Merge branch 'main' into animation

doc/ru/scripting/extensions.md

@@ -158,6 +158,12 @@ math.sum(x: number, ... | t: table) -> number
 
 -- Возвращает целое число, указывающее знак числа (-1/0/1)
 math.sign(x: number) -> int
+
+-- Одномерный шум с значениями в диапазоне [-1..1].
+math.noise(x: number, [опционально] octaves: int = 1) -> number
+
+-- Двумерный шум с значениями в диапазоне [-1..1].
+math.noise2d(x: number, y: number [опционально] octaves: int = 1) -> number
 ```
 
 ## Расширения для bit

res/layouts/pages/new_world.xml

@@ -11,7 +11,7 @@
         @World generator
     </button>
     <button id='content_btn' onclick='save_state() menu.page="content"'/>
-    <button onclick='create_world()' margin='1,20,1,1'>
+    <button onclick='create_world()' margin='0,20,0,1'>
         @Create World
     </button>
     <button onclick='menu:back()'>@Back</button>

res/modules/internal/extensions/math.lua

@@ -39,3 +39,85 @@ end
 function math.sign(x)
     return (x > 0) and 1 or (x < 0 and -1 or 0)
 end
+
+local noise_period = 3021
+local noise_rands = {}
+
+for i=1,noise_period do
+    table.insert(noise_rands, math.random() * 2.0 - 1.0)
+end
+
+local function smoothstep(t)
+    return t * t * (3 - 2 * t)
+end
+
+local function sample_noise(x)
+    x = x % noise_period
+    local left_cell = math.floor(x)
+    local right_cell = (left_cell + 1) % noise_period
+    local t = smoothstep(x - left_cell)
+    return noise_rands[left_cell + 1] * (1.0 - t)
+        + noise_rands[right_cell + 1] * t
+end
+
+function math.noise(x, octaves)
+    x = math.abs(x)
+    octaves = octaves or 1
+    local value = 0.0
+    local mul = 1.0
+    for i=1,octaves do
+        value = value * (1.0 - mul) + sample_noise(x + 37 * i) * mul
+        x = x * 2.0
+        mul = mul * 0.5
+    end
+    return value
+end
+
+local function lerp(a, b, t)
+    return a + (b - a) * t
+end
+
+local function rand_2d(x, y)
+    return noise_rands[math.floor(x * 317 + y) % noise_period + 1]
+end
+
+local function sample_noise2d(x, y)
+    x = math.abs(x)
+    y = math.abs(y)
+
+    local x0 = math.floor(x)
+    local y0 = math.floor(y)
+    local x1 = x0 + 1
+    local y1 = y0 + 1
+
+    local tx = x - x0
+    local ty = y - y0
+
+    local sx = smoothstep(tx)
+    local sy = smoothstep(ty)
+
+    local c00 = rand_2d(x0, y0)
+    local c10 = rand_2d(x1, y0)
+    local c01 = rand_2d(x0, y1)
+    local c11 = rand_2d(x1, y1)
+
+    local bottom = lerp(c00, c10, sx)
+    local top = lerp(c01, c11, sx)
+
+    return lerp(bottom, top, sy)
+end
+
+
+function math.noise2d(x, y, octaves)
+    octaves = octaves or 1
+    local value = 0.0
+    local mul = 1.0
+    for i=1,octaves do
+        value = value * (1.0 - mul)
+            + sample_noise2d(x + 37 * i, y + 73 * i) * mul
+        x = x * 2.0
+        y = y * 2.0
+        mul = mul * 0.5
+    end
+    return value
+end