[gtk+/wip/ebassi/gles] glsl: Specify precision for GLES shaders

[Emmanuele Bassi <ebassi src gnome org>]

commit 403ecebb5b614025079272ebb81ee4f51da1bc5d
Author: Emmanuele Bassi <ebassi gnome org>
Date:   Sat Apr 23 10:10:56 2016 +0100

    glsl: Specify precision for GLES shaders
    
    We need to override the precision for the UV attribute.

 gdk/resources/glsl/gles2-texture.fs.glsl |    4 +++-
 gdk/resources/glsl/gles2-texture.vs.glsl |    2 +-
 2 files changed, 4 insertions(+), 2 deletions(-)
---
diff --git a/gdk/resources/glsl/gles2-texture.fs.glsl b/gdk/resources/glsl/gles2-texture.fs.glsl
index a2a0415..68e455f 100644
--- a/gdk/resources/glsl/gles2-texture.fs.glsl
+++ b/gdk/resources/glsl/gles2-texture.fs.glsl
@@ -1,6 +1,8 @@
+precision mediump float;
+
 uniform sampler2D map;
 
-varying vec2 vUv;
+varying highp vec2 vUv;
 
 void main() {
   gl_FragColor = texture2D(map, vUv);
diff --git a/gdk/resources/glsl/gles2-texture.vs.glsl b/gdk/resources/glsl/gles2-texture.vs.glsl
index 0625cb3..62fb1c7 100644
--- a/gdk/resources/glsl/gles2-texture.vs.glsl
+++ b/gdk/resources/glsl/gles2-texture.vs.glsl
@@ -1,7 +1,7 @@
 attribute vec2 position;
 attribute vec2 uv;
 
-varying vec2 vUv;
+varying highp vec2 vUv;
 
 void main() {
   vUv = uv;