Double precision vertex calcs

lib/shaders/pick-vertex.glsl

@@ -1,11 +1,10 @@
-precision mediump float;
+precision highp float;
 
-attribute vec2 position;
+attribute vec2 positionHi, positionLo;
 attribute vec2 offset;
 attribute vec4 id;
 
-uniform mat3 viewTransform;
-uniform vec2 pixelScale;
+uniform vec2 scaleHi, scaleLo, translateHi, translateLo, pixelScale;
 uniform vec4 pickOffset;
 
 varying vec4 fragColor;
@@ -27,8 +26,8 @@ void main() {
   fragColor = fragId / 255.0;
 
   gl_Position = computePosition(
-    position,
-    offset,
-    viewTransform,
-    pixelScale);
+    positionHi, positionLo,
+    scaleHi, scaleLo,
+    translateHi, translateLo,
+    pixelScale, offset);
 }

lib/shaders/vertex.glsl

@@ -1,11 +1,10 @@
-precision mediump float;
+precision highp float;
 
-attribute vec2 position;
+attribute vec2 positionHi, positionLo;
 attribute vec2 offset;
 attribute vec4 color;
 
-uniform mat3 viewTransform;
-uniform vec2 pixelScale;
+uniform vec2 scaleHi, scaleLo, translateHi, translateLo, pixelScale;
 
 varying vec4 fragColor;
 
@@ -15,8 +14,8 @@ void main() {
   fragColor = color;
 
   gl_Position = computePosition(
-    position,
-    offset,
-    viewTransform,
-    pixelScale);
+    positionHi, positionLo,
+    scaleHi, scaleLo,
+    translateHi, translateLo,
+    pixelScale, offset);
 }

lib/shaders/xform.glsl

@@ -1,9 +1,8 @@
-vec4 computePosition(vec2 position, vec2 offset, mat3 view, vec2 scale) {
-  vec3 xposition = view * vec3(position, 1.0);
-  return vec4(
-    xposition.xy + scale * offset * xposition.z,
-    0,
-    xposition.z);
-}
-
 #pragma glslify: export(computePosition)
+vec4 computePosition(vec2 posHi, vec2 posLo, vec2 scHi, vec2 scLo, vec2 trHi, vec2 trLo, vec2 screenScale, vec2 screenOffset) {
+  return vec4(scHi * posHi + trHi
+            + scLo * posHi + trLo
+            + scHi * posLo
+            + scLo * posLo
+            + screenScale * screenOffset, 0, 1);
+}

package.json

@@ -1,6 +1,6 @@
 {
   "name": "gl-scatter2d-fancy",
-  "version": "1.1.3",
+  "version": "1.2.0",
   "description": "Fancy and slow scatter plots",
   "main": "scatter-fancy.js",
   "scripts": {
@@ -15,6 +15,7 @@
     "plot"
   ],
   "author": "Mikola Lysenko",
+  "contributors": ["Étienne Tétreault-Pinard", "Robert Monfera"],
   "license": "MIT",
   "bugs": {
     "url": "https://github.com/gl-vis/gl-scatter2d-fancy/issues"