        # store camera matrix world
+        org_cam_matrix = cam.matrix_world.copy()
+        
+        org_cam_z = cam.rotation_euler.z
+
+        ## initialize current view_offset in camera
+        view_cam_offset = mathutils.Vector(context.space_data.region_3d.view_camera_offset)
+
+        # Do the reset to parent transforms 
+        cam.matrix_world = cam.parent.matrix_world # wrong, get the parent rotation offset
+        
+        # Get diff angle
+        angle = cam.rotation_euler.z - org_cam_z
+        # create rotation matrix with negative angle (we want to counter the move)
+        neg = -angle
+        rot_mat2d = mathutils.Matrix([[math.cos(neg), -math.sin(neg)], [math.sin(neg), math.cos(neg)]])
+        
+        # restore original rotation mode
+        cam.rotation_mode = org_rotation_mode
+
+        self.get_ui_ratio(context)
+        # apply rotation matrix
+        new_cam_offset = view_cam_offset.copy()
+        new_cam_offset = mathutils.Vector((new_cam_offset[0], new_cam_offset[1] * self.ratio)) # apply screen ratio
+        new_cam_offset.rotate(rot_mat2d)
+        new_cam_offset = mathutils.Vector((new_cam_offset[0], new_cam_offset[1] * self.ratio_inv)) # restore screen ratio
+
+        context.space_data.region_3d.view_camera_offset = new_cam_offset
+
+
+        return {"FINISHED"}
+
+""" # old simple cam draw fit to cam
 class GPTB_OT_reset_cam_rot(bpy.types.Operator):
     bl_idname = "gp.reset_cam_rot"
     bl_label = "Reset rotation"
@@ -306,9 +393,8 @@ class GPTB_OT_reset_cam_rot(bpy.types.Operator):
         else:
             self.report({'ERROR'}, "No parents to refer to for rotation reset")
             return {"CANCELLED"}
-            
-            
         return {"FINISHED"}
+"""
 
 class GPTB_OT_toggle_mute_animation(bpy.types.Operator):
     bl_idname = "gp.toggle_mute_animation"