/*
* Copyright (C) 2009-2012 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 android.renderscript;
/**
* Class for exposing the native RenderScript rs_matrix3x3 type back to the Android system.
*
**/
public class Matrix3f {
/**
* Creates a new identity 3x3 matrix
*/
public Matrix3f() {
mMat = new float[9];
loadIdentity();
}
/**
* Creates a new matrix and sets its values from the given
* parameter
*
* @param dataArray values to set the matrix to, must be 9
* floats long
*/
public Matrix3f(float[] dataArray) {
mMat = new float[9];
System.arraycopy(dataArray, 0, mMat, 0, mMat.length);
}
/**
* Return a reference to the internal array representing matrix
* values. Modifying this array will also change the matrix
*
* @return internal array representing the matrix
*/
public float[] getArray() {
return mMat;
}
/**
* Returns the value for a given row and column
*
* @param x column of the value to return
* @param y row of the value to return
*
* @return value in the yth row and xth column
*/
public float get(int x, int y) {
return mMat[x*3 + y];
}
/**
* Sets the value for a given row and column
*
* @param x column of the value to set
* @param y row of the value to set
*/
public void set(int x, int y, float v) {
mMat[x*3 + y] = v;
}
/**
* Sets the matrix values to identity
*/
public void loadIdentity() {
mMat[0] = 1;
mMat[1] = 0;
mMat[2] = 0;
mMat[3] = 0;
mMat[4] = 1;
mMat[5] = 0;
mMat[6] = 0;
mMat[7] = 0;
mMat[8] = 1;
}
/**
* Sets the values of the matrix to those of the parameter
*
* @param src matrix to load the values from
*/
public void load(Matrix3f src) {
System.arraycopy(src.getArray(), 0, mMat, 0, mMat.length);
}
/**
* Sets current values to be a rotation matrix of certain angle
* about a given axis
*
* @param rot angle of rotation
* @param x rotation axis x
* @param y rotation axis y
* @param z rotation axis z
*/
public void loadRotate(float rot, float x, float y, float z) {
float c, s;
rot *= (float)(java.lang.Math.PI / 180.0f);
c = (float)java.lang.Math.cos(rot);
s = (float)java.lang.Math.sin(rot);
float len = (float)java.lang.Math.sqrt(x*x + y*y + z*z);
if (!(len != 1)) {
float recipLen = 1.f / len;
x *= recipLen;
y *= recipLen;
z *= recipLen;
}
float nc = 1.0f - c;
float xy = x * y;
float yz = y * z;
float zx = z * x;
float xs = x * s;
float ys = y * s;
float zs = z * s;
mMat[0] = x*x*nc + c;
mMat[3] = xy*nc - zs;
mMat[6] = zx*nc + ys;
mMat[1] = xy*nc + zs;
mMat[4] = y*y*nc + c;
mMat[7] = yz*nc - xs;
mMat[2] = zx*nc - ys;
mMat[5] = yz*nc + xs;
mMat[8] = z*z*nc + c;
}
/**
* Makes the upper 2x2 a rotation matrix of the given angle
*
* @param rot rotation angle
*/
public void loadRotate(float rot) {
loadIdentity();
float c, s;
rot *= (float)(java.lang.Math.PI / 180.0f);
c = (float)java.lang.Math.cos(rot);
s = (float)java.lang.Math.sin(rot);
mMat[0] = c;
mMat[1] = -s;
mMat[3] = s;
mMat[4] = c;
}
/**
* Makes the upper 2x2 a scale matrix of given dimensions
*
* @param x scale component x
* @param y scale component y
*/
public void loadScale(float x, float y) {
loadIdentity();
mMat[0] = x;
mMat[4] = y;
}
/**
* Sets current values to be a scale matrix of given dimensions
*
* @param x scale component x
* @param y scale component y
* @param z scale component z
*/
public void loadScale(float x, float y, float z) {
loadIdentity();
mMat[0] = x;
mMat[4] = y;
mMat[8] = z;
}
/**
* Sets current values to be a translation matrix of given
* dimensions
*
* @param x translation component x
* @param y translation component y
*/
public void loadTranslate(float x, float y) {
loadIdentity();
mMat[6] = x;
mMat[7] = y;
}
/**
* Sets current values to be the result of multiplying two given
* matrices
*
* @param lhs left hand side matrix
* @param rhs right hand side matrix
*/
public void loadMultiply(Matrix3f lhs, Matrix3f rhs) {
for (int i=0 ; i<3 ; i++) {
float ri0 = 0;
float ri1 = 0;
float ri2 = 0;
for (int j=0 ; j<3 ; j++) {
float rhs_ij = rhs.get(i,j);
ri0 += lhs.get(j,0) * rhs_ij;
ri1 += lhs.get(j,1) * rhs_ij;
ri2 += lhs.get(j,2) * rhs_ij;
}
set(i,0, ri0);
set(i,1, ri1);
set(i,2, ri2);
}
}
/**
* Post-multiplies the current matrix by a given parameter
*
* @param rhs right hand side to multiply by
*/
public void multiply(Matrix3f rhs) {
Matrix3f tmp = new Matrix3f();
tmp.loadMultiply(this, rhs);
load(tmp);
}
/**
* Modifies the current matrix by post-multiplying it with a
* rotation matrix of certain angle about a given axis
*
* @param rot angle of rotation
* @param x rotation axis x
* @param y rotation axis y
* @param z rotation axis z
*/
public void rotate(float rot, float x, float y, float z) {
Matrix3f tmp = new Matrix3f();
tmp.loadRotate(rot, x, y, z);
multiply(tmp);
}
/**
* Modifies the upper 2x2 of the current matrix by
* post-multiplying it with a rotation matrix of given angle
*
* @param rot angle of rotation
*/
public void rotate(float rot) {
Matrix3f tmp = new Matrix3f();
tmp.loadRotate(rot);
multiply(tmp);
}
/**
* Modifies the upper 2x2 of the current matrix by
* post-multiplying it with a scale matrix of given dimensions
*
* @param x scale component x
* @param y scale component y
*/
public void scale(float x, float y) {
Matrix3f tmp = new Matrix3f();
tmp.loadScale(x, y);
multiply(tmp);
}
/**
* Modifies the current matrix by post-multiplying it with a
* scale matrix of given dimensions
*
* @param x scale component x
* @param y scale component y
* @param z scale component z
*/
public void scale(float x, float y, float z) {
Matrix3f tmp = new Matrix3f();
tmp.loadScale(x, y, z);
multiply(tmp);
}
/**
* Modifies the current matrix by post-multiplying it with a
* translation matrix of given dimensions
*
* @param x translation component x
* @param y translation component y
*/
public void translate(float x, float y) {
Matrix3f tmp = new Matrix3f();
tmp.loadTranslate(x, y);
multiply(tmp);
}
/**
* Sets the current matrix to its transpose
*/
public void transpose() {
for(int i = 0; i < 2; ++i) {
for(int j = i + 1; j < 3; ++j) {
float temp = mMat[i*3 + j];
mMat[i*3 + j] = mMat[j*3 + i];
mMat[j*3 + i] = temp;
}
}
}
final float[] mMat;
}
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