Prepare 1.2.0 (#98)

- clearFontAtlas
- addFontDefault
- addFontFromFileTTF
- addFontFromMemoryTTF (raw only)
- buildFontAtlas

Vulkan example updated to use on f the imgui-distributed ttf files.

ChangeLog.md

@@ -1,7 +1,38 @@
 # Changelog for dear-imgui
 
-## [1.0.0] Initial Hackage release
+## [1.2.0]
 
-Based on 1.83.
+- Fixed `nullPtr` in place of default arguments.
+- Added functions for getting window position and size.
+- Added `invisibleButton`.
+- Added `inputTextMultiline` and `inputTextWithHint`.
+- Changed `beginChild` and related `withChild*` to use full arguments.
+- Added `withChildContext` to run actions inside other child window.
+- Added `getCurrentContext`, `setCurrentContext`.
+- Added `image` and `imageButton`.
+- Added font atlas utilities.
+
+## [1.1.0]
+
+- `imgui` updated to 1.84.2.
+- Removed unused Window argument from SDL `newFrame` to match 1.84.
+- Added GLFW backend callbacks.
+- Added more withXXX wrappers.
+
+## [1.0.2]
+
+- Added `withID` and `ToID(..)` to make composable components possible.
+
+## [1.0.1]
+
+- Fixed missing headers in source dist.
+
+## [1.0.0]
+
+Initial Hackage release based on 1.83.
 
 [1.0.0]: https://github.com/haskell-game/dear-imgui.hs/tree/v1.0.0
+[1.0.1]: https://github.com/haskell-game/dear-imgui.hs/tree/v1.0.1
+[1.0.2]: https://github.com/haskell-game/dear-imgui.hs/tree/v1.0.2
+[1.1.0]: https://github.com/haskell-game/dear-imgui.hs/tree/v1.1.0
+[1.2.0]: https://github.com/haskell-game/dear-imgui.hs/tree/v1.2.0

Main.hs

@@ -38,26 +38,24 @@ main = do
       tab2 <- newIORef True
       loop w checked color slider r pos size' selected tab1 tab2
 
-      openGL3Shutdown
 
-
-loop 
-  :: Window 
-  -> IORef Bool 
-  -> IORef ImVec3 
-  -> IORef (Float, Float, Float) 
-  -> IORef Int 
-  -> IORef ImVec2 
+loop
+  :: Window
+  -> IORef Bool
+  -> IORef ImVec3
+  -> IORef (Float, Float, Float)
+  -> IORef Int
   -> IORef ImVec2
-  -> IORef Int 
+  -> IORef ImVec2
+  -> IORef Int
   -> IORef Bool
   -> IORef Bool
   -> IO ()
-loop w checked color slider r pos size' selected tab1Ref tab2Ref = do
-  quit <- pollEvents
+loop window checked color slider r pos size' selected tab1Ref tab2Ref = do
+  shouldQuit <- checkEvents
 
   openGL3NewFrame
-  sdl2NewFrame w
+  sdl2NewFrame
   newFrame
 
   -- showDemoWindow
@@ -68,7 +66,7 @@ loop w checked color slider r pos size' selected tab1Ref tab2Ref = do
   setNextWindowPos pos ImGuiCond_Once Nothing
   setNextWindowSize size' ImGuiCond_Once
   -- Works, but will make the window contents illegible without doing something more involved.
-  -- setNextWindowContentSize size' 
+  -- setNextWindowContentSize size'
   -- setNextWindowSizeConstraints size' size'
   setNextWindowCollapsed False ImGuiCond_Once
 
@@ -122,7 +120,7 @@ loop w checked color slider r pos size' selected tab1Ref tab2Ref = do
 
   progressBar 0.314 (Just "Pi")
 
-  beginChild "Child"
+  beginChild "Child" (ImVec2 0 0) True ImGuiWindowFlags_None
 
   beginCombo "Label" "Preview" >>= whenTrue do
     selectable "Testing 1"
@@ -164,13 +162,15 @@ loop w checked color slider r pos size' selected tab1Ref tab2Ref = do
   glClear GL_COLOR_BUFFER_BIT
   openGL3RenderDrawData =<< getDrawData
 
-  glSwapWindow w
+  glSwapWindow window
 
-  if quit then return () else loop w checked color slider r pos size' selected tab1Ref tab2Ref
+  if shouldQuit
+    then return ()
+    else loop window checked color slider r pos size' selected tab1Ref tab2Ref
 
   where
 
-    pollEvents = do
+    checkEvents = do
       ev <- pollEventWithImGui
 
       case ev of
@@ -180,9 +180,9 @@ loop w checked color slider r pos size' selected tab1Ref tab2Ref = do
                 QuitEvent -> True
                 _         -> False
 
-          (isQuit ||) <$> pollEvents
+          (isQuit ||) <$> checkEvents
 
 
 whenTrue :: IO () -> Bool -> IO ()
 whenTrue io True  = io
-whenTrue io False = return ()
+whenTrue _io False = return ()

README.md

@@ -81,7 +81,7 @@ mainLoop w = do
 
   -- Tell ImGui we're starting a new frame
   openGL2NewFrame
-  sdl2NewFrame w
+  sdl2NewFrame
   newFrame
 
   -- Build the GUI

cabal.project

@@ -1,3 +1,4 @@
 packages: *.cabal
 package dear-imgui
   flags: +sdl2 +glfw +opengl2 +opengl3 +vulkan +examples
+  ghc-options: -Wall -Wcompat -fno-warn-unused-do-bind

dear-imgui.cabal

@@ -1,7 +1,7 @@
 cabal-version: 3.0
 
 name: dear-imgui
-version: 1.0.0
+version: 1.2.0
 author: Oliver Charles
 maintainer: ollie@ocharles.org.uk, aenor.realm@gmail.com
 license: BSD-3-Clause
@@ -15,8 +15,14 @@ description:
 build-type: Simple
 extra-source-files:
   README.md,
-  ChangeLog.md,
-  imgui/imgui.h
+  ChangeLog.md
+
+extra-source-files:
+  imgui/*.h,
+  imgui/backends/*.h,
+  imgui/backends/*.mm,
+  imgui/imconfig.h,
+  imgui/LICENSE.txt
 
 source-repository head
   type: git
@@ -175,7 +181,8 @@ library
     exposed-modules:
       DearImGui.GLFW
     build-depends:
-      GLFW-b
+      GLFW-b,
+      bindings-GLFW
     cxx-sources:
       imgui/backends/imgui_impl_glfw.cpp
 
@@ -213,7 +220,7 @@ library dear-imgui-generator
     , megaparsec
         >= 9.0 && < 9.1
     , parser-combinators
-        >= 1.2.0 && < 1.3
+        >= 1.2.0 && < 1.4
     , scientific
         >= 0.3.6.2 && < 0.3.8
     , text
@@ -253,6 +260,14 @@ executable readme
   if (!flag(examples) || !flag(sdl) || !flag(opengl2))
     buildable: False
 
+executable image
+  import: common
+  main-is: Image.hs
+  hs-source-dirs: examples/sdl
+  build-depends: sdl2, gl, dear-imgui, managed, vector
+  if (!flag(examples) || !flag(sdl) || !flag(opengl2))
+    buildable: False
+
 executable vulkan
   import: common
   main-is: Main.hs

examples/Readme.hs

@@ -24,34 +24,34 @@ main = do
 
   runManaged do
     -- Create a window using SDL. As we're using OpenGL, we need to enable OpenGL too.
-    w <- do
+    window <- do
       let title = "Hello, Dear ImGui!"
       let config = defaultWindow { windowGraphicsContext = OpenGLContext defaultOpenGL }
       managed $ bracket (createWindow title config) destroyWindow
 
     -- Create an OpenGL context
-    glContext <- managed $ bracket (glCreateContext w) glDeleteContext
+    glContext <- managed $ bracket (glCreateContext window) glDeleteContext
 
     -- Create an ImGui context
     _ <- managed $ bracket createContext destroyContext
 
     -- Initialize ImGui's SDL2 backend
-    _ <- managed_ $ bracket_ (sdl2InitForOpenGL w glContext) sdl2Shutdown
+    _ <- managed_ $ bracket_ (sdl2InitForOpenGL window glContext) sdl2Shutdown
 
     -- Initialize ImGui's OpenGL backend
     _ <- managed_ $ bracket_ openGL2Init openGL2Shutdown
 
-    liftIO $ mainLoop w
+    liftIO $ mainLoop window
 
 
 mainLoop :: Window -> IO ()
-mainLoop w = do
+mainLoop window = do
   -- Process the event loop
   untilNothingM pollEventWithImGui
 
   -- Tell ImGui we're starting a new frame
   openGL2NewFrame
-  sdl2NewFrame w
+  sdl2NewFrame
   newFrame
 
   -- Build the GUI
@@ -73,9 +73,9 @@ mainLoop w = do
   render
   openGL2RenderDrawData =<< getDrawData
 
