ReceiveTempSMS
/
Sweden-Number
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

gdi32: Add a directional bias for the case when the Bresenham error term is zero.

This commit is contained in:
Huw Davies 2011-04-20 12:52:06 +01:00 committed by Alexandre Julliard
parent a3e77bfe59
commit a9675b3509
2 changed files with 102 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

83
dlls/gdi32/dibdrv/objects.c
View File

@ -106,7 +106,31 @@ static inline BOOL pt_in_rect( const RECT *rect, const POINT *pt )
(pt->y >= rect->top) && (pt->y < rect->bottom));
}
static void WINAPI solid_pen_line_callback(INT x, INT y, LPARAM lparam)
/**********************************************************************
* get_octant_number
*
* Return the octant number starting clockwise from the +ve x-axis.
*/
static inline int get_octant_number(int dx, int dy)
{
if(dy > 0)
if(dx > 0)
return ( dx > dy) ? 1 : 2;
else
return (-dx > dy) ? 4 : 3;
else
if(dx < 0)
return (-dx > -dy) ? 5 : 6;
else
return ( dx > -dy) ? 8 : 7;
}
static inline DWORD get_octant_mask(int dx, int dy)
{
return 1 << (get_octant_number(dx, dy) - 1);
}
static void solid_pen_line_callback(INT x, INT y, LPARAM lparam)
{
dibdrv_physdev *pdev = (dibdrv_physdev *)lparam;
RECT rect;
@ -119,6 +143,61 @@ static void WINAPI solid_pen_line_callback(INT x, INT y, LPARAM lparam)
return;
}
static void bres_line_with_bias(INT x1, INT y1, INT x2, INT y2, void (* callback)(INT,INT,LPARAM), LPARAM lParam)
{
INT xadd = 1, yadd = 1;
INT err, erradd;
INT cnt;
INT dx = x2 - x1;
INT dy = y2 - y1;
DWORD octant = get_octant_mask(dx, dy);
INT bias = 0;
/* Octants 3, 5, 6 and 8 take a bias */
if(octant & 0xb4) bias = 1;
if (dx < 0)
{
dx = -dx;
xadd = -1;
}
if (dy < 0)
{
dy = -dy;
yadd = -1;
}
if (dx > dy) /* line is "more horizontal" */
{
err = 2*dy - dx; erradd = 2*dy - 2*dx;
for(cnt = 0; cnt < dx; cnt++)
{
callback(x1, y1, lParam);
if (err + bias > 0)
{
y1 += yadd;
err += erradd;
}
else err += 2*dy;
x1 += xadd;
}
}
else /* line is "more vertical" */
{
err = 2*dx - dy; erradd = 2*dx - 2*dy;
for(cnt = 0; cnt < dy; cnt++)
{
callback(x1, y1, lParam);
if (err + bias > 0)
{
x1 += xadd;
err += erradd;
}
else err += 2*dx;
y1 += yadd;
}
}
}
static BOOL solid_pen_line(dibdrv_physdev *pdev, POINT *start, POINT *end)
{
const WINEREGION *clip = get_wine_region(pdev->clip);
@ -188,7 +267,7 @@ static BOOL solid_pen_line(dibdrv_physdev *pdev, POINT *start, POINT *end)
if(clip->numRects == 1 && pt_in_rect(&clip->extents, start) && pt_in_rect(&clip->extents, end))
/* FIXME: Optimize by moving Bresenham algorithm to the primitive functions,
or at least cache adjacent points in the callback */
LineDDA(start->x, start->y, end->x, end->y, solid_pen_line_callback, (LPARAM)pdev);
bres_line_with_bias(start->x, start->y, end->x, end->y, solid_pen_line_callback, (LPARAM)pdev);
else if(clip->numRects >= 1)
ret = FALSE;
}

21
dlls/gdi32/tests/dib.c
View File

@ -78,6 +78,7 @@ static const char *sha1_graphics_a8r8g8b8[] =
"a3cadd34d95d3d5cc23344f69aab1c2e55935fcf",
"2426172d9e8fec27d9228088f382ef3c93717da9",
"9e8f27ca952cdba01dbf25d07c34e86a7820c012",
"664fac17803859a4015c6ae29e5538e314d5c827",
"17b2c177bdce5e94433574a928bda5c94a8cdfa5",
"fe6cc678fb13a3ead67839481bf22348adc69f52",
"d51bd330cec510cdccf5394328bd8e5411901e9e",
@ -150,6 +151,18 @@ static void compare_hash(BITMAPINFO *bmi, BYTE *bits, const char ***sha1, const
HeapFree(GetProcessHeap(), 0, hash);
}
static const RECT bias_check[] =
{
{100, 100, 200, 150},
{100, 100, 150, 200},
{100, 100, 50, 200},
{100, 100, 0, 150},
{100, 100, 0, 50},
{100, 100, 50, 0},
{100, 100, 150, 0},
{100, 100, 200, 50}
};
static const RECT hline_clips[] =
{
{120, 120, 140, 120}, /* unclipped */
@ -251,6 +264,14 @@ static void draw_graphics(HDC hdc, BITMAPINFO *bmi, BYTE *bits, const char ***sh
compare_hash(bmi, bits, sha1, "diagonal solid lines");
memset(bits, 0xcc, dib_size);
for(i = 0; i < sizeof(bias_check) / sizeof(bias_check[0]); i++)
{
MoveToEx(hdc, bias_check[i].left, bias_check[i].top, NULL);
LineTo(hdc, bias_check[i].right, bias_check[i].bottom);
}
compare_hash(bmi, bits, sha1, "more diagonal solid lines");
memset(bits, 0xcc, dib_size);
/* solid brush PatBlt */
solid_brush = CreateSolidBrush(RGB(0x33, 0xaa, 0xff));
orig_brush = SelectObject(hdc, solid_brush);