{ Free Pascal port of the OpenPTC C++ library. Copyright (C) 2001-2003 Nikolay Nikolov (nickysn@users.sourceforge.net) Original C++ version by Glenn Fiedler (ptc@gaffer.org) This library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with this library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA } Constructor TPTCClear.Create; Begin Fformat := Nil; { initialize hermes } If Not Hermes_Init Then Raise TPTCError.Create('could not initialize hermes'); { default current format } Fformat := TPTCFormat.Create; { create hermes clearer instance } Fhandle := Hermes_ClearerInstance; { check hermes clearer instance } If Fhandle = 0 Then Raise TPTCError.Create('could not create hermes clearer instance'); End; Destructor TPTCClear.Destroy; Begin { return the clearer instance } Hermes_ClearerReturn(Fhandle); Fformat.Free; { free hermes } Hermes_Done; Inherited Destroy; End; Procedure TPTCClear.request(Const format : TPTCFormat); Var hermes_format : PHermesFormat; Begin hermes_format := @format.Fformat; { request surface clear for this format } If Not Hermes_ClearerRequest(Fhandle, hermes_format) Then Raise TPTCError.Create('unsupported clear format'); { update current format } Fformat.Assign(format); End; Procedure TPTCClear.clear(pixels : Pointer; x, y, width, height, pitch : Integer; Const color : TPTCColor); Var r, g, b, a : LongInt; index : LongInt; Begin {$IFDEF DEBUG} { This checking is performed only when DEBUG is defined, and can be used to track down errors early caused by passing nil pointers to the clear function. Even though technically clear should never receive a nil pointer, we provide a check here to assist in debugging just in case it ever does! } If pixels = Nil Then Raise TPTCError.Create('nil pixels pointer in clear'); {$ELSE} { In release build no checking is performed for the sake of efficiency. } {$ENDIF} { check format type } If Fformat.direct Then Begin { check color type } If Not color.direct Then Raise TPTCError.Create('direct pixel formats can only be cleared with direct color'); { setup clear color } r := Trunc(color.r * 255); g := Trunc(color.g * 255); b := Trunc(color.b * 255); a := Trunc(color.a * 255); { clamp red } If r > 255 Then r := 255 Else If r < 0 Then r := 0; { clamp green } If g > 255 Then g := 255 Else If g < 0 Then g := 0; { clamp blue } If b > 255 Then b := 255 Else If b < 0 Then b := 0; { clamp alpha } If a > 255 Then a := 255 Else If a < 0 Then a := 0; { perform the clearing } Hermes_ClearerClear(Fhandle,pixels,x,y,width,height,pitch,r,g,b,a); End Else Begin { check color type } If Not color.indexed Then Raise TPTCError.Create('indexed pixel formats can only be cleared with indexed color'); { setup clear index } index := color.index; { clamp color index } If index > 255 Then index := 255 Else If index < 0 Then index := 0; { perform the clearing } Hermes_ClearerClear(Fhandle,pixels,x,y,width,height,pitch,0,0,0,index); End; End;