mirror of
https://github.com/xiaoqidun/ofdgo.git
synced 2026-10-29 16:44:23 +08:00
518 lines
17 KiB
Go
518 lines
17 KiB
Go
// Copyright 2025-2026 肖其顿 (XIAO QI DUN)
|
|
//
|
|
// 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.
|
|
|
|
package ofdgo
|
|
|
|
import (
|
|
"fmt"
|
|
basegeom "github.com/xiaoqidun/ofdgo/internal/base/geom"
|
|
"math"
|
|
"slices"
|
|
"strconv"
|
|
|
|
"github.com/tdewolff/canvas"
|
|
)
|
|
|
|
// Curves 在输出边界转换椭圆弧，其他曲线保持原样
|
|
// 入参: path 页面路径
|
|
// 返回: GeometryPath 贝塞尔路径, error 路径错误
|
|
func (CanvasBackend) Curves(path GeometryPath) (GeometryPath, error) {
|
|
p, err := geometryToCanvasPath(&path)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
return *geometryFromCanvasPath(p.ReplaceArcs()), nil
|
|
}
|
|
|
|
// Path 解析对象的标准紧缩路径并转换到页面坐标
|
|
// 入参: object 路径对象
|
|
// 返回: GeometryPath 页面路径, error 无效路径错误
|
|
func (b CanvasBackend) Path(object PathObject) (GeometryPath, error) {
|
|
return objectGeometryPath(b, object)
|
|
}
|
|
|
|
// Region 解析动作区域并保持椭圆弧及退化变换的既有处理
|
|
// 入参: region 动作区域, matrix 页面变换
|
|
// 返回: GeometryPath 页面路径, error 解析错误
|
|
func (CanvasBackend) Region(region *Region, matrix Matrix) (GeometryPath, error) {
|
|
p := actionRegionPath(region, matrix)
|
|
return *geometryFromCanvasPath(p.Transform(canvas.Matrix{{1, 0, 0}, {0, -1, 0}})), nil
|
|
}
|
|
|
|
// Bounds 计算曲线路径的精确范围
|
|
// 入参: path 页面路径
|
|
// 返回: Box 路径范围, error 无效路径错误
|
|
func (CanvasBackend) Bounds(path GeometryPath) (Box, error) {
|
|
p, err := geometryToCanvasPath(&path)
|
|
if err != nil {
|
|
return Box{}, err
|
|
}
|
|
if p.Empty() {
|
|
return Box{}, nil
|
|
}
|
|
box := p.Bounds()
|
|
return Box{X: box.X0, Y: -box.Y1, W: box.W(), H: box.H()}, nil
|
|
}
|
|
|
|
// Transform 变换路径，保持曲线与椭圆弧，不修改源路径
|
|
// 入参: path 页面路径, matrix 页面变换
|
|
// 返回: GeometryPath 新路径, error 无效路径错误
|
|
func (CanvasBackend) Transform(path GeometryPath, matrix Matrix) (GeometryPath, error) {
|
|
curves := true
|
|
for _, segment := range path {
|
|
if segment.Verb == GeometryArc {
|
|
curves = false
|
|
break
|
|
}
|
|
}
|
|
if curves {
|
|
return path.Transform(matrix)
|
|
}
|
|
p, err := geometryToCanvasPath(&path)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
m := matrix.Values()
|
|
for _, value := range m {
|
|
if !finite(value) {
|
|
return nil, fmt.Errorf("invalid geometry transform")
|
|
}
|
|
}
|
|
if basegeom.Equal(m[0]*m[3]-m[1]*m[2], 0) {
|
|
p = p.ReplaceArcs()
|
|
}
|
|
p = p.Transform(canvas.Matrix{{m[0], -m[2], m[4]}, {-m[1], m[3], -m[5]}})
|
|
return *geometryFromCanvasPath(p), nil
