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L_GetCurvePoints

Summary

Updates the pCurve array based on a curve or lines that pass through the specified points.

Syntax

#include "l_bitmap.h"

L_LTIMGEFX_API L_INT L_GetCurvePoints(pCurve, apUserPoint, uUserPointCount, puPointCount, uFlags)

Parameters

L_INT *pCurve

Pointer to the array to be filled by this function. To get the real value of the array elements, each of the values must be divided by 1000.

POINT *apUserPoint

Pointer to an array of POINT structures that contain the points on the curve used to determine the values for pCurve. The minimum x coordinate value is 0.

L_UINT uUserPointCount

Number of points in the apUserPoint array.

L_UINT *puPointCount

Pointer to a variable to be updated with the number of entries in pCurve that were actually updated by this function.

L_UINT uFlags

Flag that indicates the method to be used to update the buffer. Possible values are:

Value	Meaning
GUB_CURVE	[0x0000] Fill `pCurve` with the best curve that passes through the user points.
GUB_LINEAR	[0x0001] Fill pCurve with lines that pass through the user points.

Returns

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

Comments

This function will update pCurve using either the best curve or lines that pass through the points specified in the apUserPoint parameter. The points in the array may be sorted or not. In most cases, this function is used with the L_FreeHandShearBitmap, or L_FreeHandWaveBitmap functions.

Use the following formula to compute the size of the pCurve array:

Size = Maximum (apUserPoint.x) + uUserPointCount;

This means that the user finds the maximum x coordinate value in apUserPoint and adds to that value the number of points in the apUserPoint array. It is best to initialize the pCurve array before sending it to the function.

The values stored in pCurve represent the y coordinates of the calculated curve based on the points in the apUserPoint array. In the pCurve array there can be only one y value for each x coordinate. Therefore, circles, ellipses, and spirals cannot be represented by pCurve.

The x coordinates for the user points are sorted internally automatically.