various: sub-tile lighting; nicer visibility calculations

Signed-off-by: NotAShelf <raf@notashelf.dev>
Change-Id: I0f0a0c12db76cc8e0f4c8ccc72ca4b826a6a6964

libs/map/map.c

@@ -2,18 +2,18 @@
 #include "rng/rng.h"
 #include "settings.h"
 #include "utils.h"
+#include <math.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 
 void map_init(Map *map) {
-  // Fill entire map with walls
   for (int y = 0; y < MAP_HEIGHT; y++) {
     for (int x = 0; x < MAP_WIDTH; x++) {
       map->tiles[y][x] = TILE_WALL;
     }
   }
-  memset(map->visible, 0, sizeof(map->visible));
+  memset(map->light_map, 0, sizeof(map->light_map));
   memset(map->remembered, 0, sizeof(map->remembered));
   map->room_count = 0;
 }
@@ -300,20 +300,145 @@ int has_line_of_sight(const Map *map, int x1, int y1, int x2, int y2) {
 int can_see_entity(const Map *map, int from_x, int from_y, int to_x, int to_y, int range) {
   if (!is_in_view_range(to_x, to_y, from_x, from_y, range))
     return 0;
-  return has_line_of_sight(map, from_x, from_y, to_x, to_y);
+  if (!has_line_of_sight(map, from_x, from_y, to_x, to_y))
+    return 0;
+  return tile_brightness(map, to_x, to_y) > LIGHT_SIGHT_THRESHOLD;
 }
 
-void calculate_visibility(Map *map, int x, int y) {
+static int is_solid(const Map *map, int sub_x, int sub_y) {
-  memset(map->visible, 0, sizeof(map->visible));
+  int map_w = MAP_WIDTH;
+  int map_h = MAP_HEIGHT;
+  int tx = sub_x / SUB_TILE_RES;
+  int ty = sub_y / SUB_TILE_RES;
+  if (tx < 0 || tx >= map_w || ty < 0 || ty >= map_h)
+    return 1;
+  TileType t = map->tiles[ty][tx];
+  return t == TILE_WALL || t == TILE_DOOR_CLOSED;
+}
 
