Add car/ghost render dist

TODO.txt

@@ -1,6 +1,7 @@
 =========== GENERAL ==============
 
-- ghost visible distance
+- force chunk reload upon map restart so that there's no blinking at start
+- make a small txt game menual
 - test if the replay stretching works
 - replay validation
 - ghosts: if the replay for the ghost is too long (too many samples for the
@@ -24,16 +25,20 @@
 
 =========== BUGS =================
 
-- why does the ghost stop in front of the finish?
+- starting test replay two twice in a row breaks it
 - drawing dithered transparent objects fills z-buffer in the transparent parts
   and then the geometry behind it isn't drawn <- PARTIALLY FIXED NOW
 
 =========== HANDLED ==============
 
 - allow stopping car rotation in air like in Trackmania
+- ghost visible distance -- maybe even car should have this (watching rep with
+  free camera)? maybe generalize setCar/GhostVisibility to
+  setCarGhostVisibilityDistance where 0 means make invisible?
 - add time slow down setting
 - the horizon on background seems too low? maybe add setting to shift it a bit?
 - replay format
+- why does the ghost stop in front of the finish?
 - prevent time overflow! stop incrementing level frame once it's at maximum
 - car shadow? probably would have to be done as screen space effect with
   z-buffer (shadow as 3D model would require collision detection and would make

game.h

@@ -390,7 +390,7 @@ void LCR_gameGetNthGhostSample(unsigned int n,
 void LCR_gameGhostGetTransform(uint32_t frame,
   LCR_GameUnit position[3], LCR_GameUnit rotation[3])
 {
-  unsigned int n = ((frame >> LCR_game.ghost.stretch) / LCR_SETTING_GHOST_STEP); 
+  int n = ((frame >> LCR_game.ghost.stretch) / LCR_SETTING_GHOST_STEP); 
 
   LCR_gameGetNthGhostSample(n,position,rotation);
 
@@ -423,14 +423,10 @@ void LCR_gameGhostGetTransform(uint32_t frame,
     }
   }
 
-  /* Small hack: at the beginning the ghost can be seen misaligned with the
-    real car due to its quantized position, here we gradually snap it to the
-    nearest 1/8th of a block (which should hit the start position) during the
-    first 16 frames. */
-  if (LCR_racing.tick < 16)
-    for (int i = 0; i < 3; ++i)
-      position[i] = position[i] + (LCR_racing.tick * (position[i] -
-      ((position[i] + LCR_GAME_UNIT / 8) / (LCR_GAME_UNIT / 4)))) / 16;
+  // offset (correct rounding down):
+  position[0] += LCR_GAME_UNIT / 16;
+  position[1] += LCR_GAME_UNIT / 16;
+  position[2] += LCR_GAME_UNIT / 16;
 }
 
 void _LCR_gamePrepareGhost(void)

renderer.h

@@ -79,6 +79,9 @@ struct
 
   uint32_t frame;
 
+  uint8_t carVisibilityDist;
+  uint8_t ghostVisibilityDist;
+
   uint8_t loadedChunks[8]; ///< numbers of loaded map chunks
 
   S3L_Unit mapVerts[LCR_SETTING_MAX_MAP_VERTICES * 3];
@@ -1930,6 +1933,26 @@ void LCR_rendererDraw3D(void)
 
   LCR_rendererDrawLOD();
 
+  uint8_t carGhostVisibility = 0;
+  S3L_Model3D *m = LCR_renderer.carModel;
+
+  for (uint8_t i = 0; i < 2; ++i)
+  {
+    carGhostVisibility <<= 1;
+
+    if (LCR_renderer.carModel->config.visible)
+    {
+      carGhostVisibility |= 1;
+
+      m->config.visible = (S3L_distanceManhattan(
+        m->transform.translation,
+        LCR_renderer.scene.camera.transform.translation) / LCR_RENDERER_UNIT)
+        <= LCR_SETTING_CAR_RENDER_DISTANCE;
+    }
+
+    m = LCR_renderer.ghostModel; 
+  }
+
   LCR_LOG2("3D rendering (start)");
 
 #if LCR_SETTING_POTATO_GRAPHICS
@@ -1944,8 +1967,8 @@ void LCR_rendererDraw3D(void)
   for (int i = 0; i < LCR_renderer.scene.modelCount; ++i)
     LCR_renderer.scene.models[i].config.visible = 0;
 
-  LCR_renderer.carModel->config.visible = 1;
-  LCR_renderer.ghostModel->config.visible = 1;
+  LCR_renderer.carModel->config.visible = carGhostVisibility >> 1;
+  LCR_renderer.ghostModel->config.visible = carGhostVisibility & 0x01;
 
   S3L_newFrame();
   S3L_drawScene(LCR_renderer.scene);
@@ -1954,8 +1977,11 @@ void LCR_rendererDraw3D(void)
     LCR_renderer.scene.models[i].config.visible = 1;
 #else
   S3L_drawScene(LCR_renderer.scene);
+
+  LCR_renderer.carModel->config.visible = carGhostVisibility >> 1;
+  LCR_renderer.ghostModel->config.visible = carGhostVisibility & 0x01;
 #endif
-  
+
   LCR_renderer.frame++;
 
   LCR_LOG2("3D rendering (end)");

settings.h

@@ -220,4 +220,9 @@
   #define LCR_SETTING_GHOST_MAX_SAMPLES 128
 #endif
 
+#ifndef LCR_SETTING_CAR_RENDER_DISTANCE
+  /** Distance in blocks at which player and ghost car will be seen. */
+  #define LCR_SETTING_CAR_RENDER_DISTANCE 25
+#endif
+
 #endif // guard