Minimap (work in progress):

- Uses freelook visibility calculations
- all visible turfs represented as a 2x2 square
- - doors, windows, and structural objects that block movement show up in different colours from walls, floors, and space
- - windows and windoors that only block the edge of a tile show as a 1x2 line
- Areas that were visble but now aren't display in red. This will happen during regular activity, as doors open and close, as well as during abnormal circumstances, such as a camera being disabled/destroyed, or additional walls being constructed that block a camera's LOS.
- changes in visibility in an area triggers a map update which takes place two minutes later, reducing amount of processing (since further update triggers are ignored until the pending update has taken place), and give antagonists time after disabling a camera to conduct their business, before the map reveals that anything is out of the ordinary.

Sample screenshot: http://i.imgur.com/PS2vF.png

Todo:
- Remove test verb available to everyone, replace with AI-only (and perhaps avaiable to admins and ghosts?) verb.
- Clicking a tile immediately enters freelook and jumps to that tile
- Perhaps overlay blinking blue for areas with atmosphere alerts, brown for power? Independant of visibility, or centred on APC?
- A verb to force-update the current 3x3 area, while in freelook?

code/WorkInProgress/AI_Visibility.dm

@@ -33,9 +33,79 @@
 	var/list/turfs = list()
 	var/list/seenby = list()
 	var/visible = 0
-	var/changed = 0
+	var/changed = 1
 	var/updating = 0
 
+	var/x
+	var/y
+	var/z
+
+	var/minimap_updating = 0
+
+	var/icon/minimap_icon = new('minimap.dmi', "chunk_base")
+	var/obj/minimap_obj = new()
+
+/mob/verb/minimap_test()
+	winshow(src, "minimapwindow", 1)
+	client.screen |= cameranet.minimap
+
+
+/datum/camerachunk/proc/update_minimap()
+	if(changed && !updating)
+		update()
+
+	minimap_icon.Blend(rgb(255, 0, 0), ICON_MULTIPLY)
+
+	var/list/turfs = visibleTurfs | dimTurfs
+
+	for(var/turf/turf in turfs)
+		var/x = (turf.x & 0xf) * 2
+		var/y = (turf.y & 0xf) * 2
+
+		if(turf.density)
+			minimap_icon.DrawBox(rgb(100, 100, 100), x + 1, y + 1, x + 2, y + 2)
+			continue
+
+		else if(istype(turf, /turf/space))
+			minimap_icon.DrawBox(rgb(0, 0, 0), x + 1, y + 1, x + 2, y + 2)
+
+		else
+			minimap_icon.DrawBox(rgb(200, 200, 200), x + 1, y + 1, x + 2, y + 2)
+
+		for(var/obj/structure/o in turf)
+			if(o.density)
+				if(istype(o, /obj/structure/window) && (o.dir == NORTH || o.dir == SOUTH || o.dir == EAST || o.dir == WEST))
+					if(o.dir == NORTH)
+						minimap_icon.DrawBox(rgb(150, 150, 200), x + 1, y + 2, x + 2, y + 2)
+					else if(o.dir == SOUTH)
+						minimap_icon.DrawBox(rgb(150, 150, 200), x + 1, y + 1, x + 2, y + 1)
+					else if(o.dir == EAST)
+						minimap_icon.DrawBox(rgb(150, 150, 200), x + 3, y + 1, x + 2, y + 2)
+					else if(o.dir == WEST)
+						minimap_icon.DrawBox(rgb(150, 150, 200), x + 1, y + 1, x + 1, y + 2)
+
+				else
+					minimap_icon.DrawBox(rgb(150, 150, 150), x + 1, y + 1, x + 2, y + 2)
+					break
+
+		for(var/obj/machinery/door/o in turf)
+			if(istype(o, /obj/machinery/door/window))
+				if(o.dir == NORTH)
+					minimap_icon.DrawBox(rgb(100, 150, 100), x + 1, y + 2, x + 2, y + 2)
+				else if(o.dir == SOUTH)
+					minimap_icon.DrawBox(rgb(100, 150, 100), x + 1, y + 1, x + 2, y + 1)
+				else if(o.dir == EAST)
+					minimap_icon.DrawBox(rgb(100, 150, 100), x + 2, y + 1, x + 2, y + 2)
+				else if(o.dir == WEST)
+					minimap_icon.DrawBox(rgb(100, 150, 100), x + 1, y + 1, x + 1, y + 2)
+
+			else
+				minimap_icon.DrawBox(rgb(100, 150, 100), x + 1, y + 1, x + 2, y + 2)
+				break
+
+	minimap_obj.screen_loc = "minimap:[src.x / 16],[src.y / 16]"
+	minimap_obj.icon = minimap_icon
+
 /mob/aiEye
 	var/list/visibleCameraChunks = list()
 	var/mob/ai = null
@@ -50,6 +120,7 @@
 	seenby += ai
 	if(changed && !updating)
 		update()
+		changed = 0
 
