Merge pull request #82 from tsoding/26

(#26) tracking windows

README.md

@@ -31,24 +31,16 @@ $ nimble build -d:developer
 This will enable:
 - Reloading the shaders with `Ctrl+R`
 
-## Experimental Live Update
+## Experimental Features Compilation Flags
 
-See issue [#26]. For an experimental Live Update feature compile the application with the following flags:
+Experimental or unstable features can be enabled by passing the following flags to `nimble build` command:
 
-```console
-$ nimble build -d:live
-```
-
-For a faster Live Update feature based on MIT-SHM X11 extension use `-d:mitshm`:
-
-```console
-$ nimble build -d:live -d:mitshm
-```
-
-The MIT-SHM support would probably not work for you until
-[nim-lang/x11#31](https://github.com/nim-lang/x11/pull/31) is merged.
-
-The feature is really unstable and experimental, so use it at your own risk.
+| Flag          | Description                                                                                                                    |
+|---------------|--------------------------------------------------------------------------------------------------------------------------------|
+| `-d:live`     | Live image update. See issue [#26].                                                                                            |
+| `-d:mitshm`   | Enables fater Live image update using MIT-SHM X11 extension. Should be used along with `-d:live` to have an effect             |
+| `-d:windowed` | Run boomer in windowed mode instead of fullscreen.                                                                             |
+| `-d:select`   | Application lets the user to click on te window to "track" and it will track that specific window instead of the whole screen. |
 
 ## NixOS Overlay
 

src/boomer.nim

@@ -4,7 +4,13 @@ import navigation
 import screenshot
 import config
 
-import x11/xlib, x11/x, x11/xutil, x11/keysym, x11/xrandr, x11/xshm
+import x11/xlib,
+       x11/x,
+       x11/xutil,
+       x11/keysym,
+       x11/xrandr,
+       x11/xshm,
+       x11/cursorfont
 import opengl, opengl/glx
 import la
 
@@ -128,6 +134,38 @@ proc getCursorPosition(display: PDisplay): Vec2f =
   result.x = root_x.float32
   result.y = root_y.float32
 
+proc selectWindow(display: PDisplay): TWindow =
+  var cursor = XCreateFontCursor(display, XC_crosshair)
+  defer: discard XFreeCursor(display, cursor)
+
+  var root = DefaultRootWindow(display)
+  discard XGrabPointer(display, root, 0,
+                       ButtonMotionMask or
+                       ButtonPressMask or
+                       ButtonReleaseMask,
+                       GrabModeAsync, GrabModeAsync,
+                       root, cursor,
+                       CurrentTime)
+  defer: discard XUngrabPointer(display, CurrentTime)
+
+  discard XGrabKeyboard(display, root, 0,
+                        GrabModeAsync, GrabModeAsync,
+                        CurrentTime)
+  defer: discard XUngrabKeyboard(display, CurrentTime)
+
+  var event: TXEvent
+  while true:
+    discard XNextEvent(display, addr event)
+    case event.theType
+    of ButtonPress:
+      return event.xbutton.subwindow
+    of KeyPress:
+      return root
+    else:
+      discard
+
+  return root
+
 proc main() =
   var config = defaultConfig
   let
@@ -147,9 +185,14 @@ proc main() =
   defer:
     discard XCloseDisplay(display)
 
-  var root = DefaultRootWindow(display)
 
-  var screenConfig = XRRGetScreenInfo(display, root)
+  when defined(select):
+    echo "Please select window:"
+    var trackingWindow = selectWindow(display)
+  else:
+    var trackingWindow = DefaultRootWindow(display)
+
+  var screenConfig = XRRGetScreenInfo(display, DefaultRootWindow(display))
   let rate = XRRConfigCurrentRate(screenConfig)
   echo "Screen rate: ", rate
 
