refactor(qrcode): optimise masking stage-2 (#55)

* feat: matrix.Iterate with COLUMN is preferred. * docs(qrcode): add comment to qrcode masking evaluation conditions. * styl(qrcode): split utilities functions * styl(qrcode): reduce fillDataBinary calls
yeqown · Dec 23, 2021 · 2729998 · 2729998
1 parent 3bd5445
commit 2729998
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Showing 9 changed files with 507 additions and 250 deletions.
diff --git a/debug.go b/debug.go
@@ -83,7 +83,7 @@ func debugDrawTo(w io.Writer, mat matrix.Matrix) error {
 	// background
 	rectangle(0, 0, width, height, img, color.White)
 
-	mat.Iterate(matrix.ROW, func(x int, y int, v matrix.State) {
+	mat.Iterate(matrix.COLUMN, func(x int, y int, v matrix.State) {
 		sx := x*blockWidth + padding
 		sy := y*blockWidth + padding
 		es := (x+1)*blockWidth + padding

diff --git a/mask.go b/mask.go
@@ -27,202 +27,6 @@ const (
 	modulo7
 )
 
-// calculateScore calculate the maskScore of masking result ...
-func calculateScore(mat *matrix.Matrix) int {
-	debugLogf("calculate maskScore starting")
-	score1 := rule1(mat.Copy())
-	score2 := rule2(mat.Copy())
-	score3 := rule3(mat.Copy())
-	score4 := rule4(mat.Copy())
-
-	debugLogf("maskScore: %d", score1+score2+score3+score4)
-	return score1 + score2 + score3 + score4
-}
-
-// 第一条规则为一行（或列）中的每组五个或更多相同颜色的模块提供QR代码。
-func rule1(mat *matrix.Matrix) int {
-	// Row socre
-	var (
-		score          int
-		rowCurState    matrix.State
-		rowCurColorCnt int
-
-		colCurState    matrix.State
-		colCurColorCnt int
-	)
-
-	mat.Iterate(matrix.ROW, func(x, y int, value matrix.State) {
-		if x == 0 {
-			rowCurColorCnt = 0
-			rowCurState = value
-			return
-		}
-
-		if value == rowCurState {
-			rowCurColorCnt++
-		} else {
-			rowCurState = value
-		}
-
-		if rowCurColorCnt == 5 {
-			score += 3
-		} else if rowCurColorCnt > 5 {
-			score++
-		}
-	})
-
-	// column
-	mat.Iterate(matrix.COLUMN, func(x, y int, value matrix.State) {
-		if x == 0 {
-			colCurColorCnt = 0
-			colCurState = value
-			return
-		}
-
-		if value == colCurState {
-			colCurColorCnt++
-		} else {
-			colCurState = value
-		}
-
-		if colCurColorCnt == 5 {
-			score += 3
-		} else if colCurColorCnt > 5 {
-			score++
-		}
-	})
-	return score
-}
-
-// 第二个规则给出了QR码对矩阵中相同颜色模块的每个2x2区域的惩罚。
-func rule2(mat *matrix.Matrix) int {
-	var (
-		score          int
-		s0, s1, s2, s3 matrix.State
-	)
-	for x := 0; x < mat.Width()-1; x++ {
-		for y := 0; y < mat.Height()-1; y++ {
-			s0, _ = mat.Get(x, y)
-			s1, _ = mat.Get(x+1, y)
-			s2, _ = mat.Get(x, y+1)
-			s3, _ = mat.Get(x+1, y+1)
-
-			if s0 == s1 && s2 == s3 && s1 == s2 {
-				score += 3
-			}
-		}
-	}
-
-	return score
-}
-
-// 如果存在看起来类似于取景器模式的模式，则第三规则给QR码一个大的惩罚
-// dark-light-dark-dark-dark-light-dark
-// 1011101 0000 or 0000 1011101
-//func rule3_backup(mat *matrix.Matrix) (score int) {
-//	for y := 0; y < mat.Height(); y++ {
-//		for x := 0; x < mat.Width()-11; x++ {
-//			stateSlice := make([]matrix.State, 0, 11)
-//			for i := 0; i < 11; i++ {
-//				s, _ := mat.Get(x+i, y)
-//				stateSlice = append(stateSlice, s)
-//			}
-//			if matrix.StateSliceMatched(statePattern1, stateSlice) {
