我一直在尝试了解 bmp 文件的工作原理,以便我可以渲染一些 Mandelbrot 设置图片并将它们输出为 bmp 文件,因为这似乎是最简单的方法之一,但由于某种原因,当我使用不是 1 的纵横比时:1 尽管它是 4 的幂(所以不需要填充)我得到像这样的奇怪的工件200:100 https://i.stack.imgur.com/L4EBO.png 48:100 https://i.stack.imgur.com/bfe2y.png我想做的是将偶数为白色、奇数为黑色的像素数组转换为 bmp,这个 (100:100) https://i.stack.imgur.com/L3FOv.png就是长宽比为 1:1 的样子。
我尝试阅读维基百科文章,看看我是否能找出我做错了什么,但我仍然不明白我错过了什么。
这是我到目前为止用 Lua 编写的脚本:
ResolutionX = 100
ResolutionY = 100
local cos, atan, sin, atan2, sqrt, floor = math.cos, math.atan, math.sin, math.atan2, math.sqrt, math.floor
local insert, concat = table.insert, table.concat
local sub, char, rep = string.sub, string.char, string.rep
io.output("Test.bmp")
function Basen(n,b)
n = floor(n)
if not b or b == 10 then return tostring(n) end
local digits = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ"
local t = {}
repeat
local d = (n % b) + 1
n = floor(n / b)
insert(t, 1, digits:sub(d,d))
until n == 0
return rep("0",32-#t)..concat(t,"")
end
FileSize = Basen(ResolutionY*ResolutionX*3 + 54,2)
FileSize4 = tonumber(sub(FileSize,1,8),2) or 0
FileSize3 = tonumber(sub(FileSize,9,16),2) or 0
FileSize2 = tonumber(sub(FileSize,17,24),2) or 0
FileSize1 = tonumber(sub(FileSize,25,32),2) or 0
Width = Basen(ResolutionX,2)
print("Width: ",Width)
Width4 = tonumber(sub(Width,1,8),2) or 0
Width3 = tonumber(sub(Width,9,16),2) or 0
Width2 = tonumber(sub(Width,17,24),2) or 0
Width1 = tonumber(sub(Width,25,32),2) or 0
Height = Basen(ResolutionY,2)
print("Height: ",Height)
Height4 = tonumber(sub(Height,1,8),2) or 0
Height3 = tonumber(sub(Height,9,16),2) or 0
Height2 = tonumber(sub(Height,17,24),2) or 0
Height1 = tonumber(sub(Height,25,32),2) or 0
BMPSize = Basen(ResolutionY*ResolutionX*3,2)
BMPSize4 = tonumber(sub(BMPSize,1,8),2) or 0
BMPSize3 = tonumber(sub(BMPSize,9,16),2) or 0
BMPSize2 = tonumber(sub(BMPSize,17,24),2) or 0
BMPSize1 = tonumber(sub(BMPSize,25,32),2) or 0
print("TotalSize: ",FileSize1,FileSize2,FileSize3,FileSize4,"\nWidth: ",Width1,Width2,Width3,Width4,"\nHeight: ",Height1,Height2,Height3,Height4,"\nImage data: ",BMPSize1,BMPSize2,BMPSize3,BMPSize4)
Result = {"BM"..char( --File type
FileSize1,FileSize2,FileSize3,FileSize4,--File size
0,0,0,0, --Reserved
54,0,0,0, --Where the pixel data starts
40,0,0,0, --DIB header
Width1,Width2,Width3,Width4, --Width
Height1,Height2,Height3,Height4, --Height
1,0, --Color planes
24,00, --Bit depth
0,0,0,0, --Compression
BMPSize1,BMPSize2,BMPSize3,BMPSize4, --The amount of bytes pixel data will consume
Width1,Width2,Width3,Width4,
Height1,Height2,Height3,Height4,
0,0,0,0, --Number of colors in palatte
0,0,0,0
)}
for X = 0, ResolutionX - 1 do
for Y = 0, ResolutionY - 1 do
insert(Result,rep(char(255 * ((X + 1) % 2) * ((Y + 1) % 2)),3))
end
end
io.write(table.concat(Result))