proper collisions for block platforms

src/game.cpp

@@ -176,12 +176,24 @@ void game_advance(struct game *game)
     }
 }
 
+static bool standable(struct platform const &p)
+{
+    return p.type != PLATFORM_SEPARATING_WALL
+        && p.type != PLATFORM_BLOCK
+        && p.type != PLATFORM_BLOCK_TOP;
+}
+
+static bool collidable(struct platform const &p)
+{
+    return p.type == PLATFORM_BLOCK_TOP;
+}
+
 num game_height_at(struct game *game, num z, int face)
 {
     num max_h = -KILL_PLANE_RADIUS;
 
     for(auto const &p: game->level.platform_buffer) {
-        if(p.face == face && z >= p.z && z <= p.z + p.length)
+        if(standable(p) && p.face == face && z >= p.z && z <= p.z + p.length)
             max_h = (max_h >= p.height) ? max_h : p.height;
     }
 
@@ -195,7 +207,20 @@ struct platform *game_platform_under_player(struct game *game,
         return NULL;
 
     for(auto &p: game->level.platform_buffer) {
-        if(player->platform == p.face
+        if(standable(p) && player->platform == p.face
+           && player->z >= p.z && player->z <= p.z + p.length) {
+            return &p;
+        }
+    }
+
+    return NULL;
+}
+
+struct platform *game_block_hitting_player(struct game *game,
+    struct player const *player)
+{
+    for(auto &p: game->level.platform_buffer) {
+        if(collidable(p) && player->platform == p.face
            && player->z >= p.z && player->z <= p.z + p.length) {
             return &p;
         }

src/game.h

@@ -134,4 +134,8 @@ num game_height_at(struct game *game, num z, int face);
 struct platform *game_platform_under_player(struct game *game,
     struct player const *player);
 
+/* Returns the block platform that the player is hitting, if any. */
+struct platform *game_block_hitting_player(struct game *game,
+    struct player const *player);
+
 #endif /* __GAME_H__ */

src/main.cpp

@@ -155,8 +155,10 @@ int play_level(int level_id)
         level_update(&game.level, player->z, player->platform);
         camera_track(camera, player);
 
-        struct platform *standing_on = game_platform_under_player(&game,
-            &game.player);
+        struct platform *standing_on =
+            game_platform_under_player(&game, &game.player);
+        struct platform *hitting =
+            game_block_hitting_player(&game, &game.player);
 
         //======= Rendering =======//
 
@@ -297,7 +299,8 @@ int play_level(int level_id)
 
         /* Death condition #1/2: inside a platform (hit it in front) */
         bool death_1 = (player->height >= floor - PLAYER_HEIGHT &&
-                        player->height < floor - STEP_HEIGHT);
+                        player->height < floor - STEP_HEIGHT)
+                    || (hitting != NULL);
         /* Death condition #2/2: below the kill plane */
         bool death_2 = (player->height < LEVEL_RADIUS - KILL_PLANE_RADIUS);