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wine/graphics/path.c
François Gouget 241c730d54 Fixed some LPPOINT/LPSIZE mismatches and some missing "const" in the 
headers prototypes.
1998-10-28 10:47:09 +00:00

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/*
* Graphics paths (BeginPath, EndPath etc.)
*
* Copyright 1997, 1998 Martin Boehme
*/
#include <assert.h>
#include <malloc.h>
#include <math.h>
#include "windows.h"
#include "winerror.h"
#include "dc.h"
#include "debug.h"
#include "path.h"
/* Notes on the implementation
*
* The implementation is based on dynamically resizable arrays of points and
* flags. I dithered for a bit before deciding on this implementation, and
* I had even done a bit of work on a linked list version before switching
* to arrays. It's a bit of a tradeoff. When you use linked lists, the
* implementation of FlattenPath is easier, because you can rip the
* PT_BEZIERTO entries out of the middle of the list and link the
* corresponding PT_LINETO entries in. However, when you use arrays,
* PathToRegion becomes easier, since you can essentially just pass your array
* of points to CreatePolyPolygonRgn. Also, if I'd used linked lists, I would
* have had the extra effort of creating a chunk-based allocation scheme
* in order to use memory effectively. That's why I finally decided to use
* arrays. Note by the way that the array based implementation has the same
* linear time complexity that linked lists would have since the arrays grow
* exponentially.
*
* The points are stored in the path in device coordinates. This is
* consistent with the way Windows does things (for instance, see the Win32
* SDK documentation for GetPath).
*
* The word "stroke" appears in several places (e.g. in the flag
* GdiPath.newStroke). A stroke consists of a PT_MOVETO followed by one or
* more PT_LINETOs or PT_BEZIERTOs, up to, but not including, the next
* PT_MOVETO. Note that this is not the same as the definition of a figure;
* a figure can contain several strokes.
*
* I modified the drawing functions (MoveTo, LineTo etc.) to test whether
* the path is open and to call the corresponding function in path.c if this
* is the case. A more elegant approach would be to modify the function
* pointers in the DC_FUNCTIONS structure; however, this would be a lot more
* complex. Also, the performance degradation caused by my approach in the
* case where no path is open is so small that it cannot be measured.
*
* Martin Boehme
*/
/* FIXME: A lot of stuff isn't implemented yet. There is much more to come. */
#define NUM_ENTRIES_INITIAL 16 /* Initial size of points / flags arrays */
#define GROW_FACTOR_NUMER 2 /* Numerator of grow factor for the array */
#define GROW_FACTOR_DENOM 1 /* Denominator of grow factor */
static BOOL32 PATH_PathToRegion(const GdiPath *pPath, INT32 nPolyFillMode,
HRGN32 *pHrgn);
static void PATH_EmptyPath(GdiPath *pPath);
static BOOL32 PATH_AddEntry(GdiPath *pPath, const POINT32 *pPoint,
BYTE flags);
static BOOL32 PATH_ReserveEntries(GdiPath *pPath, INT32 numEntries);
static BOOL32 PATH_GetPathFromHDC(HDC32 hdc, GdiPath **ppPath);
static BOOL32 PATH_DoArcPart(GdiPath *pPath, FLOAT_POINT corners[],
double angleStart, double angleEnd, BOOL32 addMoveTo);
static void PATH_ScaleNormalizedPoint(FLOAT_POINT corners[], double x,
double y, POINT32 *pPoint);
static void PATH_NormalizePoint(FLOAT_POINT corners[], const FLOAT_POINT
*pPoint, double *pX, double *pY);
/***********************************************************************
* BeginPath16 (GDI.512)
*/
BOOL16 WINAPI BeginPath16(HDC16 hdc)
{
return (BOOL16)BeginPath32((HDC32)hdc);
}
/***********************************************************************
* BeginPath32 (GDI32.9)
*/
BOOL32 WINAPI BeginPath32(HDC32 hdc)
{
GdiPath *pPath;
/* Get pointer to path */
if(!PATH_GetPathFromHDC(hdc, &pPath))
{
SetLastError(ERROR_INVALID_HANDLE);
return FALSE;
}
/* If path is already open, do nothing */
if(pPath->state==PATH_Open)
