Improve struct creation helper methods by auto converting arguments: (#119)

* None to ffi.NULL
 * array and ndarray to buffer, and keep weakref so it doesn't get GCed

This makes it possible to create Mesh structs without too much faffing.

examples/extra/mesh_creation.py

@@ -0,0 +1,120 @@
+from array import array
+import pyray as pr
+
+W, H = 640, 480
+
+
+def make_cube(width, height, length):
+    vertices = array('f', [
+        -width / 2, -height / 2, length / 2,
+        width / 2, -height / 2, length / 2,
+        width / 2, height / 2, length / 2,
+        -width / 2, height / 2, length / 2,
+        -width / 2, -height / 2, -length / 2,
+        -width / 2, height / 2, -length / 2,
+        width / 2, height / 2, -length / 2,
+        width / 2, -height / 2, -length / 2,
+        -width / 2, height / 2, -length / 2,
+        -width / 2, height / 2, length / 2,
+        width / 2, height / 2, length / 2,
+        width / 2, height / 2, -length / 2,
+        -width / 2, -height / 2, -length / 2,
+        width / 2, -height / 2, -length / 2,
+        width / 2, -height / 2, length / 2,
+        -width / 2, -height / 2, length / 2,
+        width / 2, -height / 2, -length / 2,
+        width / 2, height / 2, -length / 2,
+        width / 2, height / 2, length / 2,
+        width / 2, -height / 2, length / 2,
+        -width / 2, -height / 2, -length / 2,
+        -width / 2, -height / 2, length / 2,
+        -width / 2, height / 2, length / 2,
+        -width / 2, height / 2, -length / 2
+    ])
+
+    texcoords = array('f', [
+        0.0, 0.0,
+        1.0, 0.0,
+        1.0, 1.0,
+        0.0, 1.0,
+        1.0, 0.0,
+        1.0, 1.0,
+        0.0, 1.0,
+        0.0, 0.0,
+        0.0, 1.0,
+        0.0, 0.0,
+        1.0, 0.0,
+        1.0, 1.0,
+        1.0, 1.0,
+        0.0, 1.0,
+        0.0, 0.0,
+        1.0, 0.0,
+        1.0, 0.0,
+        1.0, 1.0,
+        0.0, 1.0,
+        0.0, 0.0,
+        0.0, 0.0,
+        1.0, 0.0,
+        1.0, 1.0,
+        0.0, 1.0])
+
+    normals = array('f', [
+        0.0, 0.0, 1.0,
+        0.0, 0.0, 1.0,
+        0.0, 0.0, 1.0,
+        0.0, 0.0, 1.0,
+        0.0, 0.0, -1.0,
+        0.0, 0.0, -1.0,
+        0.0, 0.0, -1.0,
+        0.0, 0.0, -1.0,
+        0.0, 1.0, 0.0,
+        0.0, 1.0, 0.0,
+        0.0, 1.0, 0.0,
+        0.0, 1.0, 0.0,
+        0.0, -1.0, 0.0,
+        0.0, -1.0, 0.0,
+        0.0, -1.0, 0.0,
+        0.0, -1.0, 0.0,
+        1.0, 0.0, 0.0,
+        1.0, 0.0, 0.0,
+        1.0, 0.0, 0.0,
+        1.0, 0.0, 0.0,
+        -1.0, 0.0, 0.0,
+        -1.0, 0.0, 0.0,
+        -1.0, 0.0, 0.0,
+        -1.0, 0.0, 0.0
+    ])
+
+    indices = array('h',
+                    sum([[4 * k, 4 * k + 1, 4 * k + 2, 4 * k, 4 * k + 2, 4 * k + 3] for k in range(0, 6)], []))
+
+    print(vertices, indices)
+
+    return (pr.Mesh(24, 12, vertices, texcoords,
+                   None, normals, None, None, indices,
+                   None, None, None, None, 0, None))
+
+
+pr.init_window(W, H, "Mesh creation")
+
+msh = make_cube(3, 4, 40)
+pr.upload_mesh(msh, False)
+matdefault = pr.load_material_default()
+eye = pr.matrix_identity()
+
+camera = pr.Camera3D((30.0, 20.0, 30.0), (0.0, 0.0, 0.0), (0.0, 1.0, 0.0), 70.0,
+                     pr.CameraProjection.CAMERA_PERSPECTIVE)
+
+# Export so we can inspect it
+pr.export_mesh(msh, "test-cube.obj")
+
+while not pr.window_should_close():
+    pr.update_camera(camera, pr.CameraMode.CAMERA_ORBITAL)
+    pr.begin_drawing()
+    pr.clear_background(pr.BLACK)
+    pr.begin_mode_3d(camera)
+    pr.draw_grid(10, 5.0)
+    pr.draw_mesh(msh, matdefault, eye)
+    pr.end_mode_3d()
+    pr.end_drawing()
+pr.close_window()

pyray/__init__.py

@@ -11,6 +11,8 @@
 #  available at https://www.gnu.org/software/classpath/license.html.
 #
 #  SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
+import weakref
+from array import array
 
 from raylib import rl, ffi
 from raylib.colors import *
@@ -43,7 +45,7 @@ def makefunc(a):
     def func(*args):
         modified_args = []
         for (c_arg, arg) in zip(ffi.typeof(a).args, args):
-            #print("arg:",str(arg), "c_arg.kind:", c_arg.kind, "c_arg:", c_arg, "type(arg):",str(type(arg)))
+            # print("arg:",str(arg), "c_arg.kind:", c_arg.kind, "c_arg:", c_arg, "type(arg):",str(type(arg)))
             if c_arg.kind == 'pointer':
                 if type(arg) == str:
                     arg = arg.encode('utf-8')
@@ -53,7 +55,7 @@ def makefunc(a):
                     arg = ffi.new("int *", arg)
                 elif type(arg) is float:
                     arg = ffi.new("float *", arg)
-                elif type(arg) is list  and str(c_arg) == "<ctype 'char * *'>":
+                elif type(arg) is list and str(c_arg) == "<ctype 'char * *'>":
                     arg = [ffi.new("char[]", x.encode('utf-8')) for x in arg]
                 elif str(type(arg)) == "<class '_cffi_backend.__CDataOwn'>" and "*" not in str(arg):  # CPython
                     arg = ffi.addressof(arg)
@@ -74,10 +76,24 @@ def makefunc(a):
 
     return func
 
+global_weakkeydict = weakref.WeakKeyDictionary()
 
 def makeStructHelper(struct):
     def func(*args):
-        return ffi.new(f"struct {struct} *", args)[0]
+        # print(struct, args)
+        modified_args = []
+        for (field, arg) in zip(ffi.typeof(struct).fields, args):
+            # print("arg:", str(arg), "field:", field[1], "field type:", field[1].type, "type(arg):", str(type(arg)))
+            if arg is None:
+                arg = ffi.NULL
+            elif (field[1].type.kind == 'pointer'
+                  and (str(type(arg)) == "<class 'numpy.ndarray'>"
+                       or isinstance(arg, (array, bytes, bytearray, memoryview)))):
+                    arg = ffi.from_buffer(field[1].type, arg)
+            modified_args.append(arg)
+        s = ffi.new(f"struct {struct} *", modified_args)[0]
+        global_weakkeydict[s] = modified_args
+        return s
 
     return func