In This Topic ▼

L_EfxEffectBlt

Summary

Performs a bit-block transfer of the color data corresponding to a rectangle of pixels from the specified source device context into a destination device context, while applying a special effect.

Syntax

#include "l_bitmap.h"

L_LTEFX_API L_INT L_EfxEffectBlt(hdcDest, nXDest, nYDest, nWidth, nHeight, hdcSrc, nXSrc, nYSrc, uEffect, uGrain, uDelay, nSpeed, nCycles, uPass, uMaxPass, fTransparency, crTransparency, uWandWidth, crWand, uROP)

Parameters

HDC hdcDest

Handle to the target device context.

L_INT nXDest

X coordinate of the origin of the destination rectangle.

L_INT nYDest

Y coordinate of the origin of the destination rectangle.

L_INT nWidth

Width of the destination rectangle.

L_INT nHeight

Height of the destination rectangle.

HDC hdcSrc

Handle to the source device context.

L_INT nXSrc

X coordinate of the origin of the source rectangle.

L_INT nYSrc

Y coordinate of the origin of the source rectangle.

L_UINT uEffect

Effect to apply when painting. For valid values, refer to Effect Types.

L_UINT uGrain

Graining size. This is the smallest size (pixel width or height) to be updated when painting an effect. Using a small grain makes the painting smoother, but takes longer to paint. Using a large grain makes the painting more coarse, but paints faster. If the uEffect parameter is from the Wave class this represents the duration or height of the wave. Valid values are 1 to 256.

L_UINT uDelay

Delay between graining steps, in milliseconds.

L_INT nSpeed

Speed of the wave. Valid values are 1 to 256. This parameter is valid only if the uEffect parameter is from the Wave class.

L_INT nCycles

Number of cycles or repetitions used to draw the wave. This parameter is valid only if the uEffect parameter is from the Wave class.

L_UINT uPass

Pass number when using a pattern brush. Use 1 for painting in one pass.

L_UINT uMaxPass

Maximum passes for a pattern brush. Use 1 for painting in one pass.

L_BOOL fTransparency

TRUE to implement transparency by not painting pixels of the color specified in the crTransparency parameter; FALSE if transparency is not implemented.

COLORREF crTransparency

COLORREF value that specifies the transparent color.

L_UINT uWandWidth

Wand width, in pixels.

COLORREF crWand

COLORREF value that specifies the wand color.

L_UINT32 uROP

Windows ROP code for display. This parameter takes the same codes as the Windows BitBlt function. For ordinary painting, use SRCCOPY.

Returns

Value	Meaning
SUCCESS	The function was successful.
< 1	An error occurred. Refer to Return Codes.

Comments

Use this function as a replacement for the Windows BitBlt C API function when you want a special painting effect.

Use the uGrain and uDelay parameters to control the speed of the display. The uGrain parameter controls the size of the painting increment, and uDelay controls the time between increments.

The wand is a solid color bar that moves during an effect. Small grain sizes produce the best wand effects. Many of the effects listed in Effect Types can have a wand.

Use the uPass and uMaxPass parameters to paint the image in more than one pass. For example, if you want a 3-pass paint, use uMaxPass of 3 and paint 3 times, once with uPass = 1, once with uPass = 2, and once with uPass = 3.

Multipass painting for the EFX_EFFECT_PUSH_CLASS is disabled.

If the uEffect parameter is from the Twirl class, White Turnover class, Turnover class, Replace class, Laser class, Fade Normal class, Fade Black and White class, Fade Color class or Wave Class, the uPass and uMaxPass parameters have no effect.

If the uEffect parameter is from the Fade Normal class, Fade Black and White class or Fade Color class, the uGrain parameter has no effect. However, if the uEffect parameter is from the Wave class, the uGrain parameter contains the wave size.

If the uEffect parameter is from the White Turnover class, the Turnover class or the Replace class, the uWandWidth and crWand parameters have no effect. However, if the uEffect parameter is from the Fade Color class, the crWand parameter contains the bitmap color level.

The nSpeed and nCycles parameters have effect only if the uEffect parameter is from the Wave class.

For general information, refer to Implementing Special Effects.

Required DLLs and Libraries

LTEFX
For a listing of the exact DLLs and Libraries needed, based on the toolkit version, refer to Files To Be Included With Your Application.

Platforms

Win32, x64.

Example

This function shows how to use L_EfxEffectBlt to paint a bitmap to the screen using a special effect.

