let there be light

1 files changed, 39 insertions, 0 deletions

diff --git a/src/utils.lua b/src/utils.lua
new file mode 100644
index 0000000..c3e4bea
--- /dev/null
+++ b/src/utils.lua
@@ -0,0 +1,39 @@
+
+function lerp(a, b, c)
+  return a + (b - a) * c
+end
+
+function dlerp(a, b, c)
+  return lerp(b, a, 0.5^c)
+end
+
+function bton(bool)
+  return bool and 1 or 0
+end
+
+function min(a, b)
+  if a < b then
+    return a
+  end
+  return b
+end
+
+function normalize(x, y)
+  if x == 0 and y == 0 then
+    return 0, 0
+  end
+
+  local leng = math.sqrt(x*x + y*y)
+  return x / leng, y / leng
+end
+
+-- Top left corner
+function point_in_rect(px, py, rx, ry, rw, rh)
+  return px > rx and px < rx + rw and py > ry and py < ry + rh
+end
+
+function dist(x1, y1, x2, y2)
+  local dx = x1 - x2
+  local dy = y1 - y2
+  return (dx*dx + dy*dy)^0.5
+end