return TRUE;
/* Make sure that path is empty */
PATH_EmptyPath(pPath);
/* Initialize variables for new path */
pPath->newStroke=TRUE;
pPath->state=PATH_Open;
return TRUE;
}
/***********************************************************************
* EndPath16 (GDI.514)
*/
BOOL16 WINAPI EndPath16(HDC16 hdc)
{
return (BOOL16)EndPath32((HDC32)hdc);
}
/***********************************************************************
* EndPath32 (GDI32.78)
*/
BOOL32 WINAPI EndPath32(HDC32 hdc)
{
GdiPath *pPath;
/* Get pointer to path */
if(!PATH_GetPathFromHDC(hdc, &pPath))
{
SetLastError(ERROR_INVALID_HANDLE);
return FALSE;
}
/* Check that path is currently being constructed */
if(pPath->state!=PATH_Open)
{
SetLastError(ERROR_CAN_NOT_COMPLETE);
return FALSE;
}
/* Set flag to indicate that path is finished */
pPath->state=PATH_Closed;
return TRUE;
}
/***********************************************************************
* AbortPath16 (GDI.511)
*/
BOOL16 WINAPI AbortPath16(HDC16 hdc)
{
return (BOOL16)AbortPath32((HDC32)hdc);
}
/******************************************************************************
* AbortPath32 [GDI32.1]
* Closes and discards paths from device context
*
* NOTES
* Check that SetLastError is being called correctly
*
* PARAMS
* hdc [I] Handle to device context
*
* RETURNS STD
*/
BOOL32 WINAPI AbortPath32( HDC32 hdc )
{
GdiPath *pPath;
/* Get pointer to path */
if(!PATH_GetPathFromHDC(hdc, &pPath))
{
SetLastError(ERROR_INVALID_PARAMETER);
return FALSE;
}
/* Remove all entries from the path */
PATH_EmptyPath(pPath);
return TRUE;
}
/***********************************************************************
* CloseFigure16 (GDI.513)
*/
BOOL16 WINAPI CloseFigure16(HDC16 hdc)
{
return (BOOL16)CloseFigure32((HDC32)hdc);
}
/***********************************************************************
* CloseFigure32 (GDI32.16)
*
* FIXME: Check that SetLastError is being called correctly
*/
BOOL32 WINAPI CloseFigure32(HDC32 hdc)
{
GdiPath *pPath;
/* Get pointer to path */
if(!PATH_GetPathFromHDC(hdc, &pPath))
{
SetLastError(ERROR_INVALID_PARAMETER);
return FALSE;
}
/* Check that path is open */
if(pPath->state!=PATH_Open)
{
SetLastError(ERROR_CAN_NOT_COMPLETE);
return FALSE;
}
/* FIXME: Shouldn't we draw a line to the beginning of the figure? */
/* Set PT_CLOSEFIGURE on the last entry and start a new stroke */
if(pPath->numEntriesUsed)
{
pPath->pFlags[pPath->numEntriesUsed-1]|=PT_CLOSEFIGURE;
pPath->newStroke=TRUE;
}
return TRUE;
}
/***********************************************************************
* GetPath16 (GDI.517)
*/
INT16 WINAPI GetPath16(HDC16 hdc, LPPOINT16 pPoints, LPBYTE pTypes,
INT16 nSize)
{
FIXME(gdi, "(%d,%p,%p): stub\n",hdc,pPoints,pTypes);
return 0;
}
/***********************************************************************
* GetPath32 (GDI32.210)
*/
INT32 WINAPI GetPath32(HDC32 hdc, LPPOINT32 pPoints, LPBYTE pTypes,
INT32 nSize)
{
GdiPath *pPath;
/* Get pointer to path */
if(!PATH_GetPathFromHDC(hdc, &pPath))
{
SetLastError(ERROR_INVALID_PARAMETER);
return -1;
}
/* Check that path is closed */
if(pPath->state!=PATH_Closed)
{
SetLastError(ERROR_CAN_NOT_COMPLETE);
return -1;
}
if(nSize==0)
return pPath->numEntriesUsed;
else if(nSize<pPath->numEntriesUsed)
{
SetLastError(ERROR_INVALID_PARAMETER);
return -1;
}
else
{
memcpy(pPoints, pPath->pPoints, sizeof(POINT32)*pPath->numEntriesUsed);
memcpy(pTypes, pPath->pFlags, sizeof(BYTE)*pPath->numEntriesUsed);
/* Convert the points to logical coordinates */
if(!DPtoLP32(hdc, pPoints, pPath->numEntriesUsed))
{
/* FIXME: Is this the correct value? */
SetLastError(ERROR_CAN_NOT_COMPLETE);
return -1;
}
return pPath->numEntriesUsed;
}
}
/***********************************************************************
* PathToRegion32 (GDI32.261)
*
* FIXME
* Check that SetLastError is being called correctly
*
* The documentation does not state this explicitly, but a test under Windows
* shows that the region which is returned should be in device coordinates.
