From 287a47bd04f1693f53524c8115ad927278117db8 Mon Sep 17 00:00:00 2001
From: Molly Lloyd <molly@mapbox.com>
Date: Fri, 1 Jun 2018 13:48:48 -0700
Subject: [PATCH 1/2] fix zero-width line rendering

---
 src/render/draw_line.js                       |   3 +-
 src/shaders/line.vertex.glsl                  |   2 +-
 .../zero-width-function/expected.png          | Bin 0 -> 130 bytes
 .../line-width/zero-width-function/style.json |  75 ++++++++++++++++++
 .../line-width/zero-width/expected.png        | Bin 0 -> 130 bytes
 .../line-width/zero-width/style.json          |  73 +++++++++++++++++
 6 files changed, 151 insertions(+), 2 deletions(-)
 create mode 100644 test/integration/render-tests/line-width/zero-width-function/expected.png
 create mode 100644 test/integration/render-tests/line-width/zero-width-function/style.json
 create mode 100644 test/integration/render-tests/line-width/zero-width/expected.png
 create mode 100644 test/integration/render-tests/line-width/zero-width/style.json

diff --git a/src/render/draw_line.js b/src/render/draw_line.js
index 692f52436d6..f6a0bf93287 100644
--- a/src/render/draw_line.js
+++ b/src/render/draw_line.js
@@ -16,7 +16,8 @@ export default function drawLine(painter: Painter, sourceCache: SourceCache, lay
     if (painter.renderPass !== 'translucent') return;
 
     const opacity = layer.paint.get('line-opacity');
-    if (opacity.constantOr(1) === 0) return;
+    const width = layer.paint.get('line-width');
+    if (opacity.constantOr(1) === 0 || width.constantOr(1) === 0) return;
 
     const context = painter.context;
 
diff --git a/src/shaders/line.vertex.glsl b/src/shaders/line.vertex.glsl
index 76519d1aa76..c8c55ce7bb6 100644
--- a/src/shaders/line.vertex.glsl
+++ b/src/shaders/line.vertex.glsl
@@ -58,7 +58,7 @@ void main() {
     offset = -1.0 * offset;
 
     float inset = gapwidth + (gapwidth > 0.0 ? ANTIALIASING : 0.0);
-    float outset = gapwidth + halfwidth * (gapwidth > 0.0 ? 2.0 : 1.0) + ANTIALIASING;
+    float outset = gapwidth + halfwidth * (gapwidth > 0.0 ? 2.0 : 1.0) + (halfwidth == 0.0 ? 0.0 : ANTIALIASING);
 
     // Scale the extrusion vector down to a normal and then up by the line width
     // of this vertex.
diff --git a/test/integration/render-tests/line-width/zero-width-function/expected.png b/test/integration/render-tests/line-width/zero-width-function/expected.png
new file mode 100644
index 0000000000000000000000000000000000000000..ae9d962e081df568d69ce417691061c0c1771687
GIT binary patch
literal 130
zcmeAS@N?(olHy`uVBq!ia0vp^DIm<j1|$m}O$`B3Or9=|Ar*{or0OmKdDbA_+k=LT
nK=vVp-^=5;^%H<hBEW&rIZGHAg}VdHL5e+H{an^LB{Ts58on0@

literal 0
HcmV?d00001

diff --git a/test/integration/render-tests/line-width/zero-width-function/style.json b/test/integration/render-tests/line-width/zero-width-function/style.json
new file mode 100644
index 00000000000..a76540531ed
--- /dev/null
+++ b/test/integration/render-tests/line-width/zero-width-function/style.json
@@ -0,0 +1,75 @@
+{
+  "version": 8,
+  "metadata": {
+    "test": {
+      "width": 100,
+      "height": 100,
+      "diff": 0.00075
+    }
+  },
+  "zoom": 2,
+  "sources": {
+    "linesource": {
+      "type": "geojson",
+      "data": {
+        "type": "Feature",
+        "properties": {
+          "width": 0
+        },
+        "geometry": {
+          "type": "LineString",
+          "coordinates": [
+            [
+              -1,
+              8
+            ],
+            [
+              8,
+              1
+            ],
+            [
+              1,
+              -8
+            ],
+            [
+              -8,
+              -1
+            ],
+            [
+              1,
+              4
+            ],
+            [
+              4,
+              -1
+            ],
+            [
+              -1,
+              -4
+            ],
+            [
+              -2,
+              0
+            ]
+          ]
+        }
+      },
+      "lineMetrics": true
+    }
+  },
+  "layers": [
+    {
+      "id": "line",
+      "type": "line",
+      "source": "linesource",
+      "layout": {
+        "line-cap": "round",
+        "line-join": "round"
+      },
+      "paint": {
+        "line-width": ["get", "width"],
+        "line-color": "red"
+      }
+    }
+  ]
+}
diff --git a/test/integration/render-tests/line-width/zero-width/expected.png b/test/integration/render-tests/line-width/zero-width/expected.png
new file mode 100644
index 0000000000000000000000000000000000000000..ae9d962e081df568d69ce417691061c0c1771687
GIT binary patch
literal 130
zcmeAS@N?(olHy`uVBq!ia0vp^DIm<j1|$m}O$`B3Or9=|Ar*{or0OmKdDbA_+k=LT
nK=vVp-^=5;^%H<hBEW&rIZGHAg}VdHL5e+H{an^LB{Ts58on0@

