/*
* tkWinRegion.c --
*
* Tk Region emulation code.
*
* Copyright (c) 1995 Sun Microsystems, Inc.
*
* See the file "license.terms" for information on usage and redistribution of
* this file, and for a DISCLAIMER OF ALL WARRANTIES.
*/
#include "tkWinInt.h"
#undef TkCreateRegion
#undef TkDestroyRegion
#undef TkClipBox
#undef TkIntersectRegion
#undef TkUnionRectWithRegion
#undef TkRectInRegion
#undef TkSubtractRegion
/*
*----------------------------------------------------------------------
*
* TkCreateRegion --
*
* Construct an empty region.
*
* Results:
* Returns a new region handle.
*
* Side effects:
* None.
*
*----------------------------------------------------------------------
*/
TkRegion
TkCreateRegion(void)
{
RECT rect;
memset(&rect, 0, sizeof(RECT));
return (TkRegion) CreateRectRgnIndirect(&rect);
}
/*
*----------------------------------------------------------------------
*
* TkDestroyRegion --
*
* Destroy the specified region.
*
* Results:
* None.
*
* Side effects:
* Frees the storage associated with the specified region.
*
*----------------------------------------------------------------------
*/
void
TkDestroyRegion(
TkRegion r)
{
DeleteObject((HRGN) r);
}
/*
*----------------------------------------------------------------------
*
* TkClipBox --
*
* Computes the bounding box of a region.
*
* Results:
* Sets rect_return to the bounding box of the region.
*
* Side effects:
* None.
*
*----------------------------------------------------------------------
*/
void
TkClipBox(
TkRegion r,
XRectangle* rect_return)
{
RECT rect;
GetRgnBox((HRGN)r, &rect);
rect_return->x = (short) rect.left;
rect_return->y = (short) rect.top;
rect_return->width = (short) (rect.right - rect.left);
rect_return->height = (short) (rect.bottom - rect.top);
}
/*
*----------------------------------------------------------------------
*
* TkIntersectRegion --
*
* Compute the intersection of two regions.
*
* Results:
* Returns the result in the dr_return region.
*
* Side effects:
* None.
*
*----------------------------------------------------------------------
*/
void
TkIntersectRegion(
TkRegion sra,
TkRegion srb,
TkRegion dr_return)
{
CombineRgn((HRGN) dr_return, (HRGN) sra, (HRGN) srb, RGN_AND);
}
/*
*----------------------------------------------------------------------
*
* TkUnionRectWithRegion --
*
* Create the union of a source region and a rectangle.
*
* Results:
* Returns the result in the dr_return region.
*
* Side effects:
* None.
*
*----------------------------------------------------------------------
*/
void
TkUnionRectWithRegion(
XRectangle *rectangle,
TkRegion src_region,
TkRegion dest_region_return)
{
HRGN rectRgn = CreateRectRgn(rectangle->x, rectangle->y,
rectangle->x + rectangle->width, rectangle->y + rectangle->height);
CombineRgn((HRGN) dest_region_return, (HRGN) src_region,
(HRGN) rectRgn, RGN_OR);
DeleteObject(rectRgn);
}
/*
*----------------------------------------------------------------------
*
* TkpBuildRegionFromAlphaData --
*
* Set up a rectangle of the given region based on the supplied alpha
* data.
*
* Results:
* None
*
* Side effects:
* The region is updated, with extra pixels added to it.
*
*----------------------------------------------------------------------
*/
void
TkpBuildRegionFromAlphaData(
TkRegion region,
unsigned int x, unsigned int y,
/* Where in region to update. */
unsigned int width, unsigned int height,
/* Size of rectangle to update. */
unsigned char *dataPtr, /* Data to read from. */
unsigned int pixelStride, /* Num bytes from one piece of alpha data to
* the next in the line. */
unsigned int lineStride) /* Num bytes from one line of alpha data to
* the next line. */
{
unsigned char *lineDataPtr;
unsigned int x1, y1, end;
HRGN rectRgn = CreateRectRgn(0,0,1,1); /* Workspace region. */
for (y1 = 0; y1 < height; y1++) {
lineDataPtr = dataPtr;
for (x1 = 0; x1 < width; x1 = end) {
/*
* Search for first non-transparent pixel.
*/
while ((x1 < width) && !*lineDataPtr) {
x1++;
lineDataPtr += pixelStride;
}
end = x1;
/*
* Search for first transparent pixel.
*/
while ((end < width) && *lineDataPtr) {
end++;
lineDataPtr += pixelStride;
}
if (end > x1) {
/*
* Manipulate Win32 regions directly; it's more efficient.
*/
SetRectRgn(rectRgn, (int) (x+x1), (int) (y+y1),
(int) (x+end), (int) (y+y1+1));
CombineRgn((HRGN) region, (HRGN) region, rectRgn, RGN_OR);
}
}
dataPtr += lineStride;
}
DeleteObject(rectRgn);
}
/*
*----------------------------------------------------------------------
*
* TkRectInRegion --
*
* Test whether a given rectangle overlaps with a region.
*
* Results:
* Returns RectanglePart or RectangleOut. Note that this is not a
* complete implementation since it doesn't test for RectangleIn.
*
* Side effects:
* None.
*
*----------------------------------------------------------------------
*/
int
TkRectInRegion(
TkRegion r, /* Region to inspect */
int x, int y, /* Top-left of rectangle */
unsigned int width, /* Width of rectangle */
unsigned int height) /* Height of rectangle */
{
RECT rect;
rect.top = y;
rect.left = x;
rect.bottom = y+height;
rect.right = x+width;
return RectInRegion((HRGN)r, &rect) ? RectanglePart : RectangleOut;
}
/*
*----------------------------------------------------------------------
*
* TkSubtractRegion --
*
* Compute the set-difference of two regions.
*
* Results:
* Returns the result in the dr_return region.
*
* Side effects:
* None.
*
*----------------------------------------------------------------------
*/
void
TkSubtractRegion(
TkRegion sra,
TkRegion srb,
TkRegion dr_return)
{
CombineRgn((HRGN) dr_return, (HRGN) sra, (HRGN) srb, RGN_DIFF);
}
/*
* Local Variables:
* mode: c
* c-basic-offset: 4
* fill-column: 78
* End:
*/