*/
HRGN32 WINAPI PathToRegion32(HDC32 hdc)
{
GdiPath *pPath;
HRGN32 hrgnRval;
/* Get pointer to path */
if(!PATH_GetPathFromHDC(hdc, &pPath))
{
SetLastError(ERROR_INVALID_PARAMETER);
return 0;
}
/* Check that path is closed */
if(pPath->state!=PATH_Closed)
{
SetLastError(ERROR_CAN_NOT_COMPLETE);
return 0;
}
/* FIXME: Should we empty the path even if conversion failed? */
if(PATH_PathToRegion(pPath, GetPolyFillMode32(hdc), &hrgnRval))
PATH_EmptyPath(pPath);
else
hrgnRval=0;
return hrgnRval;
}
/***********************************************************************
* FillPath32 (GDI32.100)
*
* FIXME
* Check that SetLastError is being called correctly
*/
BOOL32 WINAPI FillPath32(HDC32 hdc)
{
GdiPath *pPath;
INT32 mapMode, graphicsMode;
SIZE32 ptViewportExt, ptWindowExt;
POINT32 ptViewportOrg, ptWindowOrg;
XFORM xform;
HRGN32 hrgn;
/* Get pointer to path */
if(!PATH_GetPathFromHDC(hdc, &pPath))
{
SetLastError(ERROR_INVALID_PARAMETER);
return FALSE;
}
/* Check that path is closed */
if(pPath->state!=PATH_Closed)
{
SetLastError(ERROR_CAN_NOT_COMPLETE);
return FALSE;
}
/* Construct a region from the path and fill it */
if(PATH_PathToRegion(pPath, GetPolyFillMode32(hdc), &hrgn))
{
/* Since PaintRgn interprets the region as being in logical coordinates
* but the points we store for the path are already in device
* coordinates, we have to set the mapping mode to MM_TEXT temporarily.
* Using SaveDC to save information about the mapping mode / world
* transform would be easier but would require more overhead, especially
* now that SaveDC saves the current path.
*/
/* Save the information about the old mapping mode */
mapMode=GetMapMode32(hdc);
GetViewportExtEx32(hdc, &ptViewportExt);
GetViewportOrgEx32(hdc, &ptViewportOrg);
GetWindowExtEx32(hdc, &ptWindowExt);
GetWindowOrgEx32(hdc, &ptWindowOrg);
/* Save world transform
* NB: The Windows documentation on world transforms would lead one to
* believe that this has to be done only in GM_ADVANCED; however, my
* tests show that resetting the graphics mode to GM_COMPATIBLE does
* not reset the world transform.
*/
GetWorldTransform(hdc, &xform);
/* Set MM_TEXT */
SetMapMode32(hdc, MM_TEXT);
/* Paint the region */
PaintRgn32(hdc, hrgn);
/* Restore the old mapping mode */
SetMapMode32(hdc, mapMode);
SetViewportExtEx32(hdc, ptViewportExt.cx, ptViewportExt.cy, NULL);
SetViewportOrgEx32(hdc, ptViewportOrg.x, ptViewportOrg.y, NULL);
SetWindowExtEx32(hdc, ptWindowExt.cx, ptWindowExt.cy, NULL);
SetWindowOrgEx32(hdc, ptWindowOrg.x, ptWindowOrg.y, NULL);
/* Go to GM_ADVANCED temporarily to restore the world transform */
graphicsMode=GetGraphicsMode(hdc);
SetGraphicsMode(hdc, GM_ADVANCED);
SetWorldTransform(hdc, &xform);
SetGraphicsMode(hdc, graphicsMode);
/* Empty the path */
PATH_EmptyPath(pPath);
return TRUE;
}
else
{
/* FIXME: Should the path be emptied even if conversion failed? */
/* PATH_EmptyPath(pPath); */
return FALSE;
}
}
/***********************************************************************
* SelectClipPath32 (GDI32.296)
* FIXME
* Check that SetLastError is being called correctly
*/
BOOL32 WINAPI SelectClipPath32(HDC32 hdc, INT32 iMode)
{
GdiPath *pPath;
HRGN32 hrgnPath;
BOOL32 success;
/* Get pointer to path */
if(!PATH_GetPathFromHDC(hdc, &pPath))
{
SetLastError(ERROR_INVALID_PARAMETER);
return FALSE;
}
/* Check that path is closed */
if(pPath->state!=PATH_Closed)
{
SetLastError(ERROR_CAN_NOT_COMPLETE);
return FALSE;
}
/* Construct a region from the path */
if(PATH_PathToRegion(pPath, GetPolyFillMode32(hdc), &hrgnPath))
{
success = ExtSelectClipRgn( hdc, hrgnPath, iMode ) != ERROR;
DeleteObject32(hrgnPath);
/* Empty the path */
if(success)
PATH_EmptyPath(pPath);
/* FIXME: Should this function delete the path even if it failed? */
return success;
}
else
return FALSE;
}
/***********************************************************************
* Exported functions
*/
/* PATH_InitGdiPath
*
* Initializes the GdiPath structure.