-  for (int ty = 0; ty < MAP_HEIGHT; ty++) {
+static float smoothstep_light(float edge0, float edge1, float x) {
-    for (int tx = 0; tx < MAP_WIDTH; tx++) {
+  float t = (x - edge0) / (edge1 - edge0);
-      if (is_in_view_range(tx, ty, x, y, PLAYER_VIEW_RANGE)) {
+  if (t < 0.0f)
-        if (has_line_of_sight(map, x, y, tx, ty)) {
+    return 0.0f;
-          map->visible[ty][tx] = 1;
+  if (t > 1.0f)
-          map->remembered[ty][tx] = 1;
+    return 1.0f;
+  return t * t * (3.0f - 2.0f * t);
+}
+
+static int trace_sub_los(const Map *map, int sx, int sy, int tx, int ty) {
+  int dx = abs(tx - sx);
+  int dy = abs(ty - sy);
+  int step_x = (sx < tx) ? 1 : -1;
+  int step_y = (sy < ty) ? 1 : -1;
+  int err = dx - dy;
+  int x = sx, y = sy;
+
+  while (1) {
+    if (x == tx && y == ty)
+      return 1;
+    if (is_solid(map, x, y) && !(x == sx && y == sy))
+      return 0;
+    int e2 = 2 * err;
+    if (e2 > -dy) {
+      err -= dy;
+      x += step_x;
+    }
+    if (e2 < dx) {
+      err += dx;
+      y += step_y;
+    }
+  }
+}
+
+void compute_lighting(Map *map, const LightSource *sources, int num_sources) {
+  memset(map->light_map, 0, sizeof(map->light_map));
+
+  int map_sub_w = MAP_WIDTH * SUB_TILE_RES;
+  int map_sub_h = MAP_HEIGHT * SUB_TILE_RES;
+
+  for (int si = 0; si < num_sources; si++) {
+    int cx = sources[si].x * SUB_TILE_RES + SUB_TILE_RES / 2;
+    int cy = sources[si].y * SUB_TILE_RES + SUB_TILE_RES / 2;
+    int range_sub = sources[si].range * SUB_TILE_RES;
+    int intensity = sources[si].intensity;
+
+    for (int dy = -range_sub; dy <= range_sub; dy++) {
+      for (int dx = -range_sub; dx <= range_sub; dx++) {
+        int sub_x = cx + dx;
+        int sub_y = cy + dy;
+
+        if (sub_x < 0 || sub_x >= map_sub_w || sub_y < 0 || sub_y >= map_sub_h)
+          continue;
+
+        int dist_sq = dx * dx + dy * dy;
+        if (dist_sq > range_sub * range_sub)
+          continue;
+
+        if (!trace_sub_los(map, cx, cy, sub_x, sub_y))
+          continue;
+
+        float dist = sqrtf((float)dist_sq);
+        float t = dist / (float)range_sub;
+        float brightness = 1.0f - smoothstep_light(0.35f, 1.0f, t);
+        int val = (int)(brightness * (float)intensity);
+
+        if (val > map->light_map[sub_y][sub_x])
+          map->light_map[sub_y][sub_x] = (unsigned char)val;
+      }
+    }
+
+    int src_x = sources[si].x;
+    int src_y = sources[si].y;
+    int src_range = sources[si].range;
+    int src_intensity = sources[si].intensity;
+
+    for (int ty = 0; ty < MAP_HEIGHT; ty++) {
+      for (int tx = 0; tx < MAP_WIDTH; tx++) {
+        if (map->tiles[ty][tx] != TILE_WALL && map->tiles[ty][tx] != TILE_DOOR_CLOSED)
+          continue;
+        if (!is_in_view_range(tx, ty, src_x, src_y, src_range))
+          continue;
+        if (!has_line_of_sight(map, src_x, src_y, tx, ty))
+          continue;
+
+        int dx = tx - src_x;
+        int dy = ty - src_y;
+        float t = sqrtf((float)(dx * dx + dy * dy)) / (float)src_range;
+        float fb = 1.0f - smoothstep_light(0.35f, 1.0f, t);
+        int val = (int)(fb * (float)src_intensity);
+
+        int base_x = tx * SUB_TILE_RES;
+        int base_y = ty * SUB_TILE_RES;
+        for (int cy2 = 0; cy2 < SUB_TILE_RES; cy2++) {
+          for (int cx2 = 0; cx2 < SUB_TILE_RES; cx2++) {
+            if (val > map->light_map[base_y + cy2][base_x + cx2])
+              map->light_map[base_y + cy2][base_x + cx2] = (unsigned char)val;
+          }
         }
       }
     }
   }
+
+  for (int ty = 0; ty < MAP_HEIGHT; ty++) {
+    for (int tx = 0; tx < MAP_WIDTH; tx++) {
+      if (tile_brightness(map, tx, ty) > LIGHT_SIGHT_THRESHOLD)
+        map->remembered[ty][tx] = 1;
+    }
+  }
+}
+
+int tile_brightness(const Map *map, int tx, int ty) {
+  int sum = 0;
+  int base_x = tx * SUB_TILE_RES;
+  int base_y = ty * SUB_TILE_RES;
+  for (int dy = 0; dy < SUB_TILE_RES; dy++) {
+    for (int dx = 0; dx < SUB_TILE_RES; dx++) {
+      sum += map->light_map[base_y + dy][base_x + dx];
+    }
+  }
+  return sum / (SUB_TILE_RES * SUB_TILE_RES);
+}
+
+int is_tile_revealed(const Map *map, int tx, int ty) {
+  return tile_brightness(map, tx, ty) > LIGHT_SIGHT_THRESHOLD;
 }

libs/map/map.h

@@ -21,7 +21,9 @@ void get_random_floor_tile(Map *map, int *x, int *y, int attempts);
 // Visibility / Fog of War
 int is_in_view_range(int x, int y, int view_x, int view_y, int range);
 int has_line_of_sight(const Map *map, int x1, int y1, int x2, int y2);
-void calculate_visibility(Map *map, int x, int y);
+void compute_lighting(Map *map, const LightSource *sources, int num_sources);
+int tile_brightness(const Map *map, int tx, int ty);
+int is_tile_revealed(const Map *map, int tx, int ty);
 int can_see_entity(const Map *map, int from_x, int from_y, int to_x, int to_y, int range);
 
 #endif  // MAP_H

src/common.h

@@ -29,12 +29,19 @@ typedef struct {
   int x, y, w, h;
 } Room;
 
