Fixed deformation of search marks

2 files changed, 7 insertions, 3 deletions

diff --git a/drape/shaders/user_mark.vsh b/drape/shaders/user_mark.vsh
index 724fef0756..6c475bcfb2 100644
--- a/drape/shaders/user_mark.vsh
+++ b/drape/shaders/user_mark.vsh
@@ -16,7 +16,9 @@ void main(void)
   if (a_animate > 0.0)
     normal = u_interpolationT * normal;
 
-  vec4 pos = (vec4(normal, 0, 0) + vec4(a_position, 1) * modelView) * projection;
+  lowp vec4 p = vec4(a_position, 1) * modelView;
+  highp vec4 pos = vec4(normal, 0, 0) + p;
+  pos = pos * projection;
   float w = pos.w;
   pos.xyw = (pivotTransform * vec4(pos.xy, 0.0, w)).xyw;
   pos.z *= pos.w / w;
diff --git a/drape/shaders/user_mark_billboard.vsh b/drape/shaders/user_mark_billboard.vsh
index 4ad8aa043d..81e349c4fd 100644
--- a/drape/shaders/user_mark_billboard.vsh
+++ b/drape/shaders/user_mark_billboard.vsh
@@ -16,8 +16,10 @@ void main(void)
   if (a_animate > 0.0)
     normal = u_interpolationT * normal;
 
-  vec4 pivot = vec4(a_position.xyz, 1) * modelView;
-  vec4 offset = vec4(normal, 0, 0) * projection;
+  // Here we intentionally decrease precision of 'pivot' calculation
+  // to eliminate jittering effect in process of billboard reconstruction.
+  lowp vec4 pivot = vec4(a_position.xyz, 1.0) * modelView;
+  vec4 offset = vec4(normal, 0.0, 0.0) * projection;
 
   vec4 projectedPivot = pivot * projection;
   vec4 transformedPivot = pivotTransform * vec4(projectedPivot.xy, 0.0, 1.0);