-  glSwapWindow w
+  glSwapWindow window
 
-  mainLoop w
+  mainLoop window
 
   where
     untilNothingM m = m >>= maybe (return ()) (\_ -> untilNothingM m)

examples/sdl/Image.hs

@@ -0,0 +1,181 @@
+{-# language BlockArguments #-}
+{-# language LambdaCase #-}
+{-# language OverloadedStrings #-}
+
+{- | Drawing an DearImGui image using OpenGL textures.
+
+https://github.com/ocornut/imgui/wiki/Image-Loading-and-Displaying-Examples
+-}
+
+module Main ( main ) where
+
+import Control.Exception
+import Control.Monad.IO.Class (MonadIO(..))
+import Control.Monad.Managed (managed, managed_, runManaged)
+import DearImGui
+import qualified DearImGui.Raw as Raw
+import DearImGui.OpenGL3
+import DearImGui.SDL
+import DearImGui.SDL.OpenGL
+import Graphics.GL
+import qualified SDL as SDL
+
+--  For the texture creation
+import Foreign
+import qualified Data.Vector.Storable as VS
+
+data Texture = Texture
+  { textureID     :: GLuint
+  , textureWidth  :: GLsizei
+  , textureHeight :: GLsizei
+  }
+  deriving (Show)
+
+textureSize :: Texture -> ImVec2
+textureSize texture =
+  ImVec2
+    (fromIntegral $ textureWidth texture)
+    (fromIntegral $ textureHeight texture)
+
+-- | Create a texture pointer in GL memory.
+create2DTexture :: Int -> Int -> IO Texture
+create2DTexture width height =
+  alloca \ptr -> do
+    glGenTextures 1 ptr
+    tID <- peek ptr
+    return Texture
+      { textureID     = tID
+      , textureWidth  = fromIntegral width
+      , textureHeight = fromIntegral height
+      }
+
+bindTexture :: Texture -> Ptr GLubyte -> IO ()
+bindTexture texture dataPtr = do
+  glEnable GL_TEXTURE_2D
+  glBindTexture GL_TEXTURE_2D (textureID texture)
+
+  glTexParameteri GL_TEXTURE_2D GL_TEXTURE_MIN_FILTER GL_LINEAR
+  glTexParameteri GL_TEXTURE_2D GL_TEXTURE_MAG_FILTER GL_LINEAR
+  glTexParameteri GL_TEXTURE_2D GL_TEXTURE_WRAP_S GL_REPEAT
+  glTexParameteri GL_TEXTURE_2D GL_TEXTURE_WRAP_T GL_REPEAT
+
+  glTexImage2D
+    GL_TEXTURE_2D
+    0
+    GL_RGB
+    (textureWidth texture)
+    (textureHeight texture)
+    0
+    GL_RGB
+    GL_UNSIGNED_BYTE
+    (castPtr dataPtr)
+
+fill :: Texture -> (GLubyte, GLubyte, GLubyte) -> VS.Vector GLubyte
+fill texture (r, g, b) =
+  VS.generate
+    (3 * width * height)
+    (\i ->
+        case i `mod` 3 of
+          0 -> r
+          1 -> g
+          2 -> b
+          _ -> error "assert: 3-byte pitch"
+    )
+  where
+    width  = fromIntegral (textureWidth texture)
+    height = fromIntegral (textureHeight texture)
+
+
+main :: IO ()
+main = do
+  -- Initialize SDL
+  SDL.initializeAll
+
+  runManaged do
+    -- Create a window using SDL. As we're using OpenGL, we need to enable OpenGL too.
+    window <- do
+      let title = "Hello, Dear ImGui!"
+      let config = SDL.defaultWindow { SDL.windowGraphicsContext = SDL.OpenGLContext SDL.defaultOpenGL, SDL.windowResizable = True }
+      managed $ bracket (SDL.createWindow title config) SDL.destroyWindow
+
+    -- Create an OpenGL context
+    glContext <- managed $ bracket (SDL.glCreateContext window) SDL.glDeleteContext
+
+    -- Create an ImGui context
+    _dearContext <- managed $ bracket createContext destroyContext
+
+    -- Initialize ImGui's SDL2 backend
+    managed_ $ bracket_ (sdl2InitForOpenGL window glContext) sdl2Shutdown
+
+    -- Initialize ImGui's OpenGL backend
+    managed_ $ bracket_ openGL3Init do
+      putStrLn "ImguiOpenGL shut down"
+      openGL3Shutdown
+
+    liftIO do
+      blueish <- create2DTexture 320 240
+      VS.unsafeWith (fill blueish (0x00, 0x7F, 0xFF)) $
+        bindTexture blueish
+
+      pinkish <- create2DTexture 240 320
+      VS.unsafeWith (fill pinkish (0xFF, 0x00, 0x7F)) $
+        bindTexture pinkish
+
+      err <- glGetError
+      putStrLn $ "Error-code: " ++ show err
+
+      print (blueish, pinkish)
+      mainLoop window (blueish, pinkish) False
+
+mainLoop :: SDL.Window -> (Texture, Texture) -> Bool -> IO ()
+mainLoop window textures flag = unlessQuit do
+  -- Tell ImGui we're starting a new frame
+  openGL3NewFrame
+  sdl2NewFrame
+  newFrame
+
+  -- Build the GUI
+  clicked <- withWindow "Image example" \open ->
+    if open then do
+      text "That's an image, click it"
+      newLine
+
+      let texture = if flag then fst textures else snd textures
+
+      -- Drawing images require some backend-specific code.
+      -- Meanwhile, we have to deal with raw binding.
+      let openGLtextureID = intPtrToPtr $ fromIntegral $ textureID texture
+
+      Foreign.with (textureSize texture) \sizePtr ->
+        Foreign.with (ImVec2 0 0) \uv0Ptr ->
+          Foreign.with (ImVec2 1 1) \uv1Ptr ->
+            Foreign.with (ImVec4 1 1 1 1) \tintColPtr ->
+              Foreign.with (ImVec4 1 1 1 1) \bgColPtr ->
+                Raw.imageButton openGLtextureID sizePtr uv0Ptr uv1Ptr (-1) bgColPtr tintColPtr
+    else
+      pure False
+
+  -- Render
+  glClear GL_COLOR_BUFFER_BIT
+
+  DearImGui.render
+  DearImGui.getDrawData >>= openGL3RenderDrawData
+
+  SDL.glSwapWindow window
+
+  mainLoop window textures (flag /= clicked)
+
+  where
+    unlessQuit action = do
+      shouldQuit <- checkEvents
+      if shouldQuit then pure () else action
+
+    checkEvents = do
+      pollEventWithImGui >>= \case
+        Nothing ->
+          return False
+        Just event ->
+          (isQuit event ||) <$> checkEvents
+
+    isQuit event =
+      SDL.eventPayload event == SDL.QuitEvent

examples/vulkan/Main.hs

@@ -83,6 +83,20 @@ type Handler    = LogMessage -> ResourceT IO ()
 deriving via ( ReaderT Handler (ResourceT IO) )
   instance MonadResource ( LoggingT LogMessage (ResourceT IO) )
 
+gui :: MonadIO m => m ImGui.DrawData
+gui = do
+  -- Prepare frame
+  ImGui.Vulkan.vulkanNewFrame
+  ImGui.SDL.sdl2NewFrame
+  ImGui.newFrame
+
+  -- Run your windows
+  ImGui.showDemoWindow
+
+  -- Process ImGui state into draw commands
+  ImGui.render
+  ImGui.getDrawData
+
 main :: IO ()
 main = runResourceT . ( `runLoggingT` logHandler ) $ app @( LoggingT LogMessage ( ResourceT IO ) )
 
@@ -120,6 +134,12 @@ app = do
     ImGui.createContext
     ImGui.destroyContext
 
+  logDebug "Adding fonts"
+  ImGui.clearFontAtlas
+  _default <- ImGui.addFontDefault
+  _custom <- ImGui.addFontFromFileTTF "imgui/misc/fonts/ProggyTiny.ttf" 10
+  ImGui.buildFontAtlas
+
   let
     preferredFormat :: Vulkan.SurfaceFormatKHR
     preferredFormat =
@@ -341,12 +361,6 @@ app = do
                 pure ( True, False )
               else
                 handleJust vulkanException ( pure . reloadQuit ) do
-                  ImGui.Vulkan.vulkanNewFrame
-                  ImGui.SDL.sdl2NewFrame window
-                  ImGui.newFrame
-                  ImGui.showDemoWindow
-                  ImGui.render
-                  drawData <- ImGui.getDrawData
                   let
                     commandBuffer :: Vulkan.CommandBuffer
                     commandBuffer = commandBuffers Boxed.Vector.! fromIntegral nextImageIndex
@@ -355,7 +369,10 @@ app = do
                   Vulkan.resetCommandBuffer commandBuffer Vulkan.zero
                   beginCommandBuffer commandBuffer
                   cmdBeginRenderPass commandBuffer imGuiRenderPass framebuffer clearValues swapchainExtent
+
+                  drawData <- gui
                   ImGui.Vulkan.vulkanRenderDrawData drawData commandBuffer Nothing
+
                   cmdEndRenderPass commandBuffer
                   endCommandBuffer commandBuffer
                   submitCommandBuffer
@@ -370,7 +387,7 @@ app = do
             freeOldResources
             let
               freeOldResources :: m ()
-              freeOldResources = pure ()    
+              freeOldResources = pure ()
             unless quit $ mainLoop ( AppState {..} )
 
     let

generator/DearImGui/Generator.hs

@@ -12,8 +12,6 @@ module DearImGui.Generator
 -- base
 import Control.Arrow
   ( second )
-import Data.Coerce
-  ( coerce )
 import Data.Bits
   ( Bits )
 import Data.Foldable
@@ -54,7 +52,6 @@ import qualified Language.Haskell.TH.Syntax as TH
 
 -- text
 import qualified Data.Text as Text
-  ( isInfixOf, null, unpack, unlines )
 import qualified Data.Text.IO as Text
   ( readFile )
 
