procedure TForm1.FormCreate(Sender: TObject);
begin
BufBMP := TBitmap.Create;
FormBuf := TBitmap.Create;
FormBuf.Width := Width;
FormBuf.Height := Height;
BufBMP.LoadFromFile('c:\1.bmp');
Position := Point(0,0);
Down := FALSE;
end;
procedure TForm1.FormDestroy(Sender: TObject);
begin
BufBMP.Free;
FormBuf.Free;
end;
procedure TForm1.FormPaint(Sender: TObject);
begin
Canvas.Draw(Position.X,Position.Y,BufBMP);
end;
procedure TForm1.FormMouseDown(Sender: TObject; Button: TMouseButton;
Shift: TShiftState; X, Y: Integer);
begin
Down := TRUE;
FirstPt := Point(X,Y);
end;
procedure TForm1.FormMouseUp(Sender: TObject; Button: TMouseButton;
Shift: TShiftState; X, Y: Integer);
begin
Position := Point(Position.X + X - FirstPt.X,Position.Y + Y - FirstPt.Y);
Down := FALSE;
end;
procedure TForm1.FormMouseMove(Sender: TObject; Shift: TShiftState; X,
Y: Integer);
begin
if Down then begin
FormBuf.Canvas.Pen.color := clBtnFace;
FormBuf.Canvas.Brush.color := clBtnFace;
FormBuf.Canvas.Rectangle(0,0,Width,Height);
FormBuf.Canvas.Draw(Position.X + X - FirstPt.X,Position.Y + Y - FirstPt.Y,BufBMP);
Canvas.Draw(0,0,FormBuf);
end;
end;
procedure TForm1.FormClose(Sender: TObject; var Action: TCloseAction);
begin
Jpg.Free;
end;
procedure TForm1.FormPaint(Sender: TObject);
begin
Canvas.Draw(px, py, Jpg);
end;
procedure TForm1.FormResize(Sender: TObject);
begin
if Assigned(Jpg) then begin
mx := ClientWidth - Jpg.Width;
my := ClientHeight - Jpg.Height;
end;
end;
procedure TForm1.FormMouseDown(Sender: TObject; Button: TMouseButton;
Shift: TShiftState; X, Y: Integer);
begin
if not MouseDown then begin
MouseDown := True;
StartX := X;
StartY := Y;
end;
end;
procedure TForm1.FormMouseMove(Sender: TObject; Shift: TShiftState; X,
Y: Integer);
begin
if MouseDown then begin
Dec(px, StartX - X);
Dec(py, StartY - Y);
if px > 0 then px := 0;
if px < mx then px := mx;
if py > 0 then py := 0;
if py < my then py := my;
StartX := X;
StartY := Y;
Refresh;
end;
end;
procedure TForm1.FormMouseUp(Sender: TObject; Button: TMouseButton;
Shift: TShiftState; X, Y: Integer);
begin
if MouseDown then MouseDown := False;
end;
procedure TForm1.WMEraseBkGnd(var Msg: TWMEraseBkGnd);
begin
Msg.Result := -1;
end;
One way to create a bitmap from a pixel array is to use the
Windows API function CreateDiBitmap(). This will allow you to
use one of many device independent bitmap formats that Windows
uses to store your pixel data. This has the advantage that it
will work on any Windows system, without knowing the pixel
format that the device uses ahead of time. Properly executed by
optimizing your code, theCreateDiBitmap function can be quite
fast as well. The following example creates a 256 color bitmap
from a pixel array. The bitmap fades from white to black using
256 gray shades. Note that normally, Windows reserves the first
and last ten colors for use as system colors, so you may only
get a maximum of 236 gray shades.
