1/*
2 * Copyright (C) 2011 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package android.filterpacks.imageproc;
18
19import android.filterfw.core.Filter;
20import android.filterfw.core.FilterContext;
21import android.filterfw.core.Frame;
22import android.filterfw.core.FrameFormat;
23import android.filterfw.core.GenerateFieldPort;
24import android.filterfw.core.Program;
25import android.filterfw.core.ShaderProgram;
26import android.filterfw.format.ImageFormat;
27
28import android.util.Log;
29
30public class FillLightFilter extends Filter {
31
32    @GenerateFieldPort(name = "tile_size", hasDefault = true)
33    private int mTileSize = 640;
34
35    @GenerateFieldPort(name = "strength", hasDefault = true)
36    private float mBacklight = 0f;
37
38    private Program mProgram;
39
40    private int mTarget = FrameFormat.TARGET_UNSPECIFIED;
41
42    private final String mFillLightShader =
43            "precision mediump float;\n" +
44            "uniform sampler2D tex_sampler_0;\n" +
45            "uniform float mult;\n" +
46            "uniform float igamma;\n" +
47            "varying vec2 v_texcoord;\n" +
48            "void main()\n" +
49            "{\n" +
50            "  const vec3 color_weights = vec3(0.25, 0.5, 0.25);\n" +
51            "  vec4 color = texture2D(tex_sampler_0, v_texcoord);\n" +
52            "  float lightmask = dot(color.rgb, color_weights);\n" +
53            "  float backmask = (1.0 - lightmask);\n" +
54            "  vec3 ones = vec3(1.0, 1.0, 1.0);\n" +
55            "  vec3 diff = pow(mult * color.rgb, igamma * ones) - color.rgb;\n" +
56            "  diff = min(diff, 1.0);\n" +
57            "  vec3 new_color = min(color.rgb + diff * backmask, 1.0);\n" +
58            "  gl_FragColor = vec4(new_color, color.a);\n" +
59            "}\n";
60
61    public FillLightFilter(String name) {
62      super(name);
63    }
64
65    @Override
66    public void setupPorts() {
67        addMaskedInputPort("image", ImageFormat.create(ImageFormat.COLORSPACE_RGBA));
68        addOutputBasedOnInput("image", "image");
69    }
70
71    @Override
72    public FrameFormat getOutputFormat(String portName, FrameFormat inputFormat) {
73        return inputFormat;
74    }
75
76    public void initProgram(FilterContext context, int target) {
77        switch (target) {
78            case FrameFormat.TARGET_GPU:
79                ShaderProgram shaderProgram = new ShaderProgram(context, mFillLightShader);
80                Log.e("FillLight", "tile size: " + mTileSize);
81                shaderProgram.setMaximumTileSize(mTileSize);
82                mProgram = shaderProgram;
83                break;
84
85            default:
86                throw new RuntimeException("Filter FillLight does not support frames of " +
87                    "target " + target + "!");
88        }
89        mTarget = target;
90    }
91
92
93    @Override
94    public void process(FilterContext context) {
95        // Get input frame
96        Frame input = pullInput("image");
97        FrameFormat inputFormat = input.getFormat();
98
99        // Create output frame
100        Frame output = context.getFrameManager().newFrame(inputFormat);
101
102        // Create program if not created already
103        if (mProgram == null || inputFormat.getTarget() != mTarget) {
104            initProgram(context, inputFormat.getTarget());
105            updateParameters();
106        }
107
108        // Process
109        mProgram.process(input, output);
110
111        // Push output
112        pushOutput("image", output);
113
114        // Release pushed frame
115        output.release();
116    }
117
118
119    @Override
120    public void fieldPortValueUpdated(String name, FilterContext context) {
121        if (mProgram != null) {
122            updateParameters();
123        }
124    }
125
126    private void updateParameters() {
127        float fade_gamma = 0.3f;
128        float amt = 1.0f - mBacklight;
129        float mult = 1.0f / (amt * 0.7f + 0.3f);
130        float faded = fade_gamma + (1.0f -fade_gamma) *mult;
131        float igamma = 1.0f / faded;
132
133        mProgram.setHostValue("mult", mult);
134        mProgram.setHostValue("igamma", igamma);
135    }
136}
137