@@ -128,9 +125,9 @@ declareEnumeration finiteEnumName countName ( Enumeration {..} ) = do
     classes :: [ TH.Q TH.Type ]
     classes
       | isFlagEnum
-      = map TH.conT [ ''Eq, ''Ord, ''Storable, ''Bits ]
+      = map TH.conT [ ''Eq, ''Ord, ''Show, ''Storable, ''Bits ]
       | otherwise
-      = map TH.conT [ ''Eq, ''Ord, ''Storable ]
+      = map TH.conT [ ''Eq, ''Ord, ''Show, ''Storable ]
     derivClause :: TH.Q TH.DerivClause
     derivClause = TH.derivClause ( Just TH.NewtypeStrategy ) classes
 
@@ -157,11 +154,11 @@ declareEnumeration finiteEnumName countName ( Enumeration {..} ) = do
                         <$> TH.appT ( TH.conT countName ) ( TH.conT tyName )
                         <*> TH.litT ( TH.numTyLit enumSize )
                           )
-          ]  
+          ]
       pure ( finiteEnumInst : )
     else pure id
 
-  synonyms <- for patterns \ ( patternName, patternValue, CommentText patDoc ) -> do
+  synonyms <- for patterns \ ( patternName, patternValue, CommentText _patDoc ) -> do
     let
       patNameStr :: String
       patNameStr = Text.unpack patternName
@@ -169,7 +166,7 @@ declareEnumeration finiteEnumName countName ( Enumeration {..} ) = do
     patSynSig <- TH.patSynSigD patName ( TH.conT tyName )
     pat       <-
 #if MIN_VERSION_template_haskell(2,18,0)
-      ( if   Text.null patDoc
+      ( if   Text.null _patDoc
         then TH.patSynD
         else
           \ nm args dir pat ->

nix/sources.json

@@ -5,10 +5,10 @@
         "homepage": "https://input-output-hk.github.io/haskell.nix",
         "owner": "input-output-hk",
         "repo": "haskell.nix",
-        "rev": "ef4aef4ce2060dc1a41b2690df1f54f986e0f9ab",
-        "sha256": "0537fbjh4mcnywa33h4hl135kw7i8c0j8qndyzv5i82j7mc8wjvs",
+        "rev": "970c84ad19e84d4ae42075cfe283022394f6effa",
+        "sha256": "01afbcas324n7j2bpfib7b4fazg5y6k7b74803c0i9ayrs6sgav6",
         "type": "tarball",
-        "url": "https://github.com/input-output-hk/haskell.nix/archive/ef4aef4ce2060dc1a41b2690df1f54f986e0f9ab.tar.gz",
+        "url": "https://github.com/input-output-hk/haskell.nix/archive/970c84ad19e84d4ae42075cfe283022394f6effa.tar.gz",
         "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
     },
     "niv": {
@@ -17,10 +17,10 @@
         "homepage": "https://github.com/nmattia/niv",
         "owner": "nmattia",
         "repo": "niv",
-        "rev": "3cd7914b2c4cff48927e11c216dadfab7d903fe5",
-        "sha256": "1agq4nvbhrylf2s77kb4xhh9k7xcwdwggq764k4jgsbs70py8cw3",
+        "rev": "e0ca65c81a2d7a4d82a189f1e23a48d59ad42070",
+        "sha256": "1pq9nh1d8nn3xvbdny8fafzw87mj7gsmp6pxkdl65w2g18rmcmzx",
         "type": "tarball",
-        "url": "https://github.com/nmattia/niv/archive/3cd7914b2c4cff48927e11c216dadfab7d903fe5.tar.gz",
+        "url": "https://github.com/nmattia/niv/archive/e0ca65c81a2d7a4d82a189f1e23a48d59ad42070.tar.gz",
         "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
     },
     "nixpkgs": {

nix/sources.nix

@@ -6,52 +6,63 @@ let
   # The fetchers. fetch_<type> fetches specs of type <type>.
   #
 
-  fetch_file = pkgs: spec:
-    if spec.builtin or true then
-      builtins_fetchurl { inherit (spec) url sha256; }
-    else
-      pkgs.fetchurl { inherit (spec) url sha256; };
+  fetch_file = pkgs: name: spec:
+    let
+      name' = sanitizeName name + "-src";
+    in
+      if spec.builtin or true then
+        builtins_fetchurl { inherit (spec) url sha256; name = name'; }
+      else
+        pkgs.fetchurl { inherit (spec) url sha256; name = name'; };
 
-  fetch_tarball = pkgs: spec:
-    if spec.builtin or true then
-      builtins_fetchTarball { inherit (spec) url sha256; }
-    else
-      pkgs.fetchzip { inherit (spec) url sha256; };
+  fetch_tarball = pkgs: name: spec:
+    let
+      name' = sanitizeName name + "-src";
+    in
+      if spec.builtin or true then
+        builtins_fetchTarball { name = name'; inherit (spec) url sha256; }
+      else
+        pkgs.fetchzip { name = name'; inherit (spec) url sha256; };
 
-  fetch_git = spec:
-    builtins.fetchGit { url = spec.repo; inherit (spec) rev ref; };
+  fetch_git = name: spec:
+    let
+      ref =
+        if spec ? ref then spec.ref else
+          if spec ? branch then "refs/heads/${spec.branch}" else
+            if spec ? tag then "refs/tags/${spec.tag}" else
+              abort "In git source '${name}': Please specify `ref`, `tag` or `branch`!";
+    in
+      builtins.fetchGit { url = spec.repo; inherit (spec) rev; inherit ref; };
 
-  fetch_builtin-tarball = spec:
-    builtins.trace
-      ''
-        WARNING:
-          The niv type "builtin-tarball" will soon be deprecated. You should
-          instead use `builtin = true`.
+  fetch_local = spec: spec.path;
 
-          $ niv modify <package> -a type=tarball -a builtin=true
-      ''
-      builtins_fetchTarball { inherit (spec) url sha256; };
+  fetch_builtin-tarball = name: throw
+    ''[${name}] The niv type "builtin-tarball" is deprecated. You should instead use `builtin = true`.
+        $ niv modify ${name} -a type=tarball -a builtin=true'';
 
-  fetch_builtin-url = spec:
-    builtins.trace
-      ''
-        WARNING:
-          The niv type "builtin-url" will soon be deprecated. You should
-          instead use `builtin = true`.
-
-          $ niv modify <package> -a type=file -a builtin=true
-      ''
-      (builtins_fetchurl { inherit (spec) url sha256; });
+  fetch_builtin-url = name: throw
+    ''[${name}] The niv type "builtin-url" will soon be deprecated. You should instead use `builtin = true`.
+        $ niv modify ${name} -a type=file -a builtin=true'';
 
   #
   # Various helpers
   #
 
+  # https://github.com/NixOS/nixpkgs/pull/83241/files#diff-c6f540a4f3bfa4b0e8b6bafd4cd54e8bR695
+  sanitizeName = name:
+    (
+      concatMapStrings (s: if builtins.isList s then "-" else s)
+        (
+          builtins.split "[^[:alnum:]+._?=-]+"
+            ((x: builtins.elemAt (builtins.match "\\.*(.*)" x) 0) name)
+        )
+    );
+
   # The set of packages used when specs are fetched using non-builtins.
-  mkPkgs = sources:
+  mkPkgs = sources: system:
     let
       sourcesNixpkgs =
-        import (builtins_fetchTarball { inherit (sources.nixpkgs) url sha256; }) {};
+        import (builtins_fetchTarball { inherit (sources.nixpkgs) url sha256; }) { inherit system; };
       hasNixpkgsPath = builtins.any (x: x.prefix == "nixpkgs") builtins.nixPath;
       hasThisAsNixpkgsPath = <nixpkgs> == ./.;
     in
@@ -71,14 +82,27 @@ let
 
     if ! builtins.hasAttr "type" spec then
       abort "ERROR: niv spec ${name} does not have a 'type' attribute"
-    else if spec.type == "file" then fetch_file pkgs spec
-    else if spec.type == "tarball" then fetch_tarball pkgs spec
-    else if spec.type == "git" then fetch_git spec
-    else if spec.type == "builtin-tarball" then fetch_builtin-tarball spec
-    else if spec.type == "builtin-url" then fetch_builtin-url spec
+    else if spec.type == "file" then fetch_file pkgs name spec
+    else if spec.type == "tarball" then fetch_tarball pkgs name spec
+    else if spec.type == "git" then fetch_git name spec
+    else if spec.type == "local" then fetch_local spec
+    else if spec.type == "builtin-tarball" then fetch_builtin-tarball name
+    else if spec.type == "builtin-url" then fetch_builtin-url name
     else
       abort "ERROR: niv spec ${name} has unknown type ${builtins.toJSON spec.type}";
 
+  # If the environment variable NIV_OVERRIDE_${name} is set, then use
+  # the path directly as opposed to the fetched source.
+  replace = name: drv:
+    let
+      saneName = stringAsChars (c: if isNull (builtins.match "[a-zA-Z0-9]" c) then "_" else c) name;
+      ersatz = builtins.getEnv "NIV_OVERRIDE_${saneName}";
+    in
+      if ersatz == "" then drv else
+        # this turns the string into an actual Nix path (for both absolute and
+        # relative paths)
+        if builtins.substring 0 1 ersatz == "/" then /. + ersatz else /. + builtins.getEnv "PWD" + "/${ersatz}";
+
   # Ports of functions for older nix versions
 
   # a Nix version of mapAttrs if the built-in doesn't exist
@@ -87,23 +111,37 @@ let
     listToAttrs (map (attr: { name = attr; value = f attr set.${attr}; }) (attrNames set))
   );
 
