API Calls

Also see

Marcel's homepage contains the current version, the JEDI page mostly a previous version. http://members.chello.nl/m.vanbrakel2

Online  

Online  

"Palettes Made Plain" by Ray Lischner in the July 1998 Delphi Informant, pp. 34-43. Excellent article explaining basics of Windows palettes. Shows gradient palette and palette animation demo.
www.informant.com/libs/delphi/3x/di9807rl.zip

See Microsoft's Simulating Palette Animation on Non-Palette Displays:
http://support.microsoft.com/support/kb/articles/q130/4/76.asp

See
- efg's CycleColors example for an alternative in high or true color modes.
- Palette links and info on efg's Delphi Graphics Color Algorithms page

Steve Schafer's UseNet Post with BeginPath/CloseFigure/EndPath/StrokeAndFillPath example

Wayne Sherman's UseNet Post with BeginPath/DrawText/EndPath example

Harm's UseNet Post with FillAndBlitRect example procedure

Copies bits from one device context to another. Tomes Graphical, pp. 283-285.
Processing Bitmaps Using BitBlt Functions, Delphi 2 Multimedia, pp. 335-343.
Non VCL Bitmap buffering (FAQ 2774D)
Displaying a bitmap on the client area of an MDI parent form (FAQ 176D)
A better way to print a form (TI 1412D)

Blitting Between DCs for Different Devices Is Unsupported (MS Q195830)
BitBlt and Palettes

   function ChangeDisplaySettings(lpDevMode: PDeviceMode; dwFlags: DWORD):      LongInt; stdcall;

and this in the Implementation:

    function ChangeDisplaySettings; external user32 name 'ChangeDisplaySettingsA';

Changing the display mode settings in code (FAQ 735D)

How to change video modes
www.geocities.com/SiliconValley/Lakes/1636/vidmodes.htm

Davie Reed's UseNet Post with Example

Time for a Change, PC Magazine, Sept 22, 98, p. 251-254: VB code to list available resolutions and change screen resolution using ChangeDisplaySettings

Ventanas de formas irregulares (Spanish)
www.orionis.com.mx/tallerdelphi/td05_1.htm

efg's Printer Demo #2 Lab Report

efg's Printer Demo #2 Lab Report

Creating a bitmap from a pixel array (FAQ 1205D)  

"Drawing text at different angles," pp. 295-297, Delphi Programming Problem Solver, Neil Rubenking.

Chris Hill's UseNet Post about Antialiased Fonts
NolenJ's UseNext Post with CanvasTextOutAngle method

Creating a rotated font (FAQ 615D)

How can I print a rotated font?

How to Create a Cursor from a Bitmap
Chris Hill's UseNet Post

Tomes Graphical, pp. 414-420
Secrets of Delphi 2, Ray Lischner, pp. 332, 436

See \Program Files\Borland\ Delphin\HELP\Examples\Bitmap\BMPFormU.PAS

See:
- efg's ShowDemoOne and ShowDemoMany Lab Reports
- Palette links and info on efg's Delphi Graphics Color Algorithms page

Colin Sarsfield's UsetNet Post with an example

How to Make a Polygonal Splash Screen by Michael Barnes www.undu.com/DN970101/00000006.htm

Manipulating Regions with Delphi by Don Monroe www.undu.com/DN961001/00000016.htm

How to make a triangular form
Dudás József's  UseNet Post

Chris Hill's UseNet Post with Example

efg's Printer Demo #2 Lab Report

Claire Humphrey's UseNet Post with DrawFocusRect example

David Lively in UseNet Posting:  "DrawFocusRect uses an XOR to draw the rectangle. A second draw to the same coordinates will restore the background contents:  A XOR B XOR B == A"

Kerstin Thaler's UseNet Post with example

efg's ShowCursor example of displaying cursor at any position on screen 
(based on UseNet Post by Michael Winter)

efg's Cursor Overlay Lab Report

Mauro Patiño's UseNet Post explaining how to use an OnDrawCell to make the fixed row font and text centering different than the remainder of the rows in a TStringGrid component

How can I have a TBitBtn component that has word-wrapped caption? (FAQ 1754D)

Colin Wilson's UseNet Post about DrawTextParams and DrawTextEx

Harm's UseNet Post about using DrawText

How to enumerate video modes
www.geocities.com/SiliconValley/Lakes/1636/video.htm

PC Magazine, Sept 22, 98, p. 254: VB code to list available resolutions (and change screen resolution)

