From 347eb5647bc6c765911ff59d911a824ebf508535 Mon Sep 17 00:00:00 2001
From: Joe Groff <arcata@gmail.com>
Date: Tue, 9 Dec 2008 18:55:54 -0800
Subject: [PATCH] windows backend for ui.offscreen

---
 basis/ui/windows/windows.factor        | 53 +++++++++++++++++++++++---
 basis/windows/opengl32/opengl32.factor |  8 ++--
 2 files changed, 52 insertions(+), 9 deletions(-)

diff --git a/basis/ui/windows/windows.factor b/basis/ui/windows/windows.factor
index f6f449625f..e696c3fa6f 100755
--- a/basis/ui/windows/windows.factor
+++ b/basis/ui/windows/windows.factor
@@ -69,9 +69,11 @@ M: pasteboard set-clipboard-contents drop copy ;
     <pasteboard> clipboard set-global
     <clipboard> selection set-global ;
 
-! world-handle is a <win>
-TUPLE: win hWnd hDC hRC world title ;
+TUPLE: win-base hDC hRC ;
+TUPLE: win hWnd < win-base world title ;
+TUPLE: win-offscreen < win-base hBitmap bits ;
 C: <win> win
+C: <win-offscreen> win-offscreen
 
 SYMBOLS: msg-obj class-name-ptr mouse-captured ;
 
@@ -478,7 +480,7 @@ M: windows-ui-backend do-events
     f class-name-ptr set-global
     f msg-obj set-global ;
 
-: setup-pixel-format ( hdc -- )
+: setup-pixel-format ( hdc flags -- )
     16 make-pfd [ ChoosePixelFormat dup win32-error=0/f ] 2keep
     swapd SetPixelFormat win32-error=0/f ;
 
@@ -489,7 +491,7 @@ M: windows-ui-backend do-events
     [ wglMakeCurrent win32-error=0/f ] keep ;
 
 : setup-gl ( hwnd -- hDC hRC )
-    get-dc dup setup-pixel-format dup get-rc ;
+    get-dc dup windowed-pfd-dwFlags setup-pixel-format dup get-rc ;
 
 M: windows-ui-backend (open-window) ( world -- )
     [ create-window dup setup-gl ] keep
@@ -498,12 +500,51 @@ M: windows-ui-backend (open-window) ( world -- )
     dupd (>>handle)
     hWnd>> show-window ;
 
-M: win select-gl-context ( handle -- )
+M: win-base select-gl-context ( handle -- )
     [ hDC>> ] keep hRC>> wglMakeCurrent win32-error=0/f ;
 
-M: win flush-gl-context ( handle -- )
+M: win-base flush-gl-context ( handle -- )
     hDC>> SwapBuffers win32-error=0/f ;
 
+: (bitmap-info) ( dim -- BITMAPINFO )
+    "BITMAPINFO" <c-object> [
+        BITMAPINFO-bmiHeader {
+            [ nip "BITMAPINFOHEADER" heap-size swap set-BITMAPINFOHEADER-biSize ]
+            [ [ first ] dip set-BITMAPINFOHEADER-biWidth ]
+            [ [ second ] dip set-BITMAPINFOHEADER-biHeight ]
+            [ nip 1 swap set-BITMAPINFOHEADER-biPlanes ]
+            [ nip 32 swap set-BITMAPINFOHEADER-biBitCount ]
+            [ nip BI_RGB swap set-BITMAPINFOHEADER-biCompression ]
+            [ [ first2 * 4 * ] dip swap set-BITMAPINFOHEADER-biSizeImage ]
+            [ nip 72 swap set-BITMAPINFOHEADER-biXPelsPerMeter ]
+            [ nip 72 swap set-BITMAPINFOHEADER-biYPelsPerMeter ]
+            [ nip 0 swap set-BITMAPINFOHEADER-biClrUsed ]
+            [ nip 0 swap set-BITMAPINFOHEADER-biClrImportant ]
+        } 2cleave
+    ] keep ;
+
+: make-offscreen-dc-and-bitmap ( dim -- hDC hBitmap bits )
+    f CreateCompatibleDC
+    swap (bitmap-info) DIB_RGB_COLORS f <void*>
+    [ f 0 CreateDIBSection ] keep *void*
+    [ 2dup SelectObject drop ] dip ;
+
+: setup-offscreen-gl ( dim -- hDC hRC hBitmap bits )
+    make-offscreen-dc-and-bitmap [
+        [ dup offscreen-pfd-dwFlags setup-pixel-format ]
+        [ get-rc ] bi
+    ] 2dip ;
+
+M: windows-ui-backend (open-offscreen-buffer) ( world -- )
+    dup dim>> setup-offscreen-gl <win-offscreen>
+    >>handle drop ;
+M: windows-ui-backend (close-offscreen-buffer) ( handle -- )
+    [ hDC>> DeleteObject drop ]
+    [ hBitmap>> DeleteObject drop ] bi ;
+
+M: win-offscreen offscreen-pixels ( handle -- alien )
+    bits>> ;
+
 ! Move window to front
 M: windows-ui-backend raise-window* ( world -- )
     handle>> [
diff --git a/basis/windows/opengl32/opengl32.factor b/basis/windows/opengl32/opengl32.factor
index df09d9327a..c09b30164f 100644
--- a/basis/windows/opengl32/opengl32.factor
+++ b/basis/windows/opengl32/opengl32.factor
@@ -71,15 +71,17 @@ IN: windows.opengl32
 : WGL_SWAP_UNDERLAY14     HEX: 20000000 ; inline
 : WGL_SWAP_UNDERLAY15     HEX: 40000000 ; inline
 
-: pfd-dwFlags ( -- n )
+: windowed-pfd-dwFlags ( -- n )
     { PFD_DRAW_TO_WINDOW PFD_SUPPORT_OPENGL PFD_DOUBLEBUFFER } flags ;
+: offscreen-pfd-dwFlags ( -- n )
+    { PFD_DRAW_TO_BITMAP PFD_SUPPORT_OPENGL PFD_SUPPORT_GDI } flags ;
 
 ! TODO: compare to http://www.nullterminator.net/opengl32.html
-: make-pfd ( bits -- pfd )
+: make-pfd ( flags bits -- pfd )
     "PIXELFORMATDESCRIPTOR" <c-object>
     "PIXELFORMATDESCRIPTOR" heap-size over set-PIXELFORMATDESCRIPTOR-nSize
     1 over set-PIXELFORMATDESCRIPTOR-nVersion
-    pfd-dwFlags over set-PIXELFORMATDESCRIPTOR-dwFlags
+    rot over set-PIXELFORMATDESCRIPTOR-dwFlags
     PFD_TYPE_RGBA over set-PIXELFORMATDESCRIPTOR-iPixelType
     [ set-PIXELFORMATDESCRIPTOR-cColorBits ] keep
     16 over set-PIXELFORMATDESCRIPTOR-cDepthBits
-- 
2.34.1