+  # https://github.com/NixOS/nixpkgs/blob/0258808f5744ca980b9a1f24fe0b1e6f0fecee9c/lib/lists.nix#L295
+  range = first: last: if first > last then [] else builtins.genList (n: first + n) (last - first + 1);
+
+  # https://github.com/NixOS/nixpkgs/blob/0258808f5744ca980b9a1f24fe0b1e6f0fecee9c/lib/strings.nix#L257
+  stringToCharacters = s: map (p: builtins.substring p 1 s) (range 0 (builtins.stringLength s - 1));
+
+  # https://github.com/NixOS/nixpkgs/blob/0258808f5744ca980b9a1f24fe0b1e6f0fecee9c/lib/strings.nix#L269
+  stringAsChars = f: s: concatStrings (map f (stringToCharacters s));
+  concatMapStrings = f: list: concatStrings (map f list);
+  concatStrings = builtins.concatStringsSep "";
+
+  # https://github.com/NixOS/nixpkgs/blob/8a9f58a375c401b96da862d969f66429def1d118/lib/attrsets.nix#L331
+  optionalAttrs = cond: as: if cond then as else {};
+
   # fetchTarball version that is compatible between all the versions of Nix
-  builtins_fetchTarball = { url, sha256 }@attrs:
+  builtins_fetchTarball = { url, name ? null, sha256 }@attrs:
     let
       inherit (builtins) lessThan nixVersion fetchTarball;
     in
       if lessThan nixVersion "1.12" then
-        fetchTarball { inherit url; }
+        fetchTarball ({ inherit url; } // (optionalAttrs (!isNull name) { inherit name; }))
       else
         fetchTarball attrs;
 
   # fetchurl version that is compatible between all the versions of Nix
-  builtins_fetchurl = { url, sha256 }@attrs:
+  builtins_fetchurl = { url, name ? null, sha256 }@attrs:
     let
       inherit (builtins) lessThan nixVersion fetchurl;
     in
       if lessThan nixVersion "1.12" then
-        fetchurl { inherit url; }
+        fetchurl ({ inherit url; } // (optionalAttrs (!isNull name) { inherit name; }))
       else
         fetchurl attrs;
 
@@ -115,14 +153,15 @@ let
         then abort
           "The values in sources.json should not have an 'outPath' attribute"
         else
-          spec // { outPath = fetch config.pkgs name spec; }
+          spec // { outPath = replace name (fetch config.pkgs name spec); }
     ) config.sources;
 
   # The "config" used by the fetchers
   mkConfig =
-    { sourcesFile ? ./sources.json
-    , sources ? builtins.fromJSON (builtins.readFile sourcesFile)
-    , pkgs ? mkPkgs sources
+    { sourcesFile ? if builtins.pathExists ./sources.json then ./sources.json else null
+    , sources ? if isNull sourcesFile then {} else builtins.fromJSON (builtins.readFile sourcesFile)
+    , system ? builtins.currentSystem
+    , pkgs ? mkPkgs sources system
     }: rec {
       # The sources, i.e. the attribute set of spec name to spec
       inherit sources;
@@ -130,5 +169,6 @@ let
       # The "pkgs" (evaluated nixpkgs) to use for e.g. non-builtin fetchers
       inherit pkgs;
     };
+
 in
 mkSources (mkConfig {}) // { __functor = _: settings: mkSources (mkConfig settings); }

src/DearImGui.hs

@@ -1,6 +1,7 @@
 {-# LANGUAGE BlockArguments #-}
 {-# LANGUAGE DuplicateRecordFields #-}
 {-# LANGUAGE FlexibleContexts #-}
+{-# LANGUAGE FlexibleInstances #-}
 {-# LANGUAGE LambdaCase #-}
 {-# LANGUAGE NamedFieldPuns #-}
 {-# LANGUAGE OverloadedStrings #-}
@@ -19,6 +20,8 @@ module DearImGui
     Raw.Context(..)
   , Raw.createContext
   , Raw.destroyContext
+  , Raw.getCurrentContext
+  , Raw.setCurrentContext
 
     -- * Main
   , Raw.newFrame
@@ -48,6 +51,15 @@ module DearImGui
 
   , begin
   , Raw.end
+
+    -- ** Utilities
+
+  , Raw.getWindowPos
+  , Raw.getWindowSize
+  , Raw.getWindowWidth
+  , Raw.getWindowHeight
+
+    -- ** Manipulation
   , setNextWindowPos
   , setNextWindowSize
   , Raw.setNextWindowFullscreen
@@ -56,15 +68,19 @@ module DearImGui
   , setNextWindowCollapsed
   , setNextWindowBgAlpha
 
-    -- * Child Windows
+    -- ** Child Windows
   , withChild
   , withChildOpen
+  , withChildContext
   , beginChild
   , Raw.endChild
 
     -- * Parameter stacks
+  , withStyleColor
   , pushStyleColor
   , Raw.popStyleColor
+
+  , withStyleVar
   , pushStyleVar
   , popStyleVar
 
@@ -74,9 +90,13 @@ module DearImGui
   , Raw.newLine
   , Raw.spacing
   , dummy
+
+  , withIndent
   , indent
   , unindent
+
   , setNextItemWidth
+  , withItemWidth
   , pushItemWidth
   , Raw.popItemWidth
 
@@ -87,6 +107,10 @@ module DearImGui
   , setCursorPos
   , Raw.alignTextToFramePadding
 
+    -- * ID stack
+  , withID
+  , ToID(..)
+
     -- * Widgets
     -- ** Text
   , text
@@ -99,7 +123,9 @@ module DearImGui
     -- ** Main
   , button
   , smallButton
+  , invisibleButton
   , arrowButton
+  , Raw.image
   , checkbox
   , progressBar
   , Raw.bullet
@@ -143,6 +169,8 @@ module DearImGui
 
     -- ** Text Input
   , inputText
+  , inputTextMultiline
+  , inputTextWithHint
 
     -- * Color Editor/Picker
   , colorPicker3
@@ -217,6 +245,13 @@ module DearImGui
   , Raw.wantCaptureMouse
   , Raw.wantCaptureKeyboard
 
+    -- * Fonts
+  , Raw.Font
+  , addFontFromFileTTF
+  , Raw.addFontDefault
+  , Raw.buildFontAtlas
+  , Raw.clearFontAtlas
+
     -- * Types
   , module DearImGui.Enums
   , module DearImGui.Structs
@@ -231,6 +266,9 @@ import Data.Foldable
   ( foldl' )
 import Foreign
 import Foreign.C
+import qualified GHC.Foreign as Foreign
+import System.IO
+  ( utf8 )
 
 -- dear-imgui
 import DearImGui.Enums
@@ -271,7 +309,7 @@ getVersion = liftIO do
 begin :: MonadIO m => String -> m Bool
 begin name = liftIO do
   withCString name \namePtr ->
-    Raw.begin namePtr nullPtr (ImGuiWindowFlags 0)
+    Raw.begin namePtr Nothing Nothing
 
 -- | Append items to a window.
 --
@@ -303,7 +341,7 @@ withFullscreen action = bracket open close (`when` action)
     open = liftIO do
       Raw.setNextWindowFullscreen
       withCString "FullScreen" \namePtr ->
-        Raw.begin namePtr nullPtr fullscreenFlags
+        Raw.begin namePtr (Just nullPtr) (Just fullscreenFlags)
 
     close = liftIO . const Raw.end
 
@@ -321,31 +359,58 @@ fullscreenFlags = foldl' (.|.) zeroBits
   , ImGuiWindowFlags_NoTitleBar
   ]
 
--- | Wraps @ImGui::BeginChild()@.
-beginChild :: MonadIO m => String -> m Bool
-beginChild name = liftIO do
-  withCString name Raw.beginChild
 
--- | Child windows used for self-contained independent scrolling/clipping regions
--- within a host window. Child windows can embed their own child.
+-- | Begin a self-contained independent scrolling/clipping regions within a host window.
+--
+-- Child windows can embed their own child.
+--
+-- For each independent axis of @size@:
+--   * ==0.0f: use remaining host window size
+--   * >0.0f: fixed size
+--   * <0.0f: use remaining window size minus abs(size)
+--
+-- Each axis can use a different mode, e.g. @ImVec2 0 400@.
+--
+-- @BeginChild()@ returns `False` to indicate the window is collapsed or fully clipped, so you may early out and omit submitting anything to the window.
+--
+-- Always call a matching `endChild` for each `beginChild` call, regardless of its return value.
+--
+-- Wraps @ImGui::BeginChild()@.
+beginChild :: MonadIO m => String -> ImVec2 -> Bool -> ImGuiWindowFlags -> m Bool
+beginChild name size border flags = liftIO do
+  withCString name \namePtr ->
+    with size \sizePtr ->
+      Raw.beginChild namePtr sizePtr (bool 0 1 border) flags
+
+-- | Action wrapper for child windows.
 --
 -- Action will get 'False' if the child region is collapsed or fully clipped.
-withChild :: MonadUnliftIO m => String -> (Bool -> m a) -> m a
-withChild name = bracket (beginChild name) (const Raw.endChild)
+withChild :: MonadUnliftIO m => String -> ImVec2 -> Bool -> ImGuiWindowFlags -> (Bool -> m a) -> m a
+withChild name size border flags = bracket (beginChild name size border flags) (const Raw.endChild)
 
