add random functions. literally.

Author: ianfixes

CHANGELOG.md

@@ -10,6 +10,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 - Support for all builtin Bits and Bytes functions https://www.arduino.cc/reference/en/
 - Support for GODMODE and time functions
 - Support for Character functions https://www.arduino.cc/reference/en/
+- Support for `random` functions with seed control
 - Many original Arduino `#define`s
 
 ### Changed

SampleProjects/TestSomething/test/good-godmode.cpp

@@ -15,4 +15,16 @@ unittest(millis_micros_and_delay)
   assertEqual(14000, micros());
 }
 
+unittest(random)
+{
+  randomSeed(1);
+  unsigned long x;
+  x = random(4294967293);
+  assertEqual(4294967292, x);
+  x = random(50, 100);
+  assertEqual(83, x);
+  x = random(100);
+  assertEqual(74, x);
+}
+
 unittest_main()

cpp/arduino/Arduino.cpp

@@ -21,3 +21,20 @@ void delay(unsigned long millis) {
 void delayMicroseconds(unsigned long micros) {
   godmode.micros += micros;
 }
+
+
+void randomSeed(unsigned long seed)
+{
+  godmode.seed = seed;
+}
+
+long random(long vmax)
+{
+  godmode.seed += 4294967291;  // it's a prime that fits in 32 bits
+  return godmode.seed % vmax;
+}
+
+long random(long vmin, long vmax)
+{
+  return vmin < vmax ? (random(vmax - vmin) + vmin) : vmin;
+}

cpp/arduino/Arduino.h

@@ -9,13 +9,15 @@ Where possible, variable names from the Arduino library are used to avoid confli
 class GodmodeState {
   public:
     unsigned long micros;
+    unsigned long seed;
 
     void resetClock() {
       micros = 0;
     }
 
     void reset() {
       resetClock();
+      seed = 1;
     }
 
     GodmodeState() {
@@ -87,6 +89,10 @@ inline unsigned int makeWord(unsigned char h, unsigned char l) { return (h << 8)
 
 #define word(...) makeWord(__VA_ARGS__)
 
+// random
+void randomSeed(unsigned long seed);
+long random(long vmax);
+long random(long vmin, long vmax);
 
 
 // Time