Joe Hecht's UseNet Post with example
Chris Hill's UseNet Post with example

See Listing 7 in efg's Image Feathering Lab Report

How do I use Paths and Geometric Pens? (FAQ 2724D)

ExtCreatePen info from Microsoft

// Tomes of Delphi 3 -- Win32 Core API, p. 29:
procedure TForm1.Timer1Timer(Sender:  Object);
begin
  FlashWindow(Handle, TRUE);
  FlashWindow(Application.Handle, TRUE)
end;

efg's ShowCursor example of displaying cursor at any position on screen 
(based on UseNet Post by Michael Winter)

efg's ShowCursor example of displaying cursor at any position on screen 
(based on UseNet Post by Michael Winter)

GetDC(0) returns the Device Context for the desktop, which can also be written as
GetDC(hWnd_DeskTop).

Index Values
TECHNOLOGY, RASTERCAPS, CURVECAPS, LINECAPS, POLYGONALCAPS, TEXTCAPS

Screen:
Tomes Graphical, pp. 37-52
pp. 329-333, Delphi Programming Problem Solver, Neil Rubenking, for RASTERCAPS, RC_PALETTE

TECHNOLOGY:  Determining if a canvas is a Metafile Canvas?  (FAQ 2638D)

RASTERCAPS to create IsPaletteDevice function: Creating a bitmap from a pixel array (FAQ 1205D)  
RASTERCAPS:  Raster Operations (FAQ 2622D)

GetDeviceCaps(hDC, RASTERCAPS) Description
http://support.microsoft.com/support/kb/articles/q75/9/12.asp

RC_PALETTE: A better way to print a form (TI 1412D)

Printers:
Getting printer capabilities (FAQ 1475D)
efg's Printer Demo #1

Andrew Rybenkov's UseNet Post about using GetDIBits/SetDIBits as an alternative to Scanline

Mike Mormando's UseNet Post about passing NIL parameter to get the number of palette entries.

François Gaillard's UseNet Post with SM_CYSCREEN and SM_CXSCREEN examples and SystemParametersInfo example

Charles Hacker's UseNet Post with WM_NCPAINT example also showing GetSystemMetrics with parameters SM_CYMENU, SM_CXBORDER and SM_CYCAPTION.

Shannon Broskie's UseNet Post with DrawTitleBarImage function
(SM_CYCAPTION, SM_CXDLGFRAME, SM_CXEDGE, SM_CYSMICON, ....)

Eddie Shipman's UseNet Post about capturing top-most image

Gate's UseNet Post about the right method to allocate and release the DC without causing GDI Leak

From the help file: "The GetWindowDC function retrieves the device context (DC) for the entire window, including title bar, menus, and scroll bars. A window device context permits painting anywhere in a window, because the origin of the device context is the upper-left corner of the window instead of the client area."

Renate Schaaf's UseNet Post about "dirty rectangle" technique with images and postscript.

Invalidate, InvalidateRect, and Flicker:  If you invalidate a whole form, all TLabels will flicker when they're redrawn.  An alternative is to use InvalidateRect with the False parameter to stop this background erase.  Also, Validate/Invalidate can be used for some interesting effects.  efg's Invalidate project shows how Invalidate, InvalidateRect and ValidateRect work.

How do I plot a line? (FAQ 2934D)

How to Draw Marching Ants by Robert Vivrette. "Marching Ants" (sometimes called a marquee rectangle) is essentially an animated rubber-banding line.
http://www.undu.com/DN960901/00000008.htm

Wayne Sheffield's UseNet Post about using LockWindowUpdate to avoid flicker

If you paint in White or in Black:
  PatBlt(canvas.Handle,0,0, width, height, WHITENESS)
  PatBlt(canvas.Handle,0,0, width, height, BLACKNESS)
(from post to borland.public.delphi.graphics by J.M. Dozier, 19 Jan 99)

Chris Hill's UseNet Example

Damon Chander's UseNet Post with a PlgBlt function

Gordon Whittam's UseNet Post with DrawBullet procedure for drawing a bullet using PolyBezier API call.  I tested Gordon's routine with this :

procedure TForm1.Button1Click(Sender: TObject); 
begin 
  DrawBullet(Canvas, Point(Top,Left), Point(Height, Width DIV 2), 400) 
end;

Tomes Graphical, p. 168.

Note:  To avoid a confusion with the TCanvas.PolyBezier call (and a compilation error), use Windows.PolyBezier to invoke this API function.

