matplotlib · ayshih · Jun 18, 2025 · Jun 18, 2025 · Sep 11, 2025 · Sep 29, 2025
diff --git a/extern/agg24-svn/include/agg_image_filters.h b/extern/agg24-svn/include/agg_image_filters.h
@@ -53,16 +53,25 @@ namespace agg
             double r = filter.radius();
             realloc_lut(r);
             unsigned i;
+#ifndef MPL_FIX_AGG_IMAGE_FILTER_LUT_BUGS
             unsigned pivot = diameter() << (image_subpixel_shift - 1);
             for(i = 0; i < pivot; i++)
+#else
+            unsigned pivot = (diameter() << (image_subpixel_shift - 1)) - 1;
+            for(i = 0; i < pivot + 1; i++)
+#endif
             {
                 double x = double(i) / double(image_subpixel_scale);
                 double y = filter.calc_weight(x);
                 m_weight_array[pivot + i] = 
                 m_weight_array[pivot - i] = (int16)iround(y * image_filter_scale);
             }
             unsigned end = (diameter() << image_subpixel_shift) - 1;
+#ifndef MPL_FIX_AGG_IMAGE_FILTER_LUT_BUGS
             m_weight_array[0] = m_weight_array[end];
+#else
+            m_weight_array[end] = (int16)iround(filter.calc_weight(diameter() / 2) * image_filter_scale);
+#endif
             if(normalization) 
             {
                 normalize();

diff --git a/extern/agg24-svn/include/agg_span_interpolator_linear.h b/extern/agg24-svn/include/agg_span_interpolator_linear.h
@@ -53,6 +53,10 @@ namespace agg
         //----------------------------------------------------------------
         void begin(double x, double y, unsigned len)
         {
+#ifdef MPL_FIX_AGG_INTERPOLATION_ENDPOINT_BUG
+            len -= 1;
+#endif
+
             double tx;
             double ty;
 
@@ -75,6 +79,10 @@ namespace agg
         //----------------------------------------------------------------
         void resynchronize(double xe, double ye, unsigned len)
         {
+#ifdef MPL_FIX_AGG_INTERPOLATION_ENDPOINT_BUG
+            len -= 1;
+#endif
+
             m_trans->transform(&xe, &ye);
             m_li_x = dda2_line_interpolator(m_li_x.y(), iround(xe * subpixel_scale), len);
             m_li_y = dda2_line_interpolator(m_li_y.y(), iround(ye * subpixel_scale), len);

diff --git a/extern/agg24-svn/src/agg_image_filters.cpp b/extern/agg24-svn/src/agg_image_filters.cpp
@@ -88,6 +88,7 @@ namespace agg
             }
         }
 
+#ifndef MPL_FIX_AGG_IMAGE_FILTER_LUT_BUGS
         unsigned pivot = m_diameter << (image_subpixel_shift - 1);
 
         for(i = 0; i < pivot; i++)
@@ -96,6 +97,7 @@ namespace agg
         }
         unsigned end = (diameter() << image_subpixel_shift) - 1;
         m_weight_array[0] = m_weight_array[end];
+#endif
     }
 
 

diff --git a/lib/matplotlib/colors.py b/lib/matplotlib/colors.py
@@ -2215,7 +2215,8 @@ def _init(self):
         _patch = np.empty((s[0], s[1], 4))
         _patch[:, :, :3] = self.patch
         _patch[:, :, 3] = 1
-        transform = mpl.transforms.Affine2D().translate(-0.5, -0.5)\
+        # Shift by an additional Agg subpixel (1/256 pixel) to match previous behavior
+        transform = mpl.transforms.Affine2D().translate(-0.5 - 1/256, -0.5 - 1/256)\
                                 .scale(self.N / (s[1] - 1), self.N / (s[0] - 1))
         self._lut = np.empty((self.N, self.N, 4))
 

diff --git a/lib/matplotlib/tests/baseline_images/test_axes/imshow.pdf b/lib/matplotlib/tests/baseline_images/test_axes/imshow.pdf
diff --git a/lib/matplotlib/tests/baseline_images/test_axes/imshow.png b/lib/matplotlib/tests/baseline_images/test_axes/imshow.png
diff --git a/lib/matplotlib/tests/baseline_images/test_axes/imshow.svg b/lib/matplotlib/tests/baseline_images/test_axes/imshow.svg
diff --git a/lib/matplotlib/tests/baseline_images/test_axes/imshow_clip.png b/lib/matplotlib/tests/baseline_images/test_axes/imshow_clip.png
diff --git a/lib/matplotlib/tests/baseline_images/test_axes/imshow_clip.svg b/lib/matplotlib/tests/baseline_images/test_axes/imshow_clip.svg
diff --git a/lib/matplotlib/tests/baseline_images/test_axes/use_colorizer_keyword.png b/lib/matplotlib/tests/baseline_images/test_axes/use_colorizer_keyword.png
diff --git a/lib/matplotlib/tests/baseline_images/test_colors/light_source_shading_topo.png b/lib/matplotlib/tests/baseline_images/test_colors/light_source_shading_topo.png
diff --git a/lib/matplotlib/tests/baseline_images/test_colors/test_norm_abc.png b/lib/matplotlib/tests/baseline_images/test_colors/test_norm_abc.png
diff --git a/lib/matplotlib/tests/baseline_images/test_image/bbox_image_inverted.pdf b/lib/matplotlib/tests/baseline_images/test_image/bbox_image_inverted.pdf
diff --git a/lib/matplotlib/tests/baseline_images/test_image/bbox_image_inverted.png b/lib/matplotlib/tests/baseline_images/test_image/bbox_image_inverted.png
diff --git a/lib/matplotlib/tests/baseline_images/test_image/bbox_image_inverted.svg b/lib/matplotlib/tests/baseline_images/test_image/bbox_image_inverted.svg
diff --git a/lib/matplotlib/tests/baseline_images/test_image/downsampling.png b/lib/matplotlib/tests/baseline_images/test_image/downsampling.png
diff --git a/lib/matplotlib/tests/baseline_images/test_image/image_cliprect.png b/lib/matplotlib/tests/baseline_images/test_image/image_cliprect.png