From 1ad04594fa7c2cac7b73ba15e4cd9c8e5814af2c Mon Sep 17 00:00:00 2001
From: Mihai Cara <mihail.cara@gmail.com>
Date: Thu, 24 Oct 2024 10:19:39 -0400
Subject: [PATCH] Use astropy pixel_to_pixel in calc_pixmap

---
 CHANGES.rst      | 4 +++-
 drizzle/utils.py | 6 +++---
 pyproject.toml   | 1 +
 3 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/CHANGES.rst b/CHANGES.rst
index fdfc8c6..457dc16 100644
--- a/CHANGES.rst
+++ b/CHANGES.rst
@@ -4,9 +4,11 @@
 Release Notes
 =============
 
-2.0.1 (Unreleased)
+2.0.1 (unreleased)
 ==================
 
+- Use ``astropy``'s ``pixel_to_pixel()`` in ``utils.calc_pixmap()``. [#161]
+
 - Update ``utils.calc_pixmap`` code to be ready for upcoming changes in GWCS
   due to which inverse WCS transformations will respect bounding box by
   allowing the caller of ``utils.calc_pixmap`` to disable the bounding box(es)
diff --git a/drizzle/utils.py b/drizzle/utils.py
index 93535eb..ed7ed2f 100644
--- a/drizzle/utils.py
+++ b/drizzle/utils.py
@@ -2,6 +2,8 @@
 
 import numpy as np
 
+from astropy.wcs.utils import pixel_to_pixel
+
 __all__ = ["calc_pixmap", "decode_context", "estimate_pixel_scale_ratio"]
 
 _DEG2RAD = math.pi / 180.0
@@ -112,9 +114,7 @@ def calc_pixmap(wcs_from, wcs_to, shape=None, disable_bbox="to"):
     if disable_bbox in ["to", "both"] and bbox_to is not None:
         wcs_to.bounding_box = None
     try:
-        x, y = wcs_to.world_to_pixel_values(
-            *wcs_from.pixel_to_world_values(x, y)
-        )
+        x, y = pixel_to_pixel(wcs_from, wcs_to, x, y)
     finally:
         if bbox_from is not None:
             wcs_from.bounding_box = bbox_from
diff --git a/pyproject.toml b/pyproject.toml
index 361e495..8899445 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -7,6 +7,7 @@ authors = [
 ]
 dependencies = [
     "numpy",
+    "astropy>=5.0",
 ]
 dynamic = [
     "version",