From 3dd21e4356e0e781f4a9f089114b01cd3a50afdc Mon Sep 17 00:00:00 2001
From: Alula <julekonopinska@gmail.com>
Date: Fri, 2 Oct 2020 21:27:42 +0200
Subject: [PATCH] improve npc physics

---
 src/player_hit.rs | 83 +++++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 81 insertions(+), 2 deletions(-)

diff --git a/src/player_hit.rs b/src/player_hit.rs
index 1bdee26..a61ab52 100644
--- a/src/player_hit.rs
+++ b/src/player_hit.rs
@@ -1,11 +1,13 @@
 use std::borrow::Borrow;
 
+use num_traits::abs;
+
 use crate::caret::CaretType;
 use crate::common::{Condition, Direction, Flag, Rect};
 use crate::inventory::{AddExperienceResult, Inventory};
 use crate::npc::{NPC, NPCMap};
 use crate::physics::PhysicalEntity;
-use crate::player::Player;
+use crate::player::{Player, ControlMode};
 use crate::shared_game_state::SharedGameState;
 
 impl PhysicalEntity for Player {
@@ -135,6 +137,82 @@ impl Player {
         flags
     }
 
+    fn judge_hit_npc_solid_hard(&mut self, npc: &NPC, state: &mut SharedGameState) -> Flag {
+        let mut flags = Flag(0);
+
+        let fx1 = abs(self.x - npc.x) as f32;
+        let fy1 = abs(self.y - npc.y) as f32;
+
+        let fx2 = npc.hit_bounds.right as f32;
+        let fy2 = npc.hit_bounds.top as f32;
+
+        let fx1 = if fx1 == 0.0 { 1.0 } else { fx1 };
+        let fx2 = if fx2 == 0.0 { 1.0 } else { fx2 };
+
+        if fy1 / fx1 <= fy2 / fx2 {
+            if (self.y - self.hit_bounds.top as isize) < (npc.y + npc.hit_bounds.bottom as isize)
+                && (self.y + self.hit_bounds.bottom as isize) > (npc.y - npc.hit_bounds.top as isize) {
+                if (self.x - self.hit_bounds.right as isize) < (npc.x + npc.hit_bounds.right as isize)
+                    && (self.x - self.hit_bounds.right as isize) > npc.x {
+                    if self.vel_x < npc.vel_x {
+                        self.vel_x = npc.vel_x;
+                    }
+
+                    self.x = npc.x + npc.hit_bounds.right as isize + self.hit_bounds.right as isize;
+                    flags.set_hit_left_wall(true);
+                }
+
+                if (self.x + self.hit_bounds.right as isize) > (npc.x - npc.hit_bounds.right as isize)
+                    && (self.x + self.hit_bounds.right as isize) < npc.x {
+                    if self.vel_x > npc.vel_x {
+                        self.vel_x = npc.vel_x;
+                    }
+
+                    self.x = npc.x - npc.hit_bounds.right as isize - self.hit_bounds.right as isize;
+                    flags.set_hit_right_wall(true);
+                }
+            }
+        } else if (self.x - self.hit_bounds.right as isize) < (npc.x + npc.hit_bounds.right as isize)
+            && (self.x + self.hit_bounds.right as isize) > (npc.x - npc.hit_bounds.right as isize) {
+            if (self.y - self.hit_bounds.top as isize) < (npc.y + npc.hit_bounds.bottom as isize)
+                && (self.y - self.hit_bounds.top as isize) > npc.y {
+                if self.vel_y >= npc.vel_y {
+                    if self.vel_y < 0 {
+                        self.vel_y = 0;
+                    }
+                } else {
+                    self.y = npc.y + npc.hit_bounds.bottom as isize + self.hit_bounds.top as isize + 0x200;
+                    self.vel_y = npc.vel_y;
+                }
+
+                flags.set_hit_top_wall(true);
+            }
+
+            if (self.y + self.hit_bounds.bottom as isize) > (npc.y - npc.hit_bounds.top as isize)
+                && (self.y + self.hit_bounds.bottom as isize) < (npc.y + 3 * 0x200) {
+                if self.vel_y - npc.vel_y > 2 * 0x200 {
+                    state.sound_manager.play_sfx(23);
+                }
+
+                if self.control_mode == ControlMode::IronHead {
+                    self.y = npc.y - npc.hit_bounds.top as isize - self.hit_bounds.bottom as isize + 0x200;
+                    flags.set_hit_bottom_wall(true);
+                } else if npc.npc_flags.bouncy() {
+                    self.vel_y = npc.vel_y - 0x200;
+                    flags.set_hit_bottom_wall(true);
+                } else if !self.flags.hit_bottom_wall() && self.vel_y > npc.vel_y {
+                    self.y = npc.y - npc.hit_bounds.top as isize - self.hit_bounds.bottom as isize + 0x200;
+                    self.vel_y = npc.vel_y;
+                    self.x += npc.vel_x;
+
+                    flags.set_hit_bottom_wall(true);
+                }
+            }
+        }
+
+        flags
+    }
+
     fn judge_hit_npc_non_solid(&mut self, npc: &NPC) -> Flag {
         let mut flags = Flag(0);
         let hit_left = if npc.direction == Direction::Left { npc.hit_bounds.left } else { npc.hit_bounds.right } as isize;
@@ -162,7 +240,8 @@ impl Player {
                     flags = self.judge_hit_npc_solid_soft(npc.borrow());
                     self.flags.0 |= flags.0;
                 } else if npc.npc_flags.solid_hard() {
-                    //
+                    flags = self.judge_hit_npc_solid_hard(npc.borrow(), state);
+                    self.flags.0 |= flags.0;
                 } else {
                     flags = self.judge_hit_npc_non_solid(npc.borrow());
                 }