{$IFNDEF WIN32}
type
{Used for pointer math under Win16}
PPtrRec = ^TPtrRec;
TPtrRec = record
Lo: Word;
Hi: Word;
end;
{$ENDIF}
procedure TForm1.Button1Click(Sender: TObject);
var
hPixelBuffer : THandle; {Handle to the pixel buffer}
lpPixelBuffer : pointer; {pointer to the pixel buffer}
lpPalBuffer : PLogPalette; {The palette buffer}
lpBitmapInfo : PBitmapInfo; {The bitmap info header}
BitmapInfoSize : longint; {Size of the bitmap info header}
BitmapSize : longint; {Size of the pixel array}
PaletteSize : integer; {Size of the palette buffer}
i : longint; {loop variable}
j : longint; {loop variable}
OldPal : hPalette; {temp palette}
hPal : hPalette; {handle to our palette}
hBm : hBitmap; {handle to our bitmap}
Bm : TBitmap; {temporary TBitmap}
Dc : hdc; {used to convert the DOB to a DDB}
IsPaletteDevice : bool;
begin
Application.ProcessMessages;
{If range checking is on - turn it off for now}
{we will remember if range checking was on by defining}
{a define called CKRANGE if range checking is on.}
{We do this to access array members past the arrays}
{defined index range without causing a range check}
{error at runtime. To satisfy the compiler, we must}
{also access the indexes with a variable. ie: if we}
{have an array defined as a: array[0..0] of byte,}
{and an integer i, we can now access a[3] by setting}
{i := 3; and then accessing a[i] without error}
{$IFOPT R+}
{$DEFINE CKRANGE}
{$R-}
{$ENDIF}
{Lets check to see if this is a palette device - if so, then}
{we must do palette handling for a successful operation.}
{Get the screen's dc to use since memory dc's are not reliable}
dc := GetDc(0);
IsPaletteDevice :=
GetDeviceCaps(dc, RASTERCAPS) and RC_PALETTE = RC_PALETTE;
{Give back the screen dc}
dc := ReleaseDc(0, dc);
{The bitmap info size must be the size of the BitmapInfo}
{plus the size of the color table - one color table entry}
{is already defined in TBitmapInfo}
BitmapInfoSize := sizeof(TBitmapInfo) + (sizeof(TRGBQUAD) * 255);
{The bitmap size must be the width of the bitmap rounded}
{up to the nearest 32 bit boundary}
BitmapSize := (sizeof(byte) * 256) * 256;
{The size of the palette must be the size of a TLogPalette}
{plus the number of color palette entries - 1, since there}
{is already one palette entry defined in TLogPalette}
if IsPaletteDevice then
PaletteSize := sizeof(TLogPalette) + (sizeof(TPaletteEntry) * 255);
{Get the memory for the BitmapInfo, the PixelBuffer, and the Palette}
GetMem(lpBitmapInfo, BitmapInfoSize);
hPixelBuffer := GlobalAlloc(GHND, BitmapSize);
lpPixelBuffer := GlobalLock(hPixelBuffer);
if IsPaletteDevice then
GetMem(lpPalBuffer, PaletteSize);
{Zero out the BitmapInfo, the PixelBuffer, and the Palette}
