Triangulate a convex hull

content/Quadtree.org

@@ -12,6 +12,8 @@ Several things can be created with this;
 ** Resources
 [[http://ericandrewlewis.github.io/how-a-quadtree-works/][Visualize a Quadtree]]
 [[http://donar.umiacs.umd.edu/quadtree/][Academic Interactive Demo]]
+[[https://codepen.io/_bm/pen/ExPBMrW][Codepen (Js example)]]
+[[https://gist.github.com/patricksurry/6478178][D3.js Example]]
 ** Notes
 // exclude node if point is farther away than best distance in either axis
 if (x < x1 - best.d || x > x2 + best.d || y < y1 - best.d || y > y2 + best.d) {

content/Triangulation.org

@@ -3,5 +3,10 @@
 * Triangulation
 Generate triangles from points
 ** Convex Hull Jarvis March (Gift wrapping)                      :algorithm:
+[[file:~/Development/gaming-pads/convexhull-jarvismarch.py][Python Code]]
 ** Resources
+https://www.youtube.com/watch?v=Vu84lmMzP2o
+https://www.habrador.com/tutorials/math/8-convex-hull/
+https://www.youtube.com/watch?v=B2AJoQSZf4M
+https://www.geometrictools.com/Documentation/TriangulationByEarClipping.pdf
 ** Notes

convexhull-jarvismarch.py

@@ -65,7 +65,6 @@ def player_input(w: World):
                 w.dragging_vert.x = collision.point.x
                 w.dragging_vert.z = collision.point.z
     if RL.is_mouse_button_released(0):
-        print('no')
         w.dragging_vert = None
 
 def update(w: World):

starter.py

@@ -1,13 +1,23 @@
 import pyray as RL
-from pyray import (Rectangle as Rect, Vector2 as Vec2, Vector3 as Vec3, Camera3D)
+from pyray import (Rectangle as Rect, Vector2 as Vec2, Vector3 as Vec3, Camera3D, BoundingBox)
 import math
 import pdb
 import random
 from typing import Optional, Tuple, List
 from dataclasses import dataclass, field
 
-screen_width = 1280
-screen_height = 1024
+def dump(struct):
+    s = f"{RL.ffi.typeof(struct)}: (".replace('<ctype ', '').replace('>', '')
+    for field in dir(struct):
+        data = struct.__getattribute__(field)
+        if str(data).startswith("<cdata"):
+            data = dump(data)
+        s += f"{field}:{data} "
+    s += ")"
+    return s
+
+screen_width = 1024
+screen_height = 768
 
 @dataclass
 class World:
@@ -15,7 +25,8 @@ class World:
     frame_count: int = 0
 
 def init() -> World:
-    pass
+    cam = Camera3D(Vec3(0, 10, 10), Vec3(0, 0, 0), Vec3(0, 1, 0), 45, RL.CAMERA_PERSPECTIVE)
+    return World(cam)
 
 def player_input(w: World):
     pass
@@ -32,9 +43,7 @@ def draw_2d(w: World):
 RL.init_window(screen_width, screen_height, "Starter");
 RL.set_target_fps(60)
 
-init()
-cam = Camera3D(Vec3(0, 0, 10), RL.vector3_zero(), Vec3(0, 1, 0), 60, 1)
-w = World(cam)
+w = init()
 while not RL.window_should_close():
     player_input(w)
     update(w)

