US 2019/0197744 A1 · Method for efficient parallel visualizing vector graphic

Abstract

A method for efficiently visualizing parallel vector data rapidly renders high-quality complex vector graphics. The present invention provides a scanline algorithm for calculating and rendering on contour lines, which parallel-rasterizing on the contour lines. The algorithm firstly rasterizes the contour lines into segments corresponding to output image pixels. On each segment, color values are analytically calculated, or approximately obtained by a sampling algorithm. Contour rasterizing is efficiently completed in parallel. By analytical calculation or 32-bit sampling, high quality results are obtained. The present invention adapts parallel prefixes and algorithms in a scanline direction to obtain covering information for each pixel and generate filled areas. Finally, the contour line segments and the filled areas of the vector graphics are rendered in the output image. The present invention is entirely based on parallel many-core computing devices for real-time high-quality vector graphic rendering with hardware acceleration.

A method for effectively parallel visualizing vector graphic, comprising steps of:

(1) parallel-cutting contour lines of vector graphics, wherein each of the contour lines is cut along a pixel boundary for obtaining contour line segments within pixels;
(2) parallel-treating each of the contour line segments based on an anti-aliasing algorithm, so as to obtain intermediate results of each of the contour line segments for calculating a coverage value;
wherein the anti-aliasing algorithm is an analytic method, comprising steps of:
calculating the coverage value of each of the pixels based on a formula:
F

(
x
,
y
)
=
∫
∫
u
,
v
∈
M

h

(
u
-
x
,
v
-
x
)
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dudv
(
1
)
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=
∮
u
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(
t
)
,
v
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(
t
)
∈
∂
M
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H
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(
u
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(
t
)
-
x
,
v
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(
t
)
-
y
)
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v
′
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(
t
)
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dt
(
2
)
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=
F
0
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(
x
,
y
)
+
∑
i
=
0
x
-
1

F
1
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(
i
,
y
)
(
3
)
wherein:
h
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(
u
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v
)
=
{
1
0
<
u
,
v
<
1
0
else

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H
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(
u
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v
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=
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0
u
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h
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(
s
,
v
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ds
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F
0
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(
x
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=
∫
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1
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H
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(
u
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(
t
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-
x
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v
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v
′
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(
t
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dt
(
4
)
F
1
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(
x
,
y
)
=
∫
0
1
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H
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(
u
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(
t
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-
(
x
+
1
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,
v
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t
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v
′
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(
t
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dt
(
5
)
wherein F(x, y) represents the coverage value of a (x, y) pixel contour within a (x, y) pixel;
u and v are coordinates on the vector graphics;
u(t) and v(t) are respectively x and y components of a contour line formula within the (x, y) pixel;
M represents an internal area of the vector graphics;
am is a vector graphic boundary;
the function h has a constant value of 1 within a unit pixel with a size of 1×1;
and the function H is obtained by lateral integration of the function h;
parallel-treating each of the contour line segments, substituting the formula (4) and the formula (5) with an expression of the contour line segments, and calculating the intermediate results F0(x, y) and F1(x, y) corresponding to each of the contour line segments;
(3) parallel-sorting values corresponding to each of the contour line segments based on pixel positions, and sorting the contour line segments, with a first order of rows and a second order of columns, within each of the vector graphics;
(4) on each line of the contour lines within each of the vector graphics, parallel-calculating the coverage value of the contour line segments on the pixels;
specifically, parallel-calculating a summation term in the formula (3), which is recorded as:
A
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(
x
,
y
)
=
∑
i
=
0
x
-
1

F
1

(
i
,
y
)
parallel-adding A(x, y) with F0(i, y) at each of the pixel positions, so as to obtain the coverage value F(x, y) on the pixels;
(5) generating an area for rendering vector graphic filling colors:
if adjacent contour line segments are in a same line or belong to a same vector graphic, using a rule for judging whether a region between the adjacent contour line segments is inside the same vector graph:
judging whether the A(x, y) at a right segment is larger than 0;
parallel-treating all the adjacent contour line segments, and judging whether the region between the adjacent contour line segments is inside the vector graphics with the rule;
recording filled areas inside the vector graphics;
and
(6) rendering the contour line segments and the filled areas:
representing all the contour line segments and the filled areas with primitives;
using the coverage value of the contour line segments for anti-aliasing, and rendering all the primitives.

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Method for efficient parallel visualizing vector graphic

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Method for efficient parallel visualizing vector graphic

Life of this patent

Abstract

Claims6