FillChar(lpBitmapInfo^, BitmapInfoSize, #0);
FillChar(lpPixelBuffer^, BitmapSize, #0);
if IsPaletteDevice then
FillChar(lpPalBuffer^, PaletteSize, #0);
{Fill in the BitmapInfo color table with gray shades: black to white}
for i := 0 to 255 do
begin
lpBitmapInfo^.bmiColors[i].rgbRed := i;
lpBitmapInfo^.bmiColors[i].rgbGreen := i;
lpBitmapInfo^.bmiColors[i].rgbBlue := i;
end;
{Fill in the pixel buffer array with shades: black to white}
{In a 256 color bitmap the color is an index into the color table}
for i := 0 to 255 do
for j := 0 to 255 do
Byte(GetBigPointer(lpPixelBuffer, i + (j * 256))^) := j;
{Fill in the palette structure}
if IsPaletteDevice then
begin
lpPalBuffer^.palVersion := $300;
lpPalBuffer^.palNumEntries := 256;
{Fill in the palette structure color table}
for i := 0 to 255 do
begin
lpPalBuffer^.PalPalEntry[i].peRed := i;
lpPalBuffer^.PalPalEntry[i].peGreen := i;
lpPalBuffer^.PalPalEntry[i].peBlue := i;
end;
{Create a palette}
hPal := CreatePalette(lpPalBuffer^);
end;
{Get the screen's dc to use for the conversion since}
{memory dc's are not reliable to use for conversions}
dc := GetDc(0);
if IsPaletteDevice then
begin
{If we are using a palette, it must be}
{selected into the dc during the conversion}
OldPal := SelectPalette(dc, hPal, TRUE);
{Realize the palette}
RealizePalette(dc);
end;
if IsPaletteDevice then
begin
{Select the old palette back in}
SelectPalette(dc, OldPal, TRUE);
{Realize the old palette}
RealizePalette(dc);
end;
{Give back the screen dc}
dc := ReleaseDc(0, dc);
{Create a temporory TBitmap}
bm := TBitmap.Create;
{Free up the memory we used}
if IsPaletteDevice then
FreeMem(lpPalBuffer, PaletteSize);
GlobalUnlock(hPixelBuffer);
GlobalFree(hPixelBuffer);
FreeMem(lpBitmapInfo, BitmapInfoSize);
{Assign the palette}
if IsPaletteDevice then
bm.Palette := hPal;
概述
----目前在许多学习软件、游戏光盘中,经常会看到各种图形显示技巧,凭着图形的移动、交错、雨滴状、百页窗、积木堆叠等显现方式,使画面变得更为生动活泼,更能吸引观众。本文将探讨如何在Delphi中实现各种图形显示技巧。
基本原理
----在Delphi中,实现一副图象的显示是非常简单的,只要在Form中定义一个TImage组件,设置其picture属性,然后选择任何有效的.ICO、.BMP、.EMF或.WMF文件,进行Load,所选文
件就显示在TImage组件中了。但这只是直接将图形显示在窗体中,毫无技巧可言。为了使图形显示具有别具一格的效果,可以按下列步骤实现:
----5、定义一个TImage组件,把要显示的图形先装入到TImage组件中,也就是说,把图形内容从磁盘载入内存中,做为图形缓存。
----6、创建一新的位图对象,其尺寸跟TImage组件中的图形一样。
----7、利用画布(Canvas)的CopyRect功能(将一个画布的矩形区域拷贝到另一个画布的矩形区域),使用技巧,动态形成位图文件内容,然后在窗体中显示位图。
----实现方法
----下面介绍各种图形显示技巧:
----1.推拉效果
----将要显示的图形由上、下、左、右方向拉进屏幕内显示,同时将屏幕上原来的旧图盖掉,此种效果可分为四种,上拉、下拉、左拉、右拉,但原理都差不多,以上拉效果为例。
----原理:首先将放在暂存图形的第一条水平线,搬移至要显示的位图的最后一条,接着再将暂存图形的前两条水平线,依序搬移至要显示位图的最后两条水平线,然后搬移前三条、前四条叄?直到全部图形数据搬完为止。在搬移的过程中即可看到显示的位图由下而上浮起,而
达到上拉的效果。
----程序算法:
procedure TForm1.Button1Click(Sender: TObject);
var
newbmp: TBitmap;
i,bmpheight,bmpwidth:integer;
begin
newbmp:= TBitmap.Create;