+// Light source for sub-tile lighting system
+typedef struct {
+  int x, y;
+  int intensity;
+  int range;
+} LightSource;
+
 // Map
 typedef struct {
   TileType tiles[MAP_HEIGHT][MAP_WIDTH];
   Room rooms[MAX_ROOMS];
   int room_count;
-  unsigned char visible[MAP_HEIGHT][MAP_WIDTH];
+  unsigned char light_map[MAP_HEIGHT * SUB_TILE_RES][MAP_WIDTH * SUB_TILE_RES];
   unsigned char remembered[MAP_HEIGHT][MAP_WIDTH];
 } Map;
 

src/game_state.h

@@ -68,6 +68,9 @@ typedef struct {
   unsigned int run_seed;
   // Tileset atlas for rendering
   Tileset tileset;
+  // Sub-tile lighting
+  LightSource static_lights[32];
+  int static_light_count;
   // Slash effect timer for attack animations
   int slash_timer;              // frames remaining for slash effect
   int slash_x, slash_y;         // position of slash effect

src/main.c

@@ -131,8 +131,12 @@ static void init_floor(GameState *gs, int floor_num) {
   }
   gs->player.floor = floor_num;
 
-  // Calculate initial visibility
+  // Set initial player light and compute visibility
-  calculate_visibility(&gs->map, gs->player.position.x, gs->player.position.y);
+  LightSource player_light = {gs->player.position.x, gs->player.position.y, PLAYER_LIGHT_INTENSITY, PLAYER_LIGHT_RANGE};
+  LightSource sources[1 + 32];
+  sources[0] = player_light;
+  memcpy(sources + 1, gs->static_lights, gs->static_light_count * sizeof(LightSource));
+  compute_lighting(&gs->map, sources, 1 + gs->static_light_count);
 
   // Spawn enemies
   enemy_spawn(gs->enemies, &gs->enemy_count, &gs->map, &gs->player, floor_num);
@@ -228,7 +232,11 @@ static void post_action(GameState *gs, Enemy *attacked_enemy) {
   }
 
   // Update visibility based on player's new position
-  calculate_visibility(&gs->map, gs->player.position.x, gs->player.position.y);
+  LightSource p_light = {gs->player.position.x, gs->player.position.y, PLAYER_LIGHT_INTENSITY, PLAYER_LIGHT_RANGE};
+  LightSource srcs[1 + 32];
+  srcs[0] = p_light;
+  memcpy(srcs + 1, gs->static_lights, gs->static_light_count * sizeof(LightSource));
+  compute_lighting(&gs->map, srcs, 1 + gs->static_light_count);
 
   // Enemy turns - uses speed/cooldown system
   enemy_update_all(gs->enemies, gs->enemy_count, &gs->player, &gs->map);
@@ -269,7 +277,13 @@ static int handle_stun_turn(GameState *gs) {
   if (gs->game_over)
     return 1;
   enemy_update_all(gs->enemies, gs->enemy_count, &gs->player, &gs->map);
-  calculate_visibility(&gs->map, gs->player.position.x, gs->player.position.y);
+  {
+    LightSource l = {gs->player.position.x, gs->player.position.y, PLAYER_LIGHT_INTENSITY, PLAYER_LIGHT_RANGE};
+    LightSource s[1 + 32];
+    s[0] = l;
+    memcpy(s + 1, gs->static_lights, gs->static_light_count * sizeof(LightSource));
+    compute_lighting(&gs->map, s, 1 + gs->static_light_count);
+  }
   if (gs->player.hp <= 0)
     gs->game_over = 1;
   gs->last_message = "You are stunned!";
@@ -652,8 +666,8 @@ static void game_loop(unsigned int run_seed, FontManager *fm) {
     cam.offset = (Vector2){(float)gs.shake_x, (float)gs.shake_y};
     BeginMode2D(cam);
     render_map(&gs.map, &gs.tileset);
-    render_items(gs.items, gs.item_count, gs.map.visible, &gs.tileset);
+    render_items(gs.items, gs.item_count, &gs.map, &gs.tileset);
-    render_enemies(gs.enemies, gs.enemy_count, gs.map.visible, &gs.tileset, frame_counter);
+    render_enemies(gs.enemies, gs.enemy_count, &gs.map, &gs.tileset, frame_counter);
     render_player(&gs.player, &gs.tileset, frame_counter);
     // Draw slash effect on top of entities
     if (gs.slash_timer > 0) {

src/render.c

@@ -1,6 +1,7 @@
 #include "render.h"
 #include "items.h"
 #include "settings.h"
+#include "map/map.h"
 #include "map/utils.h"
 #include <math.h>
 #include <stddef.h>
@@ -69,10 +70,10 @@ void render_map(const Map *map, const Tileset *tileset) {
   for (int y = 0; y < MAP_HEIGHT; y++) {
     for (int x = 0; x < MAP_WIDTH; x++) {
       Rectangle dst = {(float)(x * TILE_SIZE), (float)(y * TILE_SIZE), (float)TILE_SIZE, (float)TILE_SIZE};
-      int visible = map->visible[y][x];
       int remembered = map->remembered[y][x];
+      int brightness = tile_brightness(map, x, y);
 