--- | Child windows used for self-contained independent scrolling/clipping regions
--- within a host window. Child windows can embed their own child.
+-- | Action-skipping wrapper for child windows.
 --
 -- Action will be skipped if the child region is collapsed or fully clipped.
-withChildOpen :: MonadUnliftIO m => String -> m () -> m ()
-withChildOpen name action =
-  withChild name (`when` action)
+withChildOpen :: MonadUnliftIO m => String -> ImVec2 -> Bool -> ImGuiWindowFlags -> m () -> m ()
+withChildOpen name size border flags action =
+  withChild name size border flags (`when` action)
+
+-- | Action wrapper to run in a context of another child window addressed by its name.
+--
+-- Action will get 'False' if the child region is collapsed or fully clipped.
+withChildContext :: MonadUnliftIO m => String -> (Bool -> m a) -> m a
+withChildContext name action =
+  bracket
+    (liftIO $ withCString name Raw.beginChildContext)
+    (const Raw.endChild)
+    action
+
 
 -- | Plain text.
 text :: MonadIO m => String -> m ()
 text t = liftIO do
   withCString t \textPtr ->
-    Raw.textUnformatted textPtr nullPtr
+    Raw.textUnformatted textPtr Nothing
 
 -- | Colored text.
 textColored :: (HasGetter ref ImVec4, MonadIO m) => ref -> String -> m ()
@@ -395,6 +460,19 @@ smallButton label = liftIO do
   withCString label Raw.smallButton
 
 
+-- | Flexible button behavior without the visuals.
+--
+-- Frequently useful to build custom behaviors using the public api
+-- (along with IsItemActive, IsItemHovered, etc).
+--
+-- Wraps @ImGui::InvisibleButton()@.
+invisibleButton :: MonadIO m => String -> ImVec2 -> ImGuiButtonFlags -> m Bool
+invisibleButton label size flags = liftIO do
+  withCString label \labelPtr ->
+    with size \sizePtr ->
+      Raw.invisibleButton labelPtr sizePtr flags
+
+
 -- | Square button with an arrow shape.
 --
 -- Wraps @ImGui::ArrowButton()@.
@@ -1053,18 +1131,69 @@ vSliderScalar label size dataType ref refMin refMax format flags = liftIO do
 
 -- | Wraps @ImGui::InputText()@.
 inputText :: (MonadIO m, HasSetter ref String, HasGetter ref String) => String -> ref -> Int -> m Bool
-inputText desc ref refSize = liftIO do
+inputText label ref bufSize =
+  withInputString ref bufSize \bufPtrLen ->
+      Foreign.withCString utf8 label \labelPtr ->
+        Raw.inputText
+          labelPtr
+          bufPtrLen
+          ImGuiInputTextFlags_None
+
+
+-- | Wraps @ImGui::InputTextMultiline()@.
+inputTextMultiline :: (MonadIO m, HasSetter ref String, HasGetter ref String) => String -> ref -> Int -> ImVec2 -> m Bool
+inputTextMultiline label ref bufSize size =
+  withInputString ref bufSize \bufPtrLen ->
+    Foreign.withCString utf8 label \labelPtr ->
+      with size \sizePtr ->
+        Raw.inputTextMultiline
+          labelPtr
+          bufPtrLen
+          sizePtr
+          ImGuiInputTextFlags_None
+
+
+-- | Wraps @ImGui::InputTextWithHint()@.
+inputTextWithHint :: (MonadIO m, HasSetter ref String, HasGetter ref String) => String -> String -> ref -> Int -> m Bool
+inputTextWithHint label hint ref bufSize =
+  withInputString ref bufSize \bufPtrLen ->
+    Foreign.withCString utf8 label \labelPtr ->
+      Foreign.withCString utf8 hint \hintPtr ->
+        Raw.inputTextWithHint
+          labelPtr
+          hintPtr
+          bufPtrLen
+          ImGuiInputTextFlags_None
+
+
+-- | Internal helper to prepare appropriately sized and encoded input buffer.
+withInputString
+  :: (MonadIO m, HasSetter ref String, HasGetter ref String)
+  => ref
+  -> Int
+  -> (CStringLen -> IO Bool)
+  -> m Bool
+withInputString ref bufSize action = liftIO do
   input <- get ref
-  withCString input \ refPtr -> do
-    withCString desc \ descPtr -> do
-      let refSize' :: CInt
-          refSize' = fromIntegral refSize
-      changed <- Raw.inputText descPtr refPtr refSize'
+  Foreign.withCStringLen utf8 input \(refPtr, refSize) ->
+    -- XXX: Allocate and zero buffer to receive imgui updates.
+    bracket (mkBuf refSize) free \bufPtr -> do
+      -- XXX: Copy the original input.
+      copyBytes bufPtr refPtr refSize
+
+      changed <- action (bufPtr, bufSize)
 
       when changed do
-        peekCString refPtr >>= ($=!) ref
+        -- XXX: Assuming Imgui wouldn't write over the bump stop so peekCString would finish.
+        newValue <- Foreign.peekCString utf8 bufPtr
+        ref $=! newValue
 
       return changed
+  where
+    mkBuf refSize =
+      callocBytes $
+        max refSize bufSize +
+        5 -- XXX: max size of UTF8 code point + NUL terminator
 
 
 -- | Wraps @ImGui::ColorPicker3()@.
@@ -1357,9 +1486,9 @@ setNextWindowPos posRef cond pivotMaybe = liftIO do
       Just pivotRef -> do
         pivot <- get pivotRef
         with pivot $ \pivotPtr ->
-          Raw.setNextWindowPos posPtr cond pivotPtr
+          Raw.setNextWindowPos posPtr cond (Just pivotPtr)
       Nothing ->
-        Raw.setNextWindowPos posPtr cond nullPtr
+        Raw.setNextWindowPos posPtr cond Nothing
 
 -- | Set next window size. Call before `begin`
 --
@@ -1415,6 +1544,9 @@ dummy sizeRef = liftIO do
   size' <- get sizeRef
   with size' Raw.dummy
 
+withIndent :: MonadUnliftIO m => Float -> m a -> m a
+withIndent width =
+  bracket_ (indent width) (unindent width)
 
 -- | Move content position toward the right, by indent_w, or style.IndentSpacing if indent_w <= 0
 --
@@ -1440,6 +1572,10 @@ setNextItemWidth itemWidth = liftIO do
   Raw.setNextItemWidth (CFloat itemWidth)
 
 
+withItemWidth :: MonadUnliftIO m => Float -> m a -> m a
+withItemWidth width =
+  bracket_ (pushItemWidth width) Raw.popItemWidth
+
 -- Wraps @ImGui::PushItemWidth()@
 pushItemWidth :: (MonadIO m) => Float -> m ()
 pushItemWidth itemWidth = liftIO do
@@ -1460,8 +1596,52 @@ setCursorPos posRef = liftIO do
   pos <- get posRef
   with pos Raw.setCursorPos
 
+-- | Add an element to a ID stack
+--
+-- Read the FAQ (http://dearimgui.org/faq) for more details
+-- about how ID are handled in dear imgui.
+--
+-- Those questions are answered and impacted by understanding of the ID stack system:
+-- * "Q: Why is my widget not reacting when I click on it?"
+-- * "Q: How can I have widgets with an empty label?"
+-- * "Q: How can I have multiple widgets with the same label?"
+--
+-- Wraps @ImGui::PushId@ and @ImGui::PopId@
+withID :: (MonadUnliftIO m, ToID id) => id -> m a -> m a
+withID i = bracket_ (liftIO $ pushID i) Raw.popID
 
--- | Modify a style color by pushing to the shared stack. always use this if you modify the style after `newFrame`
+-- | A supplementary class to match overloaded functions in C++ the library.
+class ToID a where
+  pushID :: MonadIO m => a -> m ()
+
+instance ToID CInt where
+  pushID = Raw.pushIDInt
+
+instance ToID Int where
+  pushID = Raw.pushIDInt . fromIntegral
+
+instance ToID Integer where
+  pushID = Raw.pushIDInt . fromInteger
+
+instance {-# OVERLAPPABLE #-} ToID (Ptr a) where
+  pushID = Raw.pushIDPtr
+
+instance {-# OVERLAPPING #-} ToID (Ptr CChar) where
+  pushID = Raw.pushIDStr
+
+instance ToID (Ptr CChar, Int) where
+  pushID = Raw.pushIDStrLen
+
+instance ToID String where
+  pushID s = liftIO $ withCStringLen s pushID
+
+withStyleColor :: (MonadUnliftIO m, HasGetter ref ImVec4) => ImGuiCol -> ref -> m a -> m a
+withStyleColor color ref =
+  bracket_ (pushStyleColor color ref) (Raw.popStyleColor 1)
+
+-- | Modify a style color by pushing to the shared stack.
+--
+-- Always use this if you modify the style after `newFrame`.
 --
 -- Wraps @ImGui::PushStyleColor()@
 pushStyleColor :: (MonadIO m, HasGetter ref ImVec4) => ImGuiCol -> ref -> m ()
@@ -1470,8 +1650,13 @@ pushStyleColor col colorRef = liftIO do
   with color \colorPtr ->
     Raw.pushStyleColor col colorPtr
 
+withStyleVar :: (MonadUnliftIO m, HasGetter ref ImVec2) => ImGuiStyleVar -> ref -> m a -> m a
+withStyleVar style ref =
+  bracket_ (pushStyleVar style ref) (Raw.popStyleVar 1)
 
--- | Modify a style variable by pushing to the shared stack. always use this if you modify the style after `newFrame`
+-- | Modify a style variable by pushing to the shared stack.
+--
+-- Always use this if you modify the style after `newFrame`.
 --
 -- Wraps @ImGui::PushStyleVar()@
 pushStyleVar :: (MonadIO m, HasGetter ref ImVec2) => ImGuiStyleVar -> ref -> m ()
@@ -1480,10 +1665,28 @@ pushStyleVar style valRef = liftIO do
   with val \valPtr ->
     Raw.pushStyleVar style valPtr
 
