From 0928b5cbbde02d4a6c58ca940040ae4a1c2ac2e4 Mon Sep 17 00:00:00 2001
From: citrons <citrons@mondecitronne.com>
Date: Sat, 14 Oct 2023 00:20:50 -0500
Subject: give the terrain a texture

---
 random.c | 17 ++++++++++++++---
 random.h |  1 +
 world.c  | 16 +++++++++++++---
 3 files changed, 28 insertions(+), 6 deletions(-)

diff --git a/random.c b/random.c
index c53d378..90dc3b5 100644
--- a/random.c
+++ b/random.c
@@ -2,14 +2,25 @@
 
 static Uint64 random = 0xbee;
 
+Uint64 hash(Uint64 n) {
+	Uint64 h = 0;
+	for (int i = 0; i < 8; i++) {
+		h += (n >> i * 8) & 0xFF;
+		h += h << 10;
+		h ^= h >> 6;
+	}
+	h += h << 3;
+	h ^= h >> 11;
+	h += h << 15;
+	return h;
+}
+
 void seed_rand(Uint64 seed) {
 	random ^= seed;
 }
 
 Uint64 get_rand() {
-	random ^= random >> 7;
-	random ^= random << 9;
-	random ^= random >> 13;
+	random = hash(random);
 	return random;
 }
 
diff --git a/random.h b/random.h
index 18a032b..ed07bcd 100644
--- a/random.h
+++ b/random.h
@@ -1,6 +1,7 @@
 #ifndef RANDOM_H
 #define RANDOM_H
 
+Uint64 hash(Uint64 i);
 void seed_rand(Uint64 seed);
 Uint64 get_rand(void);
 int rand_int(void);
diff --git a/world.c b/world.c
index 2ab924e..8899ff6 100644
--- a/world.c
+++ b/world.c
@@ -12,7 +12,7 @@ SDL_Color tile_colors[] = {
 	[TILE_BLUE] = {0x00, 0x00, 0xFF, 0xFF},
 	[TILE_LIGHT] = {0xFF, 0xFF, 0xFF, 0xFF},
 	[TILE_EMPTY] = {0x00, 0x00, 0x00, 0xFF},
-	[TILE_WALL] = {0x50, 0x50, 0x50, 0xFF},
+	[TILE_WALL] = {0x40, 0x40, 0x40, 0xFF},
 	[TILE_BLOCK_WHITE] = {0x80, 0x80, 0x80, 0xFF},
 };
 
@@ -79,14 +79,24 @@ SDL_Texture *render_chunk(SDL_Renderer *rend, chunk *c) {
 		SDL_assert(c->tex);
 		c->dirty = SDL_TRUE;
 	}
+
 	if (c->dirty) {
 		int pitch;
 		void *out;
 		SDL_assert(SDL_LockTexture(c->tex, NULL, &out, &pitch) >= 0);
 		SDL_Color *pixels = out;
 
-		for (int i = 0; i < CHUNK_DIM * CHUNK_DIM; i++)
-			pixels[i] = tile_colors[c->tiles[i]];
+		for (int i = 0; i < CHUNK_DIM * CHUNK_DIM; i++) {
+			tile t = c->tiles[i];
+			SDL_Color color = tile_colors[t];
+			if (t == TILE_WALL) {
+				int variance = hash(i) % 5;
+				color.r += variance;
+				color.g += variance;
+				color.b += variance;
+			}
+			pixels[i] = color;
+		}
 
 		SDL_UnlockTexture(c->tex);
 		c->dirty = SDL_FALSE;
-- 
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