See Microsoft's HowTo:  How to Get Windows NT PolyDraw functionality in Windows 95.  http://support.microsoft.com/support/kb/articles/Q135/0/59.asp 

Microsoft's Q121960:  Alternative to PtInRegion for Hit Testing
http://support.microsoft.com/support/kb/articles/Q121/9/60.asp

See Palettes Section of efg's Delphi Graphics Color Page

See Palettes Section of efg's Delphi Graphics Color Page

VAR ButtonOriginInScreenCoordinates: TPoint;
...
ButtonOriginInScreenCoordinates := 
     ClientToScreen( Point(BitBtnNo.Left, BitBtnNo.Top) );

Windows.SetCursorPos(
   ButtonOriginInScreenCoordinates.X + BitBtnNo.Width  DIV 2,
   ButtonOriginInScreenCoordinates.Y + BitBtnNo.Height Div 2);

Andrew Rybenkov's UseNet Post about using GetDIBits/SetDIBits as an alternative to Scanline

Dave Shapiro's UseNet Post explaining "Why is 'y' upside down?" (or how to make the y-axis increase from bottom-to-top instead of top-to-bottom)

Steve Schafer's UseNet Post about SetMapMode not affecting mouse position coordinates:  "The mouse position is always given in terms of screen coordinates. The only variation is that they may be either screen-relative or window-relative. In either case, the GDI mapping mode does not apply."

Windows API documentation says STRETCH_DELETESCANS is "typically used to preserve color in color bitmaps." Image fidelity is not good without this call when using EPIX pxd_StretchDIBits."
     SetStretchBltMode(Bitmap.Canvas.Handle, STRETCH_DELETESCANS);

When a bitmap is compressed as a result of a call to StretchBlt, the colors of some pixels in the original bitmap are lost.  To get the best results when using StretchBlt, set the bitmap stretching mode to ColorOnColor before calling StretchBlt, e.g.,
          SetStretechBltMode(hDC, ColorOnColor).

See efg's Newsgroup Post about using SetStretchBltMode before CopyRect (but not before StretchDraw)

See Microsoft's Bug:  SetStretchBltMode Ignored

Also see  Palettes Section of efg's Delphi Graphics Color Page

How to Make a Polygonal Splash Screen by Michael Barnes
www.undu.com/DN970101/00000006.htm

Non-Rectangular Windows by Robert Vivrette
www.undu.com/DN961001/00000007.htm

Ventanas de formas irregulares (Spanish)
www.orionis.com.mx/tallerdelphi/td05_1.htm

Complex Window Regions
www.undu.com/Articles/990114c.html

TTrianglePanel
www.silicmdr.com/downloads/TrianglePanel.zip
TRegionPanel
www.silicmdr.com/downloads/RegionPanel.zip

Draw and StretchDraw methods use the StretchBlt API call.   See Item #1, "How can I print a Bitmap?" or the Printer Demo #1 Lab Report.

StretchBlt and Palettes

Also see SetStretchBltMode above.

Ignacio Alvarez's UseNet Post with modified TransparentStretchBlt function

Shannon Broskie's UseNet Post with DrawTitleBarImage function (shows TransparentStretchBlt)

efg's Lead Tools-to-Delphi conversions show how to start with a hDIB and end up with a TBitmap.  In particular, look at Method 1. hDIB to TBitmap resulting in bmDDB using StretchDIBits

See StrokePath example based on UseNet Posting by Gordon Whittam

See SystemParametersInfo.Txt for Windows 95 trick to block CTRL+ALT+DEL or ALT+TAB

Toni Sanders' UseNet Post about how to turn off windows font anti-aliasing
Dick Claessens' UseNet Post to switch on the resizing rectangle
Eddie Shipman's UseNet Post about getting the title bar's font name and size

François Gaillard's UseNet Post with SM_CYSCREEN and SM_CXSCREEN examples and SystemParametersInfo example

Non-Delphi:

How to Use SystemParametersInfo API for Control Panel Settings
- SPI_GETWORKAREA = height of windows taskbar
http://support.microsoft.com/support/kb/articles/Q97/1/42.ASP

How To: Determine the Size of the Desktop Area
http://support.microsoft.com/support/kb/articles/Q154/8/23.asp

Chris Hill's UseNet Post with example

Invalidate, InvalidateRect, and Flicker:  If you invalidate a whole form, all TLabels will flicker when they're redrawn.  An alternative is to use InvalidateRect with the False parameter to stop this background erase.  Also, Validate/Invalidate can be used for some interesting effects.  efg's Invalidate project shows how Invalidate, InvalidateRect and ValidateRect work.

