first commit

tools/icocheck/main.go

@@ -0,0 +1,170 @@
+// icocheck：校验生成的 .ico 结构，并把它内嵌的每个尺寸导出成 PNG，
+// 方便肉眼确认缩放质量、以及圆角有没有被 premultiplied alpha 处理对。
+//
+// 用法：
+//
+//	go run ./tools/icocheck build/windows/icon.ico <导出目录>
+package main
+
+import (
+	"bytes"
+	"encoding/binary"
+	"fmt"
+	"image"
+	"image/png"
+	"os"
+	"path/filepath"
+)
+
+func main() {
+	if len(os.Args) < 2 {
+		fmt.Fprintln(os.Stderr, "用法: go run ./tools/icocheck <icon.ico> [导出目录]")
+		os.Exit(1)
+	}
+	icoPath := os.Args[1]
+	outDir := ""
+	if len(os.Args) > 2 {
+		outDir = os.Args[2]
+	}
+
+	raw, err := os.ReadFile(icoPath)
+	if err != nil {
+		fail(err)
+	}
+	fmt.Printf("文件: %s  (%d 字节)\n", icoPath, len(raw))
+	if len(raw) < 6 {
+		fail(fmt.Errorf("文件太短，不是 ICO"))
+	}
+
+	reserved := binary.LittleEndian.Uint16(raw[0:2])
+	typ := binary.LittleEndian.Uint16(raw[2:4])
+	count := int(binary.LittleEndian.Uint16(raw[4:6]))
+	fmt.Printf("ICONDIR: reserved=%d type=%d (1=icon) count=%d\n", reserved, typ, count)
+	if reserved != 0 || typ != 1 {
+		fail(fmt.Errorf("头部不对：reserved=%d type=%d", reserved, typ))
+	}
+	if 6+16*count > len(raw) {
+		fail(fmt.Errorf("目录表超出文件长度"))
+	}
+
+	if outDir != "" {
+		if err := os.MkdirAll(outDir, 0o755); err != nil {
+			fail(err)
+		}
+	}
+
+	fmt.Println()
+	fmt.Printf("%-10s %-6s %-9s %-9s %-7s %s\n", "尺寸", "编码", "数据长度", "偏移", "实际", "四角alpha(应≈0=圆角透明)")
+	for i := 0; i < count; i++ {
+		o := 6 + 16*i
+		w := int(raw[o])
+		h := int(raw[o+1])
+		dim := fmt.Sprintf("%dx%d", w, h)
+		if w == 0 && h == 0 {
+			dim = "256x256"
+		}
+		size := int(binary.LittleEndian.Uint32(raw[o+8 : o+12]))
+		off := int(binary.LittleEndian.Uint32(raw[o+12 : o+16]))
+		if off < 0 || size < 0 || off+size > len(raw) {
+			fail(fmt.Errorf("第 %d 项越界: off=%d size=%d 文件=%d", i, off, size, len(raw)))
+		}
+
+		body := raw[off : off+size]
+		var kind string
+		var img image.Image
+		switch {
+		case bytes.HasPrefix(body, []byte{0x89, 'P', 'N', 'G'}):
+			kind = "PNG"
+			im, err := png.Decode(bytes.NewReader(body))
+			if err != nil {
+				fail(fmt.Errorf("第 %d 项 PNG 解不开: %v", i, err))
+			}
+			img = im
+		case binary.LittleEndian.Uint32(body[0:4]) == 40:
+			kind = "DIB"
+			im, err := decodeDIB(body)
+			if err != nil {
+				fail(fmt.Errorf("第 %d 项 DIB 解不开: %v", i, err))
+			}
+			img = im
+		default:
+			fail(fmt.Errorf("第 %d 项既不是 PNG 也不是 DIB: % x", i, body[:min(4, len(body))]))
+		}
+
+		b := img.Bounds()
+		if b.Dx() != b.Dy() {
+			fail(fmt.Errorf("第 %d 项不是正方形: %dx%d", i, b.Dx(), b.Dy()))
+		}
+
+		if outDir != "" {
+			name := filepath.Join(outDir, fmt.Sprintf("ico-%03d-%s.png", b.Dx(), kind))
+			f, err := os.Create(name)
+			if err != nil {
+				fail(err)
+			}
+			if err := png.Encode(f, img); err != nil {
+				fail(err)
+			}
+			f.Close()
+		}
+
+		fmt.Printf("%-10s %-6s %-9d %-9d %-7s %v\n",
+			dim, kind, size, off,
+			fmt.Sprintf("%dx%d", b.Dx(), b.Dy()),
+			cornerAlpha(img))
+	}
+	fmt.Println()
+	fmt.Println("✓ 全部条目校验通过")
+}
+
+func cornerAlpha(im image.Image) [4]uint32 {
+	var out [4]uint32
+	b := im.Bounds()
+	pts := [][2]int{{b.Min.X, b.Min.Y}, {b.Max.X - 1, b.Min.Y}, {b.Min.X, b.Max.Y - 1}, {b.Max.X - 1, b.Max.Y - 1}}
+	for i, p := range pts {
+		_, _, _, a := im.At(p[0], p[1]).RGBA()
+		out[i] = a >> 8
+	}
+	return out
+}
+
+// decodeDIB 解 BITMAPINFOHEADER + 自下而上 BGRA + AND 掩码
+func decodeDIB(b []byte) (image.Image, error) {
+	if len(b) < 40 {
+		return nil, fmt.Errorf("DIB 太短")
+	}
+	w := int(int32(binary.LittleEndian.Uint32(b[4:8])))
+	hFull := int(int32(binary.LittleEndian.Uint32(b[8:12])))
+	bits := binary.LittleEndian.Uint16(b[14:16])
+	h := hFull / 2 // biHeight 含 AND 掩码那一半
+	if w <= 0 || h <= 0 {
+		return nil, fmt.Errorf("DIB 尺寸非法 w=%d h=%d", w, h)
+	}
+	if bits != 32 {
+		return nil, fmt.Errorf("只支持 32bpp，实际 %d", bits)
+	}
+
+	img := image.NewNRGBA(image.Rect(0, 0, w, h))
+	xor := b[40:]
+	stride := w * 4
+	for row := 0; row < h; row++ {
+		srcRow := h - 1 - row // DIB 自下而上
+		for x := 0; x < w; x++ {
+			i := srcRow*stride + x*4
+			if i+4 > len(xor) {
+				return nil, fmt.Errorf("像素数据不足")
+			}
+			o := row*img.Stride + x*4
+			img.Pix[o+0] = xor[i+2] // R
+			img.Pix[o+1] = xor[i+1] // G
+			img.Pix[o+2] = xor[i+0] // B
+			img.Pix[o+3] = xor[i+3] // A
+		}
+	}
+	return img, nil
+}
+
+func fail(err error) {
+	fmt.Fprintln(os.Stderr, "✗ "+err.Error())
+	os.Exit(1)
+}