Reduce under the ground workload

As nobody (even developers) should go/see under the map.

src/main.rs

@@ -183,11 +183,8 @@ fn main() {
                         case 17u:
                             f_color = texture(tex17, v_tex_coords);
                             break;
-                        case 18u:
+                        default: // case 18u:
                             f_color = texture(tex18, v_tex_coords);
-                            break;
-                        default: // case 19u:
-                            f_color = vec4(0.0, 0.0, 0.0, 1.0);
                     }
                 }
             "

src/support/mod.rs

@@ -77,7 +77,6 @@ fn get_altitude(height_columns: &Vec<&str>, columns_index: usize) -> f32 {
 const SEABED_ALTITUDE: f32 = -100.0;
 // seabed altitude - biggest drop * tiles in a chunk * (chunks in a row - 1)
 const ALTITUDE_BETWEEN_CHUNKS: f32 = SEABED_ALTITUDE - 16.17 * 250.0 * 30.0;
-const BELOW_MAP_BIOME: u32 = 19;
 
 /// Returns a vertex buffer that should be rendered as `TrianglesList`.
 pub fn load_ground(display: &Display) -> VertexBufferAny {
@@ -116,7 +115,6 @@ pub fn load_ground(display: &Display) -> VertexBufferAny {
         ];
 
         // have deleted a few height files to make it work
-        // TODO: use triangle strip
         let height_contents = fs::read_to_string(&format!(
             "Extensions/LemnosLife/Map/Altis/Ground/{}.height",
             file_name
@@ -171,19 +169,10 @@ pub fn load_ground(display: &Display) -> VertexBufferAny {
                     vertex_data.push(Vertex {
                         altitude: ALTITUDE_BETWEEN_CHUNKS,
                         index,
-                        biome: BELOW_MAP_BIOME,
-                        chunk,
-                    });
-                    // This vertex ends correctly the across chunks triangle under the ground.
-                    // It is useful to keep a specific color for the triangle under the ground.
-                    vertex_data.push(Vertex {
-                        altitude: column,
-                        index,
-                        biome: BELOW_MAP_BIOME,
+                        biome,
                         chunk,
                     });
                     // This vertex defines the cursor ready to be used.
-                    // It resets the specific color for the triangle under the ground.
                     vertex_data.push(Vertex {
                         altitude: column,
                         index,
@@ -213,7 +202,7 @@ pub fn load_ground(display: &Display) -> VertexBufferAny {
         vertex_data.push(Vertex {
             altitude: ALTITUDE_BETWEEN_CHUNKS,
             index,
-            biome: BELOW_MAP_BIOME,
+            biome: 0,
             chunk,
         });
         i += 1;