spritebatch with hdr colour

src/shaders/default.vert

@@ -2,16 +2,18 @@
 
 in vec4 a_position;
 in vec4 a_color;
+in vec4 a_generic;
 in vec2 a_texCoord0;
 
 uniform mat4 u_projTrans;
 
 out vec4 v_color;
 out vec2 v_texCoords;
+out vec4 v_generic;
 
 void main() {
     v_color = a_color;
-    v_color.a = v_color.a * (255.0/254.0); // GDX will crush the alpha value to 0,2,4,6,8,10,...,254; see com.badlogic.gdx.utils.NumberUtils.intToFloatColor
     v_texCoords = a_texCoord0;
+    v_generic = a_generic;
     gl_Position = u_projTrans * a_position;
 }