Vincent Povirk : gdiplus: Properly draw points outside of line gradients.
Alexandre Julliard
julliard at winehq.org
Mon May 4 09:06:37 CDT 2009
Module: wine
Branch: master
Commit: 966fd5ec092a3745fe8d2d371e24d4b3161dd0b8
URL: http://source.winehq.org/git/wine.git/?a=commit;h=966fd5ec092a3745fe8d2d371e24d4b3161dd0b8
Author: Vincent Povirk <vincent at codeweavers.com>
Date: Fri May 1 15:23:02 2009 -0500
gdiplus: Properly draw points outside of line gradients.
Theoretically, a line gradient covers the area enclosed by the
starting and ending gradient lines, which intersect the start and end
points respectively and are perpendicular to a line joining the start
and end points.
---
dlls/gdiplus/graphics.c | 115 ++++++++++++++++++++++------------------------
1 files changed, 55 insertions(+), 60 deletions(-)
diff --git a/dlls/gdiplus/graphics.c b/dlls/gdiplus/graphics.c
index b467dc7..219ed75 100644
--- a/dlls/gdiplus/graphics.c
+++ b/dlls/gdiplus/graphics.c
@@ -185,6 +185,19 @@ static ARGB blend_line_gradient(GpLineGradient* brush, REAL position)
{
REAL blendfac;
+ /* clamp to between 0.0 and 1.0, using the wrap mode */
+ if (brush->wrap == WrapModeTile)
+ {
+ position = fmodf(position, 1.0f);
+ if (position < 0.0f) position += 1.0f;
+ }
+ else /* WrapModeFlip* */
+ {
+ position = fmodf(position, 2.0f);
+ if (position < 0.0f) position += 2.0f;
+ if (position > 1.0f) position = 2.0f - position;
+ }
+
if (brush->blendcount == 1)
blendfac = position;
else
@@ -217,7 +230,6 @@ static void brush_fill_path(GpGraphics *graphics, GpBrush* brush)
{
GpLineGradient *line = (GpLineGradient*)brush;
RECT rc;
- int num_steps = 255;
SelectClipPath(graphics->hdc, RGN_AND);
if (GetClipBox(graphics->hdc, &rc) != NULLREGION)
@@ -228,9 +240,6 @@ static void brush_fill_path(GpGraphics *graphics, GpBrush* brush)
SelectObject(graphics->hdc, GetStockObject(NULL_PEN));
- /* fill with starting color */
- FillRect(graphics->hdc, &rc, brush->gdibrush);
-
endpointsf[0] = line->startpoint;
endpointsf[1] = line->endpoint;
transform_and_round_points(graphics, endpointsi, endpointsf, 2);
@@ -238,114 +247,100 @@ static void brush_fill_path(GpGraphics *graphics, GpBrush* brush)
if (abs(endpointsi[0].x-endpointsi[1].x) > abs(endpointsi[0].y-endpointsi[1].y))
{
/* vertical-ish gradient */
- int endborderx; /* vertical rectangle boundary near endpoint */
int startx, endx; /* x co-ordinates of endpoints shifted to intersect the top of the visible rectangle */
- int startbottomx, endbottomx; /* x co-ordinate of endpoints shifted to intersect the bottom of the visible rectangle */
+ int startbottomx; /* x co-ordinate of start point shifted to intersect the bottom of the visible rectangle */
int width;
COLORREF col;
HBRUSH hbrush, hprevbrush;
- int i;
-
- if (endpointsi[1].x > endpointsi[0].x)
- endborderx = rc.right;
- else
- endborderx = rc.left;
+ int leftx, rightx; /* x co-ordinates where the leftmost and rightmost gradient lines hit the top of the visible rectangle */
+ int x;
+ int tilt; /* horizontal distance covered by a gradient line */
startx = roundr((rc.top - endpointsf[0].Y) * (endpointsf[1].Y - endpointsf[0].Y) / (endpointsf[0].X - endpointsf[1].X) + endpointsf[0].X);
endx = roundr((rc.top - endpointsf[1].Y) * (endpointsf[1].Y - endpointsf[0].Y) / (endpointsf[0].X - endpointsf[1].X) + endpointsf[1].X);
width = endx - startx;
startbottomx = roundr((rc.bottom - endpointsf[0].Y) * (endpointsf[1].Y - endpointsf[0].Y) / (endpointsf[0].X - endpointsf[1].X) + endpointsf[0].X);
- endbottomx = startbottomx+width;
+ tilt = startx - startbottomx;
- if (num_steps > abs(width)) num_steps = abs(width);
+ if (startx >= startbottomx)
+ {
+ leftx = rc.left;
+ rightx = rc.right + tilt;
+ }
+ else
+ {
+ leftx = rc.left + tilt;
