Do the texel-uv-to-pixel-uv conversion in floating point instead of in

integers. Before, the truncation rounded all texel uvs to zero, resulting in unblurred glyphs overwriting whatever was at (0,0) in the texture cache! Addresses servo/servo#10136.
servo · bors-servo · Mar 30, 2016 · Mar 30, 2016 · Mar 30, 2016 · 032f1e8b5cf48aed7d1ccb9a8b4bd7eb3b531214
commit 032f1e8b5cf48aed7d1ccb9a8b4bd7eb3b531214
diff --git a/src/texture_cache.rs b/src/texture_cache.rs
@@ -538,8 +538,9 @@ impl TextureCacheItem {
                 Point2D::new(self.uv_rect().top_left.x, self.uv_rect().top_left.y),
                 Size2D::new(self.uv_rect().bottom_right.x - self.uv_rect().top_left.x,
                             self.uv_rect().bottom_right.y - self.uv_rect().top_left.y)),
-            pixel_uv: Point2D::new(self.uv_rect().top_left.x as u32 * texture_size.width,
-                                   self.uv_rect().top_left.y as u32 * texture_size.height),
+            pixel_uv:
+                Point2D::new((self.uv_rect().top_left.x * texture_size.width as f32) as u32,
+                             (self.uv_rect().top_left.y * texture_size.height as f32) as u32),
         }
     }
 

diff --git a/tests/bug_servo_10136.html b/tests/bug_servo_10136.html
@@ -0,0 +1,11 @@
+<!DOCTYPE html>
+<style>
+body {
+    background: black;
+}
+div {
+    color: white;
+    text-shadow: 5px 5px 5px white;
+}
+</style>
+<div>whoa</div>