L_INT EfxEffectBltFirstExample(HWND hWnd) 
{ 
   L_INT          nRet; 
   HDC            hdcDest;                // Device context for the current window 
   HDC            hdcSrc;                 // Device context for the source image 
   BITMAPHANDLE   Bitmap;                 // image that will be blt 
   HBITMAP        hbmMem;                 // image that will be blt 
   HPALETTE       hSavedPalette = NULL;   // Temporary copy of the current system palette 
   HPALETTE       hPaintPal = NULL;       // The palette that we will use to paint 
   L_INT          nBitsPerPixel; 
 
   // Get the device context 
   hdcDest = GetDC(hWnd); 
 
   // Check the device to see if we need a palette 
   nBitsPerPixel = GetDeviceCaps(hdcDest, BITSPIXEL) * GetDeviceCaps(hdcDest, PLANES); 
 
   // Load an image to BLT 
   // Load the image as screen bit-depth 
   nRet = L_LoadBitmap(MAKE_IMAGE_PATH("IMAGE1.CMP"), &Bitmap, sizeof(BITMAPHANDLE), (nBitsPerPixel <= 8) ? nBitsPerPixel : 24, ORDER_BGR, NULL, NULL); 
   if (nRet != SUCCESS) 
      return nRet; 
 
   // Create the source DC 
   hdcSrc = CreateCompatibleDC(hdcDest); 
 
   // Convert the image to DDB and select it into the source dc 
   hbmMem = L_ConvertToDDB(hdcDest, &Bitmap); 
   hbmMem = (HBITMAP)SelectObject(hdcSrc, hbmMem); 
   if (nBitsPerPixel <= 8) 
   { 
      hPaintPal = L_CreatePaintPalette(hdcDest, &Bitmap); 
      hSavedPalette = SelectPalette(hdcDest, hPaintPal, FALSE); 
 
      // Realize our palette 
      RealizePalette(hdcDest); 
   } 
    
   // Paint the image using nRet = L_EfxEffectBlt and 3 steps 
   nRet = L_EfxEffectBlt(hdcDest,   // handle to target dc 
      0,                            // x-coordinate of destination rectangle's upper-left corner 
      0,                            // x-coordinate of destination rectangle's upper-left corner 
      Bitmap.Width,                 // width of destination rectangle 
      Bitmap.Height,                // height of destination rectangle 
      hdcSrc,                       // handle to source device context 
      0,                            // x-coordinate of source rectangle's upper-left corner 
      0,                            // y-coordinate of source rectangle's upper-left corner 
      EFX_EFFECT_WIPE_L_TO_R,       // paint effect to use 
      1,                            // graining size 
      1,                            // delay between graining steps 
      0,                            // speed of the wave 
      0,                            // number of cycles or repetitions 
      1,                            // step number for the pattern brush 
      3,                            // maximum steps for the pattern brush 
      FALSE,                        // do not use transparency 
      0,                            // transparent color, black 
      3,                            // wand width 
      RGB(255, 0, 0),               // wand color, red 
      SRCCOPY);                     // Windows raster operation code 
   if (nRet != SUCCESS) 
      return nRet; 
 
   nRet = L_EfxEffectBlt(hdcDest,   // handle to target DC 
      0,                            // x-coordinate of destination rectangle's upper-left corner 
      0,                            // x-coordinate of destination rectangle's upper-left corner 
      Bitmap.Width,                 // width of destination rectangle 
      Bitmap.Height,                // height of destination rectangle 
      hdcSrc,                       // handle to source device context 
      0,                            // x-coordinate of source rectangle's upper-left corner 
      0,                            // y-coordinate of source rectangle's upper-left corner 
      EFX_EFFECT_WIPE_R_TO_L,       // paint effect to use 
      1,                            // graining size 
      1,                            // delay between graining steps 
      0,                            // speed of the wave 
      0,                            // number of cycles or repetitions 
      2,                            // step number for the pattern brush 
      3,                            // maximum steps for the pattern brush 
      FALSE,                        // do not use transparency 
      0,                            // transparent color, black 
      3,                            // wand width 
      RGB(255, 0, 0),               // wand color, red 
      SRCCOPY);                     // Windows raster operation code 
   if (nRet != SUCCESS) 
      return nRet; 
 
   nRet = L_EfxEffectBlt(hdcDest,   // handle to target dc 
      0,                            // x-coordinate of destination rectangle's upper-left corner 
      0,                            // x-coordinate of destination rectangle's upper-left corner 
      Bitmap.Width,                 // width of destination rectangle 
      Bitmap.Height,                // height of destination rectangle 
      hdcSrc,                       // handle to source device context 
      0,                            // x-coordinate of source rectangle's upper-left corner 
      0,                            // y-coordinate of source rectangle's upper-left corner 
      EFX_EFFECT_WIPE_L_TO_R,       // paint effect to use 
      1,                            // graining size 
      1,                            // delay between graining steps 
      0,                            // speed of the wave 
      0,                            // number of cycles or repetitions 
      3,                            // step number for the pattern brush 
      3,                            // maximum steps for the pattern brush 
      FALSE,                        // do not use transparency 
      0,                            // transparent color, black 
      3,                            // wand width 
      RGB(255, 0, 0),               // wand color, red 
      SRCCOPY);                     // Windows raster operation code 
   if (nRet != SUCCESS) 
      return nRet; 
 
