# vr_overlay.py - compare the model with the user's front render 5.jpg pixel by pixel.
# pose_ref5(): the render's pose without the bow (joint positions read off a pixel grid on 5.jpg,
#   1.37 mm/px, centre x = 1000 px, floor y = 1525 px; depths guessed).
# camera_ref5(): a camera matching 5.jpg (85 mm, 36 mm sensor, 2000 x 1611, level at 0.99 m).
# render_mask(path): flat silhouette render with alpha, for vr_overlay_compose.py (system Python).
import bpy, math
from mathutils import Vector as V, Matrix

REF5 = {  # world targets (m) for the joints in 5.jpg
    "elbow_r": (-0.40, 0.02, 1.285), "wrist_r": (-0.15, -0.16, 1.29),
    "elbow_l": (0.29, 0.10, 1.31), "wrist_l": (0.165, -0.07, 1.05),
    "knee_l": (0.28, -0.01, 0.61), "ankle_l": (0.31, 0.02, 0.165),
    "knee_r": (-0.30, -0.01, 0.61), "ankle_r": (-0.33, 0.02, 0.165),
}


def pose_ref5(ps):
    rig = bpy.data.objects["VR_Rig"]
    ps["rest"](rig)
    P = lambda b: rig.matrix_world @ rig.pose.bones[b].head
    for s in ("_l", "_r"):
        foot = rig.pose.bones["foot" + s].matrix.copy()
        ps["_aim"](rig, "thigh" + s, V(REF5["knee" + s]) - P("thigh" + s))
        ps["_aim"](rig, "calf" + s, V(REF5["ankle" + s]) - P("calf" + s))
        fy = Matrix.Rotation(math.radians(22 if s == "_l" else -22), 3, 'Z') @ V((foot[0][1], foot[1][1], foot[2][1]))
        ps["_aim"](rig, "foot" + s, fy)                              # toes turned out, as in 5.jpg
        ps["_aim"](rig, "upperarm" + s, V(REF5["elbow" + s]) - P("upperarm" + s))
        ps["_aim"](rig, "lowerarm" + s, V(REF5["wrist" + s]) - P("lowerarm" + s))
    for pb in rig.pose.bones:
        if pb.name.split("_")[0] in ("index", "middle", "ring", "pinky", "thumb"):
            pb.rotation_mode = 'XYZ'
            pb.rotation_euler = (math.radians(-55 if not pb.name.startswith("thumb") else -30), 0, 0)
    bpy.context.view_layer.update()


def camera_ref5():
    sc = bpy.context.scene
    cam = bpy.data.objects.get("VR_Cam_Ref5")
    if cam is None:
        cam = bpy.data.objects.new("VR_Cam_Ref5", bpy.data.cameras.new("VR_Cam_Ref5"))
        bpy.data.collections["VR | Studio"].objects.link(cam)
    cam.data.lens = 85; cam.data.sensor_fit = 'HORIZONTAL'; cam.data.sensor_width = 36
    cam.location = (0, -6.47, 0.99); cam.rotation_euler = (math.radians(90), 0, 0)
    sc.camera = cam
    sc.render.resolution_x = 2000; sc.render.resolution_y = 1611; sc.render.resolution_percentage = 100
    return cam


def render_mask(path):
    sc = bpy.context.scene
    keep = (sc.render.engine, sc.render.film_transparent, sc.display.shading.light, sc.display.shading.color_type)
    floor = bpy.data.objects.get("VR_Studio_Floor")
    if floor:
        floor.hide_render = True
    sc.render.engine = 'BLENDER_WORKBENCH'; sc.render.film_transparent = True
    sc.display.shading.light = 'FLAT'; sc.display.shading.color_type = 'SINGLE'
    sc.display.shading.single_color = (1, 1, 1)
    sc.render.filepath = path
    bpy.ops.render.render(write_still=True)
    sc.render.engine, sc.render.film_transparent, sc.display.shading.light, sc.display.shading.color_type = keep
    if floor:
        floor.hide_render = False