-
 -- | Remove style variable modifications from the shared stack
 --
 -- Wraps @ImGui::PopStyleVar()@
 popStyleVar :: (MonadIO m) => Int -> m ()
 popStyleVar n = liftIO do
   Raw.popStyleVar (fromIntegral n)
+
+
+-- | Load a font from TTF file.
+--
+-- Specify font path and atlas glyph size.
+--
+-- Use 'addFontDefault' if you want to retain built-in font too.
+--
+-- Call 'buildFontAtlas' after adding all the fonts.
+--
+-- Call backend-specific `CreateFontsTexture` before using 'newFrame'.
+addFontFromFileTTF :: MonadIO m => FilePath -> Float -> m (Maybe Raw.Font)
+addFontFromFileTTF font size = liftIO do
+  res@(Raw.Font ptr) <- withCString font \fontPtr ->
+    Raw.addFontFromFileTTF fontPtr (CFloat size)
+  pure $
+    if castPtr ptr == nullPtr
+      then Nothing
+      else Just res

src/DearImGui/Context.hs

@@ -33,5 +33,7 @@ imguiContext = mempty
       [ ( TypeName "ImVec2", [t| ImVec2 |] )
       , ( TypeName "ImVec3", [t| ImVec3 |] )
       , ( TypeName "ImVec4", [t| ImVec4 |] )
+      , ( TypeName "ImGuiContext", [t| ImGuiContext |] )
+      , ( TypeName "ImFont", [t| ImFont |] )
       ]
   }

src/DearImGui/GLFW.hs

@@ -19,9 +19,33 @@ module DearImGui.GLFW (
     -- ** GLFW
     glfwNewFrame
   , glfwShutdown
+
+    -- $callbacks
+  , glfwWindowFocusCallback
+  , glfwCursorEnterCallback
+  , glfwMouseButtonCallback
+  , glfwScrollCallback
+  , glfwKeyCallback
+  , glfwCharCallback
+  , glfwMonitorCallback
   )
   where
 
+-- base
+import Foreign
+  ( Ptr, castPtr )
+import Foreign.C.Types
+  ( CInt, CDouble, CUInt )
+import Unsafe.Coerce (unsafeCoerce)
+
+-- bindings-GLFW
+import Bindings.GLFW
+  ( C'GLFWmonitor, C'GLFWwindow )
+
+-- GLFW-b
+import Graphics.UI.GLFW
+  ( Monitor, Window )
+
 -- inline-c
 import qualified Language.C.Inline as C
 
@@ -44,8 +68,121 @@ glfwNewFrame :: MonadIO m => m ()
 glfwNewFrame = liftIO do
   [C.exp| void { ImGui_ImplGlfw_NewFrame(); } |]
 
+-- $callbacks
+-- == GLFW callbacks
+-- * When calling Init with @install_callbacks=true@:
+--   GLFW callbacks will be installed for you.
+--   They will call user's previously installed callbacks, if any.
+-- * When calling Init with @install_callbacks=false@:
+--   GLFW callbacks won't be installed.
+--   You will need to call those function yourself from your own GLFW callbacks.
 
 -- | Wraps @ImGui_ImplGlfw_Shutdown@.
 glfwShutdown :: MonadIO m => m ()
 glfwShutdown = liftIO do
-  [C.exp| void { ImGui_ImplGlfw_Shutdown(); } |]
+  [C.exp| void { ImGui_ImplGlfw_Shutdown(); } |]
+
+glfwWindowFocusCallback :: MonadIO m => Window -> CInt -> m ()
+glfwWindowFocusCallback window focused = liftIO do
+  [C.exp| void {
+    ImGui_ImplGlfw_WindowFocusCallback(
+      static_cast<GLFWwindow *>(
+        $(void * windowPtr)
+      ),
+      $(int focused)
+    );
+  } |]
+  where
+    windowPtr = castPtr $ unWindow window
+
+glfwCursorEnterCallback :: MonadIO m => Window -> CInt -> m ()
+glfwCursorEnterCallback window entered = liftIO do
+  [C.exp| void {
+    ImGui_ImplGlfw_CursorEnterCallback(
+      static_cast<GLFWwindow *>(
+        $(void * windowPtr)
+      ),
+      $(int entered)
+    );
+  } |]
+  where
+    windowPtr = castPtr $ unWindow window
+
+glfwMouseButtonCallback :: MonadIO m => Window -> CInt -> CInt -> CInt -> m ()
+glfwMouseButtonCallback window button action mods = liftIO do
+  [C.exp| void {
+    ImGui_ImplGlfw_MouseButtonCallback(
+      static_cast<GLFWwindow *>(
+        $(void * windowPtr)
+      ),
+      $(int button),
+      $(int action),
+      $(int mods)
+    );
+  } |]
+  where
+    windowPtr = castPtr $ unWindow window
+
+glfwScrollCallback :: MonadIO m => Window -> CDouble -> CDouble -> m ()
+glfwScrollCallback window xoffset yoffset = liftIO do
+  [C.exp| void {
+    ImGui_ImplGlfw_ScrollCallback(
+      static_cast<GLFWwindow *>(
+        $(void * windowPtr)
+      ),
+      $(double xoffset),
+      $(double yoffset)
+    );
+  } |]
+  where
+    windowPtr = castPtr $ unWindow window
+
+glfwKeyCallback :: MonadIO m => Window -> CInt -> CInt -> CInt -> CInt -> m ()
+glfwKeyCallback window key scancode action mods = liftIO do
+  [C.exp| void {
+    ImGui_ImplGlfw_KeyCallback(
+      static_cast<GLFWwindow *>(
+        $(void * windowPtr)
+      ),
+      $(int key),
+      $(int scancode),
+      $(int action),
+      $(int mods)
+    );
+  } |]
+  where
+    windowPtr = castPtr $ unWindow window
+
+glfwCharCallback :: MonadIO m => Window -> CUInt -> m ()
+glfwCharCallback window c = liftIO do
+  [C.exp| void {
+    ImGui_ImplGlfw_CharCallback(
+      static_cast<GLFWwindow *>(
+        $(void * windowPtr)
+      ),
+      $(unsigned int c)
+    );
+  } |]
+  where
+    windowPtr = castPtr $ unWindow window
+
+glfwMonitorCallback :: MonadIO m => Monitor -> CInt -> m ()
+glfwMonitorCallback monitor event = liftIO do
+  [C.exp| void {
+    ImGui_ImplGlfw_MonitorCallback(
+      static_cast<GLFWmonitor *>(
+        $(void * monitorPtr)
+      ),
+      $(int event)
+    );
+  } |]
+  where
+    monitorPtr = castPtr $ unMonitor monitor
+
+-- | Strip the unpublished newtype wrapper.
+unWindow :: Window -> Ptr C'GLFWwindow
+unWindow = unsafeCoerce
+
+-- | Strip the unpublished newtype wrapper.
+unMonitor :: Monitor -> Ptr C'GLFWmonitor
+unMonitor = unsafeCoerce

src/DearImGui/Raw.hs

@@ -7,6 +7,7 @@
 {-# LANGUAGE PatternSynonyms #-}
 {-# LANGUAGE QuasiQuotes #-}
 {-# LANGUAGE TemplateHaskell #-}
+{-# LANGUAGE ViewPatterns #-}
 
 {-|
 Module: DearImGui
@@ -19,6 +20,8 @@ module DearImGui.Raw
     Context(..)
   , createContext
   , destroyContext
+  , getCurrentContext
+  , setCurrentContext
 
     -- * Main
   , newFrame
@@ -43,6 +46,16 @@ module DearImGui.Raw
     -- * Windows
   , begin
   , end
+
+    -- ** Utilities
+
+  , getWindowPos
+  , getWindowSize
+  , getWindowWidth
+  , getWindowHeight
+
+    -- ** Manipulation
+
   , setNextWindowPos
   , setNextWindowSize
   , setNextWindowFullscreen
@@ -51,8 +64,9 @@ module DearImGui.Raw
   , setNextWindowCollapsed
   , setNextWindowBgAlpha
 
-    -- * Child Windows
+    -- ** Child Windows
   , beginChild
+  , beginChildContext
   , endChild
 
     -- * Parameter stacks
@@ -89,7 +103,10 @@ module DearImGui.Raw
     -- ** Main
   , button
   , smallButton
+  , invisibleButton
   , arrowButton
+  , image
+  , imageButton
   , checkbox
   , progressBar
   , bullet
@@ -131,6 +148,8 @@ module DearImGui.Raw
 
     -- ** Text Input
   , inputText
+  , inputTextMultiline
+  , inputTextWithHint
 
     -- * Color Editor/Picker
   , colorPicker3
@@ -178,11 +197,26 @@ module DearImGui.Raw
   , openPopup
   , closeCurrentPopup
 
+    -- * ID stack/scopes
+  , pushIDInt
+  , pushIDPtr
+  , pushIDStr
+  , pushIDStrLen
+  , popID
+
     -- * Item/Widgets Utilities
   , isItemHovered
   , wantCaptureMouse
   , wantCaptureKeyboard
 
+    -- * Fonts in default font atlas
+  , Font(..)
+  , addFontDefault
+  , addFontFromFileTTF
+  , addFontFromMemoryTTF
+  , buildFontAtlas
+  , clearFontAtlas
+
     -- * Types
   , module DearImGui.Enums
   , module DearImGui.Structs
@@ -213,19 +247,30 @@ Cpp.using "namespace ImGui"
 
 
 -- | Wraps @ImGuiContext*@.
-newtype Context = Context (Ptr ())
+newtype Context = Context (Ptr ImGuiContext)
 
