Initial dynamic weather support

Author: Lihis

rwengine/src/data/Weather.hpp

@@ -40,6 +40,14 @@ class Weather {
                       float a, float tod);
 
     std::vector<Entry> entries;
+
+    // Taken from: https://www.gtamodding.com/wiki/Time_cycle#Weather_lists
+    // TODO: This weather list applies only for GTA III
+    const uint16_t WeatherList[64] = {
+            0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 2, 2, 1, 0,
+            0, 0, 1, 3, 3, 1, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 2,
+            2, 1, 2, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 3, 0, 0, 0, 2, 1
+    };
 };
 
 #endif

rwengine/src/engine/GameState.hpp

@@ -64,7 +64,7 @@ struct BasicState {
     uint8_t _align3[2]{0};
     uint16_t nextWeather{0};
     uint8_t _align4[2]{0};
-    uint16_t forcedWeather{0};
+    uint16_t forcedWeather{0xFFFF};
     uint8_t _align5[2]{0};
     float weatherInterpolation{1.f};
     uint8_t dateTime[24]{0};  // Unused

rwengine/src/script/modules/GTA3ModuleImpl.inl

@@ -4870,8 +4870,7 @@ void opcode_01b6(const ScriptArguments& args, const ScriptWeather weatherID) {
     opcode 01b7
 */
 void opcode_01b7(const ScriptArguments& args) {
-    RW_UNUSED(args);
-    args.getState()->basic.forcedWeather = -1;
+    args.getState()->basic.forcedWeather = UINT16_MAX;
 }
 
 /**

rwgame/RWGame.cpp

@@ -533,6 +533,7 @@ void RWGame::tick(float dt) {
     static float clockAccumulator = 0.f;
     static float scriptTimerAccumulator = 0.f;
     static ScriptInt beepTime = std::numeric_limits<ScriptInt>::max();
+    static uint8_t prevGameHour = state.basic.gameHour;
     if (currState->shouldWorldUpdate()) {
         world->chase.update(dt);
 
@@ -554,6 +555,8 @@ void RWGame::tick(float dt) {
             clockAccumulator -= 1.f;
         }
 
+        interpolateWeather(prevGameHour);
+
         constexpr float timerClockRate = 1.f / 30.f;
 
         if (state.scriptTimerVariable && !state.scriptTimerPaused) {
@@ -844,3 +847,23 @@ void RWGame::globalKeyEvent(const SDL_Event& event) {
         handleCheatInput(symbol);
     }
 }
+
+void RWGame::interpolateWeather(uint8_t prevGameHour) {
+    if (prevGameHour != state.basic.gameHour) {
+        state.basic.lastWeather = state.basic.nextWeather;
+
+        // TODO: VC and SA has more than 4 weather conditions
+        if (state.basic.forcedWeather > 3) {
+            if (state.basic.weatherType < 63) {
+                ++state.basic.weatherType;
+            } else {
+                state.basic.weatherType = 0;
+            }
+            state.basic.nextWeather =
+                data.weather.WeatherList[state.basic.weatherType];
+        }
+    }
+
+    state.basic.weatherInterpolation = state.basic.gameMinute / 60.f;
+}
+

rwgame/RWGame.hpp

@@ -131,6 +131,9 @@ class RWGame final : public GameBase {
     void renderDebugView();
 
     void tickObjects(float dt) const;
+
+    void interpolateWeather(uint8_t prevGameHour);
 };
 
 #endif
+