Add support for specifying UV coordinates of vector models

Author: jonathanhogg

docs/canvas3d.md

@@ -856,6 +856,10 @@ To create a mesh from scratch use the attributes:
 : Optional attribute providing a *3m*-vector of vertex numbers in the range
 *[0,n)*, representing the corner vertices of *m* triangular faces.
 
+`uv=` *UV*
+: Optional attribute providing a *2n*-vector of *u* and *v* texture-mapping
+coordinates for *n* vertices.
+
 If the `faces` attribute is not provided, then a convex hull will be computed
 around the given vertices. This provides a quick way of describing simple
 geometric forms.
@@ -866,12 +870,12 @@ anti-clockwise  direction – as viewed from outside the model – for the surfa
 normals to be computed correctly.
 :::
 
-Models created from `vertices` and `faces` are cached according to the specific
+Models created from `vertices`/`faces`/`uv` are cached according to the specific
 values provided. This means that, as long as the attribute values do not change,
 the model will be constructed once and reused. However, these models are cached
 less aggressively than other models and will be immediately unloaded if not
 used. This allows animated surfaces to be created by continuously varying the
-`vertices` (and `faces`) attributes without using huge amounts of memory.
+attributes without using huge amounts of memory.
 
 ### Controlling Model Shading
 

src/flitter/render/window/canvas3d.pyx

@@ -448,7 +448,7 @@ cdef inline Matrix44 get_model_transform(Node node, Matrix44 transform_matrix):
 cdef Model get_model(Node node, bint top):
     cdef Node child
     cdef Model model = None
-    cdef Vector origin, normal, function, minimum, maximum, vertices, faces
+    cdef Vector origin, normal, function, minimum, maximum, vertices, faces, uv
     cdef double snap_angle, resolution
     cdef str mapping, filename
     cdef list models
@@ -464,10 +464,11 @@ cdef Model get_model(Node node, bint top):
         filename = node.get_str('filename', None)
         vertices = node.get_fvec('vertices', 0, None)
         faces = node.get_fvec('faces', 0, None)
+        uv = node.get_fvec('uv', 0, None)
         if filename:
             model = Model._external(filename)
         elif vertices is not None:
-            model = Model._vector(vertices, faces)
+            model = Model._vector(vertices, faces, uv)
         if model is not None and node.get_bool('repair', False):
             model = model.repair()
     elif not top and node.kind is 'transform':

src/flitter/render/window/models.pxd

@@ -66,7 +66,7 @@ cdef class Model:
     cdef Model _external(str filename)
 
     @staticmethod
-    cdef Model _vector(Vector vertices, Vector faces)
+    cdef Model _vector(Vector vertices, Vector faces, Vector uv)
 
     @staticmethod
     cdef Model _sdf(Function function, Model original, Vector minimum, Vector maximum, double resolution)

src/flitter/render/window/models.pyx

@@ -433,12 +433,12 @@ cdef class Model:
         return ExternalModel._get(str(filename))
 
     @staticmethod
-    cdef Model _vector(Vector vertices, Vector faces):
-        return VectorModel._get(vertices, faces)
+    cdef Model _vector(Vector vertices, Vector faces, Vector uv):
+        return VectorModel._get(vertices, faces, uv)
 
     @staticmethod
-    def vector(vertices, faces=None):
-        return VectorModel._get(Vector._coerce(vertices), Vector._coerce(faces))
+    def vector(vertices, faces=None, uv=None):
+        return VectorModel._get(Vector._coerce(vertices), Vector._coerce(faces), Vector._coerce(uv))
 
     @staticmethod
     cdef Model _sdf(Function function, Model original, Vector minimum, Vector maximum, double resolution):
@@ -1615,24 +1615,30 @@ cdef class ExternalModel(Model):
 cdef class VectorModel(Model):
     cdef Vector vertices
     cdef Vector faces
+    cdef Vector uv
 
     @staticmethod
-    cdef VectorModel _get(Vector vertices, Vector faces):
+    cdef VectorModel _get(Vector vertices, Vector faces, Vector uv):
         if vertices is None or vertices.numbers == NULL:
             return None
         if faces is not None and faces.numbers == NULL:
             faces = None
+        if uv is not None and uv.numbers == NULL:
+            uv = None
         cdef uint64_t id = VECTOR
         id = HASH_UPDATE(id, vertices.hash(False))
         if faces is not None:
             id = HASH_UPDATE(id, faces.hash(False))
+        if uv is not None:
+            id = HASH_UPDATE(id, uv.hash(False))
         cdef VectorModel model
         cdef PyObject* objptr = PyDict_GetItem(ModelCache, id)
         if objptr == NULL:
             model = VectorModel.__new__(VectorModel)
             model.id = id
             model.vertices = vertices
             model.faces = faces
+            model.uv = uv
             ModelCache[id] = model
         else:
             model = <VectorModel>objptr
@@ -1641,9 +1647,13 @@ cdef class VectorModel(Model):
 
     @property
     def name(self):
+        cdef str name = f'vector({self.vertices.hash(False):x}'
         if self.faces is not None:
-            return f'vector({self.vertices.hash(False):x}, {self.faces.hash(False):x})'
-        return f'vector({self.vertices.hash(False):x})'
+            name += f', faces={self.faces.hash(False):x}'
+        if self.uv is not None:
+            name += f', uv={self.uv.hash(False):x}'
+        name += ')'
+        return name
 
     cpdef void check_for_changes(self):
         pass
@@ -1678,6 +1688,13 @@ cdef class VectorModel(Model):
             vertices[i, 0] = <float>self.vertices.numbers[i*3]
             vertices[i, 1] = <float>self.vertices.numbers[i*3+1]
             vertices[i, 2] = <float>self.vertices.numbers[i*3+2]
+        if self.uv is not None:
+            if self.uv.length != n*2:
+                logger.error("Bad uv vector length: {}", self.name)
+                return None
+            for i in range(n):
+                vertices[i, 6] = <float>self.uv.numbers[i*2]
+                vertices[i, 7] = <float>self.uv.numbers[i*2+1]
         if self.faces is None:
             points = trimesh.points.PointCloud(vertices=vertices_array[:, :3]).convex_hull
             faces_array = np.array(points.faces, dtype='i4')