Fixed some shaders for Intel HD Graphics compatibility.

modules/vectorfield/glsl/particleflowrenderer.frag

@@ -25,7 +25,7 @@
 #include "tools/shading.frag"
 #include "tools/transferfunction.frag"
 
-in vec3 ex_Velocity;
+in vec3 ex_Direction;
 in float ex_Transparency;
 
 out vec4 out_Color; ///< outgoing fragment color
@@ -46,14 +46,14 @@ void main() {
             out_Color = lookupTF(_transferFunction, _transferFunctionParams, ex_Transparency);
             break;
         case 1: // velocity
-            float f = length(ex_Velocity);
+            float f = length(ex_Direction);
             f -= _threshold.x;
             f /= (_threshold.y - _threshold.x);
             f *= _scale;
             out_Color = lookupTF(_transferFunction, _transferFunctionParams, f);
             break;
         case 2: // direction
-            out_Color = vec4(normalize(abs(ex_Velocity)), 1.0);
+            out_Color = vec4(normalize(abs(ex_Direction)), 1.0);
             break;
         default:
             discard;

modules/vectorfield/glsl/particleflowrenderer.vert

@@ -36,6 +36,7 @@ out vec3 ex_Position;
 out vec3 ex_Velocity;
 out float ex_StartTime;
 
+out vec3 ex_Direction;
 out float ex_Transparency;
 
 /// Matrix defining model-to-world transformation
@@ -109,6 +110,7 @@ void render() {
 
     //vec4 normalTmp = (normalMatrix * vec4(in_Normal, 0.0));
     // ex_Normal = normalize((normalTmp).xyz);
+	ex_Direction = in_Velocity;
 }
 
 void main() {

modules/vis/glsl/slicerenderer3d.frag

@@ -39,6 +39,6 @@ void main() {
     out_Color = lookupTF(_transferFunction, _transferFunctionParams, intensity);
 
     // don't write fragment if fully transparent (in particular don't write to depth buffer!)
-    if (out_Color == 0.0)
+    if (out_Color.a == 0.0)
         discard;
 }