Make SkRandom::next[US]Fixed1 private; update documentation for SkRandom::nextSScalar1.

SkRandom is unused in Chromium, Android, Mozilla, and Google3.

SkRandom::nextSScalar1 and LCGRandom::nextSScalar1 appear to me by inspection to potentially return -1, so I updated the documentation to match.

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1846773002

Review URL: https://codereview.chromium.org/1846773002

3 files changed, 16 insertions, 16 deletions

diff --git a/bench/GrMemoryPoolBench.cpp b/bench/GrMemoryPoolBench.cpp
index f1872fc136..9b60c3cc2c 100644
--- a/bench/GrMemoryPoolBench.cpp
+++ b/bench/GrMemoryPoolBench.cpp
@@ -50,9 +50,9 @@ protected:
         };
         A* objects[kMaxObjects];
 
-        // We delete if a random [-1, 1] fixed pt is < the thresh. Otherwise,
+        // We delete if a random number [-1, 1] is < the thresh. Otherwise,
         // we allocate. We start allocate-biased and ping-pong to delete-biased
-        SkFixed delThresh = -SK_FixedHalf;
+        SkScalar delThresh = -SK_ScalarHalf;
         const int kSwitchThreshPeriod = loops / (2 * kMaxObjects);
         int s = 0;
 
@@ -62,7 +62,7 @@ protected:
                 delThresh = -delThresh;
                 s = 0;
             }
-            SkFixed del = r.nextSFixed1();
+            SkScalar del = r.nextSScalar1();
             if (count &&
                 (kMaxObjects == count || del < delThresh)) {
                 delete objects[count-1];
diff --git a/include/utils/SkRandom.h b/include/utils/SkRandom.h
index aee2d7a0aa..ecaedafc2f 100644
--- a/include/utils/SkRandom.h
+++ b/include/utils/SkRandom.h
@@ -97,16 +97,6 @@ public:
         return this->nextRangeU(0, count - 1);
     }
 
-    /** Return the next pseudo random number expressed as an unsigned SkFixed
-     in the range [0..SK_Fixed1).
-     */
-    SkFixed nextUFixed1() { return this->nextU() >> 16; }
-
-    /** Return the next pseudo random number expressed as a signed SkFixed
-     in the range (-SK_Fixed1..SK_Fixed1).
-     */
-    SkFixed nextSFixed1() { return this->nextS() >> 15; }
-
     /** Return the next pseudo random number expressed as a SkScalar
      in the range [0..SK_Scalar1).
      */
@@ -120,7 +110,7 @@ public:
     }
 
     /** Return the next pseudo random number expressed as a SkScalar
-     in the range (-SK_Scalar1..SK_Scalar1).
+     in the range [-SK_Scalar1..SK_Scalar1).
      */
     SkScalar nextSScalar1() { return SkFixedToScalar(this->nextSFixed1()); }
 
@@ -164,6 +154,16 @@ private:
     }
     static uint32_t NextLCG(uint32_t seed) { return kMul*seed + kAdd; }
 
+    /** Return the next pseudo random number expressed as an unsigned SkFixed
+     in the range [0..SK_Fixed1).
+     */
+    SkFixed nextUFixed1() { return this->nextU() >> 16; }
+
+    /** Return the next pseudo random number expressed as a signed SkFixed
+     in the range [-SK_Fixed1..SK_Fixed1).
+     */
+    SkFixed nextSFixed1() { return this->nextS() >> 15; }
+
     //  See "Numerical Recipes in C", 1992 page 284 for these constants
     //  For the LCG that sets the initial state from a seed
     enum {
diff --git a/src/effects/SkDiscretePathEffect.cpp b/src/effects/SkDiscretePathEffect.cpp
index 5e68dc67ef..5af6ab4ceb 100644
--- a/src/effects/SkDiscretePathEffect.cpp
+++ b/src/effects/SkDiscretePathEffect.cpp
@@ -47,7 +47,7 @@ public:
     LCGRandom(uint32_t seed) : fSeed(seed) {}
 
     /** Return the next pseudo random number expressed as a SkScalar
-        in the range (-SK_Scalar1..SK_Scalar1).
+        in the range [-SK_Scalar1..SK_Scalar1).
     */
     SkScalar nextSScalar1() { return SkFixedToScalar(this->nextSFixed1()); }
 
@@ -61,7 +61,7 @@ private:
     int32_t nextS() { return (int32_t)this->nextU(); }
 
     /** Return the next pseudo random number expressed as a signed SkFixed
-     in the range (-SK_Fixed1..SK_Fixed1).
+     in the range [-SK_Fixed1..SK_Fixed1).
      */
     SkFixed nextSFixed1() { return this->nextS() >> 15; }