From 9daefbdb94822ca94b78eb2d8ada27aebcc5db82 Mon Sep 17 00:00:00 2001
From: Zach Pomerantz <zach@highfidelity.io>
Date: Fri, 19 Feb 2016 11:39:11 -0800
Subject: [PATCH] Fix grid antialiasing

---
 interface/src/ui/overlays/Grid3DOverlay.cpp  |  2 +-
 libraries/render-utils/src/GeometryCache.cpp |  4 +--
 libraries/render-utils/src/GeometryCache.h   |  2 +-
 libraries/render-utils/src/grid.slf          | 27 ++++++++++----------
 4 files changed, 18 insertions(+), 17 deletions(-)

diff --git a/interface/src/ui/overlays/Grid3DOverlay.cpp b/interface/src/ui/overlays/Grid3DOverlay.cpp
index d02219bcb6..b47ecdbd6c 100644
--- a/interface/src/ui/overlays/Grid3DOverlay.cpp
+++ b/interface/src/ui/overlays/Grid3DOverlay.cpp
@@ -81,7 +81,7 @@ void Grid3DOverlay::render(RenderArgs* args) {
 }
 
 const render::ShapeKey Grid3DOverlay::getShapeKey() {
-    return render::ShapeKey::Builder().withTranslucent();
+    return render::ShapeKey::Builder().withOwnPipeline();
 }
 
 void Grid3DOverlay::setProperties(const QScriptValue& properties) {
diff --git a/libraries/render-utils/src/GeometryCache.cpp b/libraries/render-utils/src/GeometryCache.cpp
index e1f5ce67ba..0a7ca2a450 100644
--- a/libraries/render-utils/src/GeometryCache.cpp
+++ b/libraries/render-utils/src/GeometryCache.cpp
@@ -600,9 +600,9 @@ void GeometryCache::renderGrid(gpu::Batch& batch, const glm::vec2& minCorner, co
         gridBuffer.edit<GridSchema>().offset.y = -(majorEdge / majorCols) / 2;
         gridBuffer.edit<GridSchema>().offset.z = -(minorEdge / minorRows) / 2;
         gridBuffer.edit<GridSchema>().offset.w = -(minorEdge / minorCols) / 2;
-        gridBuffer.edit<GridSchema>().balance = glm::vec4(glm::vec2(1.0f - majorEdge),
+        gridBuffer.edit<GridSchema>().edge = glm::vec4(glm::vec2(majorEdge),
             // If rows or columns are not set, do not draw minor gridlines
-            glm::vec2((minorRows != 0 && minorCols != 0) ? 1.0f - minorEdge : 0.0f));
+            glm::vec2((minorRows != 0 && minorCols != 0) ? minorEdge : 0.0f));
     }
 
     // Set the grid pipeline
diff --git a/libraries/render-utils/src/GeometryCache.h b/libraries/render-utils/src/GeometryCache.h
index a10ec84db5..b4b933ecdb 100644
--- a/libraries/render-utils/src/GeometryCache.h
+++ b/libraries/render-utils/src/GeometryCache.h
@@ -322,7 +322,7 @@ private:
         // data is arranged as majorRow, majorCol, minorRow, minorCol
         glm::vec4 period;
         glm::vec4 offset;
-        glm::vec4 balance;
+        glm::vec4 edge;
     };
     using GridBuffer = gpu::BufferView;
     void useGridPipeline(gpu::Batch& batch, GridBuffer gridBuffer);
diff --git a/libraries/render-utils/src/grid.slf b/libraries/render-utils/src/grid.slf
index 0c2b00b3b0..04e35ac5ca 100644
--- a/libraries/render-utils/src/grid.slf
+++ b/libraries/render-utils/src/grid.slf
@@ -11,36 +11,37 @@
 //  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
 //
 
-float paintStripe(float value, float offset, float scale, float balance) {
+float paintStripe(float value, float offset, float scale, float edge) {
     float width = fwidth(value);
     float normalizedWidth = width * scale;
 
     float x0 = (value + offset) * scale - normalizedWidth / 2;
     float x1 = x0 + normalizedWidth;
 
-    float i0 = balance * floor(x0) + max(0.0, fract(x0) - balance);
-    float i1 = balance * floor(x1) + max(0.0, fract(x1) - balance);
+    float balance = 1.0 - edge;
+    float i0 = edge * floor(x0) + max(0.0, fract(x0) - balance);
+    float i1 = edge * floor(x1) + max(0.0, fract(x1) - balance);
     float strip = (i1 - i0) / normalizedWidth;
 
     return clamp(strip, 0.0, 1.0);
 }
 
-float paintGrid(vec2 value, vec2 offset, vec2 scale, vec2 balance) {
+float paintGrid(vec2 value, vec2 offset, vec2 scale, vec2 edge) {
     return max(
-        paintStripe(value.x, offset.x, scale.x, balance.x),
-        paintStripe(value.y, offset.y, scale.y, balance.y));
+        paintStripe(value.x, offset.x, scale.x, edge.x),
+        paintStripe(value.y, offset.y, scale.y, edge.y));
 }
 
-float paintGridMajorMinor(vec2 value, vec4 offset, vec4 scale, vec4 balance) {
+float paintGridMajorMinor(vec2 value, vec4 offset, vec4 scale, vec4 edge) {
     return max(
-        paintGrid(value, offset.xy, scale.xy, balance.xy),
-        paintGrid(value, offset.zw, scale.zw, balance.zw));
+        paintGrid(value, offset.xy, scale.xy, edge.xy),
+        paintGrid(value, offset.zw, scale.zw, edge.zw));
 }
 
 struct Grid {
     vec4 period;
     vec4 offset;
-    vec4 balance;
+    vec4 edge;
 };
 
 uniform gridBuffer { Grid grid; };
@@ -55,10 +56,10 @@ void main(void) {
     Grid grid = getGrid();
 
     float alpha;
-    if (grid.balance.z == 0.0) {
-        alpha = paintGrid(varTexCoord0, grid.offset.xy, grid.period.xy, grid.balance.xy);
+    if (grid.edge.z == 0.0) {
+        alpha = paintGrid(varTexCoord0, grid.offset.xy, grid.period.xy, grid.edge.xy);
     } else {
-        alpha = paintGridMajorMinor(varTexCoord0, grid.offset, grid.period, grid.balance);
+        alpha = paintGridMajorMinor(varTexCoord0, grid.offset, grid.period, grid.edge);
     }
     if (alpha == 0.0) {
         discard;