Rename grf -> graphics.

Full names are better.

common/graphics.fs

@@ -0,0 +1,81 @@
+\ Copyright 2022 Bradley D. Nelson
+\
+\ Licensed under the Apache License, Version 2.0 (the "License");
+\ you may not use this file except in compliance with the License.
+\ You may obtain a copy of the License at
+\
+\     http://www.apache.org/licenses/LICENSE-2.0
+\
+\ Unless required by applicable law or agreed to in writing, software
+\ distributed under the License is distributed on an "AS IS" BASIS,
+\ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+\ See the License for the specific language governing permissions and
+\ limitations under the License.
+
+( Generic Graphics Interface )
+\ Startup:
+\   window ( w h -- )
+\ Drawing region:
+\   pixel ( x y -- a ) (format [b g r x])
+\   width ( -- n )
+\   height ( -- n )
+\   flip ( -- )
+\ Getting events:
+\   wait ( -- )
+\   poll ( -- )
+\ Event info:
+\   mouse-x ( -- n )
+\   mouse-y ( -- n )
+\   last-key ( -- n )
+\   last-char ( -- n )
+\   pressed? ( k -- f )
+\   event ( -- n )
+\ Event constants:
+\   IDLE RESIZED EXPOSED MOTION
+\   PRESSED RELEASED TYPED FINISHED
+\ Key/Button constants:
+\   LEFT-BUTTON MIDDLE-BUTTON RIGHT-BUTTON
+
+vocabulary graphics   graphics definitions
+vocabulary internals
+
+0 constant IDLE
+1 constant RESIZED
+2 constant EXPOSED
+3 constant MOTION
+4 constant PRESSED
+5 constant RELEASED
+6 constant TYPED
+7 constant FINISHED
+
+255 constant LEFT-BUTTON
+254 constant MIDDLE-BUTTON
+253 constant RIGHT-BUTTON
+
+0 value mouse-x
+0 value mouse-y
+0 value last-key
+0 value last-char
+0 value event
+0 value width
+0 value height
+
+internals definitions
+
+0 value backbuffer
+
+256 constant key-count
+create key-state key-count allot
+key-state key-count erase
+
+: key-state! ( f k ) key-count mod key-state + c! ;
+
+graphics definitions also internals
+
+: pixel ( w h -- a ) width * + 4* backbuffer + ;
+
+: pressed? ( k -- f ) key-state + c@ 0<> ;
+
+( Rest of the core definitions per platform. )
+
+only forth definitions