summaryrefslogtreecommitdiffstats
path: root/win/tkWinRegion.c
blob: d097047511c8f3330ec08fe6cc42d2520c00c556 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
/*
 * 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:
 */