Initial rendering

README.md

@@ -0,0 +1,7 @@
+# Zooming User Agent
+
+## Goals
+- Zoomable
+- Network transparent
+- Reimplementable
+- Display device agnostic (LCD, E-ink, ocular-bypass)

flake.lock

@@ -0,0 +1,59 @@
+{
+  "nodes": {
+    "nimble": {
+      "inputs": {
+        "nixpkgs": "nixpkgs"
+      },
+      "locked": {
+        "lastModified": 1633263146,
+        "narHash": "sha256-rbWhymf0OXVla79UE+sx8GKV1aK8QsOL2COwJLsvRZk=",
+        "owner": "nix-community",
+        "repo": "flake-nimble",
+        "rev": "e50410e3e559d4384bd0bbb47280188532d55f63",
+        "type": "github"
+      },
+      "original": {
+        "id": "nimble",
+        "type": "indirect"
+      }
+    },
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1633193040,
+        "narHash": "sha256-by9sL3A+Bpv84dOcBJ0AJwDF4x+Xt5vSqvpsyG0PPMc=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "2edf68513fcc329d391a6268cebc77043c9f341c",
+        "type": "github"
+      },
+      "original": {
+        "id": "nixpkgs",
+        "type": "indirect"
+      }
+    },
+    "nixpkgs_2": {
+      "locked": {
+        "lastModified": 1638592813,
+        "narHash": "sha256-842jUCj8fTZKJHygEu75V0mQw/SmxnM9MllSM5xTLm0=",
+        "owner": "nixos",
+        "repo": "nixpkgs",
+        "rev": "66c4ae20a3b6fffd54fa240701af3f3d8834c7da",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nixos",
+        "ref": "release-21.11",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "root": {
+      "inputs": {
+        "nimble": "nimble",
+        "nixpkgs": "nixpkgs_2"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}

flake.nix

@@ -0,0 +1,47 @@
+{
+  description = "Zooming User Agent";
+
+  inputs.nixpkgs.url = "github:nixos/nixpkgs/release-21.11";
+
+  outputs = { self, nixpkgs, nimble }:
+    let
+      systems = [ "aarch64-linux" "x86_64-linux" ];
+      forAllSystems = nixpkgs.lib.genAttrs systems;
+    in {
+      overlay = final: prev: {
+        zua = with prev;
+
+          nimPackages.buildNimPackage rec {
+            pname = "zua";
+            version = "unstable";
+
+            nimBinOnly = true;
+
+            src = self;
+            nativeBuildInputs = [ pkg-config ];
+            buildInputs = [ fontconfig ] ++ (with nimPackages; [
+              bumpy
+              chroma
+              flatty
+              nimsimd
+              pixie
+              sdl2
+              typography
+              vmath
+              zippy
+            ]);
+
+            meta = with lib; {
+              description = "Simple RSVP speed-reading utility";
+              license = licenses.unlicense;
+              homepage = "https://git.sr.ht/~ehmry/hottext";
+              maintainers = with maintainers; [ ehmry ];
+            };
+          };
+      };
+
+      defaultPackage = forAllSystems (system:
+        let pkgs = nixpkgs.legacyPackages.${system}.extend self.overlay;
+        in pkgs.zua);
+    };
+}

protocol.prs

@@ -0,0 +1,3 @@
+version 1.
+
+Pane = <svg @svg string>.

