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 17 18package android.filterpacks.imageproc; 19 20import android.filterfw.core.Filter; 21import android.filterfw.core.FilterContext; 22import android.filterfw.core.Frame; 23import android.filterfw.core.FrameFormat; 24import android.filterfw.core.KeyValueMap; 25import android.filterfw.core.NativeProgram; 26import android.filterfw.core.NativeFrame; 27import android.filterfw.core.Program; 28import android.filterfw.core.ShaderProgram; 29 30import java.util.Set; 31 32/** 33 * @hide 34 */ 35public class ContrastFilter extends SimpleImageFilter { 36 37 private static final String mContrastShader = 38 "precision mediump float;\n" + 39 "uniform sampler2D tex_sampler_0;\n" + 40 "uniform float contrast;\n" + 41 "varying vec2 v_texcoord;\n" + 42 "void main() {\n" + 43 " vec4 color = texture2D(tex_sampler_0, v_texcoord);\n" + 44 " color -= 0.5;\n" + 45 " color *= contrast;\n" + 46 " color += 0.5;\n" + 47 " gl_FragColor = color;\n" + // this will clamp 48 "}\n"; 49 50 public ContrastFilter(String name) { 51 super(name, "contrast"); 52 } 53 54 @Override 55 protected Program getNativeProgram(FilterContext context) { 56 return new NativeProgram("filterpack_imageproc", "contrast"); 57 } 58 59 @Override 60 protected Program getShaderProgram(FilterContext context) { 61 return new ShaderProgram(context, mContrastShader); 62 } 63 64} 65