Use GLSL 300 es for shaders

example/shader_fragment_2d.glsl

@@ -1,10 +1,14 @@
+#version 300 es
 // fragment shaders don't have a default precision so we need
 // to pick one. mediump is a good default
 precision mediump float;
 
 // color varying received from vertex shader
-varying vec4 v_color;
+in vec4 v_color;
+
+// equvalent of gl_FragColor in GLSL 100
+out vec4 out_color;
 
 void main() {
-	gl_FragColor = v_color;
+	out_color = v_color;
 }

example/shader_fragment_3d.glsl

@@ -1,7 +1,11 @@
+#version 300 es
+
 precision mediump float;
 
-varying vec4 v_color;
+in vec4 v_color;
+
+out vec4 out_color;
 
 void main() {
-	gl_FragColor = v_color;
+	out_color = v_color;
 }

example/shader_vertex_2d.glsl

@@ -1,12 +1,13 @@
+#version 300 es
 // an attribute will receive data from a buffer
-attribute vec2 a_position;
-attribute vec4 a_color;
+in vec2 a_position;
+in vec4 a_color;
 
 uniform mat3 u_matrix;
 
 // color to pass to the fragment shader
 // value in fragment shader will be interpolated
-varying vec4 v_color;
+out vec4 v_color;
 
 void main() {
 	// Multiply the position by the matrix.

example/shader_vertex_3d.glsl

@@ -1,10 +1,11 @@
+#version 300 es
 // will pass vec3, but will be converted to vec4 with w = 1.0
-attribute vec4 a_position;
-attribute vec4 a_color;
+in vec4 a_position;
+in vec4 a_color;
 
 uniform mat4 u_matrix;
 
-varying vec4 v_color;
+out vec4 v_color;
 
 void main() {
 	// Multiply the position by the matrix.