47 lines
940 B
C
47 lines
940 B
C
/*
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* LineDDA
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*
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* Copyright 1993 Bob Amstadt
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*/
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static char Copyright[] = "Copyright Bob Amstadt, 1993";
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#include <stdlib.h>
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#include "win.h"
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/**********************************************************************
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* LineDDA (GDI.100)
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*/
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void LineDDA(short nXStart, short nYStart, short nXEnd, short nYEnd,
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FARPROC callback, long lParam)
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{
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int x, y;
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int b;
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int x_diff = nXEnd - nXStart;
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int y_diff = nYEnd - nYStart;
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if (x_diff == 0 && y_diff == 0)
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return;
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if ((abs(x_diff) < abs(y_diff) && x_diff != 0) || y_diff == 0)
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{
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b = (nXStart * y_diff) / x_diff - nYStart;
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for (x = nXStart; x <= nXEnd; x++)
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{
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y = (x * y_diff) / x_diff + b;
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CallLineDDAProc(callback, x, y, lParam);
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}
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}
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else
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{
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b = (nYStart * x_diff) / y_diff - nXStart;
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for (y = nYStart; y <= nYEnd; y++)
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{
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x = (y * x_diff) / y_diff + b;
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CallLineDDAProc(callback, x, y, lParam);
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}
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}
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}
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