Be1zebub/gmod_fonts_viewer.lua

## gmod_fonts_viewer.lua
local HTML = [[<html>
	<head>
		<script src="https://cdn.jsdelivr.net/npm/opentype.js@latest/dist/opentype.min.js"></script>

		<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/highlight.js/11.11.1/styles/default.min.css">
		<script src="https://cdnjs.cloudflare.com/ajax/libs/highlight.js/11.11.1/highlight.min.js"></script>

		<style>
			html, body {
				background-color: rgba(0, 0, 0, 0.1);
			}
		</style>

		<script>
			window.RenderOpenTypeData = (base64) => {
				const binary = atob(base64)
				const len = binary.length
				const buffer = new Uint8Array(len)
				for (let i = 0; i < len; i++) buffer[i] = binary.charCodeAt(i)

				const fontData = opentype.parse(buffer.buffer)
				const codeBlock = document.getElementById("json-block")

				codeBlock.textContent = safeStringify(fontData)
				hljs.highlightElement(codeBlock)
			}

			function safeStringify(obj) {
				const seen = new WeakSet()

				return JSON.stringify(obj, function(key, value) {
					if (typeof value === "object" && value !== null) {
						if (seen.has(value)) return "[=[circular]=]"
						seen.add(value)
					}
					if (typeof value === "function") {
						return "[=[function]=]"
					}

					return value
				}, 2);
			}
		</script>
		<body>
			<pre>
				<code class="json" id="json-block"></code>
			</pre>
		</body>
	</head>
</html>
]]

if IsValid(g_FontsViewer) then g_FontsViewer:Remove() end

g_FontsViewer = vgui.Create("DFrame")
g_FontsViewer:SetSize(1280, 720)
g_FontsViewer:Center()
g_FontsViewer:MakePopup()
g_FontsViewer:SetTitle("Fonts Viewer")

g_FontsViewer.scroll = g_FontsViewer:Add("DScrollPanel")
g_FontsViewer.scroll:Dock(LEFT)
g_FontsViewer.scroll:SetWide(320)

g_FontsViewer.openTypeBridge = g_FontsViewer:Add("DHTML")
g_FontsViewer.openTypeBridge:Dock(FILL)
g_FontsViewer.openTypeBridge:SetHTML(HTML)

local function ReadUShortBE(f)
	local b1 = f:ReadByte() or 0
	local b2 = f:ReadByte() or 0
	return b1 * 256 + b2
end

local function ReadULongBE(f)
	local b1 = f:ReadByte() or 0
	local b2 = f:ReadByte() or 0
	local b3 = f:ReadByte() or 0
	local b4 = f:ReadByte() or 0
	return b1 * 16777216 + b2 * 65536 + b3 * 256 + b4
end

function GetTTFFontName(filepath)
	if not file.Exists(filepath, "GAME") then return nil, "File does not exist" end

	local f = file.Open(filepath, "rb", "GAME")
	if not f then return nil, "Could not open file" end

	f:Seek(4)
	local numTables = ReadUShortBE(f)
	f:Seek(f:Tell() + 6) --we skip searchRange, entrySelector, rangeShift

	local nameOffset, nameLength

	for i = 1, numTables do
		local tag = f:Read(4)
		local checkSum = ReadULongBE(f)
		local offset = ReadULongBE(f)
		local length = ReadULongBE(f)

		if tag == "name" then
			nameOffset, nameLength = offset, length
		end
	end

	if not nameOffset then return nil, "No name table" end
	f:Seek(nameOffset)

	local version = ReadUShortBE(f)
	local count = ReadUShortBE(f)
	local storageOffset = ReadUShortBE(f)

	for i = 1, count do
		local platformID = ReadUShortBE(f)
		local encodingID = ReadUShortBE(f)
		local languageID = ReadUShortBE(f)
		local nameID = ReadUShortBE(f)
		local length = ReadUShortBE(f)
		local stringOffset = ReadUShortBE(f)

		if nameID == 4 or nameID == 1 then
			local pos = nameOffset + stringOffset + storageOffset
			f:Seek(pos)
			local raw = f:Read(length)

			if platformID == 0 or platformID == 3 then
				local out = {}

				for j = 1, #raw, 2 do
					local hi = raw:byte(j)
					local lo = raw:byte(j + 1)
					local code = hi * 256 + lo

					if code > 0 and code < 128 then
						table.insert(out, string.char(code))
					end
				end

				return table.concat(out)
			else
				return raw
			end
		end
	end

	return nil, "Font name not found"
end

local fontFiles = file.Find("resource/fonts/*", "GAME")
for index, fileName in ipairs(fontFiles) do
	local fontName = fileName

	if fileName:match("%.ttf$") then
		g_FontNamesCache = g_FontNamesCache or {}
		if g_FontNamesCache[fileName] == nil then
			local name = GetTTFFontName("resource/fonts/" .. fileName)
			g_FontNamesCache[fileName] = name and (name .. " (" .. fileName .. ")") or fileName
		end

		fontName = g_FontNamesCache[fileName]
	end

	local btn = g_FontsViewer.scroll:Add("DButton")
	btn:Dock(TOP)
	btn:SetText(fontName)
	btn:DockMargin(0, 0, 0, 5)
	btn:SetFont("DermaDefault")
	btn:SetContentAlignment(4)
	btn:SetTextInset(8, 0)

	btn.DoClick = function()
		local raw = file.Read("resource/fonts/" .. fileName, "GAME")
		local b64 = util.Base64Encode(raw)
		local js = string.format("window.RenderOpenTypeData(%q)", b64)

		g_FontsViewer.openTypeBridge:QueueJavascript(js)
	end
end
	local HTML = [[<html>
	<head>
	<script src="https://cdn.jsdelivr.net/npm/opentype.js@latest/dist/opentype.min.js"></script>