src/zua.nim

@@ -0,0 +1,151 @@
+# SPDX-FileCopyrightText: ☭ 2021 Emery Hemingway
+# SPDX-License-Identifier: Unlicense
+
+import std/[asyncdispatch, hashes, os, strutils, tables, xmlparser, xmltree]
+import preserves, preserves/parse
+import syndicate,
+  syndicate/[actors, capabilities, dataspaces, patterns, relay],
+  syndicate/protocols/[simpleChatProtocol]
+
+import nimsvg
+import pixie, pixie/fileformats/svg
+
+import math, sdl2, sdl2/gfx
+
+import ./zua/protocol
+
+const
+  rmask = uint32 0x000000ff
+  gmask = uint32 0x0000ff00
+  bmask = uint32 0x00ff0000
+  amask = uint32 0xff000000
+
+type
+  Pane = ref object
+    svg: string
+    image: Image
+
+type
+  App = ref object
+    screen: Image
+    # ctx: Context
+    window: WindowPtr
+    renderer: RendererPtr
+    surface: SurfacePtr
+    texture: TexturePtr
+    panes: Table[Hash, Pane]
+
+proc newPane(svg: string): Pane =
+  Pane(svg: svg)
+
+proc newApp(width, height: int): App =
+  new result
+  discard createWindowAndRenderer(
+    cint width, cint height,
+    SDL_WINDOW_RESIZABLE,
+    result.window, result.renderer)
+
+proc equalDimensions(a, b: Image): bool =
+  a.width == b.width and a.height == b.height
+
+proc update(app: App; pane: Pane) =
+  try:
+    assert(not app.screen.isNil)
+    pane.image = decodeSvg(pane.svg) # , app.screen.width, app.screen.height)
+      # TODO: determine the width and height from zoom level
+    draw(app.screen, pane.image)
+  except Exception as e:
+    stderr.writeLine "Failed to render SVG, ", e.msg
+
+proc update(app: App) =
+  let (w, h) = app.window.getSize
+  if app.screen.isNil or app.screen.width != w or app.screen.height != h:
+    app.screen = newImage(w, h)
+  app.screen.fill(rgba(255, 255, 255, 255))
+  for pane in app.panes.values:
+    app.update(pane)
+
+  var dataPtr = app.screen.data[0].addr
+  var mainSurface = createRGBSurfaceFrom(
+    dataPtr, cint w, cint h, cint 32, cint 4*w,
+    rmask, gmask, bmask, amask)
+  var mainTexture = app.renderer.createTextureFromSurface(mainSurface)
+  destroy(mainSurface)
+
+  app.renderer.clear()
+  app.renderer.copy(mainTexture, nil, nil)
+  destroy(mainTexture)
+
+  app.renderer.present()
+
+discard sdl2.init(INIT_TIMER or INIT_VIDEO or INIT_EVENTS)
+
+const svgTextSimple = """
+<?xml version="1.0" standalone="no"?>
+<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN"
+"http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
+<svg width="10cm" height="3cm" viewBox="0 0 1000 300"
+xmlns="http://www.w3.org/2000/svg" version="1.1">
+<desc>Example text01 - 'Hello, out there' in blue</desc>
+<text x="250" y="150"
+font-family="Verdana" font-size="55" fill="blue" >
+Hello, out there
+</text>
+<!-- Show outline of canvas using 'rect' element -->
+<rect x="1" y="1" width="998" height="298"
+fill="none" stroke="blue" stroke-width="2" />
+</svg>
+"""
+
+proc main() =
+  let app = newApp(1024, 768)
+  app.update()
+
+  let cap =  mint()
+
+  asyncCheck runActor("chat") do (turn: var Turn):
+
+    connectUnix(turn, "/run/syndicate/ds", cap) do (turn: var Turn; a: Assertion) -> TurnAction:
+      let ds = unembed a
+
+      onPublish(turn, ds, protocol.Pane ? {0: `?*`()}) do (svg: string):
+        echo "an SVG was published"
+        onRetract:
+          echo "an SVG was retracted"
+          app.panes.del(hash svg)
+          app.update()
+          # TODO: keep dead panes around until they are cleaned up.
+          # If something crashes then the last state should be visable.
+        var pane = app.panes.getOrDefault(hash svg)
+        if pane.isNil:
+          pane = newPane(svg)
+          app.panes[hash svg] = pane
+        else:
+          pane.svg = svg
+        app.update(pane)
+        app.update() # TODO: wait til end of turn
+
+      var
+        svgHandle: Handle
+        groups: Table[Hash, Nodes]
+
+  const
+    sdlTimeout = 500
+    asyncPollTimeout = 500
+
+  var evt = sdl2.defaultEvent
+  asyncdispatch.poll(0)
+  while true:
+    # TODO asyncdispatch.poll(0) or make an SDL event thread
+    if not waitEventTimeout(evt, sdlTimeout):
+      asyncdispatch.poll(0)
+    else:
+      case evt.kind
+      of QuitEvent:
+        quit(0)
+      of WindowEvent:
+        if evt.window.event == WindowEvent_Resized:
+          app.update()
+      else: discard
+
+main()

