/*
* Copyright (C) 2012 CyberAgent
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package jp.co.cyberagent.android.gpuimage;
import android.graphics.PointF;
import android.opengl.GLES20;
/**
* Creates a swirl distortion on the image.
*/
public class GPUImageSwirlFilter extends GPUImageFilter {
public static final String SWIRL_FRAGMENT_SHADER = "" +
"varying highp vec2 textureCoordinate;\n" +
"\n" +
"uniform sampler2D inputImageTexture;\n" +
"\n" +
"uniform highp vec2 center;\n" +
"uniform highp float radius;\n" +
"uniform highp float angle;\n" +
"\n" +
"void main()\n" +
"{\n" +
"highp vec2 textureCoordinateToUse = textureCoordinate;\n" +
"highp float dist = distance(center, textureCoordinate);\n" +
"if (dist < radius)\n" +
"{\n" +
"textureCoordinateToUse -= center;\n" +
"highp float percent = (radius - dist) / radius;\n" +
"highp float theta = percent * percent * angle * 8.0;\n" +
"highp float s = sin(theta);\n" +
"highp float c = cos(theta);\n" +
"textureCoordinateToUse = vec2(dot(textureCoordinateToUse, vec2(c, -s)), dot(textureCoordinateToUse, vec2(s, c)));\n" +
"textureCoordinateToUse += center;\n" +
"}\n" +
"\n" +
"gl_FragColor = texture2D(inputImageTexture, textureCoordinateToUse );\n" +
"\n" +
"}\n";
private float mAngle;
private int mAngleLocation;
private float mRadius;
private int mRadiusLocation;
private PointF mCenter;
private int mCenterLocation;
public GPUImageSwirlFilter() {
this(0.5f, 1.0f, new PointF(0.5f, 0.5f));
}
public GPUImageSwirlFilter(float radius, float angle, PointF center) {
super(NO_FILTER_VERTEX_SHADER, SWIRL_FRAGMENT_SHADER);
mRadius = radius;
mAngle = angle;
mCenter = center;
}
@Override
public void onInit() {
super.onInit();
mAngleLocation = GLES20.glGetUniformLocation(getProgram(), "angle");
mRadiusLocation = GLES20.glGetUniformLocation(getProgram(), "radius");
mCenterLocation = GLES20.glGetUniformLocation(getProgram(), "center");
}
@Override
public void onInitialized() {
super.onInitialized();
setRadius(mRadius);
setAngle(mAngle);
setCenter(mCenter);
}
/**
* The radius of the distortion, ranging from 0.0 to 1.0, with a default of 0.5.
*
* @param radius from 0.0 to 1.0, default 0.5
*/
public void setRadius(float radius) {
mRadius = radius;
setFloat(mRadiusLocation, radius);
}
/**
* The amount of distortion to apply, with a minimum of 0.0 and a default of 1.0.
*
* @param angle minimum 0.0, default 1.0
*/
public void setAngle(float angle) {
mAngle = angle;
setFloat(mAngleLocation, angle);
}
/**
* The center about which to apply the distortion, with a default of (0.5, 0.5).
*
* @param center default (0.5, 0.5)
*/
public void setCenter(PointF center) {
mCenter = center;
setPoint(mCenterLocation, center);
}
}