1 files changed, 55 insertions, 0 deletions
diff --git a/include/gpu/GrRandom.h b/include/gpu/GrRandom.h
new file mode 100644
index 0000000000..c98a8fbd94
--- /dev/null
+++ b/include/gpu/GrRandom.h
@@ -0,0 +1,55 @@
+
+/*
+ * Copyright 2010 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+
+
+#ifndef GrRandom_DEFINED
+#define GrRandom_DEFINED
+
+class GrRandom {
+public:
+    GrRandom() : fSeed(0) {}
+    GrRandom(uint32_t seed) : fSeed(seed) {}
+
+    uint32_t seed() const { return fSeed; }
+
+    uint32_t nextU() {
+        fSeed = fSeed * kMUL + kADD;
+        return fSeed;
+    }
+
+    int32_t nextS() { return (int32_t)this->nextU(); }
+
+    /**
+     *  Returns value [0...1) as a float
+     */
+    float nextF() {
+        // const is 1 / (2^32 - 1)
+        return (float)(this->nextU() * 2.32830644e-10);
+    }
+
+    /**
+     *  Returns value [min...max) as a float
+     */
+    float nextF(float min, float max) {
+        return min + this->nextF() * (max - min);
+    }
+
+private:
+    /*
+     *  These constants taken from "Numerical Recipes in C", reprinted 1999
+     */
+    enum {
+        kMUL = 1664525,
+        kADD = 1013904223
+    };
+    uint32_t    fSeed;
+};
+
+#endif
+