*/
void PATH_InitGdiPath(GdiPath *pPath)
{
assert(pPath!=NULL);
pPath->state=PATH_Null;
pPath->pPoints=NULL;
pPath->pFlags=NULL;
pPath->numEntriesUsed=0;
pPath->numEntriesAllocated=0;
}
/* PATH_DestroyGdiPath
*
* Destroys a GdiPath structure (frees the memory in the arrays).
*/
void PATH_DestroyGdiPath(GdiPath *pPath)
{
assert(pPath!=NULL);
free(pPath->pPoints);
free(pPath->pFlags);
}
/* PATH_AssignGdiPath
*
* Copies the GdiPath structure "pPathSrc" to "pPathDest". A deep copy is
* performed, i.e. the contents of the pPoints and pFlags arrays are copied,
* not just the pointers. Since this means that the arrays in pPathDest may
* need to be resized, pPathDest should have been initialized using
* PATH_InitGdiPath (in C++, this function would be an assignment operator,
* not a copy constructor).
* Returns TRUE if successful, else FALSE.
*/
BOOL32 PATH_AssignGdiPath(GdiPath *pPathDest, const GdiPath *pPathSrc)
{
assert(pPathDest!=NULL && pPathSrc!=NULL);
/* Make sure destination arrays are big enough */
if(!PATH_ReserveEntries(pPathDest, pPathSrc->numEntriesUsed))
return FALSE;
/* Perform the copy operation */
memcpy(pPathDest->pPoints, pPathSrc->pPoints,
sizeof(POINT32)*pPathSrc->numEntriesUsed);
memcpy(pPathDest->pFlags, pPathSrc->pFlags,
sizeof(INT32)*pPathSrc->numEntriesUsed);
pPathDest->state=pPathSrc->state;
pPathDest->numEntriesUsed=pPathSrc->numEntriesUsed;
pPathDest->newStroke=pPathSrc->newStroke;
return TRUE;
}
/* PATH_MoveTo
*
* Should be called when a MoveTo is performed on a DC that has an
* open path. This starts a new stroke. Returns TRUE if successful, else
* FALSE.
*/
BOOL32 PATH_MoveTo(HDC32 hdc)
{
GdiPath *pPath;
/* Get pointer to path */
if(!PATH_GetPathFromHDC(hdc, &pPath))
return FALSE;
/* Check that path is open */
if(pPath->state!=PATH_Open)
/* FIXME: Do we have to call SetLastError? */
return FALSE;
/* Start a new stroke */
pPath->newStroke=TRUE;
return TRUE;
}
/* PATH_LineTo
*
* Should be called when a LineTo is performed on a DC that has an
* open path. This adds a PT_LINETO entry to the path (and possibly
* a PT_MOVETO entry, if this is the first LineTo in a stroke).
* Returns TRUE if successful, else FALSE.
*/
BOOL32 PATH_LineTo(HDC32 hdc, INT32 x, INT32 y)
{
GdiPath *pPath;
POINT32 point, pointCurPos;
/* Get pointer to path */
if(!PATH_GetPathFromHDC(hdc, &pPath))
return FALSE;
/* Check that path is open */
if(pPath->state!=PATH_Open)
return FALSE;
/* Convert point to device coordinates */
point.x=x;
point.y=y;
if(!LPtoDP32(hdc, &point, 1))
return FALSE;
/* Add a PT_MOVETO if necessary */
if(pPath->newStroke)
{
pPath->newStroke=FALSE;
if(!GetCurrentPositionEx32(hdc, &pointCurPos) ||
!LPtoDP32(hdc, &pointCurPos, 1))
return FALSE;
if(!PATH_AddEntry(pPath, &pointCurPos, PT_MOVETO))
return FALSE;
}
/* Add a PT_LINETO entry */
return PATH_AddEntry(pPath, &point, PT_LINETO);
}
/* PATH_Rectangle
*
* Should be called when a call to Rectangle is performed on a DC that has
* an open path. Returns TRUE if successful, else FALSE.
