feat(后端架构): 完善后端解耦

ofdgo_render_bounds.go

@@ -0,0 +1,96 @@
+// 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"
+
+// ObjectBounds 获取文字、路径、图片或复合对象在页面坐标中的轴对齐范围，不修改对象
+// 文字采用字形范围，路径包含描边与裁剪，图片采用裁剪后的几何范围，不解码像素或排除透明像素
+// 底纹按填充或描边轮廓度量，不展开图案单元
+// 不应用页面边界或父级变换；无可见范围时返回零值，不支持的对象类型返回错误
+// 入参: object 图形对象, drawParam 图层绘制参数标识，无继承时为空
+// 返回: Box 毫米坐标范围, error 错误信息
+func (r *Renderer) ObjectBounds(object GraphicObject, drawParam string) (Box, error) {
+	result, err := r.MeasureObject(object, MeasureOptions{Defaults: r.drawParamDefaults(drawParam, nil)})
+	return result.Bounds, err
+}
+
+// ObjectContour 页面坐标中的填充轮廓，Path为SVG路径，EvenOdd表示奇偶填充
+type ObjectContour struct {
+	Path    string `json:"path"`
+	EvenOdd bool   `json:"evenOdd,omitempty"`
+}
+
+// AnnotationGeometry 获取注解外观的实际内容轮廓，不将Appearance容器边界视为绘制内容
+// 链接保留透明对象定义的交互区域，图片按几何范围度量而不解码透明像素
+// 入参: annotation 注解
+// 返回: Box 页面范围, []ObjectContour 命中轮廓, error 错误信息
+func (r *Renderer) AnnotationGeometry(annotation Annotation) (Box, []ObjectContour, error) {
+	object := GraphicObject{Type: "CompositeObject", CompositeGraphicUnit: CompositeGraphicUnit{Boundary: annotation.Appearance.Boundary, Objects: annotation.Appearance.Objects}}
+	box, contours, err := r.ObjectGeometry(object, "")
+	if err != nil {
+		return box, contours, err
+	}
+	for _, source := range r.annotationActionSources([]Annotation{annotation}) {
+		for _, action := range source.Actions {
+			if action.Event != "CLICK" {
+				continue
+			}
+			region, path, err := r.actionLinkRegion(source, action)
+			if err != nil {
+				return Box{}, nil, err
+			}
+			if region.W <= 0 || region.H <= 0 {
+				continue
+			}
+			if path == "" {
+				path = fmt.Sprintf("M%g %gH%gV%gH%gZ", region.X, region.Y, region.X+region.W, region.Y+region.H, region.X)
+			}
+			box = unionTextBox(box, region)
+			contours = append(contours, ObjectContour{Path: path})
+		}
+	}
+	return box, contours, nil
+}
+
+// ObjectContours 获取路径、图片或复合对象的实际绘制区域，包含描边、虚线、变换及对象裁剪
+// 图片不解码像素，底纹不展开图案单元；不包含页面边界或父级变换
+// 入参: object 路径、图片或复合对象, drawParam 图层绘制参数标识
+// 返回: []ObjectContour 可用于点选的轮廓, error 错误信息
+func (r *Renderer) ObjectContours(object GraphicObject, drawParam string) ([]ObjectContour, error) {
+	_, contours, err := r.ObjectGeometry(object, drawParam)
+	return contours, err
+}
+
+// ObjectGeometry 一次度量路径、图片或复合对象的范围与轮廓，语义与ObjectBounds和ObjectContours一致
+// 入参: object 图形对象, drawParam 图层绘制参数标识
+// 返回: Box 毫米范围, []ObjectContour 绘制轮廓, error 错误信息
+func (r *Renderer) ObjectGeometry(object GraphicObject, drawParam string) (Box, []ObjectContour, error) {
+	if object.Type != "PathObject" && object.Type != "ImageObject" && object.Type != "CompositeObject" && object.Type != "CompositeGraphicUnit" {
+		return Box{}, nil, fmt.Errorf("contours require a path, image or composite object")
+	}
+	result, err := r.MeasureObject(object, MeasureOptions{Defaults: r.drawParamDefaults(drawParam, nil), Contours: true})
+	return result.Bounds, result.Contours, err
+}
+
+// MeasureObject 使用当前页面编译器度量对象，保持绘制与选区的字体和几何语义一致
+// 入参: object 图形对象, options 度量上下文
+// 返回: ObjectMeasurement 度量结果, error 错误信息
+func (r *Renderer) MeasureObject(object GraphicObject, options MeasureOptions) (ObjectMeasurement, error) {
+	if r.backends.Compiler == nil {
+		return ObjectMeasurement{}, fmt.Errorf("%w: object measurement", ErrBackendUnavailable)
+	}
+	return r.backends.Compiler.MeasureObject(r, object, options)
+}