📄 cxdrawing.c
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// For Open Source Computer Vision Library
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#include "_cxcore.h"
#define XY_SHIFT 16
#define XY_ONE (1 << XY_SHIFT)
#define CV_DRAWING_STORAGE_BLOCK ((1 << 12) - 256)
typedef struct CvPolyEdge
{
int x, dx;
union
{
struct CvPolyEdge *next;
int y0;
};
int y1;
}
CvPolyEdge;
static void
icvCollectPolyEdges( CvMat* img, CvSeq* v, CvContour* edges,
const void* color, int line_type,
int shift, CvPoint offset CV_DEFAULT(cvPoint(0,0)) );
static void
icvFillEdgeCollection( CvMat* img, CvContour* edges, const void* color );
static void
icvPolyLine( CvMat* img, CvPoint *v, int count, int closed,
const void* color, int thickness, int line_type, int shift );
static void
icvFillConvexPoly( CvMat* img, CvPoint* v, int npts,
const void* color, int line_type, int shift );
/****************************************************************************************\
* Lines *
\****************************************************************************************/
CV_IMPL int
cvClipLine( CvSize img_size, CvPoint* pt1, CvPoint* pt2 )
{
int result = 0;
CV_FUNCNAME( "cvClipLine" );
__BEGIN__
int x1, y1, x2, y2;
int c1, c2;
int right = img_size.width-1, bottom = img_size.height-1;
if( !pt1 || !pt2 )
CV_ERROR( CV_StsNullPtr, "One of point pointers is NULL" );
if( right < 0 || bottom < 0 )
CV_ERROR( CV_StsOutOfRange, "Image width or height are negative" );
x1 = pt1->x; y1 = pt1->y; x2 = pt2->x; y2 = pt2->y;
c1 = (x1 < 0) + (x1 > right) * 2 + (y1 < 0) * 4 + (y1 > bottom) * 8;
c2 = (x2 < 0) + (x2 > right) * 2 + (y2 < 0) * 4 + (y2 > bottom) * 8;
if( (c1 & c2) == 0 && (c1 | c2) != 0 )
{
int a;
if( c1 & 12 )
{
a = c1 < 8 ? 0 : bottom;
x1 += (int) (((int64) (a - y1)) * (x2 - x1) / (y2 - y1));
y1 = a;
c1 = (x1 < 0) + (x1 > right) * 2;
}
if( c2 & 12 )
{
a = c2 < 8 ? 0 : bottom;
x2 += (int) (((int64) (a - y2)) * (x2 - x1) / (y2 - y1));
y2 = a;
c2 = (x2 < 0) + (x2 > right) * 2;
}
if( (c1 & c2) == 0 && (c1 | c2) != 0 )
{
if( c1 )
{
a = c1 == 1 ? 0 : right;
y1 += (int) (((int64) (a - x1)) * (y2 - y1) / (x2 - x1));
x1 = a;
c1 = 0;
}
if( c2 )
{
a = c2 == 1 ? 0 : right;
y2 += (int) (((int64) (a - x2)) * (y2 - y1) / (x2 - x1));
x2 = a;
c2 = 0;
}
}
assert( (c1 & c2) != 0 || (x1 | y1 | x2 | y2) >= 0 );
pt1->x = x1;
pt1->y = y1;
pt2->x = x2;
pt2->y = y2;
}
result = ( c1 | c2 ) == 0;
__END__;
return result;
}
/*
Initializes line iterator.
Returns number of points on the line or negative number if error.
