From 2221c839c3a1e39d7baccdb9482c76605f5a6e2f Mon Sep 17 00:00:00 2001
From: Bradley Austin Davis <austin@highfidelity.io>
Date: Tue, 4 Aug 2015 15:06:18 -0700
Subject: [PATCH] Fix star point smoothing... sort of

---
 libraries/render-utils/src/stars.slf | 18 +++++++++++++++++-
 libraries/render-utils/src/stars.slv | 11 +++++++----
 2 files changed, 24 insertions(+), 5 deletions(-)

diff --git a/libraries/render-utils/src/stars.slf b/libraries/render-utils/src/stars.slf
index 8d1ba0da51..14191f2a6a 100644
--- a/libraries/render-utils/src/stars.slf
+++ b/libraries/render-utils/src/stars.slf
@@ -11,8 +11,24 @@
 //
 
 in vec4 varColor;
+in float varSize;
+
 out vec4 outFragColor;
 
+const float EDGE_SIZE = 0.25;
+const float ALPHA_BOUNDARY = 1.0 - EDGE_SIZE;
+
 void main(void) {
-    outFragColor = varColor; //vec4(varColor, 1.0);
+    vec2 coord = gl_PointCoord * vec2(2.0) - vec2(1.0);
+    coord = coord * coord;
+
+    float l = coord.x + coord.y;
+    if (l > 1.0) {
+        discard;
+    }
+    
+    outFragColor = varColor; 
+    if (l >= ALPHA_BOUNDARY) {
+        outFragColor.a = smoothstep(1.0, ALPHA_BOUNDARY, l);
+    }
 }
diff --git a/libraries/render-utils/src/stars.slv b/libraries/render-utils/src/stars.slv
index f9be6d0139..b9ad736d5e 100644
--- a/libraries/render-utils/src/stars.slv
+++ b/libraries/render-utils/src/stars.slv
@@ -18,9 +18,12 @@
 
 <$declareStandardTransform()$>
 
-out vec3 varPosition;
-out vec4 varColor;
+// TODO we need to get the viewport resolution and FOV passed to us so we can modify the point size
+// and effectively producing a points that take up a constant angular size regardless of the display resolution 
+// or projection matrix
 
+out vec4 varColor;
+out float varSize;
 
 void main(void) {
     varColor = inColor.rgba;
@@ -29,6 +32,6 @@ void main(void) {
     TransformCamera cam = getTransformCamera();
     TransformObject obj = getTransformObject();
     <$transformModelToClipPos(cam, obj, inPosition, gl_Position)$>
-    varPosition = inPosition.xyz;
-    gl_PointSize = inColor.a;
+    varSize = inColor.a;
+    gl_PointSize = varSize; 
 }
\ No newline at end of file