From 84d4e52eaee3947e0111c882cecafea938e90de5 Mon Sep 17 00:00:00 2001
From: marc <marc@lazarus-ide.org>
Date: Sun, 23 Jun 2013 19:46:43 +0000
Subject: [PATCH] Add scanline support

git-svn-id: trunk@41855 -
---
 lcl/graphics.pp             | 3 ++-
 lcl/graphtype.pp            | 9 +++++++++
 lcl/include/rasterimage.inc | 8 ++++++++
 3 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/lcl/graphics.pp b/lcl/graphics.pp
index 2970bbdc1b..e4925be268 100644
--- a/lcl/graphics.pp
+++ b/lcl/graphics.pp
@@ -1297,6 +1297,7 @@ type
     procedure FreeCanvasContext;
     function  GetCanvas: TCanvas;
     function  GetRawImage: TRawImage;
+    function  GetScanline(ARow: Integer): Pointer;
     function  GetTransparentColor: TColor;
     procedure SetTransparentColor(AValue: TColor);
   protected
@@ -1379,7 +1380,7 @@ type
     property MaskHandle: HBITMAP read GetMaskHandle write SetMaskHandle;
     property PixelFormat: TPixelFormat read GetPixelFormat write SetPixelFormat default pfDevice;
     property RawImage: TRawImage read GetRawImage; // be carefull with this, modify only within a begin/endupdate
-    // property ScanLine[Row: Integer]: Pointer; -> Use TLazIntfImage for such things
+    property ScanLine[Row: Integer]: Pointer read GetScanLine; platform; // Use only when wrpped by a begin/endupdate
     property TransparentColor: TColor read GetTransparentColor
                                       write SetTransparentColor default clDefault;
     property TransparentMode: TTransparentMode read FTransparentMode
diff --git a/lcl/graphtype.pp b/lcl/graphtype.pp
index 7aeb2e3bb6..54e297bb36 100644
--- a/lcl/graphtype.pp
+++ b/lcl/graphtype.pp
@@ -209,6 +209,7 @@ type
     procedure ReleaseData;
     procedure ExtractRect(const ARect: TRect; out ADst: TRawImage);
 
+    function  GetLineStart(ALine: Cardinal): PByte;
     procedure PerformEffect(const ADrawEffect: TGraphicsDrawEffect; CreateNewData: Boolean = True; FreeOldData: boolean = false);
     function  ReadBits(const APosition: TRawImagePosition; APrec, AShift: Byte): Word;
     procedure ReadChannels(const APosition: TRawImagePosition; out ARed, AGreen, ABlue, AAlpha: Word);
@@ -1585,6 +1586,14 @@ begin
               Description.MaskLineEnd, ADst.Mask, ADst.MaskSize);
 end;
 
+function TRawImage.GetLineStart(ALine: Cardinal): PByte;
+begin
+  Result := Data;
+  if Result = nil then Exit;
+  if ALine = 0 then Exit;
+  Inc(Result, ALine * Description.BytesPerLine);
+end;
+
 procedure TRawImage.PerformEffect(const ADrawEffect: TGraphicsDrawEffect;
   CreateNewData: Boolean; FreeOldData: boolean);
   
diff --git a/lcl/include/rasterimage.inc b/lcl/include/rasterimage.inc
index fefdbe88a1..5f407ffb98 100644
--- a/lcl/include/rasterimage.inc
+++ b/lcl/include/rasterimage.inc
@@ -467,6 +467,14 @@ begin
   else Result := p^;
 end;
 
+function TRasterImage.GetScanline(ARow: Integer): Pointer;
+var
+  RI: TRawImage;
+begin
+  RI := GetRawImage;
+  Result := RI.GetLineStart(ARow);
+end;
+
 function TRasterImage.GetTransparentColor: TColor;
 begin
   if FTransparentColor = clDefault