Fix native randomization opcodes.

CHANGELOG.md

@@ -39,6 +39,8 @@
   - new opcode **2304 ([get_script_filename](https://library.sannybuilder.com/#/sa/file/2304))**
 - new [Math](https://github.com/cleolibrary/CLEO5/tree/master/cleo_plugins/Math) plugin
   - math related opcodes moved from CLEO core into separated plugin
+  - fixed poor randomization of **0208 ([generate_random_float_in_range](https://library.sannybuilder.com/#/sa/default/0208))** and **0209 ([generate_random_int_in_range](https://library.sannybuilder.com/#/sa/default/0209))**
+  - fixed invalid result range of **0098 ([generate_random_float](https://library.sannybuilder.com/#/sa/default/0098))**
   - new opcode **2700 ([is_bit_set](https://library.sannybuilder.com/#/sa/math/2700))**
   - new opcode **2701 ([set_bit](https://library.sannybuilder.com/#/sa/math/2701))**
   - new opcode **2702 ([clear_bit](https://library.sannybuilder.com/#/sa/math/2702))**

cleo_plugins/Math/Math.cpp

@@ -19,6 +19,12 @@ class Math
         }
 
         // register opcodes
+
+        // reimplemented original (bugged) game's random opcodes
+        CLEO_RegisterOpcode(0x0098, opcode_0098); // generate_random_float
+        CLEO_RegisterOpcode(0x0208, opcode_0208); // generate_random_float_in_range
+        CLEO_RegisterOpcode(0x0209, opcode_0209); // generate_random_int_in_range
+
         CLEO_RegisterOpcode(0x0A8E, opcode_0A8E); // x = a + b (int)
         CLEO_RegisterOpcode(0x0A8F, opcode_0A8F); // x = a - b (int)
         CLEO_RegisterOpcode(0x0A90, opcode_0A90); // x = a * b (int)
@@ -50,6 +56,54 @@ class Math
         CLEO_RegisterOpcode(0x2704, opcode_2704); // is_truthy
     }
 
+    //0098=1,generate_random_float
+    static OpcodeResult WINAPI opcode_0098(CRunningScript* thread)
+    {
+        uniform_real_distribution<float> dist(0.0f, std::nextafterf(1.0f, FLT_MAX)); // includes max value
+        auto value = dist(Instance.randomGenerator);
+
+        OPCODE_WRITE_PARAM_FLOAT(value);
+        return OR_CONTINUE;
+    }
+
+    //0208=3,generate_random_float_in_range min %1d% max %2d% store_to %3d%
+    static OpcodeResult WINAPI opcode_0208(CRunningScript* thread)
+    {
+        auto valMin = OPCODE_READ_PARAM_FLOAT();
+        auto valMax = OPCODE_READ_PARAM_FLOAT();
+
+        if (valMax < valMin)
+        {
+            SHOW_ERROR("Argument 'min' (%f) greater than 'max' (%f) in script %s\nScript suspended.", valMin, valMax, ScriptInfoStr(thread).c_str());
+            return thread->Suspend();
+        }
+
+        uniform_real_distribution<float> dist(valMin, std::nextafterf(valMax, FLT_MAX)); // includes max value
+        auto value = dist(Instance.randomGenerator);
+
+        OPCODE_WRITE_PARAM_FLOAT(value);
+        return OR_CONTINUE;
+    }
+
+    //0209=3,generate_random_int_in_range min %1d% max %2d% store_to %3d%
+    static OpcodeResult WINAPI opcode_0209(CRunningScript* thread)
+    {
+        auto valMin = OPCODE_READ_PARAM_INT();
+        auto valMax = OPCODE_READ_PARAM_INT();
+
+        // may happen when user thinks about input params as unsigned hex
+        if (valMax < valMin)
+        {
+            swap(valMin, valMax);
+        }
+
+        uniform_int_distribution<int> dist(valMin, valMax);
+        auto value = dist(Instance.randomGenerator);
+
+        OPCODE_WRITE_PARAM_INT(value);
+        return OR_CONTINUE;
+    }
+
     //0A8E=3,%3d% = %1d% + %2d% ; int
     static OpcodeResult WINAPI opcode_0A8E(CRunningScript* thread)
     {

tests/cleo_tests/Math/0098.txt

@@ -0,0 +1,42 @@
+{$CLEO .s}
+{$INCLUDE_ONCE ../cleo_tester.inc}
+
+script_name '0098'
+test("0098 (generate_random_float)", tests)
+terminate_this_custom_script
+
+
+function tests
+    it("should generate random floats", test1)
+    return
+
+    function test1
+        float min = 999.0
+        float max = -999.0
+        float avg = 0.0
+
+        int i
+        for i = 1 to 1000
+            float value = generate_random_float
+
+            if
+                value < min
+            then
+                min = value
+            end
+
+            if
+                value > max
+            then
+                max = value
+            end 
+
+            avg += value
+        end
+        avg /= 1000.0
+
+        assert_rangef(min, 0.00, 0.05)
+        assert_rangef(max, 0.95, 1.00)
+        assert_rangef(avg, 0.40, 0.60) // expected value of uniform distribution
+    end
+end

tests/cleo_tests/Math/0208.txt

@@ -0,0 +1,41 @@
+{$CLEO .s}
+{$INCLUDE_ONCE ../cleo_tester.inc}
+
+script_name '0208'
+test("0208 (generate_random_float_in_range)", tests)
+terminate_this_custom_script
+
+function tests
+    it("should generate random floats in range", test1)
+    return
+
+    function test1
+        float min = 999.0
+        float max = -999.0
+        float avg = 0.0
+
+        int i
+        for i = 1 to 2000
+            float value = generate_random_float_in_range {min} -10.0 {max} 40.0
+
+            if
+                value < min
+            then
+                min = value
+            end
+
+            if
+                value > max
+            then
+                max = value
+            end 
+
+            avg += value
+        end
+        avg /= 2000.0
+
+        assert_rangef(min, -10.0, -9.0)
+        assert_rangef(max, 39.0, 40.0)
+        assert_rangef(avg, 14.0, 16.0) // expected value of uniform distribution
+    end
+end

tests/cleo_tests/Math/0209.txt

@@ -0,0 +1,41 @@
+{$CLEO .s}
+{$INCLUDE_ONCE ../cleo_tester.inc}
+
+script_name '0209'
+test("0209 (generate_random_int_in_range)", tests)
+terminate_this_custom_script
+
+function tests
+    it("should generate random ints in range", test1)
+    return
+
+    function test1
+        int min = 999
+        int max = -999
+        int avg = 0
+
+        int i
+        for i = 1 to 2000
+            int value = generate_random_int_in_range {min} -10 {max} 40
+
+            if
+                value < min
+            then
+                min = value
+            end
+
+            if
+                value > max
+            then
+                max = value
+            end 
+
+            avg += value
+        end
+        avg /= 2000
+
+        assert_eq(min, -10)
+        assert_eq(max, 40)
+        assert_range(avg, 14, 16) // expected value of uniform distribution
+    end
+end