指定背景的淡入淡出

天云上人

创建步骤：
! q$ p7 h4 ?# u! ?0 t. ]$ ^1、如果系统支持调色板，创建动态调色板pAnimate与初始调色板pOriginal。
) `  v  M. f% y) j; w从位图中获取初始调色板，若为淡入将背景色赋予动态调色板。利用前面所
  R8 v4 _. }- G! `提到的公式，根据淡入淡出标志，在循环中更改动态调色板，用AnimatePalette
函数设置调色板，改变显示结果。
2、如果系统不支持调色板，保存位图调色板到初始调色板，若为淡入将背景
& Q1 V1 `. ?# p8 g色赋予位图调色板，利用前面所提到的公式，根据淡入淡出标志，在循环中更
- I& x& k9 H4 I# z$ @改位图调色板，显示位图改变显示结果
返回：位图的淡入淡出
3 O' m- n3 j7 G8 o& t( g* z//参数说明：
) K: M7 `1 h% g) J- f//hDIB -位图句柄
1 I. \6 C/ ]' c0 z1 m, Q9 y8 K3 ?: e//color -指定背景色
: Q% [# I5 E( G  S+ V- {//xDest -显示位图的左上角x坐标
//yDest -显示位图的左上角y坐标
//nLoops -循环次数
//nDelay -每次循环中的延时
//nFlag -淡入淡出标志 1--淡入 其它--淡出
; X0 N( \+ M* P- G/ o" hvoid FadeInORFadeOut( CDC *pDC, HANDLE hDIB, COLORREF color, int xDest, int yDest,
0 m4 j+ {) d9 P# m; \int nLoops, int nDelay ,int nFlag)
- A: T4 w3 G: `5 wint i,j;
HPALETTE hPal;
PALETTEENTRY pAnimate[256];
PALETTEENTRY pOriginal[256];
$ s+ p3 @8 Q! J3 v7 K2 }" \7 }! jCPalette pal;
/ k) g) W, [# d. R3 D. }5 A// 创建236色调色板
7 P* G; A5 p" R2 @　
BITMAPINFO &bmInfo = *(LPBITMAPINFO)hDIB ;
. r1 @2 V3 S- O/ Z- j1 e　
3 K2 l. b$ E' i) G1 bint nColors = bmInfo.bmiHeader.biClrUsed ? bmInfo.bmiHeader.biClrUsed :
: H4 ^( r& Q5 L3 E1 << bmInfo.bmiHeader.biBitCount;
int nWidth = bmInfo.bmiHeader.biWidth;
- [# [% d# c1 ^% h  ~" A$ Zint nHeight = bmInfo.bmiHeader.biHeight;
LPVOID lpDIBBits = (LPVOID)(bmInfo.bmiColors + nColors);
1 [. d, Y) n0 T3 ?" I' Vint clrRValue = GetRValue(color);
int clrGValue = GetGValue(color);
int clrBValue = GetBValue(color);
3 T7 ^- ~2 _4 fif( pDC->GetDeviceCaps(RASTERCAPS) & RC_PALETTE && nColors <= 256 )
if (!(hPal = Create236Palette(hDIB)))
- f4 c% f+ W  a, q) qreturn;
pal.Attach( hPal );
// 得到调色板初始值
GetPaletteEntries(hPal, 0, nColors, (LPPALETTEENTRY)&pOriginal);
! ?" ?  L7 z9 ]. j// 设定动态调色板初始值为指定色
if(nFlag==1)
9 j2 G7 ~0 z5 R% E! r! Mfor (j = 0; j < nColors; j++)
4 `9 A: Y( T$ u& |- r# Z* ^% `pAnimate[j].peRed = clrRValue;
. _& y- t! E3 K9 q; |# N8 FpAnimate[j].peGreen = clrGValue;
6 D. [+ U  [9 M: D5 mpAnimate[j].peBlue = clrBValue;
pAnimate[j].peFlags = PC_RESERVED;
else
GetPaletteEntries(hPal, 0, nColors, (LPPALETTEENTRY)&pAnimate);
CPalette *pOldPalette = pDC->SelectPalette(&pal, FALSE);
  b& @. h4 z& ]pDC->RealizePalette();
CDC memDC;
  _' L6 A0 \, A! v. k9 pmemDC.CreateCompatibleDC( pDC );
& T9 O% g) I- Y8 }/ Q/ m* HCBitmap bmp;
8 I$ Q# ^4 I8 Q5 x. U+ j! L/ ebmp.CreateCompatibleBitmap( pDC, nWidth, nHeight );
CBitmap *pOldBitmap = memDC.SelectObject( &bmp );
CPalette *pOldMemPalette = memDC.SelectPalette(&pal, FALSE);
memDC.RealizePalette();
::SetDIBitsToDevice(memDC.m_hDC,0,0,nWidth,nHeight,0,0,0,nHeight,lpDIBBits,(LPBITMAPINFO)hDIB,DIB_RGB_COLORS);