   // Restore the old palette 
   if (hPaintPal) 
   { 
      SelectPalette(hdcDest, hSavedPalette, FALSE); 
      DeleteObject(hPaintPal); 
   } 
 
   // Release the device context 
   ReleaseDC(hWnd, hdcDest); 
   DeleteDC(hdcSrc); 
   DeleteObject(hbmMem); 
   L_FreeBitmap(&Bitmap); 
 
   return SUCCESS; 
} 
 
// This function shows how to use L_EfxEffectBlt with wave effect 
 L_INT EfxEffectBltSecondExample(HWND hWnd) 
{ 
   L_INT nRet; 
   HDC          hdcDest;               // Device context for the current window 
   HDC          hdcSrc;                // Device context for the source image 
   BITMAPHANDLE Bitmap;                // image that will be blt 
   HBITMAP      hbmMem;                // image that will be blt 
   HPALETTE     hSavedPalette = NULL;  // Temporary copy of the current system palette 
   HPALETTE     hPaintPal = NULL;      // The palette that we will use to paint 
   L_INT        nBitsPerPixel; 
 
   // Get the device context 
   hdcDest = GetDC(hWnd); 
 
   // Check the device to see if we need a palette 
   nBitsPerPixel = GetDeviceCaps(hdcDest, BITSPIXEL) * GetDeviceCaps(hdcDest, PLANES); 
 
   // Load an image to BLT 
   // Load the image as screen bit-depth 
   nRet = L_LoadBitmap(MAKE_IMAGE_PATH("IMAGE1.CMP"), &Bitmap, sizeof(BITMAPHANDLE), (nBitsPerPixel <= 8) ? nBitsPerPixel : 24, ORDER_BGR, NULL, NULL); 
   if (nRet != SUCCESS) 
      return nRet; 
 
   // Create the source DC 
   hdcSrc = CreateCompatibleDC(hdcDest); 
 
   // Convert the image to DDB and select it into the source dc 
   hbmMem = L_ConvertToDDB(hdcDest, &Bitmap); 
   hbmMem = (HBITMAP)SelectObject(hdcSrc, hbmMem); 
   if (nBitsPerPixel <= 8) 
   { 
      hPaintPal = L_CreatePaintPalette(hdcDest, &Bitmap); 
      hSavedPalette = SelectPalette(hdcDest, hPaintPal, FALSE); 
 
      // Realize our palette 
      RealizePalette(hdcDest); 
   } 
 
   nRet = L_EfxEffectBlt(hdcDest,   // handle to target dc 
      0,                            // x-coordinate of destination rectangle's upper-left corner 
      0,                            // x-coordinate of destination rectangle's upper-left corner 
      Bitmap.Width,                 // width of destination rectangle 
      Bitmap.Height,                // height of destination rectangle 
      hdcSrc,                       // handle to source device context 
      0,                            // x-coordinate of source rectangle's upper-left corner 
      0,                            // y-coordinate of source rectangle's upper-left corner 
      EFX_EFFECT_WAVE_TB,           // paint effect to use 
      1,                            // graining size 
      1,                            // delay between graining steps 
      20,                           // speed of the wave 
      1,                            // number of cycles or repetitions 
      1,                            // step number for the pattern brush 
      3,                            // maximum steps for the pattern brush 
      FALSE,                        // do not use transparency 
      0,                            // transparent color, black 
      3,                            // wand width 
      RGB(255, 0, 0),               // wand color, red 
      SRCCOPY);                     // Windows raster operation code 
   if (nRet != SUCCESS) 
      return nRet; 
 
   // Restore the old palette 
   if (hPaintPal) 
   { 
      SelectPalette(hdcDest, hSavedPalette, FALSE); 
      DeleteObject(hPaintPal); 
   } 
 
   // Release the device context 
   ReleaseDC(hWnd, hdcDest); 
   DeleteDC(hdcSrc); 
   DeleteObject(hbmMem); 
   L_FreeBitmap(&Bitmap); 
 
   return SUCCESS; 
}