*/
BOOL32 PATH_Rectangle(HDC32 hdc, INT32 x1, INT32 y1, INT32 x2, INT32 y2)
{
GdiPath *pPath;
POINT32 corners[2], pointTemp;
INT32 temp;
/* Get pointer to path */
if(!PATH_GetPathFromHDC(hdc, &pPath))
return FALSE;
/* Check that path is open */
if(pPath->state!=PATH_Open)
return FALSE;
/* Convert points to device coordinates */
corners[0].x=x1;
corners[0].y=y1;
corners[1].x=x2;
corners[1].y=y2;
if(!LPtoDP32(hdc, corners, 2))
return FALSE;
/* Make sure first corner is top left and second corner is bottom right */
if(corners[0].x>corners[1].x)
{
temp=corners[0].x;
corners[0].x=corners[1].x;
corners[1].x=temp;
}
if(corners[0].y>corners[1].y)
{
temp=corners[0].y;
corners[0].y=corners[1].y;
corners[1].y=temp;
}
/* In GM_COMPATIBLE, don't include bottom and right edges */
if(GetGraphicsMode(hdc)==GM_COMPATIBLE)
{
corners[1].x--;
corners[1].y--;
}
/* Close any previous figure */
if(!CloseFigure32(hdc))
{
/* The CloseFigure call shouldn't have failed */
assert(FALSE);
return FALSE;
}
/* Add four points to the path */
pointTemp.x=corners[1].x;
pointTemp.y=corners[0].y;
if(!PATH_AddEntry(pPath, &pointTemp, PT_MOVETO))
return FALSE;
if(!PATH_AddEntry(pPath, corners, PT_LINETO))
return FALSE;
pointTemp.x=corners[0].x;
pointTemp.y=corners[1].y;
if(!PATH_AddEntry(pPath, &pointTemp, PT_LINETO))
return FALSE;
if(!PATH_AddEntry(pPath, corners+1, PT_LINETO))
return FALSE;
/* Close the rectangle figure */
if(!CloseFigure32(hdc))
{
/* The CloseFigure call shouldn't have failed */
assert(FALSE);
return FALSE;
}
return TRUE;
}
/* PATH_Ellipse
*
* Should be called when a call to Ellipse is performed on a DC that has
* an open path. This adds four Bezier splines representing the ellipse
* to the path. Returns TRUE if successful, else FALSE.
*/
BOOL32 PATH_Ellipse(HDC32 hdc, INT32 x1, INT32 y1, INT32 x2, INT32 y2)
{
// TODO: This should probably be revised to call PATH_AngleArc
// (once it exists)
return PATH_Arc(hdc, x1, y1, x2, y2, x1, (y1+y2)/2, x1, (y1+y2)/2);
}
/* PATH_Arc
*
* Should be called when a call to Arc is performed on a DC that has
* an open path. This adds up to five Bezier splines representing the arc
* to the path. Returns TRUE if successful, else FALSE.
