More docs
Change-Id: I3dfea7d83bf8525efda59cef6fafa854b5aa9fe3
diff --git a/graphics/java/android/renderscript/Matrix2f.java b/graphics/java/android/renderscript/Matrix2f.java
index 2fffe8c..c9a0ea8 100644
--- a/graphics/java/android/renderscript/Matrix2f.java
+++ b/graphics/java/android/renderscript/Matrix2f.java
@@ -26,28 +26,61 @@
**/
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[2];
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 i row of the value to return
+ * @param j column of the value to return
+ *
+ * @return value in the ith row and jth column
+ */
public float get(int i, int j) {
return mMat[i*2 + j];
}
+ /**
+ * Sets the value for a given row and column
+ *
+ * @param i row of the value to set
+ * @param j column of the value to set
+ */
public void set(int i, int j, float v) {
mMat[i*2 + j] = v;
}
+ /**
+ * Sets the matrix values to identity
+ */
public void loadIdentity() {
mMat[0] = 1;
mMat[1] = 0;
@@ -56,10 +89,20 @@
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);
@@ -71,11 +114,25 @@
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;
@@ -90,21 +147,42 @@
}
}
+ /**
+ * 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];