Added basic fog effect

1 files changed, 32 insertions, 12 deletions

diff --git a/src/main.c b/src/main.c
index 6e0b7d0..51fb50a 100644
--- a/src/main.c
+++ b/src/main.c
@@ -3,19 +3,29 @@
 #include <math.h>
 
 // TODO: move to implicit map definition with level editor in future
-#define MAP_HEIGHT 10
-#define MAP_WIDTH 10
+#define MAP_HEIGHT 20
+#define MAP_WIDTH 20
 int world_map[MAP_HEIGHT][MAP_WIDTH] = {
-    {1, 1, 1, 1, 1, 1, 1, 1, 1, 1},
-    {1, 0, 0, 0, 0, 0, 0, 0, 0, 1},
-    {1, 0, 0, 0, 0, 0, 2, 2, 0, 1},
-    {1, 0, 0, 0, 0, 0, 2, 2, 0, 1},
-    {1, 0, 0, 0, 0, 0, 0, 0, 0, 1},
-    {1, 0, 0, 0, 0, 0, 0, 0, 0, 1},
-    {1, 0, 3, 3, 0, 0, 4, 4, 0, 1},
-    {1, 0, 3, 3, 0, 0, 4, 4, 0, 1},
-    {1, 0, 0, 0, 0, 0, 0, 0, 0, 1},
-    {1, 1, 1, 1, 1, 1, 1, 1, 1, 1}
+    {1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1},
+    {1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1},
+    {1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 2, 2, 0, 1},
+    {1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 2, 2, 0, 1},
+    {1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 2, 2, 0, 1},
+    {1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1},
+    {1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1},
+    {1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1},
+    {1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1},
+    {1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1},
+    {1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1},
+    {1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1},
+    {1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1},
+    {1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1},
+    {1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1},
+    {1, 0, 3, 3, 3, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 4, 4, 0, 1},
+    {1, 0, 3, 3, 3, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 4, 4, 0, 1},
+    {1, 0, 3, 3, 3, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 4, 4, 0, 1},
+    {1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1},
+    {1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1},
 };
 
 // TODO: move player code to dedicated file after complication demands it
@@ -98,6 +108,11 @@ void raycast(Player *player) {
 		double perp_wall_dist;
 		if (side == 0 || side == 2) { perp_wall_dist = (map_x - player->pos_x + (1 - step_x) / 2) / ray_dir_x; }
 		else           { perp_wall_dist = (map_y - player->pos_y + (1 - step_y) / 2) / ray_dir_y; }
+
+		// fog effect
+		float fog_distance = 20.0f;
+		float scale_factor = 1.0f - perp_wall_dist / fog_distance;
+		if (scale_factor < 0.0f) { scale_factor = 0.0f; }
 		
 		// calculate height of line on screen
 		int line_height = (int)(screen_height / perp_wall_dist);
@@ -130,6 +145,11 @@ void raycast(Player *player) {
 			color.b /= 4;
 		}
 
+		// scale brightness in accordance with distance (for fog)
+		color.r *= scale_factor;
+		color.g *= scale_factor;
+		color.b *= scale_factor;
+
 		// TODO: recommended to put this in its own function or something at some point,
 		// as it deals with library calls outside of this function's scope
 		glBegin(GL_LINES);