Feature: change GLES2.0 to GLES3.0

CameraFilter/src/main/java/com/frank/camerafilter/filter/advance/BeautySketchFilter.java

@@ -1,7 +1,7 @@
 package com.frank.camerafilter.filter.advance;
 
 import android.content.Context;
-import android.opengl.GLES20;
+import android.opengl.GLES30;
 
 import com.frank.camerafilter.R;
 import com.frank.camerafilter.filter.BaseFilter;
@@ -18,8 +18,8 @@ public class BeautySketchFilter extends BaseFilter {
 
     protected void onInit() {
         super.onInit();
-        strengthLocation = GLES20.glGetUniformLocation(getProgramId(), "strength");
-        stepOffsetLocation = GLES20.glGetUniformLocation(getProgramId(), "singleStepOffset");
+        strengthLocation = GLES30.glGetUniformLocation(getProgramId(), "strength");
+        stepOffsetLocation = GLES30.glGetUniformLocation(getProgramId(), "singleStepOffset");
     }
 
     @Override

CameraFilter/src/main/res/raw/default_fragment.glsl

@@ -7,7 +7,25 @@ varying mediump vec2 textureCoordinate;
 uniform samplerExternalOES inputImageTexture;
 
 void main(){
+    vec2 xy = textureCoordinate.xy;
+    // two screen(0.25~0.75)
+//    if (xy.x <= 0.5) {
+//        xy.x += 0.25;
+//    } else {
+//        xy.x -= 0.25;
+//    }
+    // four screen
+//    if (xy.x <= 0.5) {
+//        xy.x = xy.x * 2.0;
+//    } else {
+//        xy.x = (xy.x - 0.5) * 2.0;
+//    }
+//    if (xy.y <= 0.5) {
+//        xy.y = xy.y * 2.0;
+//    } else {
+//        xy.y = (xy.y - 0.5) * 2.0;
+//    }
 
-    vec3 centralColor = texture2D(inputImageTexture, textureCoordinate).rgb;
+    vec3 centralColor = texture2D(inputImageTexture, xy).rgb;
     gl_FragColor = vec4(centralColor.rgb,1.0);
 }