+ rightx = rc.right;
+ }
- poly[0].x = endborderx;
+ poly[0].x = rc.right;
poly[0].y = rc.bottom;
- poly[1].x = endborderx;
+ poly[1].x = rc.right;
poly[1].y = rc.top;
poly[2].y = rc.top;
poly[3].y = rc.bottom;
- for (i=1; i<num_steps; i++)
+ for (x=leftx; x<=rightx; x++)
{
- ARGB argb = blend_line_gradient(line, i/(REAL)num_steps);
- int ofs = width * i / num_steps;
+ ARGB argb = blend_line_gradient(line, (x-startx)/(REAL)width);
col = ARGB2COLORREF(argb);
hbrush = CreateSolidBrush(col);
hprevbrush = SelectObject(graphics->hdc, hbrush);
- poly[2].x = startx + ofs;
- poly[3].x = startbottomx + ofs;
+ poly[2].x = x;
+ poly[3].x = x - tilt;
Polygon(graphics->hdc, poly, 4);
SelectObject(graphics->hdc, hprevbrush);
DeleteObject(hbrush);
}
-
- poly[2].x = endx;
- poly[3].x = endbottomx;
-
- /* draw the ending color */
- col = ARGB2COLORREF(line->endcolor);
- hbrush = CreateSolidBrush(col);
- hprevbrush = SelectObject(graphics->hdc, hbrush);
- Polygon(graphics->hdc, poly, 4);
- SelectObject(graphics->hdc, hprevbrush);
- DeleteObject(hbrush);
}
else if (endpointsi[0].y != endpointsi[1].y)
{
/* horizontal-ish gradient */
- int endbordery; /* horizontal rectangle boundary near endpoint */
int starty, endy; /* y co-ordinates of endpoints shifted to intersect the left of the visible rectangle */
- int startrighty, endrighty; /* y co-ordinate of endpoints shifted to intersect the right of the visible rectangle */
+ int startrighty; /* y co-ordinate of start point shifted to intersect the right of the visible rectangle */
int height;
COLORREF col;
HBRUSH hbrush, hprevbrush;
- int i;
-
- if (endpointsi[1].y > endpointsi[0].y)
- endbordery = rc.bottom;
- else
- endbordery = rc.top;
+ int topy, bottomy; /* y co-ordinates where the topmost and bottommost gradient lines hit the left of the visible rectangle */
+ int y;
+ int tilt; /* vertical distance covered by a gradient line */
starty = roundr((rc.left - endpointsf[0].X) * (endpointsf[0].X - endpointsf[1].X) / (endpointsf[1].Y - endpointsf[0].Y) + endpointsf[0].Y);
endy = roundr((rc.left - endpointsf[1].X) * (endpointsf[0].X - endpointsf[1].X) / (endpointsf[1].Y - endpointsf[0].Y) + endpointsf[1].Y);
height = endy - starty;
startrighty = roundr((rc.right - endpointsf[0].X) * (endpointsf[0].X - endpointsf[1].X) / (endpointsf[1].Y - endpointsf[0].Y) + endpointsf[0].Y);
- endrighty = startrighty+height;
+ tilt = starty - startrighty;
- if (num_steps > abs(height)) num_steps = abs(height);
+ if (starty >= startrighty)
+ {
+ topy = rc.top;
+ bottomy = rc.bottom + tilt;
+ }
+ else
+ {
+ topy = rc.top + tilt;
+ bottomy = rc.bottom;
+ }
poly[0].x = rc.right;
- poly[0].y = endbordery;
+ poly[0].y = rc.bottom;
poly[1].x = rc.left;
- poly[1].y = endbordery;
+ poly[1].y = rc.bottom;
poly[2].x = rc.left;
poly[3].x = rc.right;
- for (i=1; i<num_steps; i++)
+ for (y=topy; y<=bottomy; y++)
{
- ARGB argb = blend_line_gradient(line, i/(REAL)num_steps);
- int ofs = height * i / num_steps;
+ ARGB argb = blend_line_gradient(line, (y-starty)/(REAL)height);
col = ARGB2COLORREF(argb);
hbrush = CreateSolidBrush(col);
hprevbrush = SelectObject(graphics->hdc, hbrush);
- poly[2].y = starty + ofs;
- poly[3].y = startrighty + ofs;
+ poly[2].y = y;
+ poly[3].y = y - tilt;
Polygon(graphics->hdc, poly, 4);
SelectObject(graphics->hdc, hprevbrush);
DeleteObject(hbrush);
}
-
- poly[2].y = endy;
- poly[3].y = endrighty;
-
- /* draw the ending color */
- col = ARGB2COLORREF(line->endcolor);
- hbrush = CreateSolidBrush(col);
- hprevbrush = SelectObject(graphics->hdc, hbrush);
- Polygon(graphics->hdc, poly, 4);
- SelectObject(graphics->hdc, hprevbrush);
- DeleteObject(hbrush);
}
/* else startpoint == endpoint */
}
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