-      if (!visible && !remembered) {
+      if (!remembered) {
         DrawRectangleRec(dst, (Color){5, 5, 10, 255});
         continue;
       }
@@ -102,9 +103,12 @@ void render_map(const Map *map, const Tileset *tileset) {
       if (tile_id >= 0 && tileset != NULL && tileset->finalized) {
         Rectangle src = tileset_get_region(tileset, tile_id);
         if (src.width > 0) {
-          Color tint = WHITE;
+          Color tint;
-          if (!visible) {
+          if (brightness > 0) {
-            // Dim remembered tiles
+            float lit = (float)brightness / 255.0f;
+            tint = (Color){(unsigned char)(128 + (int)(127.0f * lit)), (unsigned char)(128 + (int)(127.0f * lit)),
+                           (unsigned char)(128 + (int)(127.0f * lit)), 255};
+          } else {
             tint = (Color){128, 128, 128, 255};
           }
           DrawTexturePro(tileset->atlas, src, dst, (Vector2){0, 0}, 0.0f, tint);
@@ -112,11 +116,10 @@ void render_map(const Map *map, const Tileset *tileset) {
         }
       }
 
-      // Fallback to solid colors if tileset not available
+      Color wall_color = brightness > 0 ? DARKGRAY : (Color){25, 25, 30, 255};
-      Color wall_color = visible ? DARKGRAY : (Color){25, 25, 30, 255};
+      Color floor_color = brightness > 0 ? BLACK : (Color){15, 15, 20, 255};
-      Color floor_color = visible ? BLACK : (Color){15, 15, 20, 255};
+      Color stairs_color = brightness > 0 ? (Color){180, 160, 100, 255} : (Color){60, 55, 50, 255};
-      Color stairs_color = visible ? (Color){180, 160, 100, 255} : (Color){60, 55, 50, 255};
+      Color door_color = brightness > 0 ? (Color){139, 119, 89, 255} : (Color){60, 55, 50, 255};
-      Color door_color = visible ? (Color){139, 119, 89, 255} : (Color){60, 55, 50, 255};
 
       switch (map->tiles[y][x]) {
       case TILE_WALL:
@@ -136,13 +139,13 @@ void render_map(const Map *map, const Tileset *tileset) {
               }
             }
           }
-          if (is_adjacent_to_stairs && visible) {
+          if (is_adjacent_to_stairs && brightness > 0) {
             int flicker = (int)(sinf(GetTime() * 5.0f) * 15.0f);
             DrawRectangleRec(dst, (Color){40 + flicker, 25, 10, 60});
           }
         }
         // Grid lines
-        if (DRAW_GRID_LINES && visible) {
+        if (DRAW_GRID_LINES && brightness > 0) {
           DrawRectangleLines((int)dst.x, (int)dst.y, (int)dst.width, (int)dst.height, (Color){20, 20, 20, 80});
         }
         break;
@@ -151,7 +154,7 @@ void render_map(const Map *map, const Tileset *tileset) {
         // Make stairs very visible with bright symbol and bounce
         {
           int bounce = (int)(sinf(GetTime() * 3.0f) * 1.5f);
-          if (visible)
+          if (brightness > 0)
             DrawText(">", x * TILE_SIZE + 4, y * TILE_SIZE + 1 + bounce, NORM_FONT + 2, (Color){255, 255, 200, 255});
           else
             DrawText(">", x * TILE_SIZE + 4, y * TILE_SIZE + 1 + bounce, NORM_FONT + 2, (Color){100, 90, 70, 255});
@@ -159,7 +162,7 @@ void render_map(const Map *map, const Tileset *tileset) {
         break;
       case TILE_DOOR_CLOSED:
         DrawRectangleRec(dst, door_color);
-        if (visible) {
+        if (brightness > 0) {
           DrawRectangle(x * TILE_SIZE + 2, y * TILE_SIZE + 2, TILE_SIZE - 4, TILE_SIZE - 4, (Color){100, 80, 60, 255});
           DrawRectangleLines(x * TILE_SIZE + 2, y * TILE_SIZE + 2, TILE_SIZE - 4, TILE_SIZE - 4,
                              (Color){60, 50, 40, 255});
@@ -168,7 +171,7 @@ void render_map(const Map *map, const Tileset *tileset) {
         break;
       case TILE_DOOR_OPEN:
         DrawRectangleRec(dst, floor_color);
-        if (visible) {
+        if (brightness > 0) {
           DrawRectangle(x * TILE_SIZE + 2, y * TILE_SIZE + 2, TILE_SIZE - 4, TILE_SIZE - 4, (Color){80, 70, 50, 180});
           DrawRectangleLines(x * TILE_SIZE + 2, y * TILE_SIZE + 2, TILE_SIZE - 4, TILE_SIZE - 4,
                              (Color){60, 50, 40, 200});
@@ -177,7 +180,7 @@ void render_map(const Map *map, const Tileset *tileset) {
         break;
       case TILE_DOOR_RUINED:
         DrawRectangleRec(dst, (Color){60, 45, 30, 255});
-        if (visible) {
+        if (brightness > 0) {
           DrawRectangle(x * TILE_SIZE + 1, y * TILE_SIZE + 1, TILE_SIZE - 2, TILE_SIZE - 2, (Color){80, 60, 40, 200});
           DrawLine(x * TILE_SIZE + 2, y * TILE_SIZE + 2, x * TILE_SIZE + TILE_SIZE - 2, y * TILE_SIZE + TILE_SIZE - 2,
                    (Color){120, 90, 60, 255});
@@ -260,12 +263,11 @@ void render_player(const Player *p, const Tileset *tileset, int frame_counter) {
   }
 }
 
