1 files changed, 25 insertions, 1 deletions
diff --git a/src/datavisualization/engine/shaders/texture3d.vert b/src/datavisualization/engine/shaders/texture3d.vert
index cad1ce06..ef3f1b25 100644
--- a/src/datavisualization/engine/shaders/texture3d.vert
+++ b/src/datavisualization/engine/shaders/texture3d.vert
@@ -1,12 +1,36 @@
 uniform highp mat4 MVP;
+uniform highp vec3 minBounds;
+uniform highp vec3 maxBounds;
+uniform highp vec3 cameraPositionRelativeToModel;
 
 attribute highp vec3 vertexPosition_mdl;
 attribute highp vec2 vertexUV;
 attribute highp vec3 vertexNormal_mdl;
 
 varying highp vec3 pos;
+varying highp vec3 rayDir;
 
 void main() {
     gl_Position = MVP * vec4(vertexPosition_mdl, 1.0);
-    pos = vertexPosition_mdl;
+
+    highp vec3 minBoundsNorm = minBounds;
+    highp vec3 maxBoundsNorm = maxBounds;
+
+    // Y and Z are flipped in bounds to be directly usable in texture calculations,
+    // so flip them back to normal for position calculations
+    minBoundsNorm.yz = -minBoundsNorm.yz;
+    maxBoundsNorm.yz = -maxBoundsNorm.yz;
+
+    minBoundsNorm = 0.5 * (minBoundsNorm + 1.0);
+    maxBoundsNorm = 0.5 * (maxBoundsNorm + 1.0);
+
+    pos = vertexPosition_mdl
+            + ((1.0 - vertexPosition_mdl) * minBoundsNorm)
+            - ((1.0 + vertexPosition_mdl) * (1.0 - maxBoundsNorm));
+
+    rayDir = -(cameraPositionRelativeToModel - pos);
+
+    // Flip Y and Z so QImage bits work directly for texture and first image is in the front
+    rayDir.yz = -rayDir.yz;
+    pos.yz = -pos.yz;
 }