1 files changed, 12 insertions, 8 deletions
diff --git a/drape/shaders/texturing_billboard_vertex_shader.vsh b/drape/shaders/texturing_billboard_vertex_shader.vsh
index fa901f6ec9..4ddb8941a3 100644
--- a/drape/shaders/texturing_billboard_vertex_shader.vsh
+++ b/drape/shaders/texturing_billboard_vertex_shader.vsh
@@ -1,4 +1,4 @@
-attribute vec3 a_position;
+attribute vec4 a_position;
 attribute vec2 a_normal;
 attribute vec2 a_colorTexCoords;
 
@@ -12,14 +12,18 @@ void main(void)
 {
   // Here we intentionally decrease precision of 'pivot' calculation
   // to eliminate jittering effect in process of billboard reconstruction.
-  lowp vec4 pivot = vec4(a_position, 1) * modelView;
-  vec4 offset = vec4(a_normal, 0, 0) * projection;
-
+  lowp vec4 pivot = vec4(a_position.xyz, 1.0) * modelView;
+  vec4 offset = vec4(a_normal, 0.0, 0.0) * projection;
+  
+  float pivotZ = a_position.w;
+  float zScale = projection[0][0] * length(vec4(1.0, 0.0, 0.0, 0.0) * modelView);
+  
   vec4 projectedPivot = pivot * projection;
-  vec4 transformedPivot = pivotTransform * vec4(projectedPivot.xy, 0.0, 1.0);
-
-  vec4 scale = pivotTransform * vec4(1.0, -1.0, 0, 1.0);
-  gl_Position = transformedPivot + vec4(offset.xy * transformedPivot.w / scale.w * scale.x, 0, 0);
+  float logicZ = projectedPivot.z / projectedPivot.w;
+  vec4 transformedPivot = pivotTransform * vec4(projectedPivot.xy, pivotZ * zScale, projectedPivot.w);
+  
+  vec4 scale = pivotTransform * vec4(1.0, -1.0, 0.0, 1.0);
+  gl_Position = vec4(transformedPivot.xy / transformedPivot.w, logicZ, 1.0) + vec4(offset.xy / scale.w * scale.x, 0.0, 0.0);
 
   v_colorTexCoords = a_colorTexCoords;
 }