  f7 i4 H; n+ G8 |3 q6 E  R$ Y* oAnimatePalette(hPal, 0, nColors, (LPPALETTEENTRY)&pAnimate);
1 H' h% E. k0 W$ J( ]" R2 GpDC->BitBlt(xDest, yDest, nWidth, nHeight, &memDC,0,0,SRCCOPY );
: E# }/ o* _! J% j// 淡入淡出
for( i=1; i <= nLoops; i++ )
for (j = 0; j < nColors; j++)
if(nFlag==1)
pAnimate[j].peRed = clrRValue - ((clrRValue-pOriginal[j].peRed)*i)/nLoops;
pAnimate[j].peGreen = clrGValue - ((clrGValue-pOriginal[j].peGreen)*i)/nLoops;
pAnimate[j].peBlue = clrBValue - ((clrBValue-pOriginal[j].peBlue)*i)/nLoops;
else
1 m5 z$ a) ^; G) HpAnimate[j].peRed = pOriginal[j].peRed - ((pOriginal[j].peRed - clrRValue)*i)/nLoops;
pAnimate[j].peGreen = pOriginal[j].peGreen - ((pOriginal[j].peGreen - clrGValue)*i)/nLoops;
pAnimate[j].peBlue = pOriginal[j].peBlue - ((pOriginal[j].peBlue - clrBValue)*i)/nLoops;
& t7 K3 R& w, [5 `/ ^pal.AnimatePalette(0, nColors, (LPPALETTEENTRY)&pAnimate);
// Delay...
Sleep(nDelay);
memDC.SelectPalette(pOldMemPalette, FALSE);
memDC.SelectObject( pOldBitmap );
; @; ]  m2 \/ t9 t5 R' U; upDC->SelectPalette(pOldPalette, FALSE);
* C8 S4 \- c5 q, H. I5 x1 Delse if( (pDC->GetDeviceCaps(RASTERCAPS) & RC_PALETTE) == 0 && nColors <= 256 )
for( int i=0; i < nColors; i++)
2 o3 }  I, X: HpOriginal.peRed = bmInfo.bmiColors.rgbRed ;
pOriginal.peGreen = bmInfo.bmiColors.rgbGreen;
5 N8 c2 p9 R( j' ypOriginal.peBlue = bmInfo.bmiColors.rgbBlue ;
$ z0 B5 Q# l2 y& s) E( @if(nFlag==1)
bmInfo.bmiColors.rgbRed = clrRValue;
) o; W+ m+ ?# `* e0 rbmInfo.bmiColors.rgbGreen = clrGValue;
4 X. |% w# u- ?: E, @1 ObmInfo.bmiColors.rgbBlue = clrBValue;
::SetDIBitsToDevice(pDC->m_hDC,0,0,nWidth,nHeight,0,0,0,nHeight,lpDIBBits,(LPBITMAPINFO)hDIB,DIB_RGB_COLORS);
// 淡入淡出
5 `" y- y, B& G8 L% z* bfor( i=1; i <= nLoops; i++ )
* E' b) a! {2 ~+ A6 lfor (j = 0; j < nColors; j++)
9 @9 s. `6 R) m  B3 x8 X$ Tif(nFlag==1)
9 f( v7 {0 g9 s  f( G1 sbmInfo.bmiColors[j].rgbRed = clrRValue - ((clrRValue-pOriginal[j].peRed)*i)/nLoops;
bmInfo.bmiColors[j].rgbGreen = clrGValue - ((clrGValue-pOriginal[j].peGreen)*i)/nLoops;
$ }$ d+ M2 f* {bmInfo.bmiColors[j].rgbBlue = clrBValue - ((clrBValue-pOriginal[j].peBlue)*i)/nLoops;
else
bmInfo.bmiColors[j].rgbRed = pOriginal[j].peRed - ((pOriginal[j].peRed-clrRValue)*i)/nLoops;
bmInfo.bmiColors[j].rgbGreen = pOriginal[j].peGreen - ((pOriginal[j].peGreen-clrGValue)*i)/nLoops;
bmInfo.bmiColors[j].rgbBlue = pOriginal[j].peBlue - ((pOriginal[j].peBlue-clrBValue)*i)/nLoops;
9 Y: V: h8 n+ t* o::SetDIBitsToDevice(pDC->m_hDC,0,0,nWidth,nHeight,0,0,0,nHeight,lpDIBBits,(LPBITMAPINFO)hDIB,DIB_RGB_COLORS);
) q* S+ R" R6 }9 A5 d) {; S7 `// Delay...
3 N2 I2 O2 z9 I1 w) BSleep(nDelay);