newbmp.Width:=image1.Width;
newbmp.Height:=image1.Height;
bmpheight:=image1.Height;
bmpwidth:=image1.Width;
for i:=0 to bmpheight do
begin
newbmp.Canvas.CopyRect(Rect
(0,bmpheight-i,bmpwidth,bmpheight),
image1.Canvas,
Rect(0,0,bmpwidth,i));
form1.Canvas.Draw(120,100,newbmp);
end;
newbmp.free;
newbmp.free;
end;
----2.垂直交错效果
----原理:将要显示的图形拆成两部分,奇数条扫描线由上往下搬移,偶数条扫描线的部分则由下往上搬移,而且两者同时进行。从屏幕上便可看到分别由上下两端出现的较淡图形向屏幕中央移动,直到完全清楚为止。
----程序算法:
procedure TForm1.Button4Click(Sender: TObject);
var
newbmp:TBitmap;
i,j,bmpheight,bmpwidth:integer;
begin
newbmp:= TBitmap.Create;
newbmp.Width:=image1.Width;
newbmp.Height:=image1.Height;
bmpheight:=image1.Height;
bmpwidth:=image1.Width;
i:=0;
while i< =bmpheight do
begin
j:=i;
while j >0 do
begin
newbmp.Canvas.CopyRect(Rect(0,j-1,bmpwidth,j),
image1.Canvas,
Rect(0,bmpheight-i+j-1,bmpwidth,bmpheight-i+j));
newbmp.Canvas.CopyRect(Rect
(0,bmpheight-j,bmpwidth,bmpheight-j+1),
image1.Canvas,
Rect(0,i-j,bmpwidth,i-j+1));
j:=j-2;
end;
form1.Canvas.Draw(120,100,newbmp);
i:=i+2;
end;
newbmp.free;
end;
----3.水平交错效果
----原理:同垂直交错效果原理一样,只是将分成两组后的图形分别由左右两端移进屏幕。
----程序算法:
procedure TForm1.Button5Click(Sender: TObject);
var
newbmp:TBitmap;
i,j,bmpheight,bmpwidth:integer;
begin
newbmp:= TBitmap.Create;
newbmp.Width:=image1.Width;
newbmp.Height:=image1.Height;
bmpheight:=image1.Height;
bmpwidth:=image1.Width;
i:=0;
while i< =bmpwidth do
begin
j:=i;
while j >0 do
begin
newbmp.Canvas.CopyRect(Rect(j-1,0,j,bmpheight),
image1.Canvas,
image1.Canvas,
Rect(bmpwidth-i+j-1,0,bmpwidth-i+j,bmpheight));
newbmp.Canvas.CopyRect(Rect
(bmpwidth-j,0,bmpwidth-j+1,bmpheight),
image1.Canvas,
Rect(i-j,0,i-j+1,bmpheight));
j:=j-2;
end;
form1.Canvas.Draw(120,100,newbmp);
i:=i+2;
end;
newbmp.free;
end;
----4.雨滴效果----原理:将暂存图形的最后一条扫描线,依序搬移到可视位图的第一条到最后一条扫描线,让此条扫描线在屏幕上留下它的轨迹。接着再把暂存图形的倒数第二条扫描线,依序搬移到可视位图的第一条到倒数第二条扫描线。其余的扫描线依此类推。----程序算法:
procedure TForm1.Button3Click(Sender: TObject);
var
newbmp:TBitmap;
i,j,bmpheight,bmpwidth:integer;
begin
newbmp:= TBitmap.Create;
newbmp.Width:=image1.Width;
newbmp.Height:=image1.Height;
bmpheight:=image1.Height;
bmpwidth:=image1.Width;
for i:=bmpheight downto 1 do
for j:=1 to i do
begin
newbmp.Canvas.CopyRect(Rect(0,j-1,bmpwidth,j),
image1.Canvas,
Rect(0,i-1,bmpwidth,i));
form1.Canvas.Draw(120,100,newbmp);
end;
newbmp.free;
end;
----5.百叶窗效果----原理:将放在暂存图形的数据分成若干组,然后依次从第一组到最后一组搬移,第一次每组各搬移第一条扫描线到可视位图的相应位置,第二次搬移第二条扫描线,接着搬移第三条、第四条扫描线.----程序算法:
procedure TForm1.Button6Click(Sender: TObject);
var
newbmp:TBitmap;
i,j,bmpheight,bmpwidth:integer;
xgroup,xcount:integer;
begin
newbmp:= TBitmap.Create;
newbmp.Width:=image1.Width;
newbmp.Height:=image1.Height;
bmpheight:=image1.Height;
bmpwidth:=image1.Width;
xgroup:=16;