|
|
}
|
|
|
|
// Normalize 按填充规则整理自交区域
|
|
// 入参: path 页面路径, evenOdd 是否采用奇偶规则
|
|
// 返回: GeometryPath 非零填充路径, error 无效路径错误
|
|
func (CanvasBackend) Normalize(path GeometryPath, evenOdd bool) (GeometryPath, error) {
|
|
p, err := geometryToCanvasPath(&path)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
rule := canvas.NonZero
|
|
if evenOdd {
|
|
rule = canvas.EvenOdd
|
|
}
|
|
p = p.Settle(rule)
|
|
if p.Empty() {
|
|
return nil, nil
|
|
}
|
|
return *geometryFromCanvasPath(p), nil
|
|
}
|
|
|
|
// Combine 计算两个非零填充区域的布尔运算
|
|
// 入参: left 左路径, right 右路径, operation 运算类型
|
|
// 返回: GeometryPath 结果路径, error 运算错误
|
|
func (CanvasBackend) Combine(left, right GeometryPath, operation GeometryOperation) (GeometryPath, error) {
|
|
a, err := geometryToCanvasPath(&left)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
b, err := geometryToCanvasPath(&right)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
var result *canvas.Path
|
|
switch operation {
|
|
case GeometryIntersect:
|
|
result = applyClipPath(a, b)
|
|
case GeometryUnion:
|
|
result = a.Or(b)
|
|
case GeometrySubtract:
|
|
result = a.Not(b)
|
|
case GeometryXor:
|
|
result = a.Xor(b)
|
|
default:
|
|
return nil, fmt.Errorf("unsupported geometry operation %d", operation)
|
|
}
|
|
if result.Empty() {
|
|
return nil, nil
|
|
}
|
|
return *geometryFromCanvasPath(result), nil
|
|
}
|
|
|
|
// Stroke 将绝对长度虚线与描边转换为填充区域，几何后端异常时使用本库非零描边
|
|
// 入参: path 页面路径, options 描边样式
|
|
// 返回: GeometryPath 描边区域, error 样式或路径错误
|
|
func (CanvasBackend) Stroke(path GeometryPath, options StrokeOptions) (result GeometryPath, err error) {
|
|
if err := basegeom.ValidateStroke(options); err != nil {
|
|
return nil, err
|
|
}
|
|
if slices.Contains(options.Dashes, 0) {
|
|
return path.Stroke(options)
|
|
}
|
|
p, err := geometryToCanvasPath(&path)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
tolerance := options.Tolerance
|
|
if tolerance == 0 {
|
|
tolerance = canvas.Tolerance
|
|
}
|
|
options.Tolerance = tolerance
|
|
defer func() {
|
|
if failure := recover(); failure != nil {
|
|
result, err = path.Stroke(options)
|
|
if err != nil {
|
|
err = fmt.Errorf("stroke fallback after %v: %w", failure, err)
|
|
}
|
|
}
|
|
}()
|
|
style := pathStyle{lineJoin: canvas.MiterJoin, lineCap: canvas.ButtCap, miterLimit: defaultMiterLimit}
|
|
style.applyLineJoin(options.Join, options.MiterLimit, options.MiterLimitSet)
|
|
style.lineCap = pathLineCap(options.Cap, style.lineCap)
|
|
p = p.Dash(options.DashOffset, options.Dashes...)
