require "Vector"
local V = Vector
-local function make_phong(lights, colour, amb, spec, shiny)
+local function make_phong_texture(lights, pigment, amb, diff, spec, shiny)
+ local normalize = V.normalize
return function (location, ray_dir, normal, count)
- local thiscol = {0, 0, 0}
- local reflected_ray = V.normalize(normal*(ray_dir*normal*2) - ray_dir)
+ local colour = pigment(location[1],location[3])
+ local thiscol = {colour[1]*amb, colour[2]*amb, colour[3]*amb}
+
+ local reflected_ray = ray_dir - normal*(ray_dir*normal*2)
for _,light in ipairs(lights) do
local light_dir = V.normalize(light-location)
- local Iamb = math.max(normal*light_dir, 0)
+ local Idiff = math.max(normal*light_dir, 0)
local Ispec = math.pow(math.max(light_dir*reflected_ray,0),shiny)
- thiscol[1] = thiscol[1] + colour[1]*Iamb*amb + Ispec*spec
- thiscol[2] = thiscol[2] + colour[2]*Iamb*amb + Ispec*spec
- thiscol[3] = thiscol[3] + colour[3]*Iamb*amb + Ispec*spec
+ thiscol[1] = thiscol[1] + colour[1]*Idiff*diff + Ispec*spec
+ thiscol[2] = thiscol[2] + colour[2]*Idiff*diff + Ispec*spec
+ thiscol[3] = thiscol[3] + colour[3]*Idiff*diff + Ispec*spec
end
return thiscol
end
end
-local function make_count_texture()
+local function make_count_texture(scale)
+ return function (location, ray_dir, normal, count)
+ return {count*scale, count*scale, count*scale}
+ end
+end
+
+local function make_flat_texture(pigment)
return function (location, ray_dir, normal, count)
- return {count/10, count/10, count/10}
+ return pigment(location[1], location[2])
end
end
+local function make_solid_pigment(colour)
+ return function (x,y)
+ return colour
+ end
+end
+
+local function make_checkered_pigment(colour1, colour2)
+ return function (x,y)
+ if (x%1 < 0.5 and y%1 < 0.5) or (x%1 > 0.5 and y%1 > 0.5) then
+ return colour1
+ else
+ return colour2
+ end
+ end
+end
Textures = {
- make_phong = make_phong,
- make_count_texture = make_count_texture
+ make_phong_texture = make_phong_texture,
+ make_flat_texture = make_flat_texture,
+ make_count_texture = make_count_texture,
+ make_solid_pigment = make_solid_pigment,
+ make_checkered_pigment = make_checkered_pigment
}
return Textures