Wrap the OpenGL 3 backend (#20)

Main.hs

@@ -8,7 +8,7 @@ module Main (main) where
 import Control.Monad
 import Data.IORef
 import DearImGui
-import DearImGui.OpenGL
+import DearImGui.OpenGL3
 import DearImGui.SDL
 import DearImGui.SDL.OpenGL
 import Control.Exception
@@ -23,7 +23,7 @@ main = do
     bracket (glCreateContext w) glDeleteContext \glContext ->
     bracket createContext destroyContext \_imguiContext ->
     bracket_ (sdl2InitForOpenGL w glContext) sdl2Shutdown $
-    bracket_ openGL2Init openGL2Shutdown do
+    bracket_ openGL3Init openGL3Shutdown do
       checkVersion
       styleColorsLight
 
@@ -38,7 +38,7 @@ main = do
       tab2 <- newIORef True
       loop w checked color slider r pos size' selected tab1 tab2
 
-      openGL2Shutdown
+      openGL3Shutdown
 
 
 loop 
@@ -56,7 +56,7 @@ loop
 loop w checked color slider r pos size' selected tab1Ref tab2Ref = do
   quit <- pollEvents
 
-  openGL2NewFrame
+  openGL3NewFrame
   sdl2NewFrame w
   newFrame
 
@@ -162,7 +162,7 @@ loop w checked color slider r pos size' selected tab1Ref tab2Ref = do
   render
 
   glClear GL_COLOR_BUFFER_BIT
-  openGL2RenderDrawData =<< getDrawData
+  openGL3RenderDrawData =<< getDrawData
 
   glSwapWindow w
 

README.md

@@ -41,7 +41,7 @@ import Control.Exception
 import Control.Monad.IO.Class
 import Control.Monad.Managed
 import DearImGui
-import DearImGui.OpenGL
+import DearImGui.OpenGL2
 import DearImGui.SDL
 import DearImGui.SDL.OpenGL
 import Graphics.GL

cabal.project

@@ -1,3 +1,3 @@
 packages: *.cabal
 package dear-imgui
-  flags: +sdl2 +glfw +opengl +vulkan
+  flags: +sdl2 +glfw +opengl2 +opengl3 +vulkan

dear-imgui.cabal

@@ -5,9 +5,17 @@ build-type: Simple
 data-files:
   imgui/imgui.h
 
-flag opengl
+flag opengl2
   description:
-    Enable OpenGL backend.
+    Enable OpenGL 2 backend.
+  default:
+    False
+  manual:
+    False
+
+flag opengl3
+  description:
+    Enable OpenGL 3 backend.
   default:
     True
   manual:
@@ -76,21 +84,29 @@ library
     , inline-c-cpp
     , StateVar
 
-  if flag(opengl)
+  if flag(opengl2)
     exposed-modules:
-      DearImGui.OpenGL
+      DearImGui.OpenGL2
     cxx-sources:
       imgui/backends/imgui_impl_opengl2.cpp
+    build-depends:
+      gl
+
+  if flag(opengl3)
+    exposed-modules:
+      DearImGui.OpenGL3
+    cxx-sources:
+      imgui/backends/imgui_impl_opengl3.cpp
     if os(windows)
-      extra-libraries:
-        opengl32
+      buildable:
+        False
     else
       if os(darwin)
-        frameworks:
-          OpenGL
+        buildable:
+          False
       else
-        extra-libraries:
-          GL
+        pkgconfig-depends:
+          glew
 
   if flag(vulkan)
     exposed-modules:
@@ -128,7 +144,7 @@ library
       pkgconfig-depends:
         sdl2
 
-    if flag(opengl)
+    if flag(opengl2) || flag(opengl3)
       exposed-modules:
         DearImGui.SDL.OpenGL
 
@@ -148,7 +164,7 @@ library
       pkgconfig-depends:
         glfw3
 
-    if flag(opengl)
+    if flag(opengl2) || flag(opengl3)
       exposed-modules:
         DearImGui.GLFW.OpenGL
 

examples/Readme.hs

@@ -11,7 +11,7 @@ import Control.Exception
 import Control.Monad.IO.Class
 import Control.Monad.Managed
 import DearImGui
-import DearImGui.OpenGL
+import DearImGui.OpenGL2
 import DearImGui.SDL
 import DearImGui.SDL.OpenGL
 import Graphics.GL

examples/glfw/Main.hs

@@ -9,7 +9,7 @@ import Control.Monad
 import Control.Monad.IO.Class
 import Control.Monad.Managed
 import DearImGui
-import DearImGui.OpenGL
+import DearImGui.OpenGL2
 import DearImGui.GLFW
 import DearImGui.GLFW.OpenGL
 import Graphics.GL

src/DearImGui/OpenGL2.hs

@@ -9,10 +9,10 @@
 {-|
 Module: DearImGui.OpenGL
 
-OpenGL backend for Dear ImGui.
+OpenGL 2 backend for Dear ImGui.
 -}
 
-module DearImGui.OpenGL
+module DearImGui.OpenGL2
   ( openGL2Init
   , openGL2Shutdown
   , openGL2NewFrame

src/DearImGui/OpenGL3.hs

@@ -0,0 +1,69 @@
+{-# LANGUAGE BlockArguments #-}
+{-# LANGUAGE FlexibleContexts #-}
+{-# LANGUAGE NamedFieldPuns #-}
+{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE PatternSynonyms #-}
+{-# LANGUAGE QuasiQuotes #-}
+{-# LANGUAGE TemplateHaskell #-}
+
+{-|
+Module: DearImGui.OpenGL
+
+OpenGL 3 backend for Dear ImGui.
+-}
+
+module DearImGui.OpenGL3
+  ( openGL3Init
+  , openGL3Shutdown
+  , openGL3NewFrame
+  , openGL3RenderDrawData
+  )
+  where
+
+-- inline-c
+import qualified Language.C.Inline as C
+
+-- inline-c-cpp
+import qualified Language.C.Inline.Cpp as Cpp
+
+-- transformers
+import Control.Monad.IO.Class
+  ( MonadIO, liftIO )
+
+-- DearImGui
+import DearImGui
+  ( DrawData(..) )
+
+
+C.context (Cpp.cppCtx <> C.bsCtx)
+C.include "imgui.h"
+C.include "GL/glew.h"
+C.include "backends/imgui_impl_opengl3.h"
+Cpp.using "namespace ImGui"
+
+
+-- | Wraps @ImGui_ImplOpenGL3_Init@.
+openGL3Init :: MonadIO m => m Bool
+openGL3Init = liftIO $
+  ( 0 /= ) <$> [C.block| bool {
+    glewInit();
+    return ImGui_ImplOpenGL3_Init();
+  } |]
+
+
+-- | Wraps @ImGui_ImplOpenGL3_Shutdown@.
+openGL3Shutdown :: MonadIO m => m ()
+openGL3Shutdown = liftIO do
+  [C.exp| void { ImGui_ImplOpenGL3_Shutdown(); } |]
+
+
+-- | Wraps @ImGui_ImplOpenGL3_NewFrame@.
+openGL3NewFrame :: MonadIO m => m ()
+openGL3NewFrame = liftIO do
+  [C.exp| void { ImGui_ImplOpenGL3_NewFrame(); } |]
+
+
+-- | Wraps @ImGui_ImplOpenGL3_RenderDrawData@.
+openGL3RenderDrawData :: MonadIO m => DrawData -> m ()
+openGL3RenderDrawData (DrawData ptr) = liftIO do
+  [C.exp| void { ImGui_ImplOpenGL3_RenderDrawData((ImDrawData*) $( void* ptr )) } |]