Fix bug in clipping rectangle in Agg backend whereby if the clipping rectangle is outside the bounds of the image *everything* gets clipped.

mdboom · mdboom · commit a52b2f2cf303 · 2011-05-02T11:55:27.000-04:00
diff --git a/src/_backend_agg.cpp b/src/_backend_agg.cpp
@@ -431,8 +431,10 @@ RendererAgg::set_clipbox(const Py::Object& cliprect, R& rasterizer)
     double l, b, r, t;
     if (py_convert_bbox(cliprect.ptr(), l, b, r, t))
     {
-        rasterizer.clip_box(int(mpl_round(l)), height - int(mpl_round(b)),
-                            int(mpl_round(r)), height - int(mpl_round(t)));
+        rasterizer.clip_box(std::max(int(mpl_round(l)), 0),
+                            std::max(int(height) - int(mpl_round(b)), 0),
+                            std::min(int(mpl_round(r)), int(width)),
+                            std::min(int(height) - int(mpl_round(t)), int(height)));
     }
     else
     {

Original file line number	Diff line number	Diff line change
`@@ -431,8 +431,10 @@ RendererAgg::set_clipbox(const Py::Object& cliprect, R& rasterizer)`
`431`	`431`	`double l, b, r, t;`
`432`	`432`	`if (py_convert_bbox(cliprect.ptr(), l, b, r, t))`
`433`	`433`	`{`
`434`		`- rasterizer.clip_box(int(mpl_round(l)), height - int(mpl_round(b)),`
`435`		`- int(mpl_round(r)), height - int(mpl_round(t)));`
	`434`	`+ rasterizer.clip_box(std::max(int(mpl_round(l)), 0),`
	`435`	`+ std::max(int(height) - int(mpl_round(b)), 0),`
	`436`	`+ std::min(int(mpl_round(r)), int(width)),`
	`437`	`+ std::min(int(height) - int(mpl_round(t)), int(height)));`
`436`	`438`	`}`
`437`	`439`	`else`
`438`	`440`	`{`