feat(编辑能力): 完善对象选区与变换，精简界面文案

ofdgo_renderer_bounds.go

@@ -0,0 +1,148 @@
+// 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"
+	"image"
+
+	"github.com/tdewolff/canvas"
+)
+
+// ObjectBounds 获取文字、路径或图片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) {
+	if object.Type != "TextObject" && object.Type != "PathObject" && object.Type != "ImageObject" {
+		return Box{}, fmt.Errorf("unsupported object type %q", object.Type)
+	}
+	boundary, ctm := editorGeometry(object)
+	if _, err := creationBox(boundary); err != nil {
+		return Box{}, err
+	}
+	if ctm != "" {
+		if _, err := creationNumbers(ctm, 6); err != nil {
+			return Box{}, err
+		}
+	}
+	renderer := *r
+	renderer.pageText = nil
+	renderer.textOnly = false
+	defaults := renderer.drawParamDefaults(drawParam, nil)
+	bounds := &boundsRenderer{}
+	ctx := canvas.NewContext(bounds)
+	switch object.Type {
+	case "TextObject":
+		renderer.pageText = &PageText{}
+		renderer.textOnly = true
+		renderer.renderText(ctx, object.TextObject, 0, defaults, nil, false, nil)
+		var box Box
+		for _, run := range renderer.pageText.Runs {
+			for _, glyph := range run.Boxes {
+				box = unionTextBox(box, glyph)
+			}
+		}
+		return box, nil
+	case "PathObject":
+		obj := object.PathObject
+		defaults = renderer.drawParamDefaults(obj.DrawParam, defaults)
+		obj.DrawParam = ""
+		if defaults != nil {
+			style := *defaults
+			style.FillColor = boundsColor(style.FillColor)
+			style.StrokeColor = (*StrokeColor)(boundsColor((*FillColor)(style.StrokeColor)))
+			defaults = &style
+		}
+		obj.FillColor = boundsColor(obj.FillColor)
+		obj.StrokeColor = (*StrokeColor)(boundsColor((*FillColor)(obj.StrokeColor)))
+		renderer.renderPath(ctx, obj, 0, defaults, nil, false, nil)
+	case "ImageObject":
+		obj := object.ImageObject
+		if obj.Visible != nil && !*obj.Visible || obj.Alpha != nil && *obj.Alpha == 0 {
+			return Box{}, nil
+		}
+		box, _ := ParseBox(obj.Boundary)
+		ctm := NewMatrix(obj.CTM)
+		if obj.CTM == "" {
+			ctm = Matrix{a: box.W, d: box.H}
+		}
+		p := canvas.Rectangle(1, 1).Transform(canvas.Matrix{{ctm.a, ctm.c, box.X + ctm.e}, {-ctm.b, -ctm.d, -box.Y - ctm.f}})
+		clip := renderer.buildObjectClipPath(obj.Clips, 0, box.X, box.Y, ctm, nil, false)
+		bounds.add(applyClipPath(p, clip))
+		if obj.Border != nil {
+			border := *obj.Border
+			border.BorderColor = (*StrokeColor)(boundsColor((*FillColor)(border.BorderColor)))
+			obj.Border = &border
+			renderer.renderImageBorder(ctx, obj, box, 0, nil, false, clip)
+		}
+	}
+	return bounds.box, nil
+}
+
+// boundsColor 以底纹的基础颜色和透明度度量轮廓，不修改原画刷。
+// 入参: color 填充或描边颜色
+// 返回: *FillColor 用于度量的颜色
+func boundsColor(color *FillColor) *FillColor {
+	if color == nil || color.Pattern == nil {
+		return color
+	}
+	return &FillColor{Value: color.Value, Index: color.Index, ColorSpace: color.ColorSpace, Alpha: color.Alpha}
+}
+
+// boundsRenderer 收集绘制范围，不分配页面像素或合并独立图形轮廓。
+type boundsRenderer struct {
+	box Box
+}
+
+// Size 返回不限定边界的度量画布尺寸。
+// 返回: float64 宽度, float64 高度
+func (r *boundsRenderer) Size() (float64, float64) {
+	return 0, 0
+}
+
+// add 合并路径的精确曲线范围并转换为向下的纵轴。
+// 入参: path 绘制路径
+func (r *boundsRenderer) add(path *canvas.Path) {
+	if path.Empty() {
+		return
+	}
+	rect := path.Bounds()
+	r.box = unionTextBox(r.box, Box{X: rect.X0, Y: -rect.Y1, W: rect.W(), H: rect.H()})
+}
+
+// RenderPath 收集填充与描边范围，保持线帽、连接和虚线语义。
+// 入参: path 路径, style 绘制样式, m 变换矩阵
+func (r *boundsRenderer) RenderPath(path *canvas.Path, style canvas.Style, m canvas.Matrix) {
+	if style.HasFill() {
+		r.add(path.Copy().Transform(m))
+	}
+	if style.HasStroke() {
+		p := path.Dash(style.DashOffset, style.Dashes...).Stroke(style.StrokeWidth, style.StrokeCapper, style.StrokeJoiner, canvas.Tolerance)
+		r.add(p.Transform(m))
+	}
+}
+
+// RenderText 收集绘制文字范围。
+// 入参: text 文字, m 变换矩阵
+func (r *boundsRenderer) RenderText(text *canvas.Text, m canvas.Matrix) {
+	text.RenderTo(r, m, 0)
+}
+
+// RenderImage 度量不展开底纹图片。
+// 入参: img 图片, m 变换矩阵
+func (r *boundsRenderer) RenderImage(img image.Image, m canvas.Matrix) {}