*/
CV_IMPL int
cvInitLineIterator( const CvArr* img, CvPoint pt1, CvPoint pt2,
CvLineIterator* iterator, int connectivity,
int left_to_right )
{
int count = -1;
CV_FUNCNAME( "cvInitLineIterator" );
__BEGIN__
CvMat stub, *mat = (CvMat*)img;
int dx, dy, s;
int bt_pix, bt_pix0, step;
if( !CV_IS_MAT(mat) )
CV_CALL( mat = cvGetMat( mat, &stub, 0, 0 ));
if( !iterator )
CV_ERROR( CV_StsNullPtr, "Pointer to the iterator state is NULL" );
if( connectivity != 8 && connectivity != 4 )
CV_ERROR( CV_StsBadArg, "Connectivity must be 8 or 4" );
if( (unsigned)pt1.x >= (unsigned)(mat->width) ||
(unsigned)pt2.x >= (unsigned)(mat->width) ||
(unsigned)pt1.y >= (unsigned)(mat->height) ||
(unsigned)pt2.y >= (unsigned)(mat->height) )
CV_ERROR( CV_StsBadPoint,
"One of the ending points is outside of the image, use cvClipLine" );
bt_pix0 = bt_pix = CV_ELEM_SIZE(mat->type);
step = mat->step;
dx = pt2.x - pt1.x;
dy = pt2.y - pt1.y;
s = dx < 0 ? -1 : 0;
if( left_to_right )
{
dx = (dx ^ s) - s;
dy = (dy ^ s) - s;
pt1.x ^= (pt1.x ^ pt2.x) & s;
pt1.y ^= (pt1.y ^ pt2.y) & s;
}
else
{
dx = (dx ^ s) - s;
bt_pix = (bt_pix ^ s) - s;
}
iterator->ptr = (uchar*)(mat->data.ptr + pt1.y * step + pt1.x * bt_pix0);
s = dy < 0 ? -1 : 0;
dy = (dy ^ s) - s;
step = (step ^ s) - s;
s = dy > dx ? -1 : 0;
/* conditional swaps */
dx ^= dy & s;
dy ^= dx & s;
dx ^= dy & s;
bt_pix ^= step & s;
step ^= bt_pix & s;
bt_pix ^= step & s;
if( connectivity == 8 )
{
assert( dx >= 0 && dy >= 0 );
iterator->err = dx - (dy + dy);
iterator->plus_delta = dx + dx;
iterator->minus_delta = -(dy + dy);
iterator->plus_step = step;
iterator->minus_step = bt_pix;
count = dx + 1;
}
else /* connectivity == 4 */
{
assert( dx >= 0 && dy >= 0 );
iterator->err = 0;
iterator->plus_delta = (dx + dx) + (dy + dy);
iterator->minus_delta = -(dy + dy);
iterator->plus_step = step - bt_pix;
iterator->minus_step = bt_pix;
count = dx + dy + 1;
}
__END__;
return count;
}
static void
icvLine( CvMat* mat, CvPoint pt1, CvPoint pt2,
const void* color, int connectivity CV_DEFAULT(8) )
{
if( cvClipLine( cvGetMatSize(mat), &pt1, &pt2 ))
{
CvLineIterator iterator;
int pix_size = CV_ELEM_SIZE(mat->type);
int i, count;
if( connectivity == 0 )
connectivity = 8;
if( connectivity == 1 )
connectivity = 4;
count = cvInitLineIterator( mat, pt1, pt2, &iterator, connectivity, 1 );
for( i = 0; i < count; i++ )
{
CV_MEMCPY_AUTO( iterator.ptr, color, pix_size );
CV_NEXT_LINE_POINT( iterator );
}
}
}
/* Correction table depent on the slope */
static const uchar icvSlopeCorrTable[] = {
181, 181, 181, 182, 182, 183, 184, 185, 187, 188, 190, 192, 194, 196, 198, 201,
203, 206, 209, 211, 214, 218, 221, 224, 227, 231, 235, 238, 242, 246, 250, 254
};
/* Gaussian for antialiasing filter */
static const int icvFilterTable[] = {
168, 177, 185, 194, 202, 210, 218, 224, 231, 236, 241, 246, 249, 252, 254, 254,
254, 254, 252, 249, 246, 241, 236, 231, 224, 218, 210, 202, 194, 185, 177, 168,
158, 149, 140, 131, 122, 114, 105, 97, 89, 82, 75, 68, 62, 56, 50, 45,
