1 files changed, 56 insertions, 0 deletions
diff --git a/platform_tools/android/apps/skar_java/src/main/java/com/google/skar/SkARFingerPainting.java b/platform_tools/android/apps/skar_java/src/main/java/com/google/skar/SkARFingerPainting.java
new file mode 100644
index 0000000000..6d3d0582a4
--- /dev/null
+++ b/platform_tools/android/apps/skar_java/src/main/java/com/google/skar/SkARFingerPainting.java
@@ -0,0 +1,56 @@
+package com.google.skar;
+
+import android.graphics.Matrix;
+import android.graphics.Path;
+import android.graphics.PointF;
+
+public class SkARFingerPainting { ;
+    public Path path = new Path();
+
+    private int numberOfPoints = 0;
+
+    // Holds the model matrix of the first point added to such that the path can be drawn at the
+    // model location (i.e on the Plane)
+    private float[] modelMatrix;
+
+    // Holds the inverse model matrix of the first point that was added such that the path is drawn
+    // first at (0, 0)
+    private float[] inverseModelMatrix;
+
+    public SkARFingerPainting() {}
+
+    // Adds another point to the path in Local space (i.e apply InverseModelMatrix to points located
+    // in Global space (e.g hit positions acquired through hit tests)
+    public void addPoint(PointF p) {
+        if (numberOfPoints == 0) {
+            path.moveTo(p.x, p.y);
+        } else {
+            path.lineTo(p.x, p.y);
+        }
+        numberOfPoints++;
+    }
+
+    public boolean isEmpty() {
+        return numberOfPoints == 0;
+    }
+
+    public float[] getModelMatrix() {
+        return modelMatrix;
+    }
+
+    public float[] getRawInverseModelMatrix() {
+        return inverseModelMatrix;
+    }
+
+    public Matrix getInverseModelMatrix() {
+        return SkARMatrix.createMatrixFrom4x4(inverseModelMatrix);
+    }
+
+    public void setModelMatrix(float[] m) {
+        modelMatrix = m;
+    }
+
+    public void setInverseModelMatrix(float[] m) {
+        inverseModelMatrix = m;
+    }
+}