|
|
p = p.Flatten(tolerance)
|
|
p = p.Stroke(options.Width, style.lineCap, style.lineJoin, tolerance)
|
|
return *geometryFromCanvasPath(p), nil
|
|
}
|
|
|
|
// Clip 解析对象裁剪并与父裁剪相交，保留未裁剪与完全裁去的区别
|
|
// 入参: r 渲染器, clips OFD裁剪, matrix 裁剪坐标到页面的变换, parent 父裁剪
|
|
// 返回: *GeometryPath 页面裁剪, error 无效父路径错误
|
|
func (CanvasBackend) Clip(r *Renderer, clips *Clips, matrix Matrix, parent *GeometryPath) (*GeometryPath, error) {
|
|
p, err := geometryToCanvasPath(parent)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
renderer := *r
|
|
renderer.renderError = nil
|
|
clip := renderer.buildClipPath(clips, 0, 0, 0, matrix)
|
|
if renderer.renderError != nil {
|
|
return nil, renderer.renderError
|
|
}
|
|
return geometryFromCanvasPath(r.intersectCachedClipPath(p, clip)), nil
|
|
}
|
|
|
|
// canvasNativeStroke 判断描边是否由Canvas提供
|
|
// 入参: geometry 几何后端
|
|
// 返回: bool 是否采用原生描边
|
|
func canvasNativeStroke(geometry GeometryBackend) bool {
|
|
_, ok := geometry.(CanvasBackend)
|
|
return ok
|
|
}
|
|
|
|
// canvasStrokeOptions 转换Canvas描边样式，虚线由调用方传入
|
|
// 入参: width 线宽, cap 端点样式, join 转角样式, tolerance 展开误差
|
|
// 返回: StrokeOptions 公共描边样式
|
|
func canvasStrokeOptions(width float64, cap canvas.Capper, join canvas.Joiner, tolerance float64) StrokeOptions {
|
|
options := StrokeOptions{Width: width, Cap: "Butt", Join: "Miter", MiterLimit: defaultMiterLimit, Tolerance: tolerance}
|
|
switch cap.(type) {
|
|
case canvas.RoundCapper:
|
|
options.Cap = "Round"
|
|
case canvas.SquareCapper:
|
|
options.Cap = "Square"
|
|
}
|
|
switch value := join.(type) {
|
|
case canvas.RoundJoiner:
|
|
options.Join = "Round"
|
|
case canvas.BevelJoiner:
|
|
options.Join = "Bevel"
|
|
case canvas.MiterJoiner:
|
|
options.MiterLimit = value.Limit
|
|
options.MiterLimitSet = value.Limit == 0
|
|
}
|
|
return options
|
|
}
|
|
|
|
// canvasStrokePath 通过配置的几何后端生成描边，不修改源路径
|
|
// 入参: geometry 几何后端, path Canvas路径, options 描边样式
|
|
// 返回: *canvas.Path 描边轮廓, error 几何错误
|
|
func canvasStrokePath(geometry GeometryBackend, path *canvas.Path, options StrokeOptions) (*canvas.Path, error) {
|
|
outline, err := geometry.Stroke(*geometryFromCanvasPath(path), options)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
return geometryToCanvasPath(&outline)
|
|
}
|
|
|
|
// canvasStrokeFillPath 为直接非零填充展开复杂描边，不将重叠轮廓交给区域运算
|
|
// 入参: geometry 几何后端, path Canvas路径, options 描边样式
|
|
// 返回: *canvas.Path 描边轮廓, error 几何错误
|
|
func canvasStrokeFillPath(geometry GeometryBackend, path *canvas.Path, options StrokeOptions) (*canvas.Path, error) {
|
|
if canvasNativeStroke(geometry) && !slices.Contains(options.Dashes, 0) {
|
|
if options.Tolerance == 0 {
|
|
options.Tolerance = canvas.Tolerance
|
|
}
|
|
if err := basegeom.ValidateStroke(options); err != nil {
|
|
return nil, err
|
|
}
|
|
if len(path.Dash(options.DashOffset, options.Dashes...).Data()) > 256 {
|
