git_clone/thorvg
1
0
Fork 0
mirror of https://github.com/thorvg/thorvg.git synced 2025-06-14 12:04:29 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions 5

common bezier: code refactoring.

Browse source 
Organize bezier functions for internal share.

this bezier can be used in svg loader.

Change-Id: I78acd3273c0528688ca46ff7c29d78607bd729bd
This commit is contained in:
Hermet Park 2020-06-22 17:06:53 +09:00
parent f56a3b791c
commit ab5c1bc441
6 changed files with 188 additions and 109 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

2
src/lib/meson.build
View file

@ -4,12 +4,14 @@ subdir('gl_engine')
source_file = [
'tvgCanvasImpl.h',
'tvgCommon.h',
'tvgBezier.h',
'tvgLoader.h',
'tvgLoaderMgr.h',
'tvgRender.h',
'tvgSceneImpl.h',
'tvgShapePath.h',
'tvgShapeImpl.h',
'tvgBezier.cpp',
'tvgCanvas.cpp',
'tvgFill.cpp',
'tvgGlCanvas.cpp',

109
src/lib/sw_engine/tvgSwShape.cpp
View file

@ -30,15 +30,6 @@ struct Line
};
struct Bezier
{
Point start;
Point ctrl1;
Point ctrl2;
Point end;
};
static float _lineLength(const Point& pt1, const Point& pt2)
{
/* approximate sqrt(x*x + y*y) using alpha max plus beta min algorithm.
@ -64,102 +55,6 @@ static void _lineSplitAt(const Line& cur, float at, Line& left, Line& right)
}
static void _bezSplit(const Bezier&cur, Bezier& left, Bezier& right)
{
auto c = (cur.ctrl1.x + cur.ctrl2.x) * 0.5f;
left.ctrl1.x = (cur.start.x + cur.ctrl1.x) * 0.5f;
right.ctrl2.x = (cur.ctrl2.x + cur.end.x) * 0.5f;
left.start.x = cur.start.x;
right.end.x = cur.end.x;
left.ctrl2.x = (left.ctrl1.x + c) * 0.5f;
right.ctrl1.x = (right.ctrl2.x + c) * 0.5f;
left.end.x = right.start.x = (left.ctrl2.x + right.ctrl1.x) * 0.5f;
c = (cur.ctrl1.y + cur.ctrl2.y) * 0.5f;
left.ctrl1.y = (cur.start.y + cur.ctrl1.y) * 0.5f;
right.ctrl2.y = (cur.ctrl2.y + cur.end.y) * 0.5f;
left.start.y = cur.start.y;
right.end.y = cur.end.y;
left.ctrl2.y = (left.ctrl1.y + c) * 0.5f;
right.ctrl1.y = (right.ctrl2.y + c) * 0.5f;
left.end.y = right.start.y = (left.ctrl2.y + right.ctrl1.y) * 0.5f;
}
static float _bezLength(const Bezier& cur)
{
Bezier left, right;
auto len = _lineLength(cur.start, cur.ctrl1) + _lineLength(cur.ctrl1, cur.ctrl2) + _lineLength(cur.ctrl2, cur.end);
auto chord = _lineLength(cur.start, cur.end);
if (fabs(len - chord) > FLT_EPSILON) {
_bezSplit(cur, left, right);
