light_world.lua/lib/height_map_conv.lua
2014-09-27 13:46:46 -04:00

51 lines
1.2 KiB
Lua

height_map = {}
function height_map.toNormalMap(heightMap, strength)
local imgData = heightMap:getData()
local imgData2 = love.image.newImageData(heightMap:getWidth(), heightMap:getHeight())
local red, green, blue, alpha
local x, y
local matrix = {}
matrix[1] = {}
matrix[2] = {}
matrix[3] = {}
strength = strength or 1.0
for i = 0, heightMap:getHeight() - 1 do
for k = 0, heightMap:getWidth() - 1 do
for l = 1, 3 do
for m = 1, 3 do
if k + (l - 1) < 1 then
x = heightMap:getWidth() - 1
elseif k + (l - 1) > heightMap:getWidth() - 1 then
x = 1
else
x = k + l - 1
end
if i + (m - 1) < 1 then
y = heightMap:getHeight() - 1
elseif i + (m - 1) > heightMap:getHeight() - 1 then
y = 1
else
y = i + m - 1
end
local red, green, blue, alpha = imgData:getPixel(x, y)
matrix[l][m] = red
end
end
red = (255 + ((matrix[1][2] - matrix[2][2]) + (matrix[2][2] - matrix[3][2])) * strength) / 2.0
green = (255 + ((matrix[2][2] - matrix[1][1]) + (matrix[2][3] - matrix[2][2])) * strength) / 2.0
blue = 192
imgData2:setPixel(k, i, red, green, blue)
end
end
return love.graphics.newImage(imgData2)
end
return height_map