|
outline, err := geometryFromCanvasPath(path).Stroke(options)
|
|
if err != nil {
|
|
return canvasStrokePath(geometry, path, options)
|
|
}
|
|
return geometryToCanvasPath(&outline)
|
|
}
|
|
}
|
|
return canvasStrokePath(geometry, path, options)
|
|
}
|
|
|
|
// canvasFillClip 检查描边轮廓能否直接填充或按凸窗口独立裁剪
|
|
// 入参: clip 裁剪路径
|
|
// 返回: bool 是否不要求整理重叠区域
|
|
func canvasFillClip(clip *canvas.Path) bool {
|
|
if clip == nil {
|
|
return true
|
|
}
|
|
_, ok := convexCanvasPolygon(clip)
|
|
return ok
|
|
}
|
|
|
|
// strokeCanvasPath 将文字和复杂画刷的描边交给配置的几何后端
|
|
// 入参: path Canvas路径, width 线宽, cap 端点样式, join 转角样式
|
|
// 返回: *canvas.Path 描边轮廓
|
|
func (r *Renderer) strokeCanvasPath(path *canvas.Path, width float64, cap canvas.Capper, join canvas.Joiner) *canvas.Path {
|
|
return r.strokeDashedCanvasPath(path, width, cap, join, 0, nil, false)
|
|
}
|
|
|
|
// strokeDashedCanvasPath 通过公共几何后端展开虚线和端点样式，保留零长度绘制段
|
|
// 入参: path 路径, width 线宽, cap 端点样式, join 转角样式, offset 虚线偏移, dashes 虚线间隔序列, fill 是否直接填充或凸窗口裁剪
|
|
// 返回: *canvas.Path 描边填充轮廓
|
|
func (r *Renderer) strokeDashedCanvasPath(path *canvas.Path, width float64, cap canvas.Capper, join canvas.Joiner, offset float64, dashes []float64, fill bool) *canvas.Path {
|
|
geometry, err := r.Geometry()
|
|
if err != nil {
|
|
r.renderError = err
|
|
return &canvas.Path{}
|
|
}
|
|
options := canvasStrokeOptions(width, cap, join, canvas.Tolerance)
|
|
options.DashOffset, options.Dashes = offset, dashes
|
|
stroke := canvasStrokePath
|
|
if fill {
|
|
stroke = canvasStrokeFillPath
|
|
}
|
|
result, err := stroke(geometry, path, options)
|
|
if err != nil {
|
|
r.renderError = err
|
|
return &canvas.Path{}
|
|
}
|
|
return result
|
|
}
|
|
|
|
// geometryToCanvasPath 将页面坐标路径转换为默认几何引擎的向上纵轴
|
|
// 入参: path 独立几何路径，nil表示不裁剪
|
|
// 返回: *canvas.Path 默认引擎路径, error 无效路径
|
|
func geometryToCanvasPath(path *GeometryPath) (*canvas.Path, error) {
|
|
if path == nil {
|
|
return nil, nil
|
|
}
|
|
if err := path.validate(); err != nil {
|
|
return nil, err
|
|
}
|
|
p := canvas.NewPathFromData(make([]float64, 0, canvasPathCapacity(*path)))
|
|
for _, s := range *path {
|
|
switch s.Verb {
|
|
case GeometryMove:
|
|
p.MoveTo(s.End.X, -s.End.Y)
|
|
case GeometryLine:
|
|
p.LineTo(s.End.X, -s.End.Y)
|
|
case GeometryQuad:
|
|
p.QuadTo(s.Control1.X, -s.Control1.Y, s.End.X, -s.End.Y)
|
|
case GeometryCubic:
|
|
p.CubeTo(s.Control1.X, -s.Control1.Y, s.Control2.X, -s.Control2.Y, s.End.X, -s.End.Y)
|
|
case GeometryArc:
|
|
p.ArcTo(s.RadiusX, s.RadiusY, -s.Rotation, s.Large, !s.Sweep, s.End.X, -s.End.Y)
|
|
case GeometryClose:
|
|
p.Close()
|
|
default:
|
|
return nil, fmt.Errorf("unsupported geometry command %d", s.Verb)
|
|
}
|
|
}
|
|
return p, nil
|
|
}
|
|
|
|
// canvasObjectPath 建立对象局部路径，保留折返线和退化贝塞尔的原始端点
|
|
// 入参: path 独立路径
|
|
// 返回: *canvas.Path 适配路径, error 不支持的指令
|
|