Messages, Appendix A, Tomes Graphical, pp. 725-848

Trapping Windows Messages in Delphi (TI 1487D)

Windows Messages
www.delphi-jedi.org/Jedi:VOYFORMS3

Delphi generates a CM_MouseLeave by monitoring when a different window is getting WM_MouseMove.

In Chapter 13 of  Mastering Delphi 5 (pp. 608-609), Marco Cantù shows how to create an "active" TMdActiveButton component that captures CM_MouseEnter and CM_MouseExit events.

Mike Shkolnik's UseNet Post on MouseEnter and MouseExit events

How to detect mouse leaving a control? (CM_MOUSEENTER, CM_MOUSELEAVE)
Rick Rogers UseNet Post

efg's ColorRange Lab Report  with  TSensitiveImage experiment.

TShape descendant that has a star shape and has OnMouseEnter/Leave handlers.  Eddie Shipman's UseNet Post

Windows Messages
www.delphi-jedi.org/Jedi:VOYFORMS3

Drag and Drop with Files (FAQ 529D)

Message sent to a window when it has been invalidated. Tomes Graphical, pp. 754. Can be the cause of flicker -- intercept message to reduce flicker in some cases.

private
...
procedure WmEraseBkgnd(VAR Msg: TWmEraseBkgnd); 
  message Wm_EraseBkgnd;
...
// Tell Windows not to erase the background.
// This reduces the amount of flicker when repainting.
procedure TFormSlideShow.WmEraseBkgnd(var Msg: TWmEraseBkgnd);
begin
  Msg.Result := 1;
end;

pp. 329-333, Delphi Programming Problem Solver, Neil Rubenking
Displaying a bitmap on the client area of an MDI parent form (FAQ 176D)

See \Program Files\Borland\Delphi n\HELP\Examples\Bitmap\BMPFormU.PAS
This example uses 
  m.Result := LRESULT(FALSE),
where LRESULT is a LongInt type.  [I need to resolve the conflict between the "1" in the example above and the FALSE returned in Borland's example.]

- example in efg's MazeMaker Lab Report
- Dets' UseNet Post about form minimum size

Tomes Graphical, p. 761

How can I easily move a Window control at runtime (FAQ 896D)

How to Simulate Visual Basic's SendKeys in Delphi
(wm_lbuttondown and wm_lbuttonup)
www.drdelphi.com/delphi/right/tips/sendkeys.htm

Message sent to a window when the mouse cursor moves over the window or a mouse button is clicked. Tomes Graphical, pp. 796-797

Moving a form by clicking in its client area (FAQ 2099D)

"Unusual Windows Styles" of 
- Eliminating a form's caption but leaving the border
- Getting the "tiny title bar" effect
in Chapter 1, Delphi Programming Problem Solver by Neil Rubenking, pp. 9-16.

Trapping non client areas (FAQ 1535D)
Trapping messages in non client area of a form (FAQ 2944D)

Tomes Graphical, p. 803

Used to paint the non-client area such as the caption bar and border.

Draw on Frame (FAQ1079D)
Paulo Almeida's UseNet Post about how to change color of caption

Chapter 1, Delphi Programming Problem Solver by Neil Rubenking (p. 23-32)
- Taking over drawing a form's caption
- Putting a button on a form's title bar
- Taking over drawing a form's frame

GetPalette and PaletteChanged, pp. 211-212.
Delphi Component Design by Danny Thorpe

Eddie Shipman's UseNet Post about making a rainbow background on a form

Processing WM_PALETTECHANGED and WM_QUERYNEWPALETTE
Microsoft's Knowledge Base:  http://support.microsoft.com/support/kb/articles/Q77/7/02.ASP

efg's Palette Lab Report

see WM_PALETTECHANGED above

INFO: Changing Window Colors with Control Panel
http://support.microsoft.com/support/kb/articles/Q11/2/46.asp

How can I easily move a Window control at runtime (FAQ 896D)

Windows Messages
Unit 2.  Simple demo on how to prevent the Windows screen saver from starting
www.delphi-jedi.org/Jedi:VOYFORMS3

Tomes Graphical, p. 844

Richard's UseNet Post showing WM_WINDOWPOSCHANGED example to get background images drawn on my MDI application

"The Standard Windows Raster Operations," Delphi 2 Multimedia, pp. 338-342, 361-373.

Tim Roberts' UseNet Post about "What are ROPs?"