From 4818b21ec8f39c15ce160055c2dd9a754c79f2bc Mon Sep 17 00:00:00 2001
From: KikooDX <kikoodx@paranoici.org>
Date: Sat, 2 Jan 2021 17:52:22 +0100
Subject: [PATCH] Clipping doesn't work.

---
 src/player.c | 36 +++++++++++++++++++++++++++---------
 1 file changed, 27 insertions(+), 9 deletions(-)

diff --git a/src/player.c b/src/player.c
index 8c8222f..2a3740c 100644
--- a/src/player.c
+++ b/src/player.c
@@ -17,7 +17,10 @@
 #define JUMP_SPD (-128 * PXS)
 #define GRACE_UNITS (int)(UPS / 5)
 #define EARLY_UNITS (int)(UPS / 5)
-#define SGN(x) ((x > 0) ? (1) : ((x < 0) ? (-1) : (0)))
+#define H_CLIP_MARGIN (TILE_SIZE / 2)
+#define V_CLIP_MARGIN (TILE_SIZE / 3)
+#define SGN(x) (((x) > 0) ? (1) : (((x) < 0) ? (-1) : (0)))
+#define ABS(x) (((x) > 0) ? (x) : (-(x)))
 #define PLAYER_COLLIDE(pos) player_collide(player, pos, level, level->solid_layer)
 
 void player_move(Player *player, const Level *level) {
@@ -29,15 +32,28 @@ void player_move(Player *player, const Level *level) {
 	/* snap the player to the grid if they hit a wall */
 	destination.x += player->spd.x;
 	if (PLAYER_COLLIDE(destination)) {
-		destination.x = player->pos.x - player->pos.x % TILE_SIZE;
-		/* Move the player tile per tile until it enters an
-		 * occuped tile. */
-		while (!PLAYER_COLLIDE(destination)) {
-			destination.x += TILE_SIZE * sgn_spd_x;
+		/* Used for clipping and positionning. */
+		int offset = destination.y % TILE_SIZE;
+		if (offset > TILE_SIZE / 2) {
+			offset -= TILE_SIZE;
+		}
+		if (ABS(offset) > H_CLIP_MARGIN) {
+			offset = 0;
+		}
+		destination.y -= offset;
+		if (PLAYER_COLLIDE(destination))
+		{
+			destination.y += offset;
+			destination.x = player->pos.x - player->pos.x % TILE_SIZE;
+			/* Move the player tile per tile until it enters an
+			 * occupied tile. */
+			while (!PLAYER_COLLIDE(destination)) {
+				destination.x += TILE_SIZE * sgn_spd_x;
+			}
+			/* then, move it back one tile */
+			destination.x -= TILE_SIZE * sgn_spd_x;
+			player->spd.x = 0;
 		}
-		/* then, move it back one tile */
-		destination.x -= TILE_SIZE * sgn_spd_x;
-		player->spd.x = 0;
 	}
 	/* do the same for y */
 	destination.y += player->spd.y;
@@ -71,6 +87,8 @@ void player_step(Player *player, Input *input, const Level *level, uint step) {
 	player->spd.x += xacc; /* apply horizontal acceleration */
 	/* apply gravity */
 	if (player->spd.y < 0 && !player->jump_held) {
+		/* The player is rising and let go the jump key,
+		 * accelerate gravity until they reach 0. */
 		player->spd.y += GRAVITY * FAST_FALL_FACTOR;
 	} else {
 		player->spd.y += GRAVITY;