X-Git-Url: https://thelambdalab.xyz/gitweb/index.cgi?a=blobdiff_plain;f=Textures.lua;h=324a2d24287b0d487e15590abb998932e2da0816;hb=06059eb522f33574680bb75bb73f28e2b0f6e836;hp=ad805a6888971b357a351d4816f56c0784bfce2d;hpb=f385f4b589fc49dc55c3ce4447b4450c3e515123;p=raymarcher.git

diff --git a/Textures.lua b/Textures.lua
index ad805a6..324a2d2 100644
--- 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