@@ -177,13 +220,14 @@ proc main() =
 
   echo "Visual ", vi.visualid, " selected"
   var swa: TXSetWindowAttributes
-  swa.colormap = XCreateColormap(display, root,
+  swa.colormap = XCreateColormap(display, DefaultRootWindow(display),
                                  vi.visual, AllocNone)
   swa.event_mask = ButtonPressMask or ButtonReleaseMask or
                    KeyPressMask or KeyReleaseMask or
                    PointerMotionMask or ExposureMask or ClientMessage
-  swa.override_redirect = 1
-  swa.save_under = 1
+  when not defined(windowed):
+    swa.override_redirect = 1
+    swa.save_under = 1
 
   var attributes: TXWindowAttributes
   discard XGetWindowAttributes(
@@ -191,7 +235,7 @@ proc main() =
     DefaultRootWindow(display),
     addr attributes)
   var win = XCreateWindow(
-    display, root,
+    display, DefaultRootWindow(display),
     0, 0, attributes.width.cuint, attributes.height.cuint, 0,
     vi.depth, InputOutput, vi.visual,
     CWColormap or CWEventMask or CWOverrideRedirect or CWSaveUnder, addr swa)
@@ -219,7 +263,7 @@ proc main() =
 
   var shaderProgram = newShaderProgram(vertexShader, fragmentShader)
 
-  var screenshot = newScreenshot(display)
+  var screenshot = newScreenshot(display, trackingWindow)
   defer: screenshot.destroy(display)
 
   let w = screenshot.image.width.float32
@@ -303,7 +347,8 @@ proc main() =
   let dt = 1.0 / rate.float
   while not quitting:
     # TODO(#78): Is there a better solution to keep the focus always on the window?
-    discard XSetInputFocus(display, win, RevertToParent, CurrentTime);
+    when not defined(windowed):
+      discard XSetInputFocus(display, win, RevertToParent, CurrentTime);
 
     var wa: TXWindowAttributes
     discard XGetWindowAttributes(display, win, addr wa)
@@ -413,7 +458,7 @@ proc main() =
     glFinish()
 
     when defined(live):
-      screenshot.refresh(display)
+      screenshot.refresh(display, trackingWindow)
       glTexImage2D(GL_TEXTURE_2D,
                    0,
                    GL_RGB.GLint,

src/screenshot.nim

@@ -36,10 +36,9 @@ type Screenshot* = object
   when defined(mitshm):
     shminfo*: PXShmSegmentInfo
 
-proc newScreenshot*(display: PDisplay): Screenshot =
-  var root = DefaultRootWindow(display)
+proc newScreenshot*(display: PDisplay, window: TWindow): Screenshot =
   var attributes: TXWindowAttributes
-  discard XGetWindowAttributes(display, root, addr attributes)
+  discard XGetWindowAttributes(display, window, addr attributes)
 
   when defined(mitshm):
     result.shminfo = cast[PXShmSegmentInfo](
@@ -70,28 +69,28 @@ proc newScreenshot*(display: PDisplay): Screenshot =
 
     discard XShmAttach(display, result.shminfo)
     discard XShmGetImage(
-      display, root, result.image, 0.cint, 0.cint, AllPlanes)
+      display, window, result.image, 0.cint, 0.cint, AllPlanes)
   else:
     result.image = XGetImage(
-      display, root,
+      display, window,
       0, 0,
       attributes.width.cuint,
       attributes.height.cuint,
       AllPlanes,
       ZPixmap)
 
-proc refresh*(screenshot: var Screenshot, display: PDisplay) =
-  var root = DefaultRootWindow(display)
-
+proc refresh*(screenshot: var Screenshot, display: PDisplay, window: TWindow) =
   when defined(mitshm):
+    # TODO(#83): MITSHM live update does not support window resizing
     discard XShmGetImage(
       display,
-      root, screenshot.image,
+      window, screenshot.image,
       0.cint, 0.cint,
       AllPlanes)
   else:
+    # TODO(#84): XGetImage live update does not support window resizing
     screenshot.image = XGetSubImage(
-      display, root,
+      display, window,
       0, 0,
       screenshot.image.width.cuint,
       screenshot.image.height.cuint,