/*
* Copyright (C) 2012 The Android Open Source Project
*
* 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 com.android.gallery3d.filtershow.filters;
import java.util.Arrays;
public class ColorSpaceMatrix {
private final float[] mMatrix = new float[16];
private static final float RLUM = 0.3086f;
private static final float GLUM = 0.6094f;
private static final float BLUM = 0.0820f;
public ColorSpaceMatrix() {
identity();
}
/**
* Copy constructor
*
* @param matrix
*/
public ColorSpaceMatrix(ColorSpaceMatrix matrix) {
System.arraycopy(matrix.mMatrix, 0, mMatrix, 0, matrix.mMatrix.length);
}
/**
* get the matrix
*
* @return the internal matrix
*/
public float[] getMatrix() {
return mMatrix;
}
/**
* set matrix to identity
*/
public void identity() {
Arrays.fill(mMatrix, 0);
mMatrix[0] = mMatrix[5] = mMatrix[10] = mMatrix[15] = 1;
}
public void convertToLuminance() {
mMatrix[0] = mMatrix[1] = mMatrix[2] = 0.3086f;
mMatrix[4] = mMatrix[5] = mMatrix[6] = 0.6094f;
mMatrix[8] = mMatrix[9] = mMatrix[10] = 0.0820f;
}
private void multiply(float[] a)
{
int x, y;
float[] temp = new float[16];
for (y = 0; y < 4; y++) {
int y4 = y * 4;
for (x = 0; x < 4; x++) {
temp[y4 + x] = mMatrix[y4 + 0] * a[x]
+ mMatrix[y4 + 1] * a[4 + x]
+ mMatrix[y4 + 2] * a[8 + x]
+ mMatrix[y4 + 3] * a[12 + x];
}
}
for (int i = 0; i < 16; i++)
mMatrix[i] = temp[i];
}
private void xRotateMatrix(float rs, float rc)
{
ColorSpaceMatrix c = new ColorSpaceMatrix();
float[] tmp = c.mMatrix;
tmp[5] = rc;
tmp[6] = rs;
tmp[9] = -rs;
tmp[10] = rc;
multiply(tmp);
}
private void yRotateMatrix(float rs, float rc)
{
ColorSpaceMatrix c = new ColorSpaceMatrix();
float[] tmp = c.mMatrix;
tmp[0] = rc;
tmp[2] = -rs;
tmp[8] = rs;
tmp[10] = rc;
multiply(tmp);
}
private void zRotateMatrix(float rs, float rc)
{
ColorSpaceMatrix c = new ColorSpaceMatrix();
float[] tmp = c.mMatrix;
tmp[0] = rc;
tmp[1] = rs;
tmp[4] = -rs;
tmp[5] = rc;
multiply(tmp);
}
private void zShearMatrix(float dx, float dy)
{
ColorSpaceMatrix c = new ColorSpaceMatrix();
float[] tmp = c.mMatrix;
tmp[2] = dx;
tmp[6] = dy;
multiply(tmp);
}
/**
* sets the transform to a shift in Hue
*
* @param rot rotation in degrees
*/
public void setHue(float rot)
{
float mag = (float) Math.sqrt(2.0);
float xrs = 1 / mag;
float xrc = 1 / mag;
xRotateMatrix(xrs, xrc);
mag = (float) Math.sqrt(3.0);
float yrs = -1 / mag;
float yrc = (float) Math.sqrt(2.0) / mag;
yRotateMatrix(yrs, yrc);
float lx = getRedf(RLUM, GLUM, BLUM);
float ly = getGreenf(RLUM, GLUM, BLUM);
float lz = getBluef(RLUM, GLUM, BLUM);
float zsx = lx / lz;
float zsy = ly / lz;
zShearMatrix(zsx, zsy);
float zrs = (float) Math.sin(rot * Math.PI / 180.0);
float zrc = (float) Math.cos(rot * Math.PI / 180.0);
zRotateMatrix(zrs, zrc);
zShearMatrix(-zsx, -zsy);
yRotateMatrix(-yrs, yrc);
xRotateMatrix(-xrs, xrc);
}
/**
* set it to a saturation matrix
*
* @param s
*/
public void changeSaturation(float s) {
mMatrix[0] = (1 - s) * RLUM + s;
mMatrix[1] = (1 - s) * RLUM;
mMatrix[2] = (1 - s) * RLUM;
mMatrix[4] = (1 - s) * GLUM;
mMatrix[5] = (1 - s) * GLUM + s;
mMatrix[6] = (1 - s) * GLUM;
mMatrix[8] = (1 - s) * BLUM;
mMatrix[9] = (1 - s) * BLUM;
mMatrix[10] = (1 - s) * BLUM + s;
}
/**
* Transform RGB value
*
* @param r red pixel value
* @param g green pixel value
* @param b blue pixel value
* @return computed red pixel value
*/
public float getRed(int r, int g, int b) {
return r * mMatrix[0] + g * mMatrix[4] + b * mMatrix[8] + mMatrix[12];
}
/**
* Transform RGB value
*
* @param r red pixel value
* @param g green pixel value
* @param b blue pixel value
* @return computed green pixel value
*/
public float getGreen(int r, int g, int b) {
return r * mMatrix[1] + g * mMatrix[5] + b * mMatrix[9] + mMatrix[13];
}
/**
* Transform RGB value
*
* @param r red pixel value
* @param g green pixel value
* @param b blue pixel value
* @return computed blue pixel value
*/
public float getBlue(int r, int g, int b) {
return r * mMatrix[2] + g * mMatrix[6] + b * mMatrix[10] + mMatrix[14];
}
private float getRedf(float r, float g, float b) {
return r * mMatrix[0] + g * mMatrix[4] + b * mMatrix[8] + mMatrix[12];
}
private float getGreenf(float r, float g, float b) {
return r * mMatrix[1] + g * mMatrix[5] + b * mMatrix[9] + mMatrix[13];
}
private float getBluef(float r, float g, float b) {
return r * mMatrix[2] + g * mMatrix[6] + b * mMatrix[10] + mMatrix[14];
}
}