o3de/Gems/WhiteBox/Editor/Scripts/Cylinder.py

"""
Copyright (c) Contributors to the Open 3D Engine Project.
For complete copyright and license terms please see the LICENSE at the root of this distribution.

SPDX-License-Identifier: Apache-2.0 OR MIT
"""

import WhiteBoxMath as whiteBoxMath
import WhiteBoxInit as init 

import argparse
import azlmbr.legacy.general as general
import azlmbr.bus as bus
import azlmbr.whitebox.api as api

# usage: pyRunFile path/to/file/cylinder.py <sides> <size>
# number of sides is used to determine the number of vertices in each circle


def create_cylinder(whiteBoxMesh, sides=16, size=0.5):
    # create all the vertices as two circles (top/bottom) with one additional vertex for the center of each circle
    # create center vertices for each circle
    top_vertex_pos = whiteBoxMath.spherical_to_cartesian(0.0, 0.0, size)
    bottom_vertex_pos = whiteBoxMath.spherical_to_cartesian(180.0, 0.0, size)
    top_vertex = whiteBoxMesh.AddVertex(top_vertex_pos)
    bottom_vertex = whiteBoxMesh.AddVertex(bottom_vertex_pos)

    # set up angles/distance for each of the cylinder circles
    top_circle_vertices = []
    bottom_circle_vertices = []
    angle_increment = 360.0 / sides

    # distance from the center of the cylinder to the vertices of the top/bottom circles
    # simplifies to size times the square root of 2
    vertex_dist = size * 1.414
    # add vertices for each of the cylinder circles
    for side in range (0, sides):
        # internal angle from center of cylinder to any point on top/bottom circles
        top_circle_pos = whiteBoxMath.spherical_to_cartesian(45.0, side * angle_increment, vertex_dist)
        bottom_circle_pos = whiteBoxMath.spherical_to_cartesian(135.0, side * angle_increment, vertex_dist)

        # add to list for vertices for the top/bottom circles
        top_circle_vertex = whiteBoxMesh.AddVertex(top_circle_pos)
        bottom_circle_vertex = whiteBoxMesh.AddVertex(bottom_circle_pos)

        top_circle_vertices.append(top_circle_vertex)
        bottom_circle_vertices.append(bottom_circle_vertex)

    # create faces
    top_circle_fvh = []
    bottom_circle_fvh = []
    for side in range (0, sides):
       index1 = side
       index2 = (side + 1) % sides

       # add to list for face vertex handles for top/bottom circles
       top_circle_fvh.append(api.util_MakeFaceVertHandles(top_vertex, top_circle_vertices[index1], top_circle_vertices[index2]))
       bottom_circle_fvh.append(api.util_MakeFaceVertHandles(bottom_vertex, bottom_circle_vertices[index2], bottom_circle_vertices[index1]))

       # add quad polygons to create the side of the cylinder
       whiteBoxMesh.AddQuadPolygon(top_circle_vertices[index1], bottom_circle_vertices[index1], bottom_circle_vertices[index2], top_circle_vertices[index2])

    # add top/bottom faces
    whiteBoxMesh.AddPolygon(top_circle_fvh)
    whiteBoxMesh.AddPolygon(bottom_circle_fvh)


if __name__ == "__main__":
    # cmdline arguments
    parser = argparse.ArgumentParser(description='Creates a cylinder shaped white box mesh.')
    parser.add_argument('sides', nargs='?', default=16, type=int, help='number of vertices in each circle')
    parser.add_argument('size', nargs='?', default=0.5, type=float, help='size of the cylinder')
    args = parser.parse_args()

    # initialize whiteBoxMesh
    whiteBoxEntity = init.create_white_box_entity("WhiteBox-Cylinder")
    whiteBoxMeshComponent = init.create_white_box_component(whiteBoxEntity)
    whiteBoxMesh = init.create_white_box_handle(whiteBoxMeshComponent)

    # clear whiteBoxMesh to make a cylinder from scratch
    whiteBoxMesh.Clear()
    
    create_cylinder(whiteBoxMesh, args.sides, args.size)

    # update whiteBoxMesh
    init.update_white_box(whiteBoxMesh, whiteBoxMeshComponent)