literal 0
HcmV?d00001

diff --git a/test/integration/render-tests/line-width/zero-width/style.json b/test/integration/render-tests/line-width/zero-width/style.json
new file mode 100644
index 00000000000..bca9c45b6f9
--- /dev/null
+++ b/test/integration/render-tests/line-width/zero-width/style.json
@@ -0,0 +1,73 @@
+{
+  "version": 8,
+  "metadata": {
+    "test": {
+      "width": 100,
+      "height": 100,
+      "diff": 0.00075
+    }
+  },
+  "zoom": 2,
+  "sources": {
+    "linesource": {
+      "type": "geojson",
+      "data": {
+        "type": "Feature",
+        "properties": {},
+        "geometry": {
+          "type": "LineString",
+          "coordinates": [
+            [
+              -1,
+              8
+            ],
+            [
+              8,
+              1
+            ],
+            [
+              1,
+              -8
+            ],
+            [
+              -8,
+              -1
+            ],
+            [
+              1,
+              4
+            ],
+            [
+              4,
+              -1
+            ],
+            [
+              -1,
+              -4
+            ],
+            [
+              -2,
+              0
+            ]
+          ]
+        }
+      },
+      "lineMetrics": true
+    }
+  },
+  "layers": [
+    {
+      "id": "line",
+      "type": "line",
+      "source": "linesource",
+      "layout": {
+        "line-cap": "round",
+        "line-join": "round"
+      },
+      "paint": {
+        "line-width": 0,
+        "line-color": "red"
+      }
+    }
+  ]
+}

From f8f8c0a1fa82ce219202793cdd567cb238571b29 Mon Sep 17 00:00:00 2001
From: Molly Lloyd <molly@mapbox.com>
Date: Fri, 1 Jun 2018 16:11:06 -0700
Subject: [PATCH 2/2] fix other line types too:

---
 src/shaders/line_gradient.vertex.glsl | 2 +-
 src/shaders/line_pattern.vertex.glsl  | 2 +-
 src/shaders/line_sdf.vertex.glsl      | 2 +-
 3 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/shaders/line_gradient.vertex.glsl b/src/shaders/line_gradient.vertex.glsl
index cf791dfa522..25cf7175275 100644
--- a/src/shaders/line_gradient.vertex.glsl
+++ b/src/shaders/line_gradient.vertex.glsl
@@ -58,7 +58,7 @@ void main() {
     offset = -1.0 * offset;
 
     float inset = gapwidth + (gapwidth > 0.0 ? ANTIALIASING : 0.0);
-    float outset = gapwidth + halfwidth * (gapwidth > 0.0 ? 2.0 : 1.0) + ANTIALIASING;
+    float outset = gapwidth + halfwidth * (gapwidth > 0.0 ? 2.0 : 1.0) + (halfwidth == 0.0 ? 0.0 : ANTIALIASING);
 
     // Scale the extrusion vector down to a normal and then up by the line width
     // of this vertex.
diff --git a/src/shaders/line_pattern.vertex.glsl b/src/shaders/line_pattern.vertex.glsl
index 0be73f30511..74170762613 100644
--- a/src/shaders/line_pattern.vertex.glsl
+++ b/src/shaders/line_pattern.vertex.glsl
@@ -57,7 +57,7 @@ void main() {
     offset = -1.0 * offset;
 
     float inset = gapwidth + (gapwidth > 0.0 ? ANTIALIASING : 0.0);
-    float outset = gapwidth + halfwidth * (gapwidth > 0.0 ? 2.0 : 1.0) + ANTIALIASING;
+    float outset = gapwidth + halfwidth * (gapwidth > 0.0 ? 2.0 : 1.0) + (halfwidth == 0.0 ? 0.0 : ANTIALIASING);
 
     // Scale the extrusion vector down to a normal and then up by the line width
     // of this vertex.
diff --git a/src/shaders/line_sdf.vertex.glsl b/src/shaders/line_sdf.vertex.glsl
index a57a366d61e..84801c0e614 100644
--- a/src/shaders/line_sdf.vertex.glsl
+++ b/src/shaders/line_sdf.vertex.glsl
@@ -66,7 +66,7 @@ void main() {
     offset = -1.0 * offset;
 
     float inset = gapwidth + (gapwidth > 0.0 ? ANTIALIASING : 0.0);
-    float outset = gapwidth + halfwidth * (gapwidth > 0.0 ? 2.0 : 1.0) + ANTIALIASING;
+    float outset = gapwidth + halfwidth * (gapwidth > 0.0 ? 2.0 : 1.0) + (halfwidth == 0.0 ? 0.0 : ANTIALIASING);
 
     // Scale the extrusion vector down to a normal and then up by the line width
     // of this vertex.