From 5e0bca66e3be8644bad491bdd46a576160c05a5b Mon Sep 17 00:00:00 2001
From: xiaoqidun <xiaoqidun@gmail.com>
Date: Thu, 15 Oct 2026 22:07:31 +0800
Subject: [PATCH] =?UTF-8?q?feat(=E5=9B=BE=E5=83=8F=E5=A4=84=E7=90=86):=20?=
 =?UTF-8?q?=E4=BC=98=E5=8C=96=E5=9B=BE=E5=83=8F=E9=87=8D=E9=87=87=E6=A0=B7?=
 =?UTF-8?q?=E6=80=A7=E8=83=BD?=
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---
 internal/base/image/scale.go | 36 +++++++++++++++++++++---------------
 1 file changed, 21 insertions(+), 15 deletions(-)

diff --git a/internal/base/image/scale.go b/internal/base/image/scale.go
index f395084..c3bf1af 100644
--- a/internal/base/image/scale.go
+++ b/internal/base/image/scale.go
@@ -94,7 +94,6 @@ func drawRasterAxisImage(dst draw.Image, src image.Image, m [6]float64, op draw.
 	}
 	width := len(xs)
 	horizontal := make([]rasterImagePixel, width)
-	columns := make([]int, width)
 	output := image.NewRGBA64(image.Rect(0, 0, width, 1))
 	var active []rasterImageRow
 	var free [][]rasterImagePixel
@@ -114,7 +113,7 @@ func drawRasterAxisImage(dst draw.Image, src image.Image, m [6]float64, op draw.
 			active = append(active, rasterImageRow{sample: ys[next], values: row})
 			next++
 		}
-		rasterImageHorizontal(horizontal, pixels, xs, y, columns)
+		rasterImageHorizontal(horizontal, pixels, xs, y)
 		n := 0
 		for _, row := range active {
 			weight := row.sample.weights[y-row.sample.first]
@@ -185,16 +184,17 @@ func rasterImageAxis(first, end, source, limit int, scale, offset float64) []ras
 }
 
 // rasterImageHorizontal 按源列复用像素，保留各目标像素的权重累加顺序与中间精度
-// 入参: row 横向缓冲, src 源像素, samples 采样表, y 源行坐标, columns 活动列缓冲
-func rasterImageHorizontal(row []rasterImagePixel, src image.RGBA64Image, samples []rasterAxisSample, y int, columns []int) {
+// 入参: row 横向缓冲, src 源像素, samples 采样表, y 源行坐标
+func rasterImageHorizontal(row []rasterImagePixel, src image.RGBA64Image, samples []rasterAxisSample, y int) {
 	clear(row)
-	reversed := samples[0].first > samples[len(samples)-1].first
+	first, last := samples[0], samples[len(samples)-1]
+	reversed := first.first > last.first || first.first == last.first && len(first.weights) > len(last.weights)
 	start, end := samples[0].first, samples[0].first+len(samples[0].weights)
 	for _, sample := range samples[1:] {
 		start = min(start, sample.first)
 		end = max(end, sample.first+len(sample.weights))
 	}
-	next, count := 0, 0
+	active, next := 0, 0
 	for x := start; x < end; x++ {
 		for next < len(samples) {
 			index := next
@@ -204,13 +204,24 @@ func rasterImageHorizontal(row []rasterImagePixel, src image.RGBA64Image, sample
 			if samples[index].first > x {
 				break
 			}
-			columns[count] = index
-			count++
 			next++
 		}
+		for active < next {
+			index := active
+			if reversed {
+				index = len(samples) - active - 1
+			}
+			if x < samples[index].first+len(samples[index].weights) {
+				break
+			}
+			active++
+		}
 		p := src.RGBA64At(x, y)
-		n := 0
-		for _, index := range columns[:count] {
+		for column := active; column < next; column++ {
+			index := column
+			if reversed {
+				index = len(samples) - column - 1
+			}
 			sample := samples[index]
 			weight := sample.weights[x-sample.first]
 			if weight != 0 {
@@ -220,12 +231,7 @@ func rasterImageHorizontal(row []rasterImagePixel, src image.RGBA64Image, sample
 				value.b += float64(p.B) * weight
 				value.a += float64(p.A) * weight
 			}
-			if x+1 < sample.first+len(sample.weights) {
-				columns[n] = index
-				n++
-			}
 		}
-		count = n
 	}
 }