[androidkit] add transformation operations to Matrix

Change-Id: I5a81087eb56f10786c136df7cf68bb0e34742abf
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/402676
Commit-Queue: Jorge Betancourt <jmbetancourt@google.com>
Reviewed-by: Florin Malita <fmalita@chromium.org>

modules/androidkit/src/Matrix.cpp

@@ -20,18 +20,11 @@ static jlong Matrix_Create(JNIEnv* env, jobject, jfloat m0, jfloat m4, jfloat m8
                                              m2, m6, m10, m14,
                                              m3, m7, m11, m15));
 }
+
 static void Matrix_Release(JNIEnv* env, jobject, jlong native_matrix) {
     delete reinterpret_cast<SkM44*>(native_matrix);
 }
 
-static void Matrix_PostConcat(JNIEnv* env, jobject, jlong native_matrixA, jlong native_matrixB) {
-    if (auto* mA = reinterpret_cast<SkM44*>(native_matrixA),
-            * mB = reinterpret_cast<SkM44*>(native_matrixB); mA && mB) {
-        mA->postConcat(*mB);
-    }
-
-}
-
 static void Matrix_PreConcat(JNIEnv* env, jobject, jlong native_matrixA, jlong native_matrixB) {
     if (auto* mA = reinterpret_cast<SkM44*>(native_matrixA),
            * mB = reinterpret_cast<SkM44*>(native_matrixB); mA && mB) {
@@ -52,7 +45,6 @@ int register_androidkit_Matrix(JNIEnv* env) {
     static const JNINativeMethod methods[] = {
         {"nCreate"     , "(FFFFFFFFFFFFFFFF)J" , reinterpret_cast<void*>(Matrix_Create)},
         {"nRelease"    , "(J)V"                , reinterpret_cast<void*>(Matrix_Release)},
-        {"nPostConcat" , "(JJ)V"               , reinterpret_cast<void*>(Matrix_PostConcat)},
         {"nPreConcat"  , "(JJ)V"               , reinterpret_cast<void*>(Matrix_PreConcat)},
         {"nConcat"     , "(JJ)J"               , reinterpret_cast<void*>(Matrix_Concat)},
     };

platform_tools/android/apps/AndroidKit/src/main/java/org/skia/androidkit/Matrix.java

@@ -41,7 +41,9 @@ public class Matrix {
     }
 
     /*
-     * Concat A * B, return new matrix as result
+     * A: this Matrix
+     * B: Matrix passed in
+     * Concat A * B, return new Matrix C as result
      */
     public static Matrix Concat(Matrix a, Matrix b) {
         long nativeA = a.mNativeInstance;
@@ -51,15 +53,8 @@ public class Matrix {
     }
 
     /*
-     * Concat A * B, store result in Matrix A
+     * A: this Matrix
-     */
+     * B: Matrix passed in
-    public void postConcat(Matrix b) {
-        long nativeA = this.mNativeInstance;
-        long nativeB = b.mNativeInstance;
-        nPostConcat(nativeA, nativeB);
-    }
-
-    /*
      * Concat B * A, store result in Matrix A
      */
     public void preConcat(Matrix b) {
@@ -68,6 +63,78 @@ public class Matrix {
         nPreConcat(nativeA, nativeB);
     }
 
+    /*
+     * Translates this Matrix by x, y, z
+     * Store result in caller Matrix
+     * returns reference to this Matrix for operation chaining
+     *
+     * TODO: optimize calls to JNI
+     */
+    public Matrix translate(float x, float y, float z) {
+        Matrix t = new Matrix(1, 0, 0, x,
+                              0, 1, 0, y,
+                              0, 0, 1, z,
+                              0, 0, 0, 1);
+        this.preConcat(t);
+        return this;
+    }
+
+    /*
+     * Scales this Matrix by x, y, z
+     * Store result in caller Matrix
+     * returns reference to this Matrix for operation chaining
+     */
+    public Matrix scale(float x, float y, float z) {
+        Matrix s = new Matrix(x, 0, 0, 0,
+                              0, y, 0, 0,
+                              0, 0, z, 0,
+                              0, 0, 0, 1);
+        this.preConcat(s);
+        return this;
+    }
+
+    /*
+     * Rotates this Matrix along the x-axis by rad radians
+     * Store result in caller Matrix
+     * returns reference to this Matrix for operation chaining
+     */
+    public Matrix rotateX(float rad) {
+        Matrix r = new Matrix(1, 0,                     0,                      0,
+                              0, (float) Math.cos(rad), (float) -Math.sin(rad), 0,
+                              0, (float) Math.sin(rad), (float) Math.cos(rad),  0,
+                              0, 0,                     0,                      1);
+        this.preConcat(r);
+        return this;
+    }
+
+    /*
+     * Rotates this Matrix along the y-axis by rad radians
+     * Store result in caller Matrix
+     * returns reference to this Matrix for operation chaining
+     */
+    public Matrix rotateY(float rad) {
+        Matrix r = new Matrix((float) Math.cos(rad),  0, (float) Math.sin(rad), 0,
+                              0,                      1, 0,                     0,
+                              (float) -Math.sin(rad), 0, (float) Math.cos(rad), 0,
+                              0,                      0, 0,                     1);
+        this.preConcat(r);
+        return this;
+    }
+
+    /*
+     * Rotates this Matrix along the z-axis by rad radians
+     * Store result in caller Matrix
+     * returns reference to this Matrix for operation chaining
+     */
+    public Matrix rotateZ(float rad) {
+        Matrix r = new Matrix((float) Math.cos(rad), (float) -Math.sin(rad), 0, 0,
+                (float) Math.sin(rad), (float) Math.cos(rad),  0, 0,
+                0,                     0,                      1, 0,
+                0,                     0,                      0, 1);
+        this.preConcat(r);
+        return this;
+    }
+
     /**
      * Releases any resources associated with this Matrix.
      */
@@ -87,7 +154,6 @@ public class Matrix {
                                        float m3, float m7, float m11, float m15);
     private static native void nRelease(long nativeInstance);
 
-    private static native void nPostConcat(long mNativeInstanceA, long mNativeInstanceB);
     private static native void nPreConcat(long mNativeInstanceA, long mNativeInstanceB);
     private static native long nConcat(long mNativeInstanceA, long mNativeInstanceB);
 }