1 files changed, 80 insertions, 0 deletions
diff --git a/java/tests/VrDemo/src/com/example/android/rs/vr/engine/mandelbulb.rs b/java/tests/VrDemo/src/com/example/android/rs/vr/engine/mandelbulb.rs
new file mode 100644
index 00000000..23c1bc64
--- /dev/null
+++ b/java/tests/VrDemo/src/com/example/android/rs/vr/engine/mandelbulb.rs
@@ -0,0 +1,80 @@
+/*
+ * Copyright (C) 2015 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.
+ */
+
+#pragma version(1)
+#pragma rs java_package_name(com.example.android.rs.vr.engine)
+#pragma rs_fp_relaxed
+
+int size;
+int z;
+rs_allocation volume;
+
+static float3 nylander(float3 p, int n) {
+    float3 out;
+    float r = length(p);
+    float phi = atan2(p.y, p.x);
+    float theta = acos(p.z / r);
+    float rn = pow(r, n);
+    out.x = sin(n * theta) * cos(n * phi);
+    out.y = sin(n * theta) * sin(n * phi);
+    out.z = cos(n * theta);
+    return out * rn;
+}
+
+/**
+* 8 x faster than the above for n = 3
+*/
+static float3 nylander3(float3 p) {
+    float3 out = (float3){0.f, 0.f, 0.f};
+    float xy2 = p.x * p.x + p.y * p.y;
+    if (xy2 == 0) return out;
+    float z23x2y2 = (3 * p.z * p.z - p.x * p.x - p.y * p.y);
+    out.x = (z23x2y2 * p.x * (p.x * p.x - 3 * p.y * p.y)) / xy2;
+    out.y = (z23x2y2 * p.y * (3 * p.x * p.x - p.y * p.y)) / xy2;
+    out.z = p.z * (p.z * p.z - 3 * p.x * p.x - 3 * p.y * p.y);
+    return out;
+}
+
+static float vsize(float3 p) {
+    return sqrt(p.x * p.x + p.y * p.y + p.z * p.z);
+}
+
+short __attribute__((kernel)) mandelbulb(uint32_t x, uint32_t y) {
+    int size2 = size / 2;
+     if (z < size2) {
+          return 256-4*(size2-z+4)*hypot((float)x-size2,(float)y-size2) / size2 ;
+    }
+    float3 c = (float3) {(float) x, (float) y, (float) z};
+    c = ((c - size2) / (size2 * .9f));
+
+    int loop = 25;
+    float3 p = c;
+    float len;
+    for (int i = 0; i < loop; i++) {
+        //    p = nylander(p, 3) + c;
+        p = nylander3(p) + c;
+        len = fast_length(p);
+        if (len > 2.f) return 255 - loop*10;
+        if (len < .3f) return loop*10;
+
+    }
+    len = length(p);
+    return (short) (255 - (len * 255) / 4);
+}
+
+void __attribute__((kernel)) copy(short in, uint32_t x, uint32_t y) {
+    rsSetElementAt_short(volume, in, x, y, z);
+}