Feature: add filter of white balance

CameraFilter/src/main/java/com/frank/camerafilter/factory/BeautyFilterFactory.java

@@ -5,6 +5,7 @@ import android.content.Context;
 import com.frank.camerafilter.filter.advance.BeautyHueFilter;
 import com.frank.camerafilter.filter.advance.BeautySketchFilter;
 import com.frank.camerafilter.filter.BaseFilter;
+import com.frank.camerafilter.filter.advance.BeautyWhiteBalanceFilter;
 
 public class BeautyFilterFactory {
 
@@ -17,6 +18,8 @@ public class BeautyFilterFactory {
                 return new BeautySketchFilter(context);
             case HUE:
                 return new BeautyHueFilter(context);
+            case WHITE_BALANCE:
+                return new BeautyWhiteBalanceFilter(context);
             default:
                 return null;
         }

CameraFilter/src/main/java/com/frank/camerafilter/factory/BeautyFilterType.java

@@ -3,5 +3,6 @@ package com.frank.camerafilter.factory;
 public enum BeautyFilterType {
     NONE,
     HUE,
+    WHITE_BALANCE,
     SKETCH
 }

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

@@ -0,0 +1,36 @@
+package com.frank.camerafilter.filter.advance;
+
+import android.content.Context;
+import android.opengl.GLES30;
+
+import com.frank.camerafilter.R;
+import com.frank.camerafilter.filter.BaseFilter;
+import com.frank.camerafilter.util.OpenGLUtil;
+
+public class BeautyWhiteBalanceFilter extends BaseFilter {
+
+    private int tint;
+    private int temperature;
+
+    public BeautyWhiteBalanceFilter(Context context) {
+        super(NORMAL_VERTEX_SHADER, OpenGLUtil.readShaderFromSource(context, R.raw.whitebalance));
+    }
+
+    protected void onInit() {
+        super.onInit();
+        tint = GLES30.glGetUniformLocation(getProgramId(), "tint");
+        temperature = GLES30.glGetUniformLocation(getProgramId(), "temperature");
+    }
+
+    protected void onInitialized() {
+        super.onInitialized();
+        setFloat(tint, 0.5f);
+        setFloat(temperature, 0.3f);
+    }
+
+    @Override
+    public void onInputSizeChanged(int width, int height) {
+        super.onInputSizeChanged(width, height);
+    }
+
+}

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

@@ -0,0 +1,26 @@
+uniform sampler2D inputImageTexture;
+varying highp vec2 textureCoordinate;
+
+uniform lowp float temperature;
+uniform lowp float tint;
+
+const lowp vec3 warmFilter = vec3(0.93, 0.54, 0.0);
+
+const mediump mat3 RGBtoYIQ = mat3(0.299, 0.587, 0.114, 0.596, -0.274, -0.322, 0.212, -0.523, 0.311);
+const mediump mat3 YIQtoRGB = mat3(1.0, 0.956, 0.621, 1.0, -0.272, -0.647, 1.0, -1.105, 1.702);
+
+void main()
+{
+	lowp vec4 source = texture2D(inputImageTexture, textureCoordinate);
+
+	mediump vec3 yiq = RGBtoYIQ * source.rgb; //adjusting tint
+	yiq.b = clamp(yiq.b + tint*0.5226*0.1, -0.5226, 0.5226);
+	lowp vec3 rgb = YIQtoRGB * yiq;
+
+	lowp vec3 processed = vec3(
+	(rgb.r < 0.5 ? (2.0 * rgb.r * warmFilter.r) : (1.0 - 2.0 * (1.0 - rgb.r) * (1.0 - warmFilter.r))), //adjusting temperature
+	(rgb.g < 0.5 ? (2.0 * rgb.g * warmFilter.g) : (1.0 - 2.0 * (1.0 - rgb.g) * (1.0 - warmFilter.g))),
+	(rgb.b < 0.5 ? (2.0 * rgb.b * warmFilter.b) : (1.0 - 2.0 * (1.0 - rgb.b) * (1.0 - warmFilter.b))));
+
+	gl_FragColor = vec4(mix(rgb, processed, temperature), source.a);
+}

app/src/main/java/com/frank/ffmpeg/activity/CameraFilterActivity.kt

@@ -15,7 +15,8 @@ class CameraFilterActivity : BaseActivity() {
 
     private val filterType: Array<BeautyFilterType> = arrayOf(
         BeautyFilterType.NONE,
-        BeautyFilterType.CRAYON,
+        BeautyFilterType.HUE,
+        BeautyFilterType.WHITE_BALANCE,
         BeautyFilterType.SKETCH
     )
 

app/src/main/java/com/frank/ffmpeg/util/FilterTypeUtil.kt

@@ -13,7 +13,8 @@ object FilterTypeUtil {
     fun filterTypeToNameId(type: BeautyFilterType): Int {
         return when (type) {
             BeautyFilterType.NONE -> R.string.camera_filter_none
-            BeautyFilterType.CRAYON -> R.string.camera_filter_crayon
+            BeautyFilterType.HUE -> R.string.camera_filter_hue
+            BeautyFilterType.WHITE_BALANCE -> R.string.camera_filter_balance
             BeautyFilterType.SKETCH -> R.string.camera_filter_sketch
             else -> R.string.camera_filter_none
         }

app/src/main/res/values-en/strings.xml

@@ -113,7 +113,8 @@
     <string name="filter_sharpening">sharpen</string>
 
     <string name="camera_filter_none">None</string>
-    <string name="camera_filter_crayon">Crayon</string>
+    <string name="camera_filter_hue">Hue</string>
+    <string name="camera_filter_balance">White balance</string>
     <string name="camera_filter_sketch">Sketch</string>
 
 </resources>

app/src/main/res/values/strings.xml

@@ -113,7 +113,8 @@
     <string name="filter_sharpening">锐化</string>
 
     <string name="camera_filter_none">正常</string>
-    <string name="camera_filter_crayon">蜡笔</string>
+    <string name="camera_filter_hue">Hue</string>
+    <string name="camera_filter_balance">白平衡</string>
     <string name="camera_filter_sketch">素描</string>
 
 </resources>