From a6c1c63e3006e3f4501fa3675eb4ac9cc4d5c785 Mon Sep 17 00:00:00 2001
From: codic12 <48339289+codic12@users.noreply.github.com>
Date: Sat, 4 Dec 2021 18:34:14 -0800
Subject: [PATCH] Create realtime_xlib.nim

---
 examples/realtime_xlib.nim | 122 +++++++++++++++++++++++++++++++++++++
 1 file changed, 122 insertions(+)
 create mode 100644 examples/realtime_xlib.nim

diff --git a/examples/realtime_xlib.nim b/examples/realtime_xlib.nim
new file mode 100644
index 0000000..6d36f20
--- /dev/null
+++ b/examples/realtime_xlib.nim
@@ -0,0 +1,122 @@
+## This example show how to have real time pixie using the X11 API.
+
+import math, pixie, x11/[x, xlib], std/os
+
+let
+  w: int32 = 256
+  h: int32 = 256
+
+var
+  screen = newImage(w, h)
+  ctx = newContext(screen)
+
+var
+  display: PDisplay
+  window: Window
+  deleteMessage: Atom
+  graphicsContext: GC
+  frameCount = 0
+
+
+proc render() =
+  ## Called every frame by main while loop
+  
+  # draw shiny sphere on gradient background
+  let linerGradient = newPaint(pkGradientLinear)
+  linerGradient.gradientHandlePositions.add(vec2(0, 0))
+  linerGradient.gradientHandlePositions.add(vec2(0, 256))
+  linerGradient.gradientStops.add(
+    ColorStop(color: pixie.color(0, 0, 0, 1), position: 0))
+  linerGradient.gradientStops.add(
+    ColorStop(color: pixie.color(1, 1, 1, 1), position: 1))
+  ctx.fillStyle = linerGradient
+  ctx.fillRect(0, 0, 256, 256)
+  let radialGradient = newPaint(pkGradientRadial)
+  radialGradient.gradientHandlePositions.add(vec2(128, 128))
+  radialGradient.gradientHandlePositions.add(vec2(256, 128))
+  radialGradient.gradientHandlePositions.add(vec2(128, 256))
+  radialGradient.gradientStops.add(
+    ColorStop(color: pixie.color(1, 1, 1, 1), position: 0))
+  radialGradient.gradientStops.add(
+    ColorStop(color: pixie.color(0, 0, 0, 1), position: 1))
+  ctx.fillStyle = radialGradient
+  ctx.fillCircle(circle(
+    vec2(128.0, 128.0 + sin(float32(frameCount)/10.0) * 20),
+    76.8
+  ))
+  inc frameCount
+  var frameBuffer = addr ctx.image.data[0]
+  let image = XCreateImage(display, DefaultVisualOfScreen(
+      DefaultScreenOfDisplay(display)), 24, ZPixmap, 0, cast[cstring](
+      frameBuffer), w.cuint, h.cuint, 8, w*4)
+  discard XPutImage(display, window, graphicsContext, image, 0, 0, 0, 0, w.cuint, h.cuint)
+
+import
+  x11/xlib,
+  x11/xutil,
+  x11/x
+
+const
+  borderWidth = 0
+  eventMask = ButtonPressMask or KeyPressMask or ExposureMask
+
+proc init() =
+  display = XOpenDisplay(nil)
+  if display == nil:
+    quit "Failed to open display"
+
+  let
+    screen = XDefaultScreen(display)
+    rootWindow = XRootWindow(display, screen)
+    foregroundColor = XBlackPixel(display, screen)
+    backgroundColor = XWhitePixel(display, screen)
+
+  window = XCreateSimpleWindow(display, rootWindow, -1, -1, w.cuint, h.cuint,
+      borderWidth, foregroundColor, backgroundColor)
+
+
+  discard XSetStandardProperties(display, window, "X11 Example", "window", 0,
+      nil, 0, nil)
+
+  discard XSelectInput(display, window, eventMask)
+  discard XMapWindow(display, window)
+
+  deleteMessage = XInternAtom(display, "WM_DELETE_WINDOW", false.XBool)
+  discard XSetWMProtocols(display, window, deleteMessage.addr, 1)
+
+  graphicsContext = XDefaultGC(display, screen)
+
+
+proc mainLoop() =
+  ## Process events until the quit event is received
+  var event: XEvent
+  var exposed: bool = false
+  while true:
+    if exposed: render()
+    if XPending(display) > 0:
+      discard XNextEvent(display, event.addr)
+      case event.theType
+      of Expose:
+        render()
+        exposed = true
+      of ClientMessage:
+        if cast[Atom](event.xclient.data.l[0]) == deleteMessage:
+          break
+      of KeyPress:
+        let key = XLookupKeysym(cast[PXKeyEvent](event.addr), 0)
+        if key != 0:
+          echo "Key ", key, " pressed"
+      of ButtonPressMask:
+        echo "Mouse button ", event.xbutton.button, " pressed at ",
+            event.xbutton.x, ",", event.xbutton.y
+      else:
+        discard
+    sleep 14
+
+proc main() =
+  init()
+  mainLoop()
+  discard XDestroyWindow(display, window)
+  discard XCloseDisplay(display)
+
+main()