 
 -- | Wraps @ImGui::CreateContext()@.
 createContext :: (MonadIO m) => m Context
 createContext = liftIO do
-  Context <$> [C.exp| void* { CreateContext() } |]
+  Context <$> [C.exp| ImGuiContext* { CreateContext() } |]
 
 
 -- | Wraps @ImGui::DestroyContext()@.
 destroyContext :: (MonadIO m) => Context -> m ()
 destroyContext (Context contextPtr) = liftIO do
-  [C.exp| void { DestroyContext((ImGuiContext*)$(void* contextPtr)); } |]
+  [C.exp| void { DestroyContext($(ImGuiContext* contextPtr)); } |]
+
+-- | Wraps @ImGui::GetCurrentContext()@.
+getCurrentContext :: MonadIO m => m Context
+getCurrentContext = liftIO do
+  Context <$> [C.exp| ImGuiContext* { GetCurrentContext() } |]
+
+
+-- | Wraps @ImGui::SetCurrentContext()@.
+setCurrentContext :: MonadIO m => Context -> m ()
+setCurrentContext (Context contextPtr) = liftIO do
+  [C.exp| void { SetCurrentContext($(ImGuiContext* contextPtr)) } |]
 
 
 -- | Start a new Dear ImGui frame, you can submit any command from this point
@@ -339,10 +384,14 @@ styleColorsClassic = liftIO do
 --
 -- Passing non-null @Ptr CBool@ shows a window-closing widget in the upper-right corner of the window,
 -- wich clicking will set the boolean to false when clicked.
-begin :: (MonadIO m) => CString -> Ptr CBool -> ImGuiWindowFlags -> m Bool
-begin namePtr openPtr flags = liftIO do
+begin :: (MonadIO m) => CString -> Maybe (Ptr CBool) -> Maybe (ImGuiWindowFlags) -> m Bool
+begin namePtr (Just openPtr) (Just flags) = liftIO do
   (0 /=) <$> [C.exp| bool { Begin($(char* namePtr), $(bool* openPtr), $(ImGuiWindowFlags flags)) } |]
-
+begin namePtr (Just openPtr) Nothing = liftIO do
+  (0 /=) <$> [C.exp| bool { Begin($(char* namePtr), $(bool* openPtr)) } |]
+begin namePtr Nothing Nothing = liftIO do
+  (0 /=) <$> [C.exp| bool { Begin($(char* namePtr)) } |]
+begin _ Nothing _ = error "C++ default argument restriction."
 
 -- | Pop window from the stack.
 --
@@ -352,11 +401,47 @@ end = liftIO do
   [C.exp| void { End(); } |]
 
 
--- | Wraps @ImGui::BeginChild()@.
-beginChild :: (MonadIO m) => CString -> m Bool
-beginChild namePtr = liftIO do
-  (0 /=) <$> [C.exp| bool { BeginChild($(char* namePtr)) } |]
+-- | Begin a self-contained independent scrolling/clipping regions within a host window.
+--
+-- Child windows can embed their own child.
+--
+-- For each independent axis of @size@:
+--   * ==0.0f: use remaining host window size
+--   * >0.0f: fixed size
+--   * <0.0f: use remaining window size minus abs(size)
+--
+-- Each axis can use a different mode, e.g. @ImVec2 0 400@.
+--
+-- @BeginChild()@ returns `False` to indicate the window is collapsed or fully clipped, so you may early out and omit submitting anything to the window.
+--
+-- Always call a matching `endChild` for each `beginChild` call, regardless of its return value.
+--
+-- Wraps @ImGui::BeginChild()@.
+beginChild :: (MonadIO m) => CString -> Ptr ImVec2 -> CBool -> ImGuiWindowFlags -> m Bool
+beginChild namePtr sizePtr border flags = liftIO do
+  (0 /=) <$> [C.exp|
+    bool {
+      BeginChild(
+        $(char* namePtr),
+        *$(ImVec2* sizePtr),
+        $(bool border),
+        $(ImGuiWindowFlags flags)
+      )
+    }
+  |]
 
+-- | Switch context to another child window by its ID
+--
+-- Wraps @ImGui::BeginChild()@.
+beginChildContext :: (MonadIO m) => CString -> m Bool
+beginChildContext namePtr = liftIO do
+  (0 /=) <$> [C.exp|
+    bool {
+      BeginChild(
+        $(char* namePtr)
+      )
+    }
+  |]
 
 -- | Wraps @ImGui::EndChild()@.
 endChild :: (MonadIO m) => m ()
@@ -387,9 +472,11 @@ sameLine = liftIO do
 --   B) it's faster, no memory copy is done, no buffer size limits, recommended for long chunks of text.
 --
 -- Wraps @ImGui::TextUnformatted()@.
-textUnformatted :: (MonadIO m) => CString -> CString -> m ()
-textUnformatted textPtr textEndPtr = liftIO do
+textUnformatted :: (MonadIO m) => CString -> Maybe CString -> m ()
+textUnformatted textPtr (Just textEndPtr) = liftIO do
   [C.exp| void { TextUnformatted($(char* textPtr), $(char* textEndPtr)) } |]
+textUnformatted textPtr Nothing = liftIO do
+  [C.exp| void { TextUnformatted($(char* textPtr)) } |]
 
 -- | Shortcut for @PushStyleColor(ImGuiCol_Text, col); Text(fmt, ...); PopStyleColor();@.
 --
@@ -455,6 +542,24 @@ smallButton labelPtr = liftIO do
   (0 /=) <$> [C.exp| bool { SmallButton($(char* labelPtr)) } |]
 
 
+-- | Flexible button behavior without the visuals.
+--
+-- Frequently useful to build custom behaviors using the public api
+-- (along with IsItemActive, IsItemHovered, etc).
+--
+-- Wraps @ImGui::InvisibleButton()@.
+invisibleButton :: (MonadIO m) => CString -> Ptr ImVec2 -> ImGuiButtonFlags -> m Bool
+invisibleButton labelPtr size flags = liftIO do
+  (0 /=) <$> [C.exp|
+    bool {
+      InvisibleButton(
+        $(char* labelPtr),
+        *$(ImVec2* size),
+        $(ImGuiButtonFlags flags)
+      )
+    }
+  |]
+
 -- | Square button with an arrow shape.
 --
 -- Wraps @ImGui::ArrowButton()@.
@@ -463,6 +568,50 @@ arrowButton strIdPtr dir = liftIO do
   (0 /=) <$> [C.exp| bool { ArrowButton($(char* strIdPtr), $(ImGuiDir dir)) } |]
 
 
+-- | Image Area to draw a texture.
+--
+-- For OpenGL: The @userTextureIDPtr@ points to the texture memory (eg. @0x0000000000000001@)
+--
+-- See @examples/sdl/Image.hs@ for the whole process.
+--
+-- Wraps @ImGui::Image()@.
+image :: (MonadIO m) => Ptr () -> Ptr ImVec2 -> Ptr ImVec2 -> Ptr ImVec2 -> Ptr ImVec4 -> Ptr ImVec4 -> m ()
+image userTextureIDPtr sizePtr uv0Ptr uv1Ptr tintColPtr borderColPtr = liftIO do
+  [C.exp|
+    void {
+      Image(
+        $(void* userTextureIDPtr),
+        *$(ImVec2* sizePtr),
+        *$(ImVec2* uv0Ptr),
+        *$(ImVec2* uv1Ptr),
+        *$(ImVec4* tintColPtr),
+        *$(ImVec4* borderColPtr)
+      )
+    }
+  |]
+
+-- | Clickable Image Area.
+--
+-- Negative @frame_padding@ uses default frame padding settings. Set to 0 for no padding.
+--
+-- Wraps @ImGui::ImageButton()@.
+imageButton :: (MonadIO m) => Ptr () -> Ptr ImVec2 -> Ptr ImVec2 -> Ptr ImVec2 -> CInt -> Ptr ImVec4 -> Ptr ImVec4 -> m Bool
+imageButton userTextureIDPtr sizePtr uv0Ptr uv1Ptr framePadding bgColPtr tintColPtr = liftIO do
+  (0 /=) <$> [C.exp|
+    bool {
+      ImageButton(
+        $(void* userTextureIDPtr),
+        *$(ImVec2* sizePtr),
+        *$(ImVec2* uv0Ptr),
+        *$(ImVec2* uv1Ptr),
+        $(int framePadding),
+        *$(ImVec4* bgColPtr),
+        *$(ImVec4* tintColPtr)
+      )
+    }
+  |]
+
+
 -- | Wraps @ImGui::Checkbox()@.
 checkbox :: (MonadIO m) => CString -> Ptr CBool -> m Bool
 checkbox labelPtr boolPtr = liftIO do
@@ -850,10 +999,50 @@ vSliderScalar labelPtr sizePtr dataType dataPtr minPtr maxPtr formatPtr flags =
     minPtr_ = castPtr minPtr
     maxPtr_ = castPtr maxPtr
 