*/
BOOL32 PATH_Arc(HDC32 hdc, INT32 x1, INT32 y1, INT32 x2, INT32 y2,
INT32 xStart, INT32 yStart, INT32 xEnd, INT32 yEnd)
{
GdiPath *pPath;
DC *pDC;
double angleStart, angleEnd, angleStartQuadrant, angleEndQuadrant=0.0;
/* Initialize angleEndQuadrant to silence gcc's warning */
double x, y;
FLOAT_POINT corners[2], pointStart, pointEnd;
BOOL32 start, end;
INT32 temp;
/* FIXME: This function should check for all possible error returns */
/* FIXME: Do we have to respect newStroke? */
/* Get pointer to DC */
pDC=DC_GetDCPtr(hdc);
if(pDC==NULL)
return FALSE;
/* Get pointer to path */
if(!PATH_GetPathFromHDC(hdc, &pPath))
return FALSE;
/* Check that path is open */
if(pPath->state!=PATH_Open)
return FALSE;
/* FIXME: Do we have to close the current figure? */
/* Check for zero height / width */
/* FIXME: Only in GM_COMPATIBLE? */
if(x1==x2 || y1==y2)
return TRUE;
/* Convert points to device coordinates */
corners[0].x=(FLOAT)x1;
corners[0].y=(FLOAT)y1;
corners[1].x=(FLOAT)x2;
corners[1].y=(FLOAT)y2;
pointStart.x=(FLOAT)xStart;
pointStart.y=(FLOAT)yStart;
pointEnd.x=(FLOAT)xEnd;
pointEnd.y=(FLOAT)yEnd;
INTERNAL_LPTODP_FLOAT(pDC, corners);
INTERNAL_LPTODP_FLOAT(pDC, corners+1);
INTERNAL_LPTODP_FLOAT(pDC, &pointStart);
INTERNAL_LPTODP_FLOAT(pDC, &pointEnd);
/* Make sure first corner is top left and second corner is bottom right */
if(corners[0].x>corners[1].x)
{
temp=corners[0].x;
corners[0].x=corners[1].x;
corners[1].x=temp;
}
if(corners[0].y>corners[1].y)
{
temp=corners[0].y;
corners[0].y=corners[1].y;
corners[1].y=temp;
}
/* Compute start and end angle */
PATH_NormalizePoint(corners, &pointStart, &x, &y);
angleStart=atan2(y, x);
PATH_NormalizePoint(corners, &pointEnd, &x, &y);
angleEnd=atan2(y, x);
/* Make sure the end angle is "on the right side" of the start angle */
if(GetArcDirection32(hdc)==AD_CLOCKWISE)
{
if(angleEnd<=angleStart)
{
angleEnd+=2*M_PI;
assert(angleEnd>=angleStart);
}
}
else
{
if(angleEnd>=angleStart)
{
angleEnd-=2*M_PI;
assert(angleEnd<=angleStart);
}
}
/* In GM_COMPATIBLE, don't include bottom and right edges */
if(GetGraphicsMode(hdc)==GM_COMPATIBLE)
{
corners[1].x--;
corners[1].y--;
}
/* Add the arc to the path with one Bezier spline per quadrant that the
* arc spans */
start=TRUE;
end=FALSE;
do
{
/* Determine the start and end angles for this quadrant */
if(start)
{
angleStartQuadrant=angleStart;
if(GetArcDirection32(hdc)==AD_CLOCKWISE)
angleEndQuadrant=(floor(angleStart/M_PI_2)+1.0)*M_PI_2;
else
angleEndQuadrant=(ceil(angleStart/M_PI_2)-1.0)*M_PI_2;
}
else
{
angleStartQuadrant=angleEndQuadrant;
if(GetArcDirection32(hdc)==AD_CLOCKWISE)
angleEndQuadrant+=M_PI_2;
else
angleEndQuadrant-=M_PI_2;
}
/* Have we reached the last part of the arc? */
if((GetArcDirection32(hdc)==AD_CLOCKWISE &&
angleEnd<angleEndQuadrant) ||
(GetArcDirection32(hdc)==AD_COUNTERCLOCKWISE &&
angleEnd>angleEndQuadrant))
{
/* Adjust the end angle for this quadrant */
angleEndQuadrant=angleEnd;
end=TRUE;
}
/* Add the Bezier spline to the path */
PATH_DoArcPart(pPath, corners, angleStartQuadrant, angleEndQuadrant,
start);
start=FALSE;
} while(!end);
return TRUE;
}
/***********************************************************************
* Internal functions
*/
/* PATH_PathToRegion
*
* Creates a region from the specified path using the specified polygon
* filling mode. The path is left unchanged. A handle to the region that
* was created is stored in *pHrgn. If successful, TRUE is returned; if an
* error occurs, SetLastError is called with the appropriate value and
* FALSE is returned.
