polyadvent

commit 18ba03463e02ed86ed00b371947997c9a58dcb6f
parent 5d1a173bea9026bf34c8e135d3fe68d122710aa7
Author: William Casarin <jb55@jb55.com>
Date:   Fri,  8 May 2020 19:31:47 -0700

dampen terrain height near edge

Diffstat:
M
src/terrain.c
 | 
12
++++++++++++

1 file changed, 12 insertions(+), 0 deletions(-)
diff --git a/src/terrain.c b/src/terrain.c
@@ -195,6 +195,13 @@ static int collide_terrain_debug(struct terrain *terrain, struct terrain_cell *c
 }
 #endif /* DEBUG */
 
+static double distance_to_closest_edge(double size, double x, double y) {
+    double top    = y;
+    double left   = x;
+    double right  = size - x;
+    double bottom = size - y;
+    return min(top, min(left, min(right, bottom)));
+}
 
 void create_terrain(struct terrain *terrain, float scale, int seed) {
     u32 i;
@@ -245,6 +252,11 @@ void create_terrain(struct terrain *terrain, float scale, int seed) {
         int grid_x = verts[n] / terrain->cell_size;
         int grid_y = verts[n+1] / terrain->cell_size;
 
+        // clamp height at edge
+
+        double d = distance_to_closest_edge(size, x, y);
+        z *= d / (size/2.0);
+
         struct terrain_cell *cell =
             index_terrain_cell(terrain, grid_x, grid_y);