triangulation-earclipping.py

@@ -0,0 +1,172 @@
+import pyray as RL
+from pyray import (
+    ffi,
+    Rectangle as Rect,
+    Vector2 as Vec2,
+    Vector3 as Vec3,
+    Camera3D,
+    BoundingBox,
+    Mesh,
+    Model
+)
+import math
+import pdb
+import random
+from typing import Optional, Tuple, List
+from dataclasses import dataclass, field
+
+def dump(struct):
+    s = f"{RL.ffi.typeof(struct)}: (".replace('<ctype ', '').replace('>', '')
+    for field in dir(struct):
+        data = struct.__getattribute__(field)
+        if str(data).startswith("<cdata"):
+            data = dump(data)
+        s += f"{field}:{data} "
+    s += ")"
+    return s
+
+screen_width = 1024
+screen_height = 768
+grid_slices = 100
+grid_spacing = 0.2
+vertex_radius = 0.12
+
+@dataclass
+class World:
+    cam: Camera3D
+    floor_bb: BoundingBox
+    rotate_cam: bool = True
+    draw_wireframe: bool = RL.ffi.new('bool *', False)
+    frame_count: int = 0
+    vertices: List[Vec3] = field(default_factory=list)
+    dragging_vert: Vec3 = None
+    convex_hull_points: List[Vec3] = field(default_factory=list)
+    mesh: Mesh = None
+    model: Model = None
+
+def get_convex_hull(vertices: List[Vec3]):
+    convex_hull_points = []
+    pending = sorted(vertices, key=lambda v: v.x)
+    convex_hull_points.append(pending[0])
+    idx = 0
+    while True:
+        v1 = convex_hull_points[-1]
+        left_most = pending[(idx + 1) % len(pending)]
+        idx += 1
+        if v1 == left_most:
+            continue
+        for v2 in pending:
+            x1 = v1.x - left_most.x
+            x2 = v1.x - v2.x
+            y1 = v1.z - left_most.z
+            y2 = v1.z - v2.z
+
+            sign = y2*x1 - y1*x2
+            if v1 == v2:
+                continue
+            if sign > 0:
+                left_most = v2 
+        if left_most == convex_hull_points[0]:
+            break
+        convex_hull_points.append(left_most)
+    return convex_hull_points
+        
+def init() -> World:
+    cam = Camera3D(Vec3(0, 10, 10), Vec3(0, 0, 0), Vec3(0, 1, 0), 45, RL.CAMERA_PERSPECTIVE)
+    half_grid = grid_slices * grid_spacing * 0.5
+    floor_bb = BoundingBox(Vec3(-half_grid, -0.01, -half_grid), Vec3(half_grid, 0.01, half_grid))
+    w = World(cam, floor_bb)
+    num_starting_verts = 10
+    radius = 4
+    w.vertices = [
+        Vec3(math.cos(math.pi * 2 / num_starting_verts * i) * radius,
+             0,
+             math.sin(math.pi * 2 / num_starting_verts * i) * radius)
+        for i in range(num_starting_verts)
+    ]
+
+    vs = get_convex_hull(w.vertices)
+    def get_points(v: Vec3):
+        return v.x, v.y, v.z
+    vertices = ffi.new("float[]", len(vs) * 3 * 3)
+    # for i,v in enumerate([0,0,0   1,0,2,   2,0,0,      1,0,2,   3,0,2,   2,0,0]):
+    for i,v in enumerate(vs):
+        if i < 2:
+            continue
+        for j,vv in enumerate([*get_points(vs[0]), *get_points(vs[i - 1]), *get_points(vs[i])]):
+            vertices[(i-2)*9+j] = vv
+
+    texcoords = ffi.new("float[]", 0)
+    # for i,c in enumerate([0, 0, 0.5, 1, 1, 0]):
+    #     texcoords[i] = c
+    normals = ffi.new("float[]", 0)
+    # for i,c in enumerate([0, 1, 0, 0, 1, 0, 0, 1, 0]):
+    #     normals[i] = c
+    texcoords2 = ffi.new("float[]", 0)
+    # for i in range(6):
+    #     texcoords[i] = 0
+
+    # mesh = Mesh(6, 2, vertices, texcoords, texcoords2, normals)
+    mesh = Mesh(len(vs) * 3, len(vs), vertices, texcoords, texcoords2, normals)
+    RL.upload_mesh(mesh, False)
+    w.mesh = mesh
+    w.model = RL.load_model_from_mesh(mesh)
+    return w
+
+def player_input(w: World):
+    if RL.is_key_pressed(RL.KEY_SPACE):
+        w.rotate_cam = not w.rotate_cam
+    if RL.is_key_pressed(RL.KEY_W):
+        w.draw_wireframe = not w.draw_wireframe
+
+def update(w: World):
+    pass
+    # mesh = Mesh(
+    #     vertexCount = len(w.vertices),
+    #     triangleCount = len(w.vertices) - 2,
+    #     vertices = w.vertices
+    # )
+    # new_mesh = RL.gen_
+
+def draw_3d(w: World):
+    RL.draw_grid(grid_slices, grid_spacing)
+    RL.draw_bounding_box(w.floor_bb, RL.GREEN)
+    for vert in w.vertices:
+        RL.draw_sphere(vert, vertex_radius, RL.GREEN)
+    if w.draw_wireframe[0]:
+        RL.rl_enable_wire_mode()
+    else:
+        RL.rl_disable_wire_mode()
+    RL.draw_model(w.model, RL.vector3_zero(), 1, RL.GREEN)
+
+def draw_2d(w: World):
+    val = RL.gui_check_box(Rect(10, 30, 50, 50), "Draw Wireframe", w.draw_wireframe)
+    if val != 0:
+        print(val)
+    if val:
+        print('hello')
+        w.draw_wireframe = True
+
+RL.init_window(screen_width, screen_height, "Starter");
+RL.set_target_fps(60)
+
+w = init()
+while not RL.window_should_close():
+    player_input(w)
+    update(w)
+
+    # Drawing
+    if w.rotate_cam:
+        RL.update_camera(w.cam, RL.CameraMode.CAMERA_ORBITAL)
+    RL.begin_drawing()
+    RL.clear_background(RL.WHITE)
+
+    RL.begin_mode_3d(w.cam)
+    draw_3d(w)
+    RL.end_mode_3d()
+
+    draw_2d(w)
+
+    RL.end_drawing()
+    w.frame_count += 1
+