use texture rotation to increase angular res and use less textures

init.lua

@@ -87,22 +87,28 @@ local function show_hud_waypoint(player, point_pos, name, icon_name)
     local size_x = 9
     local size_y = 16
 
-    local angle_steps = 8 -- number pre-rotated textures
+    local angle_steps = 9 -- number pre-rotated textures
 
     -- vector pointing towards point_pos
     local v = vector.subtract(point_pos, player:get_pos())
     -- angle relative to player position
     local angle = math.atan2(v.x, v.z)
     -- snap/round to increments and convert to degrees
-    local angle_snap = round(angle/(2*math.pi) * angle_steps) * (360 / angle_steps) % 360
+    local angle_quad = math.floor(angle/(2*math.pi) * 4) * (360 / 4) % 360
+    local angle_quad_map = {[0] = "I", [90] = "R270", [180] = "R180", [270] = "R90"}
+    local angle_snap = round(angle/(2*math.pi) * angle_steps * 4) * (360 / (angle_steps * 4)) % 360
+    local angle_quad_step = (angle_snap - angle_quad) % 90
     
-    local arrow_texture = ("arrow_%03d.png"):format(angle_snap)
+    local arrow_texture = ("arrow_%03d.png"):format(angle_quad_step)
+
+    -- TODO it's possible to color the texture: use it to make waypoints have different colors
+    --local arrow_texture = arrow_texture .. "^[multiply:#11FFFF"
 
     local hud_id3 = player:hud_add({
             hud_elem_type = "compass",
             size = {x=-size_x,y=-size_y},
             --scale = {x=0.5,y=0.5}, -- unused
-            text = arrow_texture,
+            text = arrow_texture .. "^[transform" .. angle_quad_map[angle_quad],
             --alignment = {x=1,y=1}, -- top-left?
             alignment = {x=100/size_x,y=100/size_y*0.7}, -- above cursor
             --offset = {x=0,y=0}, -- in pixels?

make_compass_textures.sh

@@ -1,9 +1,9 @@
 input="compass_arrow.svg"
 size=64
-angles=8
+angles=9
 for rot in `seq 0 $((angles - 1))`; do
     #inkscape -w ${size} -h ${size} compass_arrow.svg -o "$out"
-    angle=$((360 / angles * rot))
+    angle=$((90 / angles * rot))
     out="textures/arrow_"$(printf "%03d" $angle)".png"
     convert -density 384 -background none -distort SRT $angle -gravity center -resize ${size}x${size} "$input" "$out"
 done