40, 36, 32, 28, 25, 22, 19, 16, 14, 12, 11, 9, 8, 7, 5, 5
};
static void
icvLineAA( CvMat* img, CvPoint pt1, CvPoint pt2,
const void* color )
{
int dx, dy;
int ecount, scount = 0;
int slope;
int ax, ay;
int x_step, y_step;
int i, j;
int ep_table[9];
int cb = ((uchar*)color)[0], cg = ((uchar*)color)[1], cr = ((uchar*)color)[2];
int _cb, _cg, _cr;
int nch = CV_MAT_CN( img->type );
uchar* ptr = (uchar*)(img->data.ptr);
int step = img->step;
CvSize size = cvGetMatSize( img );
assert( img && (nch == 1 || nch == 3) && CV_MAT_DEPTH(img->type) == CV_8U );
pt1.x -= XY_ONE*2;
pt1.y -= XY_ONE*2;
pt2.x -= XY_ONE*2;
pt2.y -= XY_ONE*2;
ptr += img->step*2 + 2*nch;
size.width = ((size.width - 5) << XY_SHIFT) + 1;
size.height = ((size.height - 5) << XY_SHIFT) + 1;
if( !cvClipLine( size, &pt1, &pt2 ))
return;
dx = pt2.x - pt1.x;
dy = pt2.y - pt1.y;
j = dx < 0 ? -1 : 0;
ax = (dx ^ j) - j;
i = dy < 0 ? -1 : 0;
ay = (dy ^ i) - i;
if( ax > ay )
{
dx = ax;
dy = (dy ^ j) - j;
pt1.x ^= pt2.x & j;
pt2.x ^= pt1.x & j;
pt1.x ^= pt2.x & j;
pt1.y ^= pt2.y & j;
pt2.y ^= pt1.y & j;
pt1.y ^= pt2.y & j;
x_step = XY_ONE;
y_step = (int) (((int64) dy << XY_SHIFT) / (ax | 1));
pt2.x += XY_ONE;
ecount = (pt2.x >> XY_SHIFT) - (pt1.x >> XY_SHIFT);
j = -(pt1.x & (XY_ONE - 1));
pt1.y += (int) ((((int64) y_step) * j) >> XY_SHIFT) + (XY_ONE >> 1);
slope = (y_step >> (XY_SHIFT - 5)) & 0x3f;
slope ^= (y_step < 0 ? 0x3f : 0);
/* Get 4-bit fractions for end-point adjustments */
i = (pt1.x >> (XY_SHIFT - 7)) & 0x78;
j = (pt2.x >> (XY_SHIFT - 7)) & 0x78;
}
else
{
dy = ay;
dx = (dx ^ i) - i;
pt1.x ^= pt2.x & i;
pt2.x ^= pt1.x & i;
pt1.x ^= pt2.x & i;
pt1.y ^= pt2.y & i;
pt2.y ^= pt1.y & i;
pt1.y ^= pt2.y & i;
x_step = (int) (((int64) dx << XY_SHIFT) / (ay | 1));
y_step = XY_ONE;
pt2.y += XY_ONE;
ecount = (pt2.y >> XY_SHIFT) - (pt1.y >> XY_SHIFT);
j = -(pt1.y & (XY_ONE - 1));
pt1.x += (int) ((((int64) x_step) * j) >> XY_SHIFT) + (XY_ONE >> 1);
slope = (x_step >> (XY_SHIFT - 5)) & 0x3f;
slope ^= (x_step < 0 ? 0x3f : 0);
/* Get 4-bit fractions for end-point adjustments */
i = (pt1.y >> (XY_SHIFT - 7)) & 0x78;
j = (pt2.y >> (XY_SHIFT - 7)) & 0x78;
}
slope = (slope & 0x20) ? 0x100 : icvSlopeCorrTable[slope];
/* Calc end point correction table */
{
int t0 = slope << 7;
int t1 = ((0x78 - i) | 4) * slope;
int t2 = (j | 4) * slope;
ep_table[0] = 0;
ep_table[8] = slope;
ep_table[1] = ep_table[3] = ((((j - i) & 0x78) | 4) * slope >> 8) & 0x1ff;
ep_table[2] = (t1 >> 8) & 0x1ff;
ep_table[4] = ((((j - i) + 0x80) | 4) * slope >> 8) & 0x1ff;
ep_table[5] = ((t1 + t0) >> 8) & 0x1ff;
ep_table[6] = (t2 >> 8) & 0x1ff;
ep_table[7] = ((t2 + t0) >> 8) & 0x1ff;
}
if( nch == 3 )
{
#define ICV_PUT_POINT() \
{ \
_cb = tptr[0]; \
_cb += ((cb - _cb)*a + 127)>> 8;\
_cg = tptr[1]; \
_cg += ((cg - _cg)*a + 127)>> 8;\
_cr = tptr[2]; \
_cr += ((cr - _cr)*a + 127)>> 8;\
tptr[0] = (uchar)_cb; \
tptr[1] = (uchar)_cg; \
tptr[2] = (uchar)_cr; \
}
if( ax > ay )
{
ptr += (pt1.x >> XY_SHIFT) * 3;
while( ecount >= 0 )
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