From cbf55c5d380c99759b28cf55a9f5518df74ad3b9 Mon Sep 17 00:00:00 2001
From: KikooDX <kikoodx@paranoici.org>
Date: Thu, 11 Nov 2021 00:34:14 +0100
Subject: [PATCH] wall jump

---
 inc/conf.h   |  2 +-
 inc/tile.h   |  2 +-
 src/player.c | 42 +++++++++++++++++++++++++++++++++---------
 3 files changed, 35 insertions(+), 11 deletions(-)

diff --git a/inc/conf.h b/inc/conf.h
index a635acc..ef98e52 100644
--- a/inc/conf.h
+++ b/inc/conf.h
@@ -12,6 +12,6 @@
 #define FRICTION_AIR        (ACCELERATION_AIR / MAX_WALK_SPEED)
 #define FRICTION_GROUND     (ACCELERATION_GROUND / MAX_WALK_SPEED)
 #define FRICTION_BREAK      (0.6f / MAX_WALK_SPEED)
-#define JUMP_GRACE          4
+#define JUMP_GRACE          1
 #define JUMP_BUFFER         12
 #define JUMP_SPD            -5.0
diff --git a/inc/tile.h b/inc/tile.h
index 2a238ed..bf73b95 100644
--- a/inc/tile.h
+++ b/inc/tile.h
@@ -5,5 +5,5 @@ enum Tile {
 	TILE_SOLID,
 	TILE_PLAYER,
 	TILE_SHATTERED,
-	TILE_OOB = TILE_SOLID
+	TILE_OOB = TILE_VOID
 };
diff --git a/src/player.c b/src/player.c
index b5166a8..22ec922 100644
--- a/src/player.c
+++ b/src/player.c
@@ -10,7 +10,8 @@
 
 static struct Player self;
 
-static void jump(int on_ground);
+static int jump(int on_ground);
+static void walljump(void);
 static int collide_solid(int x, int y);
 
 void
@@ -43,14 +44,22 @@ player_update(void)
 
 	/* resistance & gravity */
 	self.spd.y *= 1.0f - AIR_RESISTANCE;
-	self.spd.y += GRAVITY;
+	if (!on_ground)
+		self.spd.y += GRAVITY;
 
-	jump(on_ground);
+	/* jump buffer */
+	if (input_pressed(K_JUMP))
+		self.jump_buffer = JUMP_BUFFER;
+	else if (self.jump_buffer)
+		self.jump_buffer--;
+	/* jump or walljump */
+	if (!jump(on_ground))
+		walljump();
 
 	player_move(player_update_rem());
 }
 
-static void
+static int
 jump(int on_ground)
 {
 	/* grace */
@@ -58,11 +67,6 @@ jump(int on_ground)
 		self.jump_grace = JUMP_GRACE;
 	else if (self.jump_grace)
 		self.jump_grace--;
-	/* buffer */
-	if (input_pressed(K_JUMP))
-		self.jump_buffer = JUMP_BUFFER;
-	else if (self.jump_buffer)
-		self.jump_buffer--;
 	/* jump */
 	if (self.jump_grace && self.jump_buffer && input_down(K_JUMP)) {
 		struct Vec shatter_pos = VEC(self.pos.x, self.pos.y);
@@ -73,6 +77,26 @@ jump(int on_ground)
 		shatter(shatter_pos.x, shatter_pos.y);
 		shatter_pos.x += PLAYER_WIDTH - 1;
 		shatter(shatter_pos.x, shatter_pos.y);
+		return 1;
+	}
+	return 0;
+}
+
+static void
+walljump(void)
+{
+	const int wall_adjacent = collide_solid(self.pos.x - 2, self.pos.y) -
+	                          collide_solid(self.pos.x + 2, self.pos.y);
+	if (self.jump_buffer && wall_adjacent && input_down(K_JUMP)) {
+		struct Vec shatter_pos = VEC(self.pos.x, self.pos.y);
+		self.jump_buffer = 0;
+		self.spd.y = JUMP_SPD;
+		self.spd.x = wall_adjacent * MAX_WALK_SPEED;
+		shatter_pos.x +=
+		    (wall_adjacent == 1) ? (-2) : (PLAYER_WIDTH + 1);
+		shatter(shatter_pos.x, shatter_pos.y);
+		shatter_pos.y += PLAYER_HEIGHT - 1;
+		shatter(shatter_pos.x, shatter_pos.y);
 	}
 }