*/
static BOOL32 PATH_PathToRegion(const GdiPath *pPath, INT32 nPolyFillMode,
HRGN32 *pHrgn)
{
int numStrokes, iStroke, i;
INT32 *pNumPointsInStroke;
HRGN32 hrgn;
assert(pPath!=NULL);
assert(pHrgn!=NULL);
/* FIXME: What happens when number of points is zero? */
/* First pass: Find out how many strokes there are in the path */
/* FIXME: We could eliminate this with some bookkeeping in GdiPath */
numStrokes=0;
for(i=0; i<pPath->numEntriesUsed; i++)
if((pPath->pFlags[i] & ~PT_CLOSEFIGURE) == PT_MOVETO)
numStrokes++;
/* Allocate memory for number-of-points-in-stroke array */
pNumPointsInStroke=(int *)malloc(sizeof(int)*numStrokes);
if(!pNumPointsInStroke)
{
SetLastError(ERROR_NOT_ENOUGH_MEMORY);
return FALSE;
}
/* Second pass: remember number of points in each polygon */
iStroke=-1; /* Will get incremented to 0 at beginning of first stroke */
for(i=0; i<pPath->numEntriesUsed; i++)
{
/* Is this the beginning of a new stroke? */
if((pPath->pFlags[i] & ~PT_CLOSEFIGURE) == PT_MOVETO)
{
iStroke++;
pNumPointsInStroke[iStroke]=0;
}
pNumPointsInStroke[iStroke]++;
}
/* Create a region from the strokes */
hrgn=CreatePolyPolygonRgn32(pPath->pPoints, pNumPointsInStroke,
numStrokes, nPolyFillMode);
if(hrgn==(HRGN32)0)
{
SetLastError(ERROR_NOT_ENOUGH_MEMORY);
return FALSE;
}
/* Free memory for number-of-points-in-stroke array */
free(pNumPointsInStroke);
/* Success! */
*pHrgn=hrgn;
return TRUE;
}
/* PATH_EmptyPath
*
* Removes all entries from the path and sets the path state to PATH_Null.
*/
static void PATH_EmptyPath(GdiPath *pPath)
{
assert(pPath!=NULL);
pPath->state=PATH_Null;
pPath->numEntriesUsed=0;
}
/* PATH_AddEntry
*
* Adds an entry to the path. For "flags", pass either PT_MOVETO, PT_LINETO
* or PT_BEZIERTO, optionally ORed with PT_CLOSEFIGURE. Returns TRUE if
* successful, FALSE otherwise (e.g. if not enough memory was available).
*/
BOOL32 PATH_AddEntry(GdiPath *pPath, const POINT32 *pPoint, BYTE flags)
{
assert(pPath!=NULL);
/* FIXME: If newStroke is true, perhaps we want to check that we're
* getting a PT_MOVETO
*/
/* Check that path is open */
if(pPath->state!=PATH_Open)
return FALSE;
/* Reserve enough memory for an extra path entry */
if(!PATH_ReserveEntries(pPath, pPath->numEntriesUsed+1))
return FALSE;
/* Store information in path entry */
pPath->pPoints[pPath->numEntriesUsed]=*pPoint;
pPath->pFlags[pPath->numEntriesUsed]=flags;
/* If this is PT_CLOSEFIGURE, we have to start a new stroke next time */
if((flags & PT_CLOSEFIGURE) == PT_CLOSEFIGURE)
pPath->newStroke=TRUE;
/* Increment entry count */
pPath->numEntriesUsed++;
return TRUE;
}
/* PATH_ReserveEntries
*
* Ensures that at least "numEntries" entries (for points and flags) have
* been allocated; allocates larger arrays and copies the existing entries
* to those arrays, if necessary. Returns TRUE if successful, else FALSE.
*/
static BOOL32 PATH_ReserveEntries(GdiPath *pPath, INT32 numEntries)
{
INT32 numEntriesToAllocate;
POINT32 *pPointsNew;
BYTE *pFlagsNew;
assert(pPath!=NULL);
assert(numEntries>=0);
/* Do we have to allocate more memory? */
if(numEntries > pPath->numEntriesAllocated)
{
/* Find number of entries to allocate. We let the size of the array
* grow exponentially, since that will guarantee linear time
* complexity. */
if(pPath->numEntriesAllocated)
{
numEntriesToAllocate=pPath->numEntriesAllocated;
while(numEntriesToAllocate<numEntries)
numEntriesToAllocate=numEntriesToAllocate*GROW_FACTOR_NUMER/
GROW_FACTOR_DENOM;
}
else
numEntriesToAllocate=NUM_ENTRIES_INITIAL;
/* Allocate new arrays */
pPointsNew=(POINT32 *)malloc(numEntriesToAllocate * sizeof(POINT32));
if(!pPointsNew)
return FALSE;
pFlagsNew=(BYTE *)malloc(numEntriesToAllocate * sizeof(BYTE));
if(!pFlagsNew)
{
free(pPointsNew);
return FALSE;
}
/* Copy old arrays to new arrays and discard old arrays */
if(pPath->pPoints)
{
assert(pPath->pFlags);
memcpy(pPointsNew, pPath->pPoints,
sizeof(POINT32)*pPath->numEntriesUsed);
memcpy(pFlagsNew, pPath->pFlags,
sizeof(BYTE)*pPath->numEntriesUsed);
free(pPath->pPoints);
free(pPath->pFlags);
}
pPath->pPoints=pPointsNew;
pPath->pFlags=pFlagsNew;
pPath->numEntriesAllocated=numEntriesToAllocate;
}
return TRUE;
}
/* PATH_GetPathFromHDC
*
* Retrieves a pointer to the GdiPath structure contained in an HDC and
* places it in *ppPath. TRUE is returned if successful, FALSE otherwise.
