From d8dd8f967ec5c33d57fba093b4ad4580df413395 Mon Sep 17 00:00:00 2001
From: Eduardo Cavazos <dharmatech@finkelstein.stackeffects.info>
Date: Sun, 6 Apr 2008 16:22:05 -0500
Subject: [PATCH] Add frame-buffer

---
 extra/frame-buffer/frame-buffer.factor | 113 +++++++++++++++++++++++++
 1 file changed, 113 insertions(+)
 create mode 100644 extra/frame-buffer/frame-buffer.factor

diff --git a/extra/frame-buffer/frame-buffer.factor b/extra/frame-buffer/frame-buffer.factor
new file mode 100644
index 0000000000..eb9ada7d84
--- /dev/null
+++ b/extra/frame-buffer/frame-buffer.factor
@@ -0,0 +1,113 @@
+
+USING: kernel alien.c-types combinators sequences splitting
+       opengl.gl ui.gadgets ui.render
+       math math.vectors accessors ;
+
+IN: frame-buffer
+
+! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
+
+TUPLE: frame-buffer action dim last-dim graft ungraft pixels ;
+
+! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
+
+: init-frame-buffer-pixels ( frame-buffer -- frame-buffer )
+  dup
+    rect-dim product "uint[4]" <c-array>
+  >>pixels ;
+
+! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
+
+: <frame-buffer> ( -- frame-buffer )
+  frame-buffer construct-gadget
+    [ ]         >>action
+    { 100 100 } >>dim
+    [ ]         >>graft
+    [ ]         >>ungraft ;
+
+! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
+
+: draw-pixels ( fb -- fb )
+  dup >r
+  dup >r
+  rect-dim first2 GL_RGBA GL_UNSIGNED_INT r> pixels>> glDrawPixels
+  r> ;
+
+! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
+
+: read-pixels ( fb -- fb )
+  dup >r
+  dup >r
+      >r
+  0 0 r> rect-dim first2 GL_RGBA GL_UNSIGNED_INT r> pixels>> glReadPixels
+  r> ;
+
+! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
+
+M: frame-buffer pref-dim* dim>> ;
+M: frame-buffer graft*    graft>>   call ;
+M: frame-buffer ungraft*  ungraft>> call ;
+
+! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
+
+: copy-row ( old new -- )
+  2dup min-length swap >r head-slice 0 r> copy ;
+
+! : copy-pixels ( old-pixels old-width new-pixels new-width -- )
+!   [ group ] 2bi@
+!   [ copy-row ] 2each ;
+
+! : copy-pixels ( old-pixels old-width new-pixels new-width -- )
+!   [ 16 * group ] 2bi@
+!   [ copy-row ] 2each ;
+
+: copy-pixels ( old-pixels old-width new-pixels new-width -- )
+  [ 16 * <sliced-groups> ] 2bi@
+  [ copy-row ] 2each ;
+
+! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
+
+M: frame-buffer layout* ( fb -- )
+   {
+     {
+       [ dup last-dim>> f = ]
+       [
+         init-frame-buffer-pixels
+         dup
+           rect-dim >>last-dim
+         drop
+       ]
+     }
+     {
+       [ dup [ rect-dim ] [ last-dim>> ] bi = not ]
+       [
+         dup [ pixels>> ] [ last-dim>> first ] bi
+
+         rot init-frame-buffer-pixels
+         dup rect-dim >>last-dim
+
+         [ pixels>> ] [ rect-dim first ] bi
+
+         copy-pixels
+       ]
+     }
+     { [ t ] [ drop ] }
+   }
+   cond ;
+   
+! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
+
+M: frame-buffer draw-gadget* ( fb -- )
+
+   dup rect-dim { 0 1 } v* first2 glRasterPos2i
+
+   draw-pixels
+
+   dup action>> call
+
+   glFlush
+
+   read-pixels
+
+   drop ;
+