src/zua/Tupfile

@@ -0,0 +1 @@
+: ../../protocol.prs |> preserves_schema_nim %f |> protocol.nim

src/zua/protocol.nim

@@ -0,0 +1,13 @@
+
+import
+  std/typetraits, preserves
+
+type
+  Pane* {.preservesRecord: "svg".} = object
+    `svg`*: string
+
+proc `$`*(x: Pane): string =
+  `$`(toPreserve(x))
+
+proc encode*(x: Pane): seq[byte] =
+  encode(toPreserve(x))

tests/client.nim

@@ -0,0 +1,38 @@
+# SPDX-FileCopyrightText: ☭ 2021 Emery Hemingway
+# SPDX-License-Identifier: Unlicense
+
+import std/[asyncdispatch, os, parseopt, xmlparser, xmltree]
+import preserves
+import syndicate,
+  syndicate/[actors, capabilities, relay]
+
+import ../src/zua/protocol
+
+proc quitHook() {.noconv.} =
+  quit()
+
+proc main() =
+  setControlCHook(quitHook)
+
+  waitFor runActor("client") do (turn: var Turn):
+
+    let cap =  mint()
+
+    connectUnix(turn, "/run/syndicate/ds", cap) do (turn: var Turn; a: Assertion) -> TurnAction:
+      let ds = unembed a
+
+      for kind, arg, _ in getopt():
+        if kind == cmdArgument:
+          let megs = getFileSize(arg) shr 20
+          if megs > 1:
+            stderr.writeLine arg, " is ", megs, " MiB, not publishing"
+          else:
+            let xml = loadXml(arg)
+            if xml.tag != "svg":
+              stderr.writeLine arg, " not recognized as SVG"
+            else:
+              discard publish(turn, ds, Pane(svg: $xml))
+
+  stderr.writeLine "done"
+
+main()

tests/gemsvg.nim

@@ -0,0 +1,55 @@
+# SPDX-FileCopyrightText: ☭ 2021 Emery Hemingway
+# SPDX-License-Identifier: Unlicense
+
+import std/[asyncdispatch, os, parseopt, strutils, xmltree]
+import preserves, preserves/xmlhooks
+import syndicate, syndicate/[actors, capabilities, relay]
+import parsegemini
+import gemclient
+import nimsvg
+
+import ../src/zua/protocol
+
+proc quitHook() {.noconv.} =
+  quit()
+
+proc main() =
+  setControlCHook(quitHook)
+
+  waitFor runActor("client") do (turn: var Turn):
+
+    let cap =  mint()
+
+    connectUnix(turn, "/run/syndicate/ds", cap) do (turn: var Turn; a: Assertion) -> TurnAction:
+      let ds = unembed a
+      let client = newGeminiClient()
+
+      for kind, arg, _ in getopt():
+        if kind == cmdArgument and arg.startsWith"gemini":
+          var
+            nodes: seq[Nodes]
+            p: GeminiParser
+          let resp = client.fetch(arg)
+          open(p, resp.bodyStream)
+          # TODO: append to a text block until running into verbatim text,
+          # then push the current text and open a new block
+          while true:
+            p.next()
+            case p.kind
+            of gmiEof: break
+            else:
+              let n = buildSvg:
+                t: xmltree.escape p.text
+              nodes.add n
+          close(p)
+          let doc = buildSvg:
+            svg(viewBox="0 0 600 800", `font-family` = "Gentium Plus", `font-size`="20"):
+              text:
+                for n in nodes: embed n
+          let buf = render doc
+          stdout.writeLine buf
+          discard publish(turn, ds, Pane(svg: buf))
+
+  stderr.writeLine "done"
+
+main()

zua.nimble

@@ -0,0 +1,13 @@
+# Package
+
+version       = "0.1.0"
+author        = "Emery Hemingway"
+description   = "Zooming User Agent"
+license       = "Unlicense"
+srcDir        = "src"
+bin           = @["zua"]
+
+
+# Dependencies
+
+requires "nim >= 1.6.0"