	<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/highlight.js/11.11.1/styles/default.min.css">
	<script src="https://cdnjs.cloudflare.com/ajax/libs/highlight.js/11.11.1/highlight.min.js"></script>

	<style>
	html, body {
	background-color: rgba(0, 0, 0, 0.1);
	}
	</style>

	<script>
	window.RenderOpenTypeData = (base64) => {
	const binary = atob(base64)
	const len = binary.length
	const buffer = new Uint8Array(len)
	for (let i = 0; i < len; i++) buffer[i] = binary.charCodeAt(i)

	const fontData = opentype.parse(buffer.buffer)
	const codeBlock = document.getElementById("json-block")

	codeBlock.textContent = safeStringify(fontData)
	hljs.highlightElement(codeBlock)
	}

	function safeStringify(obj) {
	const seen = new WeakSet()

	return JSON.stringify(obj, function(key, value) {
	if (typeof value === "object" && value !== null) {
	if (seen.has(value)) return "[=[circular]=]"
	seen.add(value)
	}
	if (typeof value === "function") {
	return "[=[function]=]"
	}

	return value
	}, 2);
	}
	</script>
	<body>
	<pre>
	<code class="json" id="json-block"></code>
	</pre>
	</body>
	</head>
	</html>
	]]

	if IsValid(g_FontsViewer) then g_FontsViewer:Remove() end

	g_FontsViewer = vgui.Create("DFrame")
	g_FontsViewer:SetSize(1280, 720)
	g_FontsViewer:Center()
	g_FontsViewer:MakePopup()
	g_FontsViewer:SetTitle("Fonts Viewer")

	g_FontsViewer.scroll = g_FontsViewer:Add("DScrollPanel")
	g_FontsViewer.scroll:Dock(LEFT)
	g_FontsViewer.scroll:SetWide(320)

	g_FontsViewer.openTypeBridge = g_FontsViewer:Add("DHTML")
	g_FontsViewer.openTypeBridge:Dock(FILL)
	g_FontsViewer.openTypeBridge:SetHTML(HTML)

	local function ReadUShortBE(f)
	local b1 = f:ReadByte() or 0
	local b2 = f:ReadByte() or 0
	return b1 * 256 + b2
	end

	local function ReadULongBE(f)
	local b1 = f:ReadByte() or 0
	local b2 = f:ReadByte() or 0
	local b3 = f:ReadByte() or 0
	local b4 = f:ReadByte() or 0
	return b1 * 16777216 + b2 * 65536 + b3 * 256 + b4
	end

	function GetTTFFontName(filepath)
	if not file.Exists(filepath, "GAME") then return nil, "File does not exist" end

	local f = file.Open(filepath, "rb", "GAME")
	if not f then return nil, "Could not open file" end

	f:Seek(4)
	local numTables = ReadUShortBE(f)
	f:Seek(f:Tell() + 6) --we skip searchRange, entrySelector, rangeShift

	local nameOffset, nameLength

	for i = 1, numTables do
	local tag = f:Read(4)
	local checkSum = ReadULongBE(f)
	local offset = ReadULongBE(f)
	local length = ReadULongBE(f)

	if tag == "name" then
	nameOffset, nameLength = offset, length
	end
	end

	if not nameOffset then return nil, "No name table" end
	f:Seek(nameOffset)

	local version = ReadUShortBE(f)
	local count = ReadUShortBE(f)
	local storageOffset = ReadUShortBE(f)

	for i = 1, count do
	local platformID = ReadUShortBE(f)
	local encodingID = ReadUShortBE(f)
	local languageID = ReadUShortBE(f)
	local nameID = ReadUShortBE(f)
	local length = ReadUShortBE(f)
	local stringOffset = ReadUShortBE(f)

	if nameID == 4 or nameID == 1 then
	local pos = nameOffset + stringOffset + storageOffset
	f:Seek(pos)
	local raw = f:Read(length)

	if platformID == 0 or platformID == 3 then
	local out = {}

	for j = 1, #raw, 2 do
	local hi = raw:byte(j)
	local lo = raw:byte(j + 1)
	local code = hi * 256 + lo

	if code > 0 and code < 128 then
	table.insert(out, string.char(code))
	end
	end

	return table.concat(out)
	else
	return raw
	end
	end
	end

	return nil, "Font name not found"
	end

	local fontFiles = file.Find("resource/fonts/*", "GAME")
	for index, fileName in ipairs(fontFiles) do
	local fontName = fileName

	if fileName:match("%.ttf$") then
	g_FontNamesCache = g_FontNamesCache or {}
	if g_FontNamesCache[fileName] == nil then
	local name = GetTTFFontName("resource/fonts/" .. fileName)
	g_FontNamesCache[fileName] = name and (name .. " (" .. fileName .. ")") or fileName
	end

	fontName = g_FontNamesCache[fileName]
	end

	local btn = g_FontsViewer.scroll:Add("DButton")
	btn:Dock(TOP)
	btn:SetText(fontName)
	btn:DockMargin(0, 0, 0, 5)
	btn:SetFont("DermaDefault")
	btn:SetContentAlignment(4)
	btn:SetTextInset(8, 0)

	btn.DoClick = function()
	local raw = file.Read("resource/fonts/" .. fileName, "GAME")
	local b64 = util.Base64Encode(raw)
	local js = string.format("window.RenderOpenTypeData(%q)", b64)

	g_FontsViewer.openTypeBridge:QueueJavascript(js)
	end
	end