1 files changed, 109 insertions, 30 deletions

diff --git a/win/tkWinRegion.c b/win/tkWinRegion.c
index 713a6b1..a996ca5 100644
--- a/win/tkWinRegion.c
+++ b/win/tkWinRegion.c
@@ -1,12 +1,12 @@
-/* 
+/*
  * 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.
+ * See the file "license.terms" for information on usage and redistribution of
+ * this file, and for a DISCLAIMER OF ALL WARRANTIES.
  */
 
 #include "tkWinInt.h"
@@ -29,7 +29,7 @@
  */
 
 TkRegion
-TkCreateRegion()
+TkCreateRegion(void)
 {
     RECT rect;
     memset(&rect, 0, sizeof(RECT));
@@ -53,8 +53,8 @@ TkCreateRegion()
  */
 
 void
-TkDestroyRegion(r)
-    TkRegion r;
+TkDestroyRegion(
+    TkRegion r)
 {
     DeleteObject((HRGN) r);
 }
@@ -76,11 +76,12 @@ TkDestroyRegion(r)
  */
 
 void
-TkClipBox(r, rect_return)
-    TkRegion r;
-    XRectangle* rect_return;
+TkClipBox(
+    TkRegion r,
+    XRectangle* rect_return)
 {
     RECT rect;
+
     GetRgnBox((HRGN)r, &rect);
     rect_return->x = (short) rect.left;
     rect_return->y = (short) rect.top;
@@ -105,10 +106,10 @@ TkClipBox(r, rect_return)
  */
 
 void
-TkIntersectRegion(sra, srb, dr_return)
-    TkRegion sra;
-    TkRegion srb;
-    TkRegion dr_return;
+TkIntersectRegion(
+    TkRegion sra,
+    TkRegion srb,
+    TkRegion dr_return)
 {
     CombineRgn((HRGN) dr_return, (HRGN) sra, (HRGN) srb, RGN_AND);
 }
@@ -130,13 +131,14 @@ TkIntersectRegion(sra, srb, dr_return)
  */
 
 void
-TkUnionRectWithRegion(rectangle, src_region, dest_region_return)
-    XRectangle* rectangle;
-    TkRegion src_region;
-    TkRegion dest_region_return;
+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);
@@ -145,14 +147,84 @@ TkUnionRectWithRegion(rectangle, src_region, dest_region_return)
 /*
  *----------------------------------------------------------------------
  *
+ * 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.
+ *	Returns RectanglePart or RectangleOut. Note that this is not a
+ *	complete implementation since it doesn't test for RectangleIn.
  *
  * Side effects:
  *	None.
@@ -161,12 +233,11 @@ TkUnionRectWithRegion(rectangle, src_region, dest_region_return)
  */
 
 int
-TkRectInRegion(r, x, y, width, height)
-    TkRegion r;
-    int x;
-    int y;
-    unsigned int width;
-    unsigned int height;
+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;
@@ -193,10 +264,18 @@ TkRectInRegion(r, x, y, width, height)
  */
 
 void
-TkSubtractRegion(sra, srb, dr_return)
-    TkRegion sra;
-    TkRegion srb;
-    TkRegion dr_return;
+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:
+ */