[core] Align line vertex to 4-byte boundary

10 byte vertices are heavily penalized by common GL implementations.

1 files changed, 3 insertions, 6 deletions

diff --git a/src/mbgl/shaders/line.cpp b/src/mbgl/shaders/line.cpp
index f68cc91377..c700295a15 100644
--- a/src/mbgl/shaders/line.cpp
+++ b/src/mbgl/shaders/line.cpp
@@ -21,7 +21,7 @@ const char* line::vertexSource = R"MBGL_SHADER(
 // #define scale 63.0
 #define scale 0.015873016
 
-attribute vec3 a_pos_normal;
+attribute vec4 a_pos_normal;
 attribute vec4 a_data;
 
 uniform mat4 u_matrix;
@@ -133,12 +133,9 @@ void main() {
 
     vec2 pos = a_pos_normal.xy;
 
-    // transform y normal so that 0 => -1 and 1 => 1
-    // In the texture normal, x is 0 if the normal points straight up/down and 1 if it's a round cap
+    // x is 1 if it's a round cap, 0 otherwise
     // y is 1 if the normal points up, and -1 if it points down
-    mediump vec2 normal = unpack_float(a_pos_normal.z);
-    normal.y = sign(normal.y - 0.5);
-
+    mediump vec2 normal = a_pos_normal.zw;
     v_normal = normal;
 
     // these transformations used to be applied in the JS and native code bases.