Colours are now Vectors, added rainbow pigment.

[raymarcher.git] / Textures.lua

diff --git a/Textures.lua b/Textures.lua
index ad805a6..324a2d2 100644 (file)
--- a/Textures.lua
+++ b/Textures.lua
@@ -3,6 +3,9 @@
 require "Vector"
 local V = Vector
 
+require "Colours"
+local C = Colours
+
 local function make_phong_texture(lights, mapped_pigment, amb, diff, spec, shiny)
    local normalize = V.normalize
 
@@ -140,6 +143,18 @@ local function make_mandelbrot_pigment(set_pigment, nonset_pigment, max_iter)
    end
 end
 
+local function make_rainbow_pigment(scale)
+   return function (x,y)
+
+      local Ired = math.sin(x/math.pi/scale)^2 * math.sin(y/math.pi/scale)^2
+      local Igreen = math.cos(x/math.pi/scale)^2 * math.sin(y/math.pi/scale)^2
+      local Iblue = math.sin(x/math.pi/scale)^2 * math.cos(y/math.pi/scale)^2
+
+      return C.red*Ired + C.green*Igreen + C.blue*Iblue
+   end
+end
+
+
 -- Mapping functions
 
 -- These functions define mappings from 3D world coordinates to 2D
@@ -170,6 +185,7 @@ Textures = {
    make_solid_pigment = make_solid_pigment,
    make_checkered_pigment = make_checkered_pigment,
    make_image_pigment = make_image_pigment,
+   make_rainbow_pigment = make_rainbow_pigment,
    make_mandelbrot_pigment = make_mandelbrot_pigment,
    map_rectangular = map_rectangular,
    map_spherical = map_spherical