feat: Add texture rendering endpoints and service methods

- Introduced new API endpoints for rendering textures, avatars, capes, and previews, enhancing the texture handling capabilities.
- Implemented corresponding service methods in the TextureHandler to process rendering requests and return appropriate responses.
- Updated the TextureRenderService interface to include methods for rendering textures, avatars, and capes, along with their respective parameters.
- Enhanced error handling for invalid texture IDs and added support for different rendering types and formats.
- Updated go.mod to include the webp library for image processing.

internal/handler/routes.go

@@ -108,6 +108,10 @@ func registerTextureRoutes(v1 *gin.RouterGroup, h *TextureHandler, jwtService *a
 		// 公开路由（无需认证）
 		textureGroup.GET("", h.Search)
 		textureGroup.GET("/:id", h.Get)
+		textureGroup.GET("/:id/render", h.RenderTexture) // type/front/back/full/head/isometric
+		textureGroup.GET("/:id/avatar", h.RenderAvatar)  // mode=2d/3d
+		textureGroup.GET("/:id/cape", h.RenderCape)
+		textureGroup.GET("/:id/preview", h.RenderPreview) // 自动根据类型预览
 
 		// 需要认证的路由
 		textureAuth := textureGroup.Group("")

internal/handler/texture_handler.go

@@ -3,6 +3,7 @@ package handler
 import (
 	"carrotskin/internal/container"
 	"carrotskin/internal/model"
+	"carrotskin/internal/service"
 	"carrotskin/internal/types"
 	"strconv"
 
@@ -171,6 +172,98 @@ func (h *TextureHandler) Search(c *gin.Context) {
 	})
 }
 
+// RenderTexture 渲染皮肤/披风预览
+func (h *TextureHandler) RenderTexture(c *gin.Context) {
+	textureID, err := strconv.ParseInt(c.Param("id"), 10, 64)
+	if err != nil {
+		RespondBadRequest(c, "无效的材质ID", err)
+		return
+	}
+	renderType := service.RenderType(c.DefaultQuery("type", string(service.RenderTypeIsometric)))
+	size := parseIntWithDefault(c.DefaultQuery("size", "256"), 256)
+	format := service.ImageFormat(c.DefaultQuery("format", string(service.ImageFormatPNG)))
+
+	result, err := h.container.TextureRenderService.RenderTexture(c.Request.Context(), textureID, renderType, size, format)
+	if err != nil {
+		RespondBadRequest(c, err.Error(), err)
+		return
+	}
+	RespondSuccess(c, toRenderResponse(result))
+}
+
+// RenderAvatar 渲染头像（2D/3D）
+func (h *TextureHandler) RenderAvatar(c *gin.Context) {
+	textureID, err := strconv.ParseInt(c.Param("id"), 10, 64)
+	if err != nil {
+		RespondBadRequest(c, "无效的材质ID", err)
+		return
+	}
+	mode := service.AvatarMode(c.DefaultQuery("mode", string(service.AvatarMode2D)))
+	size := parseIntWithDefault(c.DefaultQuery("size", "256"), 256)
+	format := service.ImageFormat(c.DefaultQuery("format", string(service.ImageFormatPNG)))
+
+	result, err := h.container.TextureRenderService.RenderAvatar(c.Request.Context(), textureID, size, mode, format)
+	if err != nil {
+		RespondBadRequest(c, err.Error(), err)
+		return
+	}
+	RespondSuccess(c, toRenderResponse(result))
+}
+
+// RenderCape 渲染披风
+func (h *TextureHandler) RenderCape(c *gin.Context) {
+	textureID, err := strconv.ParseInt(c.Param("id"), 10, 64)
+	if err != nil {
+		RespondBadRequest(c, "无效的材质ID", err)
+		return
+	}
+	size := parseIntWithDefault(c.DefaultQuery("size", "256"), 256)
+	format := service.ImageFormat(c.DefaultQuery("format", string(service.ImageFormatPNG)))
+
+	result, err := h.container.TextureRenderService.RenderCape(c.Request.Context(), textureID, size, format)
+	if err != nil {
+		RespondBadRequest(c, err.Error(), err)
+		return
+	}
+	RespondSuccess(c, toRenderResponse(result))
+}
+
+// RenderPreview 自动选择预览（皮肤走等距，披风走披风渲染）
+func (h *TextureHandler) RenderPreview(c *gin.Context) {
+	textureID, err := strconv.ParseInt(c.Param("id"), 10, 64)
+	if err != nil {
+		RespondBadRequest(c, "无效的材质ID", err)
+		return
+	}
+	size := parseIntWithDefault(c.DefaultQuery("size", "256"), 256)
+	format := service.ImageFormat(c.DefaultQuery("format", string(service.ImageFormatPNG)))
+
+	result, err := h.container.TextureRenderService.RenderPreview(c.Request.Context(), textureID, size, format)
+	if err != nil {
+		RespondBadRequest(c, err.Error(), err)
+		return
+	}
+	RespondSuccess(c, toRenderResponse(result))
+}
+
+// toRenderResponse 转换为API响应
+func toRenderResponse(r *service.RenderResult) *types.RenderResponse {
+	if r == nil {
+		return nil
+	}
+	resp := &types.RenderResponse{
+		URL:         r.URL,
+		ContentType: r.ContentType,
+		ETag:        r.ETag,
+		Size:        r.Size,
+	}
+	if !r.LastModified.IsZero() {
+		t := r.LastModified
+		resp.LastModified = &t
+	}
+	return resp
+}
+
 // Update 更新材质
 func (h *TextureHandler) Update(c *gin.Context) {
 	userID, ok := GetUserIDFromContext(c)