invert shader added

android/assets/shaders/default_frag.glsl

@@ -1,16 +0,0 @@
-#ifdef GL_ES
-#define LOWP lowp
-    precision mediump float;
-#else
-    #define LOWP
-#endif
-
-varying LOWP vec4 v_color;
-varying vec2 v_texCoords;
-
-uniform sampler2D u_texture;
-
-void main()
-{
-    gl_FragColor = v_color * texture2D(u_texture, v_texCoords);
-}

android/assets/shaders/default_vertex.glsl

@@ -1,13 +0,0 @@
-attribute vec4 a_position;
-attribute vec4 a_color;
-attribute vec2 a_texCoord;
-
-uniform mat4 u_projTrans;
-
-varying vec4 v_color;
-varying vec2 v_texCoords;
-
-void main()
-{
-    gl_Position =  u_projTrans * a_position;
-}

android/assets/shaders/invert_frag.glsl

@@ -0,0 +1,16 @@
+#ifdef GL_ES
+#define LOWP lowp
+precision mediump float;
+#else
+#define LOWP
+#endif
+
+varying LOWP vec4 vColor;
+varying vec2 vTexCoord;
+
+uniform sampler2D u_texture;
+void main() {
+	vec4 texColor = texture2D(u_texture, vTexCoord);
+	texColor.rgb = 1.0 - texColor.rgb;
+	gl_FragColor = texColor * vColor;
+}

android/assets/shaders/invert_vert.glsl

@@ -0,0 +1,15 @@
+attribute vec4 a_position;
+attribute vec4 a_color;
+attribute vec2 a_texCoord0;
+
+uniform mat4 u_projTrans;
+
+varying vec4 vColor;
+varying vec2 vTexCoord;
+
+void main() {
+	vColor = a_color;
+	vTexCoord = a_texCoord0;
+
+	gl_Position = u_projTrans * a_position;
+}