 /datum/camerachunk/proc/remove(mob/aiEye/ai)
 	ai.visibleCameraChunks -= src
@@ -76,20 +147,28 @@
 	else
 		changed = 1
 
+	if(!minimap_updating)
+		minimap_updating = 1
+
+		spawn(1200)
+			if(changed && !updating)
+				update()
+				changed = 0
+
+			update_minimap()
+			minimap_updating = 0
+
 /datum/camerachunk/proc/update()
+
 	var/list/newDimTurfs = list()
 	var/list/newVisibleTurfs = list()
 
 	for(var/obj/machinery/camera/c in cameras)
 		var/lum = c.luminosity
 		c.luminosity = 7
-		for(var/turf/t in view(7, c))
-			if(t in turfs)
-				newDimTurfs += t
 
-		for(var/turf/t in view(6, c))
-			if(t in turfs)
-				newVisibleTurfs += t
+		newDimTurfs |= turfs & view(7, c)
+		newVisibleTurfs |= turfs & view(6, c)
 
 		c.luminosity = lum
 
@@ -154,29 +233,26 @@
 					m.ai.client.images += t.obscured
 
 
-
 /datum/camerachunk/New(loc, x, y, z)
 	x &= ~0xf
 	y &= ~0xf
 
+	src.x = x
+	src.y = y
+	src.z = z
+
 	for(var/obj/machinery/camera/c in range(16, locate(x + 8, y + 8, z)))
 		if(c.status)
 			cameras += c
 
-	for(var/turf/t in range(10, locate(x + 8, y + 8, z)))
-		if(t.x >= x && t.y >= y && t.x < x + 16 && t.y < y + 16)
-			turfs += t
+	turfs = block(locate(x, y, z), locate(min(world.maxx, x + 15), min(world.maxy, y + 15), z))
 
 	for(var/obj/machinery/camera/c in cameras)
 		var/lum = c.luminosity
 		c.luminosity = 7
-		for(var/turf/t in view(7, c))
-			if(t in turfs)
-				dimTurfs += t
 
-		for(var/turf/t in view(6, c))
-			if(t in turfs)
-				visibleTurfs += t
+		dimTurfs |= turfs & view(7, c)
+		visibleTurfs |= turfs & view(6, c)
 
 		c.luminosity = lum
 
@@ -197,6 +273,8 @@
 
 			dim += t.dim
 
+	cameranet.minimap += minimap_obj
+
 var/datum/cameranet/cameranet = new()
 
 /datum/cameranet
@@ -205,9 +283,18 @@ var/datum/cameranet/cameranet = new()
 	var/network = "net1"
 	var/ready = 0
 
+	var/list/minimap = list()
+
 /datum/cameranet/New()
 	..()
 
+	spawn(200)
+		for(var/x = 0, x <= world.maxx, x += 16)
+			for(var/y = 0, y <= world.maxy, y += 16)
+				sleep(1)
+				var/datum/camerachunk/c = getCameraChunk(x, y, 1)
+				c.update_minimap()
+
 /datum/cameranet/proc/chunkGenerated(x, y, z)
 	var/key = "[x],[y],[z]"
 	return key in chunks