From 609edc98f5c2c8785f90355d54847d24d0e49eec Mon Sep 17 00:00:00 2001
From: Christian Heller <c.heller@plomlompom.de>
Date: Sun, 25 Oct 2020 07:18:09 +0100
Subject: [PATCH] Make map rendering slightly more efficient.

---
 new2/rogue_chat.html | 37 ++++++++++++++++++++++---------------
 1 file changed, 22 insertions(+), 15 deletions(-)

diff --git a/new2/rogue_chat.html b/new2/rogue_chat.html
index 3d8e4c3..f584ddd 100644
--- a/new2/rogue_chat.html
+++ b/new2/rogue_chat.html
@@ -26,13 +26,14 @@ let terminal = {
   set_font: function(type='normal') {
     this.ctx.font = type + ' ' + this.charHeight + 'px monospace';
   },
+  write_cheap: function(start_y, start_x, msg) {
+    this.ctx.fillText(msg, start_x*this.charWidth, start_y*this.charHeight);
+  },
+  set_color: function(color) {
+    this.ctx.fillStyle = color;
+  },
   write: function(start_y, start_x, msg, foreground_color='white') {
-    if (foreground_color === 'black') {
-      this.ctx.fillStyle = 'white';
-    } else {
-      this.ctx.fillStyle = 'black';
-    }
-    this.ctx.fillText(msg, start_x*this.charWidth, start_y*this.charHeight); 
+    this.ctx.fillStyle = 'black';
     this.ctx.fillRect(start_x*this.charWidth, start_y*this.charHeight,
                       this.charWidth*msg.length, this.charHeight);
     this.ctx.fillStyle = foreground_color;
@@ -99,22 +100,28 @@ let tui = {
     }
   },
   draw_map: function() {
-    terminal.drawBox(0, 0, terminal.rows, terminal.cols / 2);
+    terminal.drawBox(0, 0, terminal.rows, terminal.cols / 2, 'black');
+    let last_c = '';
+    let color = 'white';
     for (let i = 0, y = 0, x = 0; i < game.map.length; i++, x++) {
       if (x >= game.map_size[1]) {
         x = 0;
 	y += 1;
       };
       let c = game.map[i];
-      let color = 'white';
-      if (c == '.') {
-        color = '#ffaa00';
-      } else if (c == '~') {
-        color = '#5555ff';
-      } else if (c == 'X') {
-        color = '#55ff00';
+      if (c != last_c) {
+	last_c = c;
+        color = 'white';
+        if (c == '.') {
+          color = '#ffaa00';
+        } else if (c == '~') {
+          color = '#5555ff';
+        } else if (c == 'X') {
+          color = '#55ff00';
+        }
+        terminal.set_color(color);
       }
-      terminal.write(y, x, game.map[i], color);
+      terminal.write_cheap(y, x, c);
     }
     for (const t in game.things) {
       terminal.write(game.things[t][0], game.things[t][1], '@');
-- 
2.30.2