From 606445f790e290fae775a00c4f5ccb257a713a0b Mon Sep 17 00:00:00 2001
From: Doug Coleman <doug.coleman@gmail.com>
Date: Sat, 29 Mar 2008 15:31:31 -0500
Subject: [PATCH] improve png

---
 extra/cairo/ffi/ffi.factor |  3 +++
 extra/cairo/png/png.factor | 27 ++++++++++++++++++++++++---
 2 files changed, 27 insertions(+), 3 deletions(-)

diff --git a/extra/cairo/ffi/ffi.factor b/extra/cairo/ffi/ffi.factor
index 76ce27975b..c319ade93b 100644
--- a/extra/cairo/ffi/ffi.factor
+++ b/extra/cairo/ffi/ffi.factor
@@ -203,6 +203,9 @@ C-ENUM:
     CAIRO_HINT_METRICS_ON
 ;
 
+FUNCTION: char* cairo_status_to_string ( cairo_status_t status ) ;
+FUNCTION: cairo_status_t cairo_status ( cairo_t* cr ) ;
+
 : cairo_create ( cairo_surface_t -- cairo_t )
     "cairo_t*" "cairo" "cairo_create" [ "void*" ] alien-invoke ;
 
diff --git a/extra/cairo/png/png.factor b/extra/cairo/png/png.factor
index eaab28e659..774a1afe8e 100755
--- a/extra/cairo/png/png.factor
+++ b/extra/cairo/png/png.factor
@@ -1,16 +1,34 @@
 ! Copyright (C) 2008 Doug Coleman.
 ! See http://factorcode.org/license.txt for BSD license.
 USING: arrays kernel accessors math ui.gadgets ui.render
-opengl.gl byte-arrays namespaces opengl cairo.ffi cairo.lib ;
+opengl.gl byte-arrays namespaces opengl cairo.ffi cairo.lib
+inspector sequences combinators io.backend ;
 IN: cairo.png
 
 TUPLE: png surface width height cairo-t array ;
 TUPLE: png-gadget png ;
 
+ERROR: cairo-error string ;
+
+: check-zero
+    dup zero? [
+        "PNG dimension is 0" cairo-error
+    ] when ;
+
+: cairo-png-error ( n -- )
+    {
+        { [ dup CAIRO_STATUS_NO_MEMORY = ] [ "Cairo: no memory" cairo-error ] }
+        { [ dup CAIRO_STATUS_FILE_NOT_FOUND = ] [ "Cairo: file not found" cairo-error ] }
+        { [ dup CAIRO_STATUS_READ_ERROR = ] [ "Cairo: read error" cairo-error ] }
+        { [ t ] [ drop ] }
+    } cond ;
+
 : <png> ( path -- png )
+    normalize-pathname
     cairo_image_surface_create_from_png
-    dup [ cairo_image_surface_get_width ]
-    [ cairo_image_surface_get_height ] [ ] tri
+    dup cairo_surface_status cairo-png-error
+    dup [ cairo_image_surface_get_width check-zero ]
+    [ cairo_image_surface_get_height check-zero ] [ ] tri
     cairo-surface>array png construct-boa ;
 
 : write-png ( png path -- )
@@ -33,6 +51,7 @@ M: png-gadget draw-gadget* ( gadget -- )
         png>>
         [ width>> ]
         [ height>> GL_RGBA GL_UNSIGNED_BYTE ]
+        ! [ height>> GL_BGRA GL_UNSIGNED_BYTE ]
         [ array>> ] tri
         glDrawPixels
     ] with-translation ;
@@ -42,3 +61,5 @@ M: png-gadget graft* ( gadget -- )
 
 M: png-gadget ungraft* ( gadget -- )
     png>> surface>> cairo_destroy ;
+
+! "resource:misc/icons/Factor_1x16.png" USE: cairo.png <png-gadget> gadget.