Examples: Adapt comments and code in the "scanline" sample project. Issue #41003.

(cherry picked from commit 52fc791feb)

Co-authored-by: wp_xyz <wp_xxyyzzz@gmx.net>

examples/scanline/bitmapscanline1.lpi

@@ -1,26 +1,26 @@
-<?xml version="1.0"?>
+<?xml version="1.0" encoding="UTF-8"?>
 <CONFIG>
   <ProjectOptions>
-    <Version Value="5"/>
+    <Version Value="12"/>
     <General>
+      <Flags>
+        <LRSInOutputDirectory Value="False"/>
+        <CompatibilityMode Value="True"/>
+      </Flags>
       <SessionStorage Value="InProjectDir"/>
-      <MainUnit Value="0"/>
-      <IconPath Value="./"/>
-      <TargetFileExt Value=""/>
       <Title Value="project1"/>
     </General>
-    <VersionInfo>
+    <BuildModes Count="1">
-      <ProjectVersion Value=""/>
+      <Item1 Name="default" Default="True"/>
-    </VersionInfo>
+    </BuildModes>
     <PublishOptions>
       <Version Value="2"/>
-      <IncludeFileFilter Value="*.(pas|pp|inc|lfm|lpr|lrs|lpi|lpk|sh|xml)"/>
-      <ExcludeFileFilter Value="*.(bak|ppu|ppw|o|so);*~;backup"/>
     </PublishOptions>
     <RunParams>
-      <local>
+      <FormatVersion Value="2"/>
-        <FormatVersion Value="1"/>
+      <Modes Count="1">
-      </local>
+        <Mode0 Name="default"/>
+      </Modes>
     </RunParams>
     <RequiredPackages Count="1">
       <Item1>
@@ -35,30 +35,30 @@
       </Unit0>
       <Unit1>
         <Filename Value="unit1.pas"/>
-        <ComponentName Value="Form1"/>
         <IsPartOfProject Value="True"/>
-        <ResourceFilename Value="unit1.lrs"/>
+        <ComponentName Value="Form1"/>
+        <HasResources Value="True"/>
+        <ResourceBaseClass Value="Form"/>
         <UnitName Value="Unit1"/>
       </Unit1>
     </Units>
   </ProjectOptions>
   <CompilerOptions>
-    <Version Value="5"/>
+    <Version Value="11"/>
-    <SearchPaths>
+    <Parsing>
-      
+      <SyntaxOptions>
-    </SearchPaths>
+        <UseAnsiStrings Value="False"/>
-    <CodeGeneration>
+      </SyntaxOptions>
-      <Generate Value="Faster"/>
+    </Parsing>
-    </CodeGeneration>
     <Linking>
+      <Debugging>
+        <DebugInfoType Value="dsDwarf3"/>
+      </Debugging>
       <Options>
         <Win32>
           <GraphicApplication Value="True"/>
         </Win32>
       </Options>
     </Linking>
-    <Other>
-      <CompilerPath Value="$(CompPath)"/>
-    </Other>
   </CompilerOptions>
 </CONFIG>

examples/scanline/unit1.lfm

@@ -8,14 +8,15 @@ object Form1: TForm1
   Caption = 'Form1'
   ClientHeight = 144
   ClientWidth = 623
+  LCLVersion = '3.99.0.0'
   OnCreate = FormCreate
   OnDestroy = FormDestroy
   OnPaint = FormPaint
   object Label1: TLabel
     Left = 156
-    Height = 43
+    Height = 15
     Top = 42
-    Width = 348
+    Width = 380
     Caption = 'You should see a small rectangle filled with black and a diagonal red line'
     ParentColor = False
     WordWrap = True

examples/scanline/unit1.pas

@@ -55,7 +55,7 @@ type
   private
   public
     MyBitmap: TBitmap;
-    procedure PaintToRGB32bitScanLine(Row, ImgWidth: integer; LineStart: Pointer);
+    procedure PaintToRGBScanLine(Row, ImgWidth: integer; LineStart: Pointer);
   end;
 
 var
@@ -76,22 +76,22 @@ var
 begin
   MyBitmap:=TBitmap.Create;
 
-  // create an image with a format similar to Delphi's pf32bit
+  // Create an image with a format similar to Delphi's pf24bit.
-  // keep in mind that you access it in bytes, not words or dwords
+  // Keep in mind that you access it in bytes, not words nor dwords
   // For example PowerPC uses another byte order (endian big)
   ScanLineImage:=TLazIntfImage.Create(0,0);
-  ImgFormatDescription.Init_BPP32_B8G8R8_BIO_TTB(30,20);
+  ImgFormatDescription.Init_BPP24_B8G8R8_BIO_TTB(30,20);
   ScanLineImage.DataDescription:=ImgFormatDescription;
 
   // call the pf24bit specific drawing function
   for y:=0 to ScanLineImage.Height-1 do
-    PaintToRGB32bitScanLine(y,ScanLineImage.Width,
+    PaintToRGBScanLine(y, ScanLineImage.Width, ScanLineImage.GetDataLineStart(y));
-                            ScanLineImage.GetDataLineStart(y));
 
   // create IntfImage with the format of the current LCL interface
   MyBitmap.Width:=ScanLineImage.Width;
   MyBitmap.Height:=ScanLineImage.Height;
   IntfImage:=MyBitmap.CreateIntfImage;
+
   // convert the content from the very specific to the current format
   IntfImage.CopyPixels(ScanLineImage);
   MyBitmap.LoadFromIntfImage(IntfImage);
@@ -110,19 +110,21 @@ begin
   Canvas.Draw(10,10,MyBitmap);
 end;
 
-procedure TForm1.PaintToRGB32bitScanLine(Row, ImgWidth: integer;
+procedure TForm1.PaintToRGBScanLine(Row, ImgWidth: integer;
   LineStart: Pointer);
-// LineStart is pointer to the start of a scanline with the following format:
+// LineStart is a pointer to the start of a scanline with the following format:
-// 4 bytes per pixel. First byte is blue, second green, third is red.
+// - 3 bytes per pixel.
+// - First byte is blue, second green, third is red.
 // Black is 0,0,0, white is 255,255,255
 var
   i: Integer;
 begin
-  // fill line with gray
+  // Fill line with background color
-  for i:=0 to (ImgWidth*4)-1 do
+  for i := 0 to ImgWidth * 3 - 1 do
-    PByte(LineStart)[i]:=0; // set red, green and blue to 0 (i.e. black)
+    PByte(LineStart)[i] := 0;  // Set red, green and blue to 0 (i.e. black)
-  // set one pixel to red (this creates a red line)
+
-  PByte(LineStart)[(Row mod ImgWidth)*4+2]:=255;
+  // Set one pixel to red (this creates a red line)
+  PByte(LineStart)[(Row mod ImgWidth) * 3 + 2] := 255;  // We add 2 to address the "red" byte
 end;
 
 end.