fix coordinates

Author: vincentsarago

.pre-commit-config.yaml

@@ -1,6 +1,6 @@
 repos:
   - repo: https://github.com/psf/black
-    rev: 19.10b0
+    rev: 22.3.0
     hooks:
       - id: black
         language_version: python
@@ -18,7 +18,7 @@ repos:
         language_version: python
 
   - repo: https://github.com/PyCQA/pydocstyle
-    rev: 5.1.1
+    rev: 6.1.1
     hooks:
       - id: pydocstyle
         language_version: python

CHANGES.md

@@ -1,3 +1,7 @@
+## 0.0.1dev3 (2022-08-08)
+
+* Fix polygon and point coordinates in `pixels_encoder`
+
 ## 0.0.1dev2 (2021-04-06)
 
 * update tests for new vector-tile-base version

README.md

@@ -28,10 +28,10 @@ More on [COG Talk](https://medium.com/devseed/search?q=cog%20talk) blog posts
 
 ### Requirements
 
-rio-tiler-mvt use [python-vtzero](https://github.com/tilery/python-vtzero) wrapper to encode point and polygons to MVT. Because VTZERO is a C++ library, python-vtzero is written in Cython, thus cython~=0.28 is required to compile this library.
+rio-tiler-mvt use [python-vtzero](https://github.com/tilery/python-vtzero) wrapper to encode point and polygons to MVT. Because VTZERO is a C++ library, python-vtzero is written in Cython, thus cython is required to compile this library.
 
 ```bash
-$ pip install cython~=0.28 # see https://github.com/tilery/python-vtzero#requirements
+$ pip install cython # see https://github.com/tilery/python-vtzero#requirements
 
 $ pip install rio-tiler-mvt
 ```
@@ -110,12 +110,16 @@ $ cd rio-tiler-mvt
 $ pip install -e .[dev]
 ```
 
-**Python3.7 only**
+**pre-commit**
 
 This repo is set to use `pre-commit` to run *isort*, *flake8*, *pydocstring*, *black* ("uncompromising Python code formatter") and mypy when committing new code.
 
 ```bash
 $ pre-commit install
 ```
 
-[satellite-3d](https://github.com/developmentseed/satellite-3d.git)
+## Links
+
+- **satellite-3d**: https://github.com/developmentseed/satellite-3d.git
+- **titiler-mvt**: https://github.com/developmentseed/titiler-mvt.git
+- **rio-viz**: https://github.com/developmentseed/rio-viz.git

rio_tiler_mvt/mvt.pyx

@@ -20,11 +20,11 @@ cpdef bytes pixels_encoder(
     str layer_name = "my_layer",
     str feature_type = "point",
 ):
-    cdef int sc = 4096 // data.shape[1]
-    cdef tuple indexes = numpy.where(mask)
+    cdef int sc = 4096 // data.shape[1]  # cell resolution
+    cdef tuple indexes = numpy.where(mask)  # Index of non-masked data
 
-    cdef tuple idx
-    cdef int x, y
+    cdef tuple
+    cdef int x, y, x_coord, y_coord
 
     if not band_names:
         band_names = [
@@ -33,31 +33,32 @@ cpdef bytes pixels_encoder(
 
     mvt = Tile()
     mvt_layer = Layer(mvt, layer_name.encode())
-    for idx in zip(indexes[1], indexes[0]):
-        x, y = idx
-        x *= sc
-        y *= sc
+    for (y, x) in zip(indexes[0], indexes[1]):
+        x_coord = sc * x
+        y_coord = sc * y
 
         if feature_type == 'point':
             feature = Point(mvt_layer)
-            feature.add_point(x + sc / 2, y - sc / 2)
+            # Point is at the center of the pixel
+            feature.add_point(x_coord + sc // 2, y_coord + sc // 2)
 
         elif feature_type == 'polygon':
             feature = Polygon(mvt_layer)
             feature.add_ring(5)
-            feature.set_point(x, y)
-            feature.set_point(x + sc, y)
-            feature.set_point(x + sc, y - sc)
-            feature.set_point(x, y - sc)
-            feature.set_point(x, y)
+            feature.set_point(x_coord, y_coord)
+            feature.set_point(x_coord + sc, y_coord)
+            feature.set_point(x_coord + sc, y_coord + sc)
+            feature.set_point(x_coord, y_coord + sc)
+            feature.set_point(x_coord, y_coord)
+
         else:
             raise Exception(f"Invalid geometry type: {feature_type}")
 
         # TODO: fix https://github.com/tilery/python-vtzero/issues/3
         for bidx in range(data.shape[0]):
             feature.add_property(
                 band_names[bidx].encode(),
-                str(data[bidx, idx[1], idx[0]]).encode()
+                str(data[bidx, y, x]).encode()
             )
         feature.commit()
 

setup.py

@@ -24,7 +24,7 @@
 setup(
     name="rio-tiler-mvt",
     version="0.0.1dev2",
-    description=u"""A rio-tiler plugin to encode tile array to MVT""",
+    description="""A rio-tiler plugin to encode tile array to MVT""",
     long_description=long_description,
     long_description_content_type="text/markdown",
     python_requires=">=3",
@@ -39,7 +39,7 @@
         "Topic :: Scientific/Engineering :: GIS",
     ],
     keywords="COG MVT mapbox vectortile GIS",
-    author=u"Vincent Sarago",
+    author="Vincent Sarago",
     author_email="[email protected]",
     url="https://github.com/cogeotiff/rio-tiler-mvt",
     license="MIT",