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Diffstat (limited to 'rs/java/android/renderscript/Matrix2f.java')
-rw-r--r-- | rs/java/android/renderscript/Matrix2f.java | 196 |
1 files changed, 196 insertions, 0 deletions
diff --git a/rs/java/android/renderscript/Matrix2f.java b/rs/java/android/renderscript/Matrix2f.java new file mode 100644 index 0000000..d3621fa --- /dev/null +++ b/rs/java/android/renderscript/Matrix2f.java @@ -0,0 +1,196 @@ +/* + * 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; + +import java.lang.Math; +import android.util.Log; + + +/** + * Class for exposing the native RenderScript rs_matrix2x2 type back to the Android system. + * + **/ +public class Matrix2f { + + /** + * Creates a new identity 2x2 matrix + */ + public Matrix2f() { + mMat = new float[4]; + loadIdentity(); + } + + /** + * Creates a new matrix and sets its values from the given + * parameter + * + * @param dataArray values to set the matrix to, must be 4 + * floats long + */ + public Matrix2f(float[] dataArray) { + mMat = new float[4]; + 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*2 + 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*2 + y] = v; + } + + /** + * Sets the matrix values to identity + */ + public void loadIdentity() { + mMat[0] = 1; + mMat[1] = 0; + + mMat[2] = 0; + mMat[3] = 1; + } + + /** + * Sets the values of the matrix to those of the parameter + * + * @param src matrix to load the values from + */ + public void load(Matrix2f src) { + System.arraycopy(src.getArray(), 0, mMat, 0, mMat.length); + } + + /** + * Sets current values to be a rotation matrix of given angle + * + * @param rot rotation angle + */ + public void loadRotate(float rot) { + 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[2] = s; + mMat[3] = c; + } + + /** + * Sets current values to be 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[3] = 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(Matrix2f lhs, Matrix2f rhs) { + for (int i=0 ; i<2 ; i++) { + float ri0 = 0; + float ri1 = 0; + for (int j=0 ; j<2 ; j++) { + float rhs_ij = rhs.get(i,j); + ri0 += lhs.get(j,0) * rhs_ij; + ri1 += lhs.get(j,1) * rhs_ij; + } + set(i,0, ri0); + set(i,1, ri1); + } + } + + /** + * Post-multiplies the current matrix by a given parameter + * + * @param rhs right hand side to multiply by + */ + public void multiply(Matrix2f rhs) { + Matrix2f tmp = new Matrix2f(); + tmp.loadMultiply(this, rhs); + load(tmp); + } + /** + * Modifies the current matrix by post-multiplying it with a + * rotation matrix of given angle + * + * @param rot angle of rotation + */ + public void rotate(float rot) { + Matrix2f tmp = new Matrix2f(); + tmp.loadRotate(rot); + 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 + */ + public void scale(float x, float y) { + Matrix2f tmp = new Matrix2f(); + tmp.loadScale(x, y); + multiply(tmp); + } + /** + * Sets the current matrix to its transpose + */ + public void transpose() { + float temp = mMat[1]; + mMat[1] = mMat[2]; + mMat[2] = temp; + } + + final float[] mMat; +} + + + |