return _bezLength(left) + _bezLength(right);
}
return len;
}
static void _bezSplitLeft(Bezier& cur, float at, Bezier& left)
{
left.start = cur.start;
left.ctrl1.x = cur.start.x + at * (cur.ctrl1.x - cur.start.x);
left.ctrl1.y = cur.start.y + at * (cur.ctrl1.y - cur.start.y);
left.ctrl2.x = cur.ctrl1.x + at * (cur.ctrl2.x - cur.ctrl1.x); // temporary holding spot
left.ctrl2.y = cur.ctrl1.y + at * (cur.ctrl2.y - cur.ctrl1.y); // temporary holding spot
cur.ctrl2.x = cur.ctrl2.x + at * (cur.end.x - cur.ctrl2.x);
cur.ctrl2.y = cur.ctrl2.y + at * (cur.end.y - cur.ctrl2.y);
cur.ctrl1.x = left.ctrl2.x + at * (cur.ctrl2.x - left.ctrl2.x);
cur.ctrl1.y = left.ctrl2.y + at * (cur.ctrl2.y - left.ctrl2.y);
left.ctrl2.x = left.ctrl1.x + at * (left.ctrl2.x - left.ctrl1.x);
left.ctrl2.y = left.ctrl1.y + at * (left.ctrl2.y - left.ctrl1.y);
left.end.x = cur.start.x = left.ctrl2.x + at * (cur.ctrl1.x - left.ctrl2.x);
left.end.y = cur.start.y = left.ctrl2.y + at * (cur.ctrl1.y - left.ctrl2.y);
}
static float _bezAt(const Bezier& bz, float at)
{
auto len = _bezLength(bz);
auto biggest = 1.0f;
if (at >= len) return 1.0f;
at *= 0.5f;
while (true) {
auto right = bz;
Bezier left;
_bezSplitLeft(right, at, left);
auto len2 = _bezLength(left);
if (fabs(len2 - len) < FLT_EPSILON) break;
if (len2 < len) {
at += (biggest - at) * 0.5f;
} else {
biggest = at;
at -= (at * 0.5f);
}
}
return at;
}
static void _bezSplitAt(const Bezier& cur, float at, Bezier& left, Bezier& right)
{
right = cur;
auto t = _bezAt(right, at);
_bezSplitLeft(right, t, left);
}
static void _growOutlineContour(SwOutline& outline, uint32_t n)
{
if (outline.reservedCntrsCnt >= outline.cntrsCnt + n) return;
@ -407,7 +302,7 @@ static void _dashCubicTo(SwDashStroke& dash, const Point* ctrl1, const Point* ct
_growOutlineContour(*dash.outline, dash.outline->cntrsCnt >> 1);
Bezier cur = { dash.ptCur, *ctrl1, *ctrl2, *to};
auto len = _bezLength(cur);
auto len = bezLength(cur);
if (len < dash.curLen) {
dash.curLen -= len;
@ -419,7 +314,7 @@ static void _dashCubicTo(SwDashStroke& dash, const Point* ctrl1, const Point* ct
while (len > dash.curLen) {
Bezier left, right;
len -= dash.curLen;
_bezSplitAt(cur, dash.curLen, left, right);
bezSplitAt(cur, dash.curLen, left, right);
dash.curIdx = (dash.curIdx + 1) % dash.cnt;
if (!dash.curOpGap) {
_outlineMoveTo(*dash.outline, &left.start);