-//				score += 40
-//			}
-//			if matrix.StateSliceMatched(statePattern2, stateSlice) {
-//				score += 40
-//			}
-//		}
-//	}
-//
-//	for x := 0; x < mat.Width(); x++ {
-//		for y := 0; y < mat.Height()-11; y++ {
-//			stateSlice := make([]matrix.State, 0, 11)
-//			for i := 0; i < 11; i++ {
-//				s, _ := mat.Get(x, y+i)
-//				stateSlice = append(stateSlice, s)
-//			}
-//			if matrix.StateSliceMatched(statePattern1, stateSlice) {
-//				score += 40
-//			}
-//			if matrix.StateSliceMatched(statePattern2, stateSlice) {
-//				score += 40
-//			}
-//		}
-//	}
-//
-//	return score
-//}
-
-// rule3 calculate punishment score in rule3, find pattern in QR Code matrix.
-func rule3(mat *matrix.Matrix) (score int) {
-	var (
-		pattern1     = binaryToStateSlice("1011101 0000")
-		pattern2     = binaryToStateSlice("0000 1011101")
-		pattern1Next = kmpGetNext(pattern1)
-		pattern2Next = kmpGetNext(pattern2)
-	)
-
-	// prerequisites:
-	//
-	// mat.Width() == mat.Height()
-	if mat.Width() != mat.Height() {
-		debugLogf("rule3 got matrix but not matched prerequisites")
-	}
-	dimension := mat.Width()
-
-	for i := 0; i < dimension; i++ {
-		col := mat.Col(i)
-		row := mat.Row(i)
-
-		// DONE(@yeqown): statePattern1 and statePattern2 are fixed, so maybe kmpGetNext
-		// could cache result to speed up.
-		score += 40 * kmp(col, pattern1, pattern1Next)
-		score += 40 * kmp(col, pattern2, pattern2Next)
-		score += 40 * kmp(row, pattern1, pattern1Next)
-		score += 40 * kmp(row, pattern2, pattern2Next)
-	}
-
-	return score
-}
-
-// 如果超过一半的模块是暗的或轻的，则第四规则给QR码一个惩罚，对较大的差异有较大的惩罚
-func rule4(mat *matrix.Matrix) int {
-	var (
-		totalCnt             = mat.Width() * mat.Height()
-		darkCnt, darkPercent int
-	)
-	mat.Iterate(matrix.ROW, func(x, y int, s matrix.State) {
-		if s == matrix.StateTrue {
-			darkCnt++
-		}
-	})
-	darkPercent = (darkCnt * 100) / totalCnt
-	x := 0
-	if darkPercent%5 == 0 {
-		x = 1
-	}
-	last5Times := abs(((darkPercent/5)-x)*5 - 50)
-	next5Times := abs(((darkPercent/5)+1)*5 - 50)
-
-	// get the min maskScore
-	if last5Times > next5Times {
-		// scoreC <- next5Times / 5 * 10
-		return next5Times * 2
-	} else {
-		return last5Times * 2
-	}
-
-}
-
-func abs(x int) int {
-	if x < 0 {
-		return -x
-	}
-	return x
-}
-
 type mask struct {
 	mat      *matrix.Matrix    // matrix
 	mode     maskPatternModulo // mode
@@ -275,7 +79,7 @@ func (m *mask) masking() {
 		panic("impossible panic, contact maintainer plz")
 	}
 
-	m.mat.Iterate(matrix.ROW, func(x, y int, s matrix.State) {
+	m.mat.Iterate(matrix.COLUMN, func(x, y int, s matrix.State) {
 		// skip the function modules
 		if state, _ := m.mat.Get(x, y); state != matrix.StateInit {
 			_ = m.mat.Set(x, y, matrix.StateInit)
@@ -336,18 +140,3 @@ func modulo6Func(x, y int) bool {
 func modulo7Func(x, y int) bool {
 	return ((x+y)%2+(x*y)%3)%2 == 0
 }
-
-func binaryToStateSlice(s string) []matrix.State {
-	var states = make([]matrix.State, 0, len(s))
-	for _, c := range s {
-		switch c {
-		case '1':
-			states = append(states, matrix.StateTrue)
-		case '0':
-			states = append(states, matrix.StateFalse)
-		default:
-			continue
-		}
-	}
-	return states
-}