From 30869f88297faa5f696b47f4e18a26ff817cdf03 Mon Sep 17 00:00:00 2001
From: ubq323 <ubq323@ubq323.website>
Date: Thu, 4 Aug 2022 20:48:28 +0100
Subject: img

---
 img/load_pnm.lua | 34 ++++++++++++++++++++++++++++++++++
 1 file changed, 34 insertions(+)
 create mode 100644 img/load_pnm.lua

(limited to 'img/load_pnm.lua')

diff --git a/img/load_pnm.lua b/img/load_pnm.lua
new file mode 100644
index 0000000..60cac8a
--- /dev/null
+++ b/img/load_pnm.lua
@@ -0,0 +1,34 @@
+local perr = require("util").perr
+
+local function load_p1(fname)
+
+	local file,err = fs.open(fname,"r")
+	perr(err,"fs.open")
+	local imgf = file.readAll()
+	--print(img)
+	assert(imgf:sub(1,2) == "P1","only P1 images are supported at the moment")
+	local width,height, cur = imgf:match("%s*(%d+)%s*(%d+)%s*()",3)
+	assert(width,"couldn't find image header")
+
+	local img=setmetatable({},{__index=function(t,k)
+		if type(k) ~= "number" then return nil end
+		local r = {}
+		rawset(t,k,r)
+		return r
+	end})
+
+	-- img[y][x]. 1,1 is top left
+	for row=1,height do
+		for col =1,width do
+			local val,ncur = imgf:match("(%d+)%s*()",cur)
+			cur = ncur
+			img[row][col] = tonumber(val)
+		end
+	end
+
+	img.width=width
+	img.height=height
+	return img
+end
+
+return load_p1
-- 
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