L_EfxGradientFillRect

#include "l_bitmap.h"

L_LTEFX_API L_INT L_EfxGradientFillRect(hDC, pRect, uStyle, crStart, crEnd, uSteps)

HDC hDC;	handle to the target device context
RECT * pRect;	pointer to the display rectangle
L_UINT uStyle;	gradient style
COLORREF crStart;	starting color
COLORREF crEnd;	ending color
L_UINT uSteps;	number of gradient color steps

Draws a rectangle into the target device context, and then fills the rectangle with a gradient from the specified starting color to the specified ending color.

Parameter	Description
hDC	Handle to the target device context.
pRect	Pointer to the display destination rectangle.
uStyle	Gradient style. For valid values, refer to Effect Gradient Styles.
crStart	COLORREF value that specifies the starting color.
crEnd	COLORREF value that specifies the ending color.
uSteps	Number of gradient color steps. Valid values are 2 to 256.

Returns

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

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 example shows the minimum requirements for using the L_EfxGradientFillRect function to draw and fill a rectangle with a color gradient.

L_INT EfxGradientFillRectExample(HWND    hWnd,RECT*   pDest) 
{ 
   L_INT nRet; 
   HDC       hdc; /* Device context for the current window */ 
   HPALETTE  hSavedPalette = NULL; /* Temporary copy of the current system palette */ 
   HPALETTE  hOurPalette = NULL;  /* The palette that we will use to paint */ 
   L_INT     nBitsPerPixel; 
   /* Get the device context */ 
   hdc = GetDC (hWnd); 
   /* Check the device to see if we need a palette */ 
   nBitsPerPixel = GetDeviceCaps( hdc, BITSPIXEL ) * GetDeviceCaps ( hdc, PLANES ); 
   if ( nBitsPerPixel <=8 ) 
   { 
      hOurPalette = (HPALETTE)GetStockObject (DEFAULT_PALETTE); 
      hSavedPalette = SelectPalette (hdc, hOurPalette, FALSE); 
      /* Realize our palette */ 
      RealizePalette (hdc); 
   } 
   /* Draw the gradient filled rectangle */ 
   nRet = L_EfxGradientFillRect(hdc,                       /* device context */ 
   pDest,                     /* destination rectangle */ 
   EFX_GRADIENT_ELLIPSE_TO_C, /* out to center */ 
   RGB ( 255,0,0 ),           /* starting color, red */ 
   RGB ( 0,0,255 ),           /* ending color, blue */ 
   12 );                      /* gradient color steps */ 
   if(nRet != SUCCESS) 
      return nRet; 
   /* Restore the old palette */ 
   if  ( hOurPalette ) 
      SelectPalette (hdc, hSavedPalette, FALSE); 
   /* Release the device context */ 
   ReleaseDC(hWnd, hdc); 
   return SUCCESS; 
}

Help Version 19.0.2017.10.27

Products | Support | Contact Us | Copyright Notices
© 1991-2017 LEAD Technologies, Inc. All Rights Reserved.

LEADTOOLS Raster Imaging C API Help

Introduction

Version History

Getting Started

LEADTOOLS Raster Imaging Features

Redistributables/Files To Be Included With Your Application

Functions:	L_EfxDraw3dShape, L_EfxDraw3dText, L_EfxDrawFrame, L_EfxDrawRotated3dText, L_EfxEffectBlt, L_EfxPaintBitmap, L_EfxPaintTransition, L_EfxPatternFillRect. L_EfxTileRect
Topics:	Implementing Special Effects
	Using Color Values in LEADTOOLS