-void render_enemies(const Enemy *enemies, int count, const unsigned char visible[MAP_HEIGHT][MAP_WIDTH],
+void render_enemies(const Enemy *enemies, int count, const Map *map, const Tileset *tileset, int frame_counter) {
-                    const Tileset *tileset, int frame_counter) {
   for (int i = 0; i < count; i++) {
     if (!enemies[i].alive)
       continue;
-    if (!visible[enemies[i].position.y][enemies[i].position.x])
+    if (!is_tile_revealed(map, enemies[i].position.x, enemies[i].position.y))
       continue;
 
     Rectangle dst = {(float)(enemies[i].position.x * TILE_SIZE), (float)(enemies[i].position.y * TILE_SIZE),
@@ -367,12 +369,11 @@ void render_enemies(const Enemy *enemies, int count, const unsigned char visible
   }
 }
 
-void render_items(const Item *items, int count, const unsigned char visible[MAP_HEIGHT][MAP_WIDTH],
+void render_items(const Item *items, int count, const Map *map, const Tileset *tileset) {
-                  const Tileset *tileset) {
   for (int i = 0; i < count; i++) {
     if (items[i].picked_up)
       continue;
-    if (!visible[items[i].y][items[i].x])
+    if (!is_tile_revealed(map, items[i].x, items[i].y))
       continue;
 
     Rectangle dst = {(float)(items[i].x * TILE_SIZE), (float)(items[i].y * TILE_SIZE), (float)TILE_SIZE,

src/render.h

@@ -108,12 +108,10 @@ void render_player(const Player *p, const Tileset *tileset, int frame_counter);
 
 // Render all enemies using tileset atlas
 // frame_counter is used for idle breathing animation
-void render_enemies(const Enemy *enemies, int count, const unsigned char visible[MAP_HEIGHT][MAP_WIDTH],
+void render_enemies(const Enemy *enemies, int count, const Map *map, const Tileset *tileset, int frame_counter);
-                    const Tileset *tileset, int frame_counter);
 
 // Render all items using tileset atlas
-void render_items(const Item *items, int count, const unsigned char visible[MAP_HEIGHT][MAP_WIDTH],
+void render_items(const Item *items, int count, const Map *map, const Tileset *tileset);
-                  const Tileset *tileset);
 
 // Render UI overlay
 void render_ui(const Player *p, const Tileset *tileset, const FontManager *fm);

src/settings.h

@@ -79,10 +79,19 @@
 #define MESSAGE_TIMER_DURATION 60
 
 // Visibility / Fog of War
-#define PLAYER_VIEW_RANGE 8
-#define ENEMY_VIEW_RANGE 6
 #define ENEMY_PATROL_MOVE_CHANCE 30
 
+// Sub-tile lighting
+#define SUB_TILE_RES 8
+#define LIGHT_SIGHT_THRESHOLD 40
+
+// Player light source parameters
+#define PLAYER_LIGHT_RANGE 8
+#define PLAYER_LIGHT_INTENSITY 255
+
+// Enemy vision (default fallback for spawn)
+#define ENEMY_VIEW_RANGE 6
+
 // Visual polish
 #define DRAW_GRID_LINES 1