Sample Code
Windows Driver Samples/ MSPLOT Plotter Driver Sample/ C++/ plotter/ path.c/
/*++ Copyright (c) 1990-2003 Microsoft Corporation Module Name: path.c Abstract: This module contains Functions related to drawing paths. The main stroke drawing entry poing DrvStrokePath, is implemented in this module. See also textout.c, bitblt.c: These two have copies of almost all the DrvStrokePath() code. Author: 17:30 on Wed 03 Apr 1991 Created it 8/18/92 AP I have pretty much rewritten most of this. Some of the original code is left in, mainly to point out things that need to be added. 15-Nov-1993 Mon 19:40:18 updated clean up / debugging information 30-Nov-1993 Tue 22:32:12 updated style clean up, updated 01-Feb-1994 updated Added the ability to stroke styled lines through a complex clipping object [Environment:] GDI Device Driver - Plotter. [Notes:] Revision History: --*/ #include "precomp.h" #pragma hdrstop #define DBG_PLOTFILENAME DbgPath #define DBG_STROKEPATH 0x00000001 #define DBG_SELECTCOLOR 0x00000002 #define DBG_STROKECLIPLINES 0x00000004 #define DBG_MOVEPEN 0x00000008 DEFINE_DBGVAR(0); BOOL DoStrokePathByEnumingClipLines( PPDEV pPDev, SURFOBJ *pso, CLIPOBJ *pco, PATHOBJ *ppo, PPOINTL pptlBrushOrg, BRUSHOBJ *pbo, ROP4 rop4, LINEATTRS *plineattrs ) /*++ Routine Description: Strokes a path through a complex clipping region by utilizing the engine helper functions. This is done because there is no way to fail a DrvStrokePath and have it come back in any simpler format by the NT graphics engine. In general, we can fail DrvXXX calls and the NT graphic engine will simply the object to draw, then call back into the driver. Stroking a path however cannot be simplified any more, so the best we can hope for is having the PATHOBJ converted to straight line segments (removing BEZIERS if present). We then must stroke the path ourselves, using the provided EngXXX helpers. Since helper functions exist that allow us to to enumerate the portions of a path as CLIPLINE segments that fall within the clipping region, we do that here, thus stroking the segments that lie inside of the passed CLIPOBJ. Arguments: pPDev Pointer to the current PDEV pso SURFOBJ to write to pco CLIPOBJ to use when enuming paths ppo PATHOBJ to stroke through clip path pptlBrushOrg BRUSH origin pbo BRUSH to stroke with rop4 ROP4 to use plineattrs LINEATTRS structure that describes the styling for the line Return Value: TRUE if sucessful FALSE if failed, If the path we are asked to stroke contains BEZIERS, this function will fail in order to allow the Engine to break the path down to line segments. Author: 2/01/94 JB Revision History: --*/ { PLOT_CLIPLINE PlotClipLine; CLIPLINE *pCurClipLine; RUN *pCurRun; POINTFIX ptsfx[2]; POINTL ptlCur; FIX iStartInFX; FIX iStopInFX; LONG dx; LONG dy; LONG i; BOOL bMore; BOOL bXordered; BOOL bFlipX; BOOL bFlipY; // // First check for Beziers and if we have them fail the call since we // want straight line segments to stroke, with the appropriate style // if (ppo->fl & PO_BEZIERS) { PLOTDBG(DBG_STROKECLIPLINES, ("DoStrokePathByEnumingClipLines:Path had BEZ returning FALSE")); return(FALSE); } PLOTDBG(DBG_STROKECLIPLINES, ("DoStrokeByEnumingClipLines: NO CLIPOBJ %p", (pco != NULL) , (LONG_PTR)pco)); PLOTDBG(DBG_STROKECLIPLINES, ("DoStrokeByEnumingClipLines: CLIPOBJ is TRIVIAL (%lx)", (pco->iDComplexity != DC_TRIVIAL) , (LONG)pco->iDComplexity )); // // Send out the line attributes , so the residue will be calculated // correctly // DoSetupOfStrokeAttributes(pPDev, pptlBrushOrg, pbo, rop4, NULL); // // Initiate enumeration of the CLIPLINES by calling the Engine helper // PATHOBJ_vEnumStartClipLines(ppo, pco, pso, plineattrs); // // Start a loop to enum through all the available CLIPLINE structures // pCurClipLine = (CLIPLINE *)&PlotClipLine; do { // // Get the first batch of CLIPLINE structures then go to work on them // bMore = PATHOBJ_bEnumClipLines(ppo, sizeof(PlotClipLine), pCurClipLine); // // Calculate dx and dy in order to determine if the line is Xordered or // Yordered this is needed because of the way the engine passes us RUNS // if dx > dy then the line is said to be Xordered and thus any given // RUN iStart and iStop values is a projection on the x axis. Given this // informatino we can calculate the adjoining Y coordinate and draw the // line appropriately. // dx = pCurClipLine->ptfxB.x - pCurClipLine->ptfxA.x; dy = pCurClipLine->ptfxB.y - pCurClipLine->ptfxA.y; if ( bFlipX = (dx < 0 )) { dx = -dx; } if ( bFlipY = (dy < 0 )) { dy = -dy; } // // Now calculate if the line is x ordered or y ordered // bXordered = (dx >= dy); PLOTDBG(DBG_STROKECLIPLINES, ("DoStrokePathByEnumingClipLines:Compute ClipLine runs=%u, xordered %d", pCurClipLine->c, bXordered )); // // Enum through all the given RUNS drawing with the pen down between any // iStart and iStop value in each RUN // for (i = 0, pCurRun = &(pCurClipLine->arun[0]); i < (LONG)pCurClipLine->c; i++, pCurRun++) { // // The value of iStart and iStop are always positive!! so // we must handle it ourselves, so the correct thing happens // iStartInFX = LTOFX(pCurRun->iStart); iStopInFX = LTOFX(pCurRun->iStop); if (bFlipX ) { ptsfx[0].x = -iStartInFX; ptsfx[1].x = -iStopInFX; } else { ptsfx[0].x = iStartInFX; ptsfx[1].x = iStopInFX; } if (bFlipY ) { ptsfx[0].y = -iStartInFX; ptsfx[1].y = -iStopInFX; } else { ptsfx[0].y = iStartInFX; ptsfx[1].y = iStopInFX; } // // We must output the correct line attributes structure with the // correct calculated residue in order for this to work correctly // HandleLineAttributes(pPDev, plineattrs, &pCurClipLine->lStyleState, pCurRun->iStart); // // The calculations for the opposing coordinate varies based on the // ordering of the line. If the line is Xordered we calculate the // Y value, if itsYordered we calculate the X value. We do this // in order to determine the correct target coordinate. Since the // RUN is given to us as START and STOP, we must manually determine // what coordinate this represents inside the device coordinate // space. If the RUN is xordered, the x-coordinate is correct, and // the y-coordinate must be projected based on the ratio. // if (bXordered) { ptsfx[0].x += pCurClipLine->ptfxA.x; ptsfx[0].y = MulDiv( ptsfx[0].y, dy, dx) + pCurClipLine->ptfxA.y; ptsfx[1].x += pCurClipLine->ptfxA.x; ptsfx[1].y = MulDiv( ptsfx[1].y, dy, dx) + pCurClipLine->ptfxA.y; } else { ptsfx[0].x = MulDiv(ptsfx[0].x, dx, dy) + pCurClipLine->ptfxA.x; ptsfx[0].y += pCurClipLine->ptfxA.y; ptsfx[1].x = MulDiv(ptsfx[1].x, dx, dy) + pCurClipLine->ptfxA.x; ptsfx[1].y += pCurClipLine->ptfxA.y; } // // Do PE with pen up first, in order to move to the starting // position. // OutputString(pPDev, "PE<"); if (!i) { // // If we are at first point then output that now. // ptlCur.x = ptlCur.y = 0; OutputString(pPDev, "="); } // // Stroke the segment with the pen down. // OutputXYParams(pPDev, (PPOINTL)ptsfx, (PPOINTL)NULL, (PPOINTL)&ptlCur, (UINT)2, (UINT)1, 'F'); OutputString(pPDev, ";"); } } while (bMore); // While we need to enum again.. return(TRUE); } _Use_decl_annotations_ BOOL WINAPI DrvStrokePath( SURFOBJ *pso, PATHOBJ *ppo, CLIPOBJ *pco, XFORMOBJ *pxo, BRUSHOBJ *pbo, PPOINTL pptlBrushOrg, LINEATTRS *plineattrs, MIX Mix ) /*++ Routine Description: The driver's function for the StrokePath Arguments: same as EngStrokePath Return Value: TRUE if sucessful FALSE if failed Author: 8/18/92 -- t-alip Rewrote it. 30-Nov-1993 Tue 22:21:51 updated updated by DC 04-Aug-1994 Thu 20:00:23 updated bug# 22348 Revision History: 31-Jan-1994 Tue 22:21:51 updated Fixed dopolygon to pass in ROP4 not just MIX --*/ { PPDEV pPDev; BOOL bRetVal; UNREFERENCED_PARAMETER(pxo); PLOTDBG(DBG_STROKEPATH, ("DrvStrokePath: Mix = %x", Mix)); if (!(pPDev = SURFOBJ_GETPDEV(pso))) { PLOTERR(("DrvStrokePath: Invalid pPDev")); return(FALSE); } if (!(bRetVal = DoPolygon(pPDev, NULL, pco, ppo, pptlBrushOrg, NULL, pbo, MixToRop4(Mix), plineattrs, FPOLY_STROKE) )) { // // Since DoPolygon failed, it can only be because we had both a complex // clip and a pathobj, so the thing to here is do the stroke via another // method using some of the engine helpers. // // We will also failed when STYLE LINE + DC_RECT when raster plotter is // used // bRetVal = DoStrokePathByEnumingClipLines( pPDev, pso, pco, ppo, pptlBrushOrg, pbo, MixToRop4(Mix), plineattrs); } return(bRetVal); } BOOL MovePen( PPDEV pPDev, PPOINTFIX pPtNewPos, PPOINTL pPtDevPos ) /*++ Routine Description: This function sends the HPGL code for the requested pen. Arguments: pPDev - Pointer to the PDEV data structure pPtNewPos - The location pen will move to, this is in 28.4 fix notation pPtDevPos - The new device coordinate device position Return Value: TRUE if sucessful FALSE otherwise Author: 1:04 on Tue 7 Nov 1989 Added this commentary, and area fill optimization code. 30-Nov-1993 Tue 22:05:32 updated Update, commented and clean up style 16-Feb-1994 Wed 17:10:54 updated Re-write to get rid of the physical position Revision History: --*/ { POINTL ptDevPos; ptDevPos.x = FXTODEVL(pPDev, pPtNewPos->x); ptDevPos.y = FXTODEVL(pPDev, pPtNewPos->y); if (pPtDevPos) { *pPtDevPos = ptDevPos; } PLOTDBG( DBG_MOVEPEN, ("MovePen: Moving Absolute to FIX = [X=%d,%d] Device = [X=%d, Y=%d]", pPtNewPos->x, pPtNewPos->y, ptDevPos.x, ptDevPos.y )); return(OutputFormatStr(pPDev, "PE<=#D#D;", ptDevPos.x, ptDevPos.y)); }
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