From ba0b3e4f7c57925fea4b418356a283a3d8135f2d Mon Sep 17 00:00:00 2001
From: Rcmaniac25 <rcmaniac25@hotmail.com>
Date: Mon, 14 Dec 2015 16:22:25 +0000
Subject: [PATCH] Defined logic for glutCreateSubWindow when negative position
 is allowed

Added check for if fgCreateWindow cannot allocate a window, it will produce an error.

(cherry picked from commit 0ed05f64589fbcc67f225e1dc3ef6f5181fd319f)

(cherry picked from commit 0ed05f64589fbcc67f225e1dc3ef6f5181fd319f)

git-svn-id: svn+ssh://svn.code.sf.net/p/freeglut/code/trunk/freeglut/freeglut@1776 7f0cb862-5218-0410-a997-914c9d46530a
---
 src/fg_structure.c |    5 ++++
 src/fg_window.c    |   64 +++++++++++++++++++++++++++++++++-------------------
 2 files changed, 46 insertions(+), 23 deletions(-)

diff --git a/src/fg_structure.c b/src/fg_structure.c
index 6fbcc57..f0bc9a2 100644
--- a/src/fg_structure.c
+++ b/src/fg_structure.c
@@ -75,6 +75,11 @@ SFG_Window* fgCreateWindow( SFG_Window* parent, const char* title,
     /* Have the window object created */
     SFG_Window *window = (SFG_Window *)calloc( 1, sizeof(SFG_Window) );
 
+    if( !window )
+    {
+        fgError( "Out of memory. Could not create window." );
+    }
+
 	fgPlatformCreateWindow ( window );
 
     fghClearCallBacks( window );
diff --git a/src/fg_window.c b/src/fg_window.c
index 09fcddf..366bbf3 100644
--- a/src/fg_window.c
+++ b/src/fg_window.c
@@ -177,12 +177,12 @@ int FGAPIENTRY glutCreateWindow( const char* title )
      * XXX application has not already done so.  The "freeglut" community
      * XXX decided not to go this route (freeglut-developer e-mail from
      * XXX Steve Baker, 12/16/04, 4:22 PM CST, "Re: [Freeglut-developer]
-     * XXX Desired 'freeglut' behaviour when there is no current window"
+     * XXX Desired 'freeglut' behaviour when there is no current window")
      */
     FREEGLUT_EXIT_IF_NOT_INITIALISED ( "glutCreateWindow" );
 
-    return fgCreateWindow( NULL, title, fgState.Position.Use,
-                           fgState.Position.X, fgState.Position.Y,
+    return fgCreateWindow( NULL, title, 
+                           fgState.Position.Use, fgState.Position.X, fgState.Position.Y,
                            fgState.Size.Use, fgState.Size.X, fgState.Size.Y,
                            GL_FALSE, GL_FALSE )->ID;
 }
@@ -199,33 +199,51 @@ int FGAPIENTRY glutCreateSubWindow( int parentID, int x, int y, int w, int h )
     FREEGLUT_EXIT_IF_NOT_INITIALISED ( "glutCreateSubWindow" );
     parent = fgWindowByID( parentID );
     freeglut_return_val_if_fail( parent != NULL, 0 );
-    if ( x < 0 )
-    {
-        x = parent->State.Width + x ;
-        if ( w >= 0 ) x -= w ;
-    }
 
-    if ( w < 0 ) w = parent->State.Width - x + w ;
-    if ( w < 0 )
+    if ( fgState.AllowNegativeWindowPosition )
     {
-        x += w ;
-        w = -w ;
-    }
+        /* XXX This results in different widths/heights than if AllowNegativeWindowPosition
+         * XXX was false. The "freeglut" community defined this logic.
+         * XXX (freeglut-developer e-mail from Diederick C. Niehorster, 11/15/2015, 4:06 PM EST.
+         * XXX "Re: [Freeglut-developer] glutInitWindowPosition with negative coordinate(s)")
+         */
 
-    if ( y < 0 )
-    {
-        y = parent->State.Height + y ;
-        if ( h >= 0 ) y -= h ;
+        if ( w < 0 ) w = parent->State.Width + w ;
+        if ( h < 0 ) h = parent->State.Height + h ;
     }
-
-    if ( h < 0 ) h = parent->State.Height - y + h ;
-    if ( h < 0 )
+    else
     {
-        y += h ;
-        h = -h ;
+        if ( ( x < 0 ) )
+        {
+            x = parent->State.Width + x ;
+            if ( w > 0 ) x -= w ;
+        }
+
+        if ( w < 0 ) w = parent->State.Width - x + w ;
+        if ( w < 0 )
+        {
+            x += w ;
+            w = -w ;
+        }
+
+        if ( ( y < 0 ) )
+        {
+            y = parent->State.Height + y ;
+            if ( h > 0 ) y -= h ;
+        }
+
+        if ( h < 0 ) h = parent->State.Height - y + h ;
+        if ( h < 0 )
+        {
+            y += h ;
+            h = -h ;
+        }
     }
 
-    window = fgCreateWindow( parent, "", GL_TRUE, x, y, GL_TRUE, w, h, GL_FALSE, GL_FALSE );
+    window = fgCreateWindow( parent, "", 
+                             GL_TRUE, x, y, 
+                             GL_TRUE, w, h, 
+                             GL_FALSE, GL_FALSE );
     ret = window->ID;
 
     return ret;
-- 
1.7.10.4