*/
static BOOL32 PATH_GetPathFromHDC(HDC32 hdc, GdiPath **ppPath)
{
DC *pDC;
pDC=DC_GetDCPtr(hdc);
if(pDC)
{
*ppPath=&pDC->w.path;
return TRUE;
}
else
return FALSE;
}
/* PATH_DoArcPart
*
* Creates a Bezier spline that corresponds to part of an arc and appends the
* corresponding points to the path. The start and end angles are passed in
* "angleStart" and "angleEnd"; these angles should span a quarter circle
* at most. If "addMoveTo" is true, a PT_MOVETO entry for the first control
* point is added to the path; otherwise, it is assumed that the current
* position is equal to the first control point.
*/
static BOOL32 PATH_DoArcPart(GdiPath *pPath, FLOAT_POINT corners[],
double angleStart, double angleEnd, BOOL32 addMoveTo)
{
double halfAngle, a;
double xNorm[4], yNorm[4];
POINT32 point;
int i;
assert(fabs(angleEnd-angleStart)<=M_PI_2);
/* FIXME: Is there an easier way of computing this? */
/* Compute control points */
halfAngle=(angleEnd-angleStart)/2.0;
if(fabs(halfAngle)>1e-8)
{
a=4.0/3.0*(1-cos(halfAngle))/sin(halfAngle);
xNorm[0]=cos(angleStart);
yNorm[0]=sin(angleStart);
xNorm[1]=xNorm[0] - a*yNorm[0];
yNorm[1]=yNorm[0] + a*xNorm[0];
xNorm[3]=cos(angleEnd);
yNorm[3]=sin(angleEnd);
xNorm[2]=xNorm[3] + a*yNorm[3];
yNorm[2]=yNorm[3] - a*xNorm[3];
}
else
for(i=0; i<4; i++)
{
xNorm[i]=cos(angleStart);
yNorm[i]=sin(angleStart);
}
/* Add starting point to path if desired */
if(addMoveTo)
{
PATH_ScaleNormalizedPoint(corners, xNorm[0], yNorm[0], &point);
if(!PATH_AddEntry(pPath, &point, PT_MOVETO))
return FALSE;
}
/* Add remaining control points */
for(i=1; i<4; i++)
{
PATH_ScaleNormalizedPoint(corners, xNorm[i], yNorm[i], &point);
if(!PATH_AddEntry(pPath, &point, PT_BEZIERTO))
return FALSE;
}
return TRUE;
}
/* PATH_ScaleNormalizedPoint
*
* Scales a normalized point (x, y) with respect to the box whose corners are
* passed in "corners". The point is stored in "*pPoint". The normalized
* coordinates (-1.0, -1.0) correspond to corners[0], the coordinates
* (1.0, 1.0) correspond to corners[1].
*/
static void PATH_ScaleNormalizedPoint(FLOAT_POINT corners[], double x,
double y, POINT32 *pPoint)
{
pPoint->x=GDI_ROUND( (double)corners[0].x +
(double)(corners[1].x-corners[0].x)*0.5*(x+1.0) );
pPoint->y=GDI_ROUND( (double)corners[0].y +
(double)(corners[1].y-corners[0].y)*0.5*(y+1.0) );
}
/* PATH_NormalizePoint
*
* Normalizes a point with respect to the box whose corners are passed in
* "corners". The normalized coordinates are stored in "*pX" and "*pY".
*/
static void PATH_NormalizePoint(FLOAT_POINT corners[],
const FLOAT_POINT *pPoint,
double *pX, double *pY)
{
*pX=(double)(pPoint->x-corners[0].x)/(double)(corners[1].x-corners[0].x) *
2.0 - 1.0;
*pY=(double)(pPoint->y-corners[0].y)/(double)(corners[1].y-corners[0].y) *
2.0 - 1.0;
}
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