From 662aee1f519319b3f3bd79d5081f38f20ca49042 Mon Sep 17 00:00:00 2001
From: Luo Yi <yilozt@outlook.com>
Date: Wed, 14 Sep 2022 11:55:40 +0800
Subject: [PATCH] Make border drawing outside of window by set a negative
 border width

---
 .vscode/settings.json                         | 22 -------------------
 ...ensions.rounded-window-corners.gschema.xml |  3 ++-
 src/effect/shader/rounded_corners.frag        | 21 +++++++++++++-----
 src/preferences/pages/general.ui              |  4 ++--
 4 files changed, 20 insertions(+), 30 deletions(-)
 delete mode 100644 .vscode/settings.json

diff --git a/.vscode/settings.json b/.vscode/settings.json
deleted file mode 100644
index 545a384..0000000
--- a/.vscode/settings.json
+++ /dev/null
@@ -1,22 +0,0 @@
-{
-    "cSpell.words": [
-        "Adwaita",
-        "cogl",
-        "GLSL",
-        "Graphene",
-        "libadwaita",
-        "libhandy",
-        "Prefs",
-        "valign",
-        "vfunc"
-    ],
-    "emeraldwalk.runonsave": {
-        "commands": [
-            {
-                "match": ".ts",
-                "isAsync": true,
-                "cmd": "yarn build"
-            }
-        ]
-    },
-}
\ No newline at end of file
diff --git a/resources/schemas/org.gnome.shell.extensions.rounded-window-corners.gschema.xml b/resources/schemas/org.gnome.shell.extensions.rounded-window-corners.gschema.xml
index 2f5401d..34b29a5 100644
--- a/resources/schemas/org.gnome.shell.extensions.rounded-window-corners.gschema.xml
+++ b/resources/schemas/org.gnome.shell.extensions.rounded-window-corners.gschema.xml
@@ -28,8 +28,9 @@
       <default>false</default>
     </key>
 
-    <key name="border-width" type="u">
+    <key name="border-width" type="i">
       <summary>Border width for rounded corners window</summary>
+      <range min="-40" max="40"/>
       <default>0</default>
     </key>
 
diff --git a/src/effect/shader/rounded_corners.frag b/src/effect/shader/rounded_corners.frag
index aa46bea..3efb000 100644
--- a/src/effect/shader/rounded_corners.frag
+++ b/src/effect/shader/rounded_corners.frag
@@ -95,11 +95,22 @@ void main() {
   vec2 texture_coord = cogl_tex_coord0_in.xy / pixel_step;
 
   float outer_alpha = rounded_rect_coverage(texture_coord, bounds, radius, exponent);
-  if(border_width > 0.1) {
-    float inner_alpha = rounded_rect_coverage(texture_coord, inner_bounds, inner_radius, exponent);
-    float border_alpha = clamp(outer_alpha - inner_alpha, 0.0, 1.0) * cogl_color_out.a;
 
-    cogl_color_out = mix(cogl_color_out, vec4(border_color.rgb, 1.0), border_alpha * border_color.a);
+  // Clip window corners first
+  cogl_color_out.a *= outer_alpha;
+
+  // Draw border later
+  if(border_width > 0.9 || border_width < -0.9) {
+    float inner_alpha = rounded_rect_coverage(texture_coord, inner_bounds, inner_radius, exponent);
+    float border_alpha = clamp(abs(outer_alpha - inner_alpha), 0.0, 1.0);
+
+    if (border_width > 0.9) {
+      // If border is drawing inside window, mix color of window
+      cogl_color_out = mix(cogl_color_out, vec4(border_color.rgb, 1.0), border_alpha * border_color.a);
+      cogl_color_out.a *= outer_alpha;
+    } else {
+      // If border is drawing outside window, just draw border
+      cogl_color_out = mix(cogl_color_out, border_color, border_alpha);
+    }
   }
-  cogl_color_out.a *=  outer_alpha;
 }
diff --git a/src/preferences/pages/general.ui b/src/preferences/pages/general.ui
index 3889ff4..54fe8b4 100644
--- a/src/preferences/pages/general.ui
+++ b/src/preferences/pages/general.ui
@@ -374,8 +374,8 @@
   </template>
 
   <object class="GtkAdjustment" id="border_width_ajustment">
-    <property name="lower">0</property>
-    <property name="upper">40</property>
+    <property name="lower">-20</property>
+    <property name="upper">20</property>
     <property name="page-increment">1</property>
     <property name="step-increment">1</property>
   </object>