144
src/lib/tvgBezier.cpp Normal file
View file

@ -0,0 +1,144 @@
/*
* Copyright (c) 2020 Samsung Electronics Co., Ltd All Rights Reserved
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/
#ifndef _TVG_BEZIER_CPP_
#define _TVG_BEZIER_CPP_
#include "tvgCommon.h"
/************************************************************************/
/* Internal Class Implementation */
/************************************************************************/
static float _lineLength(const Point& pt1, const Point& pt2)
{
/* approximate sqrt(x*x + y*y) using alpha max plus beta min algorithm.
With alpha = 1, beta = 3/8, giving results with the largest error less
than 7% compared to the exact value. */
Point diff = {pt2.x - pt1.x, pt2.y - pt1.y};
if (diff.x < 0) diff.x = -diff.x;
if (diff.y < 0) diff.y = -diff.y;
return (diff.x > diff.y) ? (diff.x + diff.y * 0.375f) : (diff.y + diff.x * 0.375f);
}
/************************************************************************/
/* External Class Implementation */
/************************************************************************/
namespace tvg
{
void bezSplit(const Bezier&cur, Bezier& left, Bezier& right)
{
auto c = (cur.ctrl1.x + cur.ctrl2.x) * 0.5f;
left.ctrl1.x = (cur.start.x + cur.ctrl1.x) * 0.5f;
right.ctrl2.x = (cur.ctrl2.x + cur.end.x) * 0.5f;
left.start.x = cur.start.x;
right.end.x = cur.end.x;
left.ctrl2.x = (left.ctrl1.x + c) * 0.5f;
right.ctrl1.x = (right.ctrl2.x + c) * 0.5f;
left.end.x = right.start.x = (left.ctrl2.x + right.ctrl1.x) * 0.5f;
c = (cur.ctrl1.y + cur.ctrl2.y) * 0.5f;
left.ctrl1.y = (cur.start.y + cur.ctrl1.y) * 0.5f;
right.ctrl2.y = (cur.ctrl2.y + cur.end.y) * 0.5f;
left.start.y = cur.start.y;
right.end.y = cur.end.y;
left.ctrl2.y = (left.ctrl1.y + c) * 0.5f;
right.ctrl1.y = (right.ctrl2.y + c) * 0.5f;
left.end.y = right.start.y = (left.ctrl2.y + right.ctrl1.y) * 0.5f;
}
float bezLength(const Bezier& cur)
{
Bezier left, right;
auto len = _lineLength(cur.start, cur.ctrl1) + _lineLength(cur.ctrl1, cur.ctrl2) + _lineLength(cur.ctrl2, cur.end);
auto chord = _lineLength(cur.start, cur.end);
if (fabs(len - chord) > FLT_EPSILON) {
bezSplit(cur, left, right);
return bezLength(left) + bezLength(right);
}
return len;
}
void bezSplitLeft(Bezier& cur, float at, Bezier& left)
{
left.start = cur.start;
left.ctrl1.x = cur.start.x + at * (cur.ctrl1.x - cur.start.x);
left.ctrl1.y = cur.start.y + at * (cur.ctrl1.y - cur.start.y);
left.ctrl2.x = cur.ctrl1.x + at * (cur.ctrl2.x - cur.ctrl1.x); // temporary holding spot
left.ctrl2.y = cur.ctrl1.y + at * (cur.ctrl2.y - cur.ctrl1.y); // temporary holding spot
cur.ctrl2.x = cur.ctrl2.x + at * (cur.end.x - cur.ctrl2.x);
cur.ctrl2.y = cur.ctrl2.y + at * (cur.end.y - cur.ctrl2.y);
cur.ctrl1.x = left.ctrl2.x + at * (cur.ctrl2.x - left.ctrl2.x);
cur.ctrl1.y = left.ctrl2.y + at * (cur.ctrl2.y - left.ctrl2.y);
left.ctrl2.x = left.ctrl1.x + at * (left.ctrl2.x - left.ctrl1.x);
left.ctrl2.y = left.ctrl1.y + at * (left.ctrl2.y - left.ctrl1.y);
left.end.x = cur.start.x = left.ctrl2.x + at * (cur.ctrl1.x - left.ctrl2.x);
left.end.y = cur.start.y = left.ctrl2.y + at * (cur.ctrl1.y - left.ctrl2.y);
}
float bezAt(const Bezier& bz, float at)
{
auto len = bezLength(bz);
auto biggest = 1.0f;
if (at >= len) return 1.0f;
at *= 0.5f;
while (true) {
auto right = bz;
Bezier left;
bezSplitLeft(right, at, left);
auto len2 = bezLength(left);
if (fabs(len2 - len) < FLT_EPSILON) break;
if (len2 < len) {
at += (biggest - at) * 0.5f;
} else {
biggest = at;
at -= (at * 0.5f);
}
}
return at;
}
void bezSplitAt(const Bezier& cur, float at, Bezier& left, Bezier& right)
{
right = cur;
auto t = bezAt(right, at);
bezSplitLeft(right, t, left);
}
}
#endif //_TVG_BEZIER_CPP_

39
src/lib/tvgBezier.h Normal file
View file

@ -0,0 +1,39 @@
/*
* Copyright (c) 2020 Samsung Electronics Co., Ltd All Rights Reserved
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/
#ifndef _TVG_BEZIER_H_
#define _TVG_BEZIER_H_
namespace tvg
{
struct Bezier
{
Point start;
Point ctrl1;
Point ctrl2;
Point end;
};
void bezSplit(const Bezier&cur, Bezier& left, Bezier& right);
float bezLength(const Bezier& cur);
void bezSplitLeft(Bezier& cur, float at, Bezier& left);
float bezAt(const Bezier& bz, float at);
void bezSplitAt(const Bezier& cur, float at, Bezier& left, Bezier& right);
}
#endif //_TVG_BEZIER_H_

1
src/lib/tvgCommon.h
View file

@ -37,6 +37,7 @@ using namespace tvg;
#define FILL_ID_LINEAR 0
#define FILL_ID_RADIAL 1
#include "tvgBezier.h"
#include "tvgLoader.h"
#include "tvgLoaderMgr.h"
#include "tvgRender.h"

2
src/lib/tvgRender.cpp
View file

@ -18,8 +18,6 @@
#define _TVG_RENDER_CPP_
#include "tvgCommon.h"
#include "tvgRender.h"
/************************************************************************/
/* Internal Class Implementation */