Adding quaternion functions to math library.
Change-Id: I692214648892120943ca7d3b00034e27d1c330cf
diff --git a/graphics/java/android/renderscript/Matrix4f.java b/graphics/java/android/renderscript/Matrix4f.java
index e854cd9..5ffc21a 100644
--- a/graphics/java/android/renderscript/Matrix4f.java
+++ b/graphics/java/android/renderscript/Matrix4f.java
@@ -179,6 +179,76 @@
tmp.loadTranslate(x, y, z);
multiply(tmp);
}
+ private float computeCofactor(int i, int j) {
+ int c0 = (i+1) % 4;
+ int c1 = (i+2) % 4;
+ int c2 = (i+3) % 4;
+ int r0 = (j+1) % 4;
+ int r1 = (j+2) % 4;
+ int r2 = (j+3) % 4;
+
+ float minor = (mMat[c0 + 4*r0] * (mMat[c1 + 4*r1] * mMat[c2 + 4*r2] -
+ mMat[c1 + 4*r2] * mMat[c2 + 4*r1]))
+ - (mMat[c0 + 4*r1] * (mMat[c1 + 4*r0] * mMat[c2 + 4*r2] -
+ mMat[c1 + 4*r2] * mMat[c2 + 4*r0]))
+ + (mMat[c0 + 4*r2] * (mMat[c1 + 4*r0] * mMat[c2 + 4*r1] -
+ mMat[c1 + 4*r1] * mMat[c2 + 4*r0]));
+
+ float cofactor = ((i+j) & 1) != 0 ? -minor : minor;
+ return cofactor;
+ }
+
+ public boolean inverse() {
+
+ Matrix4f result = new Matrix4f();
+
+ for (int i = 0; i < 4; ++i) {
+ for (int j = 0; j < 4; ++j) {
+ result.mMat[4*i + j] = computeCofactor(i, j);
+ }
+ }
+
+ // Dot product of 0th column of source and 0th row of result
+ float det = mMat[0]*result.mMat[0] + mMat[4]*result.mMat[1] +
+ mMat[8]*result.mMat[2] + mMat[12]*result.mMat[3];
+
+ if (Math.abs(det) < 1e-6) {
+ return false;
+ }
+
+ det = 1.0f / det;
+ for (int i = 0; i < 16; ++i) {
+ mMat[i] = result.mMat[i] * det;
+ }
+
+ return true;
+ }
+
+ public boolean inverseTranspose() {
+
+ Matrix4f result = new Matrix4f();
+
+ for (int i = 0; i < 4; ++i) {
+ for (int j = 0; j < 4; ++j) {
+ result.mMat[4*j + i] = computeCofactor(i, j);
+ }
+ }
+
+ float det = mMat[0]*result.mMat[0] + mMat[4]*result.mMat[4] +
+ mMat[8]*result.mMat[8] + mMat[12]*result.mMat[12];
+
+ if (Math.abs(det) < 1e-6) {
+ return false;
+ }
+
+ det = 1.0f / det;
+ for (int i = 0; i < 16; ++i) {
+ mMat[i] = result.mMat[i] * det;
+ }
+
+ return true;
+ }
+
public void transpose() {
for(int i = 0; i < 3; ++i) {
for(int j = i + 1; j < 4; ++j) {