Agg: Increase maximum size to 2**23

QuLogic · QuLogic · commit 9259989e017e · 2024-10-02T04:32:00.000-04:00
With 32-bit scan lines, we are able to take advantage of the full 32-bit
range of coordinates. However, as noted in
`extern/agg24-svn/include/agg_rasterizer_scanline_aa.h`, Agg uses
24.8-bit fixed point coordinates. With one bit taken for the sign, the
maximum coordinate is now 2**23.
diff --git a/doc/users/next_whats_new/increased_figure_limits.rst b/doc/users/next_whats_new/increased_figure_limits.rst
@@ -0,0 +1,9 @@
+Increased Figure limits with Agg renderer
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Figures using the Agg renderer are now limited to 2**23 pixels in each
+direction, instead of 2**16. Additionally, bugs that caused artists to not
+render past 2**15 pixels horizontally have been fixed.
+
+Note that if you are using a GUI backend, it may have its own smaller limits
+(which may themselves depend on screen size.)
diff --git a/lib/matplotlib/tests/test_agg.py b/lib/matplotlib/tests/test_agg.py
@@ -199,7 +199,7 @@ def process_image(self, padded_src, dpi):
 
 
 def test_too_large_image():
-    fig = plt.figure(figsize=(300, 1000))
+    fig = plt.figure(figsize=(300, 2**25))
     buff = io.BytesIO()
     with pytest.raises(ValueError):
         fig.savefig(buff)
diff --git a/src/_backend_agg.cpp b/src/_backend_agg.cpp
@@ -33,10 +33,10 @@ RendererAgg::RendererAgg(unsigned int width, unsigned int height, double dpi)
         throw std::range_error("dpi must be positive");
     }
 
-    if (width >= 1 << 16 || height >= 1 << 16) {
+    if (width >= 1 << 23 || height >= 1 << 23) {
         throw std::range_error(
             "Image size of " + std::to_string(width) + "x" + std::to_string(height) +
-            " pixels is too large. It must be less than 2^16 in each direction.");
+            " pixels is too large. It must be less than 2^23 in each direction.");
     }
 
     unsigned stride(width * 4);

Original file line number	Diff line number	Diff line change
`@@ -33,10 +33,10 @@ RendererAgg::RendererAgg(unsigned int width, unsigned int height, double dpi)`
`33`	`33`	`throw std::range_error("dpi must be positive");`
`34`	`34`	`}`
`35`	`35`
`36`		`- if (width >= 1 << 16 \|\| height >= 1 << 16) {`
	`36`	`+ if (width >= 1 << 23 \|\| height >= 1 << 23) {`
`37`	`37`	`throw std::range_error(`
`38`	`38`	`"Image size of " + std::to_string(width) + "x" + std::to_string(height) +`
`39`		`- " pixels is too large. It must be less than 2^16 in each direction.");`
	`39`	`+ " pixels is too large. It must be less than 2^23 in each direction.");`
`40`	`40`	`}`
`41`	`41`
`42`	`42`	`unsigned stride(width * 4);`