+
 -- | Wraps @ImGui::InputText()@.
-inputText :: (MonadIO m) => CString -> CString -> CInt -> m Bool
-inputText descPtr refPtr refSize = liftIO do
-  (0 /= ) <$> [C.exp| bool { InputText( $(char* descPtr), $(char* refPtr), $(int refSize) ) } |]
+inputText :: (MonadIO m) => CString -> CStringLen -> ImGuiInputTextFlags -> m Bool
+inputText labelPtr (bufPtr, fromIntegral -> bufSize) flags = liftIO do
+  (0 /= ) <$> [C.exp|
+    bool {
+      InputText(
+        $(char* labelPtr),
+        $(char* bufPtr),
+        $(int bufSize),
+        $(ImGuiInputTextFlags flags)
+      )
+    }
+  |]
+
+-- | Wraps @ImGui::InputTextMultiline()@.
+inputTextMultiline :: (MonadIO m) => CString -> CStringLen -> Ptr ImVec2 -> ImGuiInputTextFlags -> m Bool
+inputTextMultiline labelPtr (bufPtr, fromIntegral -> bufSize) sizePtr flags = liftIO do
+  (0 /= ) <$> [C.exp|
+    bool {
+      InputTextMultiline(
+        $(char* labelPtr),
+        $(char* bufPtr),
+        $(size_t bufSize),
+        *$(ImVec2* sizePtr),
+        $(ImGuiInputTextFlags flags)
+      )
+    }
+  |]
+
+-- | Wraps @ImGui::InputTextWithHint()@.
+inputTextWithHint :: (MonadIO m) => CString -> CString -> CStringLen -> ImGuiInputTextFlags -> m Bool
+inputTextWithHint labelPtr hintPtr (bufPtr, fromIntegral -> bufSize) flags = liftIO do
+  (0 /= ) <$> [C.exp|
+    bool {
+      InputTextWithHint(
+        $(char* labelPtr),
+        $(char* hintPtr),
+        $(char* bufPtr),
+        $(int bufSize),
+        $(ImGuiInputTextFlags flags)
+      )
+    }
+  |]
 
 
 -- | Wraps @ImGui::ColorPicker3()@.
@@ -1075,13 +1264,40 @@ isItemHovered :: (MonadIO m) => m Bool
 isItemHovered = liftIO do
   (0 /=) <$> [C.exp| bool { IsItemHovered() } |]
 
+getWindowPos :: (MonadIO m) => m ImVec2
+getWindowPos = liftIO do
+  C.withPtr_ \ptr ->
+    [C.block|
+      void {
+        *$(ImVec2 * ptr) = GetWindowPos();
+      }
+    |]
+
+getWindowSize :: (MonadIO m) => m ImVec2
+getWindowSize = liftIO do
+  C.withPtr_ \ptr ->
+    [C.block|
+      void {
+        *$(ImVec2 * ptr) = GetWindowSize();
+      }
+    |]
+
+getWindowWidth :: (MonadIO m) => m CFloat
+getWindowWidth = liftIO do
+  [C.exp| float { GetWindowWidth() } |]
+
+getWindowHeight :: (MonadIO m) => m CFloat
+getWindowHeight = liftIO do
+  [C.exp| float { GetWindowHeight() } |]
 
 -- | Set next window position. Call before `begin` Use pivot=(0.5,0.5) to center on given point, etc.
 --
 -- Wraps @ImGui::SetNextWindowPos()@
-setNextWindowPos :: (MonadIO m) => Ptr ImVec2 -> ImGuiCond -> Ptr ImVec2 -> m ()
-setNextWindowPos posPtr cond pivotPtr = liftIO do
+setNextWindowPos :: (MonadIO m) => Ptr ImVec2 -> ImGuiCond -> Maybe (Ptr ImVec2) -> m ()
+setNextWindowPos posPtr cond (Just pivotPtr) = liftIO do
   [C.exp| void { SetNextWindowPos(*$(ImVec2* posPtr), $(ImGuiCond cond), *$(ImVec2* pivotPtr)) } |]
+setNextWindowPos posPtr cond Nothing = liftIO do
+  [C.exp| void { SetNextWindowPos(*$(ImVec2* posPtr), $(ImGuiCond cond)) } |]
 
 
 -- | Set next window size. Call before `begin`
@@ -1261,6 +1477,44 @@ popStyleVar :: (MonadIO m) => CInt -> m ()
 popStyleVar n = liftIO do
   [C.exp| void { PopStyleVar($(int n)) } |]
 
+
+-- | Push integer into the ID stack (will hash int).
+--
+-- Wraps @ImGui::PushId@
+pushIDInt :: (MonadIO m) => CInt -> m ()
+pushIDInt intId = liftIO do
+  [C.exp| void { PushID($(int intId)) } |]
+
+-- | Push pointer into the ID stack (will hash pointer).
+--
+-- Wraps @ImGui::PushId@
+pushIDPtr :: (MonadIO m) => Ptr a -> m ()
+pushIDPtr ptr = liftIO do
+  [C.exp| void { PushID($(void * ptr_)) } |]
+  where
+    ptr_ = castPtr ptr
+
+-- | Push string into the ID stack (will hash string).
+--
+-- Wraps @ImGui::PushId@
+pushIDStr :: (MonadIO m) => CString -> m ()
+pushIDStr strId = liftIO do
+  [C.exp| void { PushID($(char * strId)) } |]
+
+-- | Push string into the ID stack (will hash string).
+--
+-- Wraps @ImGui::PushId@
+pushIDStrLen :: (MonadIO m) => CStringLen -> m ()
+pushIDStrLen (strBegin, strLen) = liftIO do
+  [C.exp| void { PushID($(char * strBegin), $(char * strEnd)) } |]
+  where
+    strEnd = plusPtr strBegin strLen
+
+popID :: (MonadIO m) => m ()
+popID = liftIO do
+  [C.exp| void { PopID() } |]
+
+
 wantCaptureMouse :: MonadIO m => m Bool
 wantCaptureMouse = liftIO do
   (0 /=) <$> [C.exp| bool { GetIO().WantCaptureMouse } |]
@@ -1268,3 +1522,54 @@ wantCaptureMouse = liftIO do
 wantCaptureKeyboard :: MonadIO m => m Bool
 wantCaptureKeyboard = liftIO do
   (0 /=) <$> [C.exp| bool { GetIO().WantCaptureKeyboard } |]
+
+
+-- | Wraps @ImFont*@.
+newtype Font = Font (Ptr ImFont)
+
+addFontDefault :: MonadIO m => m Font
+addFontDefault = liftIO do
+  Font <$> [C.block|
+    ImFont* {
+      return GetIO().Fonts->AddFontDefault();
+    }
+  |]
+
+addFontFromFileTTF :: MonadIO m => CString -> CFloat -> m Font
+addFontFromFileTTF filenamePtr sizePixels = liftIO do
+  Font <$> [C.block|
+    ImFont* {
+      return GetIO().Fonts->AddFontFromFileTTF(
+        $(char* filenamePtr),
+        $(float sizePixels));
+    }
+  |]
+
+-- | Transfer a buffer with TTF data to font atlas builder.
+addFontFromMemoryTTF :: MonadIO m => CStringLen -> CFloat -> m Font
+addFontFromMemoryTTF (castPtr -> fontDataPtr, fromIntegral -> fontSize) sizePixels = liftIO do
+  Font <$> [C.block|
+    ImFont* {
+      return GetIO().Fonts->AddFontFromMemoryTTF(
+        $(void* fontDataPtr),
+        $(int fontSize),
+        $(float sizePixels)
+      );
+    }
+  |]
+
+buildFontAtlas :: MonadIO m => m ()
+buildFontAtlas = liftIO do
+  [C.block|
+    void {
+      GetIO().Fonts->Build();
+    }
+  |]
+
+clearFontAtlas :: MonadIO m => m ()
+clearFontAtlas = liftIO do
+  [C.block|
+    void {
+      GetIO().Fonts->Clear();
+    }
+  |]

src/DearImGui/SDL.hs

@@ -40,7 +40,6 @@ import qualified Language.C.Inline.Cpp as Cpp
 
 -- sdl2
 import SDL
-import SDL.Internal.Types
 import SDL.Raw.Enum as Raw
 import qualified SDL.Raw.Event as Raw
 
@@ -57,9 +56,9 @@ Cpp.using "namespace ImGui"
 
 
 -- | Wraps @ImGui_ImplSDL2_NewFrame@.
-sdl2NewFrame :: MonadIO m => Window -> m ()
-sdl2NewFrame (Window windowPtr) = liftIO do
-  [C.exp| void { ImGui_ImplSDL2_NewFrame((SDL_Window*)($(void* windowPtr))); } |]
+sdl2NewFrame :: MonadIO m => m ()
+sdl2NewFrame = liftIO do
+  [C.exp| void { ImGui_ImplSDL2_NewFrame(); } |]
 
 
 -- | Wraps @ImGui_ImplSDL2_Shutdown@.

src/DearImGui/Structs.hs

@@ -9,6 +9,7 @@ import Foreign
 
 --------------------------------------------------------------------------------
 data ImVec2 = ImVec2 { x, y :: {-# unpack #-} !Float }
+  deriving (Show)
 
 
 instance Storable ImVec2 where
@@ -27,6 +28,7 @@ instance Storable ImVec2 where
 
 
 data ImVec3 = ImVec3 { x, y, z :: {-# unpack #-} !Float }
+  deriving (Show)
 
 
 instance Storable ImVec3 where
@@ -47,6 +49,7 @@ instance Storable ImVec3 where
 
 
 data ImVec4 = ImVec4 { x, y, z, w :: {-# unpack #-} !Float }
+  deriving (Show)
 
 
 instance Storable ImVec4 where
@@ -66,3 +69,11 @@ instance Storable ImVec4 where
     z <- peek (castPtr ptr `plusPtr` (sizeOf x * 2))
     w <- peek (castPtr ptr `plusPtr` (sizeOf x * 3))
     return ImVec4{ x, y, z, w }
+
+--------------------------------------------------------------------------------
+
+-- | DearImGui context handle.
+data ImGuiContext
+
+-- | Individual font handle.
+data ImFont