xcount:=bmpheight div xgroup;
for i:=0 to xcount do
for j:=0 to xgroup do
begin
newbmp.Canvas.CopyRect(Rect
(0,xcount*j+i-1,bmpwidth,xcount*j+i),
image1.Canvas,
Rect(0,xcount*j+i-1,bmpwidth,xcount*j+i));
form1.Canvas.Draw(120,100,newbmp);
end;
newbmp.Free;
end;
----6.积木效果----原理:是雨滴效果的一种变化,不同之处在于,积木效果每次搬移的是一块图形,而不只是一根扫描线。----程序算法:
procedure TForm1.Button7Click(Sender: TObject);
var
newbmp:TBitmap;
i,j,bmpheight,bmpwidth:integer;
begin
newbmp:= TBitmap.Create;
newbmp.Width:=image1.Width;
newbmp.Height:=image1.Height;
bmpheight:=image1.Height;
bmpwidth:=image1.Width;
i:=bmpheight;
while i>0 do
begin
for j:=10 to i do
begin
newbmp.Canvas.CopyRect(Rect(0,j-10,bmpwidth,j),
image1.Canvas,
Rect(0,i-10,bmpwidth,i));
form1.Canvas.Draw(120,100,newbmp);
end;
i:=i-10;
end;
newbmp.free;
end;
结 束 语
---- 上 述 图 形 显 示 效 果 均 已 上 机 通 过, 软 件 环 境Delphi 3.0
, 硬 件 环 境Pentium 100M 兼 容 机。 使 用 效 果 很 好。
一、界面色彩渐变效果的实现
界面色彩渐变效果是通过用渐变的画刷刷绘依次相邻的矩形块实现的。下面
列举实例说明:
1.新建一个表单,假设其Width为500,设置一个按钮Button1,按此按钮将把表
单置为由左向右由黄变白的渐变效果。
2.Button1按钮的代码如下:
procedure TForm1.Button1Click(Sender: TObject);
var i,j:Integer;
Dct:TRect;
begin
j:=Form1.height;
//获得表单高度
for i:=0 to 255 do
//此处设置RGB()中一个颜色值
begin
Canvas.Brush.Color:=RGB(255,255,i);
//每次画矩形的画刷颜色
Dct:=Rect(i*2,0,(i+1)*2,j);
//每次刷绘的矩形区域
Canvas.FillRect(Dct);
//填充颜色
end;
end;
二、图形整体拉出效果
单纯的图形整体拉出效果比较简单,动态地改变图形区域的大小就可以实现,
但事先应将图形的“Stretch”设置为“True”。
举例说明下拉效果:
1.在表单上放置一图片,高度为200,属性“Height”设为0,“Stretch”设置
为True。添加“Timer”构件, “Interval”设为200,“Enable”设为Ture。
2.在Timer1Timer中添加代码:
procedure TForm1.Timer1Timer(Sender: TObject);
begin
Image1.Height:=Image1.Height+20;
//设置增量
if image1.Height=200 then Timer1.Enabled:=FALSE;
//图形整体拉出完毕
end;
以上两例在Windows95,Delphi3.0环境下运行通过。
太阳冰转载《电脑报》1999年02月1日第05期
*********************
// 旋转显示
procedure TForm1.Button1Click(Sender: TObject);
begin form1.repaint;
for j:=0 to bitmap.height do
for i:=0 to bitmap.width do
begin
with rect1 do
begin
left:=i;
top:=j;
right:=i+1;
bottom:=j+1;
end;
with rect3 do
begin
left:=j;
top:=i;
right:=j+1;
bottom:=i+1;
end;
canvas.copyrect(rect3,bitmap.canvas,rect1);
end;
end;
//抽点逐渐显示
procedure TForm1.Button2Click(Sender: TObject);
begin
form1.repaint;
for n:=0 to 1 do
for m:=0 to 1 do
for j:=0 to bitmap.height div 2 do
for i:=0 to bitmap.width div 2 do
begin
with rect1 do begin
left:=2*i+m;
top:=2*j+n;
right:=2*i+1+m;
bottom:=2*j+1+n;
end; with rect3 do
begin
left:=2*i+m;
top:=2*j+n;
right:=2*i+1+m;
bottom:=2*j+1+n;
end;
canvas.copyrect(rect3,bitmap.canvas,rect1);
end;
end;
//缩小四分之一
procedure TForm1.Button3Click(Sender: TObject);
begin
form1.repaint;
for j:=0 to bitmap.height div 2 do
for i:=0 to bitmap.width div 2 do
begin
with rect1 do
begin
left:=2*i;
top:=2*j;
rig