func canvasObjectPath(path GeometryPath) (*canvas.Path, error) {
|
|
data := make([]float64, 0, canvasPathCapacity(path))
|
|
for _, s := range path {
|
|
end := s.End
|
|
switch s.Verb {
|
|
case GeometryMove:
|
|
data = append(data, canvas.MoveToCmd, end.X, end.Y, canvas.MoveToCmd)
|
|
case GeometryLine:
|
|
data = append(data, canvas.LineToCmd, end.X, end.Y, canvas.LineToCmd)
|
|
case GeometryQuad:
|
|
data = append(data, canvas.QuadToCmd, s.Control1.X, s.Control1.Y, end.X, end.Y, canvas.QuadToCmd)
|
|
case GeometryCubic:
|
|
data = append(data, canvas.CubeToCmd, s.Control1.X, s.Control1.Y, s.Control2.X, s.Control2.Y, end.X, end.Y, canvas.CubeToCmd)
|
|
case GeometryArc:
|
|
p := canvas.NewPathFromData(data)
|
|
p.ArcTo(s.RadiusX, s.RadiusY, s.Rotation, s.Large, s.Sweep, end.X, end.Y)
|
|
data = p.Data()
|
|
case GeometryClose:
|
|
p := canvas.NewPathFromData(data)
|
|
p.Close()
|
|
data = p.Data()
|
|
default:
|
|
return nil, fmt.Errorf("unsupported geometry command %d", s.Verb)
|
|
}
|
|
}
|
|
return canvas.NewPathFromData(data), nil
|
|
}
|
|
|
|
// canvasPathCapacity 按指令估算路径容量，避免长路径逐段扩容
|
|
// 入参: path 独立几何路径
|
|
// 返回: int 坐标存储容量
|
|
func canvasPathCapacity(path GeometryPath) int {
|
|
count := 0
|
|
for _, segment := range path {
|
|
switch segment.Verb {
|
|
case GeometryMove, GeometryLine, GeometryClose:
|
|
count += 4
|
|
case GeometryQuad:
|
|
count += 6
|
|
default:
|
|
count += 8
|
|
}
|
|
}
|
|
return count
|
|
}
|
|
|
|
// geometryFromCanvasPath 将默认引擎路径转换为独立的页面坐标路径，保留曲线和椭圆弧
|
|
// 入参: path 默认引擎路径
|
|
// 返回: *GeometryPath 独立路径，nil表示不裁剪
|
|
func geometryFromCanvasPath(path *canvas.Path) *GeometryPath {
|
|
if path == nil {
|
|
return nil
|
|
}
|
|
result := make(GeometryPath, 0, path.Len())
|
|
scanner := path.Scanner()
|
|
for scanner.Scan() {
|
|
end := scanner.End()
|
|
segment := GeometrySegment{End: Point{X: end.X, Y: -end.Y}}
|
|
switch scanner.Cmd() {
|
|
case canvas.MoveToCmd:
|
|
segment.Verb = GeometryMove
|
|
case canvas.LineToCmd:
|
|
segment.Verb = GeometryLine
|
|
case canvas.QuadToCmd:
|
|
control := scanner.CP1()
|
|
segment.Verb, segment.Control1 = GeometryQuad, Point{X: control.X, Y: -control.Y}
|
|
case canvas.CubeToCmd:
|
|
c1, c2 := scanner.CP1(), scanner.CP2()
|
|
segment.Verb = GeometryCubic
|
|
segment.Control1, segment.Control2 = Point{X: c1.X, Y: -c1.Y}, Point{X: c2.X, Y: -c2.Y}
|
|
case canvas.ArcToCmd:
|
|
segment.Verb = GeometryArc
|
|
segment.RadiusX, segment.RadiusY, segment.Rotation, segment.Large, segment.Sweep = scanner.Arc()
|
|
segment.Rotation, segment.Sweep = -segment.Rotation, !segment.Sweep
|
|
case canvas.CloseCmd:
|
|
segment.Verb = GeometryClose
|
|
}
|
|
result = append(result, segment)
|
|
}
|
|
return &result
|
|
}
|
|
|
|
// clipLinearFillGeometry 裁剪直线填充轮廓，保留原填充规则，不用于区域布尔运算
|
|
// 入参: path 闭合绘制轮廓, clip 凸裁剪窗口
|
|
// 返回: GeometryPath 填充轮廓, bool 是否适用, error 路径错误
|
|
func clipLinearFillGeometry(path, clip GeometryPath) (GeometryPath, bool, error) {
|
|
a, err := geometryToCanvasPath(&path)
|
|
if err != nil {
|
|
return nil, false, err
|
|
}
|
|
b, err := geometryToCanvasPath(&clip)
|
|
if err != nil {
|
|
return nil, false, err
|
|
}
|
|
result, ok := intersectLinearCanvasContours(a, b)
|
|
if !ok {
|
|
return nil, false, nil
|
|
}
|
|
return *geometryFromCanvasPath(result), true, nil
|
|
}
|
|
|
|
// actionCanvasMatrix 转换页面坐标矩阵，不翻转Y轴
|
|
// 入参: matrix 页面变换
|
|
// 返回: canvas.Matrix 路径变换
|
|
func actionCanvasMatrix(matrix Matrix) canvas.Matrix {
|
|
return canvas.Matrix{{matrix.a, matrix.c, matrix.e}, {matrix.b, matrix.d, matrix.f}}
|
|
}
|
|
|
|
// actionRegionPath 解析复杂点击区域并转换为页面坐标
|
|
// 入参: region 动作区域, matrix 坐标变换
|
|
// 返回: *canvas.Path 点击路径
|
|
func actionRegionPath(region *Region, matrix Matrix) *canvas.Path {
|
|
path := &canvas.Path{}
|
|
for _, area := range region.Area {
|
|
start := parseFloats(area.Start)
|
|
if len(start) != 2 {
|
|
continue
|
|
}
|
|
part := &canvas.Path{}
|
|
part.MoveTo(start[0], start[1])
|
|
for _, command := range area.Command {
|
|
p1, p2, p3 := parseFloats(command.Point1), parseFloats(command.Point2), parseFloats(command.Point3)
|
|
switch command.Type {
|
|
case "Move":
|
|
if len(p1) == 2 {
|
|
part.Close()
|
|
part.MoveTo(p1[0], p1[1])
|
|
}
|
|
case "Line":
|
|
if len(p1) == 2 {
|
|
part.LineTo(p1[0], p1[1])
|
|
}
|
|
case "QuadraticBezier":
|
|
if len(p1) == 2 && len(p2) == 2 {
|
|
part.QuadTo(p1[0], p1[1], p2[0], p2[1])
|
|
}
|
|
case "CubicBezier":
|
|
if len(p3) == 2 {
|
|
first, second := part.Pos(), canvas.Point{X: p3[0], Y: p3[1]}
|
|
if len(p1) == 2 {
|
|
first = canvas.Point{X: p1[0], Y: p1[1]}
|
|
}
|
|
if len(p2) == 2 {
|
|
second = canvas.Point{X: p2[0], Y: p2[1]}
|
|
}
|
|
part.CubeTo(first.X, first.Y, second.X, second.Y, p3[0], p3[1])
|
|
}
|
|
case "Arc":
|
|
size, end := parseFloats(command.EllipseSize), parseFloats(command.EndPoint)
|
|
angle, err := strconv.ParseFloat(command.RotationAngle, 64)
|
|
large, largeErr := strconv.ParseBool(command.LargeArc)
|
|
sweep, sweepErr := strconv.ParseBool(command.SweepDirection)
|
|
if len(end) == 2 && finite(end[0]) && finite(end[1]) && err == nil && finite(angle) && largeErr == nil && sweepErr == nil {
|
|
rx, ry := 0.0, 0.0
|
|
if len(size) > 0 {
|
|
rx, ry = math.Abs(size[0]), math.Abs(size[0])
|
|
}
|
|
if len(size) > 1 {
|
|
rx, ry = rx/2, math.Abs(size[1])/2
|
|
}
|
|
if finite(rx) && finite(ry) {
|
|
part.ArcTo(rx, ry, math.Mod(angle, 360), large, sweep, end[0], end[1])
|
|
}
|
|
}
|
|
case "Close":
|
|
part.Close()
|
|
}
|
|
}
|
|
part.Close()
|
|
path = path.Append(part)
|
|
}
|
|
if canvas.Equal(matrix.a*matrix.d-matrix.b*matrix.c, 0) {
|
|
path = path.ReplaceArcs()
|
|
}
|
|
return path.Transform(actionCanvasMatrix(matrix))
|
|
}
|