fix: scanmode

pkg/geo/grids/grid_test.go

@@ -736,3 +736,20 @@ func BenchmarkGridPoint(b *testing.B) {
 		}
 	})
 }
+
+func TestTianjiGrid(t *testing.T) {
+	grid := latlon.NewLatLonGrid(-89.95, 89.95, 0.05, 359.95, 0.1, 0.1)
+
+	var tests = []gridTestCase{
+		// 网格点精确匹配
+		{name: "First Column Start", lat: -89.95, lon: 0.05, expectedIdx: 0, gridLat: -89.95, gridLon: 0.05},
+		{name: "First Column Second Point", lat: -89.95, lon: 0.15, expectedIdx: 1, gridLat: -89.95, gridLon: 0.15},
+		{name: "First Column End", lat: -89.95, lon: 359.95, expectedIdx: 3599, gridLat: -89.95, gridLon: 359.95},
+		{name: "Second Column Start", lat: -89.85, lon: 0.05, expectedIdx: 3600, gridLat: -89.85, gridLon: 0.05},
+		{name: "Second Column End", lat: -89.85, lon: 359.95, expectedIdx: 3600 + 3599, gridLat: -89.85, gridLon: 359.95},
+		{name: "Last Column Start", lat: 89.95, lon: 0.05, expectedIdx: 3600 * 1799, gridLat: 89.95, gridLon: 0.05},
+		{name: "Last Column End", lat: 89.95, lon: 359.95, expectedIdx: 3600*1799 + 3599, gridLat: 89.95, gridLon: 359.95},
+	}
+
+	runGridTests(t, grid, tests, grids.ScanModePositiveJ)
+}

pkg/geo/grids/scan_mode.go

@@ -8,73 +8,73 @@ type ScanMode uint8
 
 const (
 	// Bit 1: i (x) direction scanning
-	ScanModePositiveI ScanMode = 0 // Points scan in +i direction
-	ScanModeNegativeI ScanMode = 1 // Points scan in -i direction
+	ScanModePositiveI ScanMode = 0          // Points scan in +i direction
+	ScanModeNegativeI ScanMode = 0b10000000 // Points scan in -i direction
 
 	// Bit 2: j (y) direction scanning
-	ScanModeNegativeJ ScanMode = 0 // Points scan in -j direction
-	ScanModePositiveJ ScanMode = 2 // Points scan in +j direction
+	ScanModeNegativeJ ScanMode = 0          // Points scan in -j direction
+	ScanModePositiveJ ScanMode = 0b01000000 // Points scan in +j direction
 
 	// Bit 3: Adjacent points
-	ScanModeConsecutiveI ScanMode = 0 // Adjacent points in i direction are consecutive
-	ScanModeConsecutiveJ ScanMode = 4 // Adjacent points in j direction are consecutive
+	ScanModeConsecutiveI ScanMode = 0          // Adjacent points in i direction are consecutive
+	ScanModeConsecutiveJ ScanMode = 0b00100000 // Adjacent points in j direction are consecutive
 
 	// Bit 4: Row direction
-	ScanModeSameDirection ScanMode = 0 // All rows scan in same direction
-	ScanModeOppositeRows  ScanMode = 8 // Adjacent rows scan in opposite direction
+	ScanModeSameDirection ScanMode = 0          // All rows scan in same direction
+	ScanModeOppositeRows  ScanMode = 0b00010000 // Adjacent rows scan in opposite direction
 
 	// Bit 5: Odd row offset
-	ScanModeNoOddOffset ScanMode = 0  // Points within odd rows not offset
-	ScanModeOddOffset   ScanMode = 16 // Points within odd rows offset by Di/2
+	ScanModeNoOddOffset ScanMode = 0          // Points within odd rows not offset
+	ScanModeOddOffset   ScanMode = 0b00001000 // Points within odd rows offset by Di/2
 
 	// Bit 6: Even row offset
-	ScanModeNoEvenOffset ScanMode = 0  // Points within even rows not offset
-	ScanModeEvenOffset   ScanMode = 32 // Points within even rows offset by Di/2
+	ScanModeNoEvenOffset ScanMode = 0          // Points within even rows not offset
+	ScanModeEvenOffset   ScanMode = 0b00000100 // Points within even rows offset by Di/2
 
 	// Bit 7: J direction offset
-	ScanModeNoJOffset ScanMode = 0  // Points not offset in j direction
-	ScanModeJOffset   ScanMode = 64 // Points offset by Dj/2 in j direction
+	ScanModeNoJOffset ScanMode = 0          // Points not offset in j direction
+	ScanModeJOffset   ScanMode = 0b00000010 // Points offset by Dj/2 in j direction
 
 	// Bit 8: Row/Column point counts
-	ScanModeRegularPoints ScanMode = 0   // Regular Ni x Nj points
-	ScanModeOffsetPoints  ScanMode = 128 // Points may be reduced based on offsets
+	ScanModeRegularPoints ScanMode = 0          // Regular Ni x Nj points
+	ScanModeOffsetPoints  ScanMode = 0b00000001 // Points may be reduced based on offsets
 )
 
 // Helper methods to check individual bits
 func (s ScanMode) IsNegativeI() bool {
-	return s&1 == 1
+	return s&ScanModeNegativeI == ScanModeNegativeI
 }
 
 func (s ScanMode) IsPositiveJ() bool {
-	return s&2 == 2
+	return s&ScanModePositiveJ == ScanModePositiveJ
 }
 
 func (s ScanMode) IsConsecutiveI() bool {
-	return s&4 == 0
+	return s&ScanModeConsecutiveJ == 0
 }
 
 func (s ScanMode) IsConsecutiveJ() bool {
-	return s&4 == 4
+	return s&ScanModeConsecutiveJ == ScanModeConsecutiveJ
 }
 
 func (s ScanMode) HasOppositeRows() bool {
-	return s&8 == 8
+	return s&ScanModeOppositeRows == ScanModeOppositeRows
 }
 
 func (s ScanMode) HasOddOffset() bool {
-	return s&16 == 16
+	return s&ScanModeOddOffset == ScanModeOddOffset
 }
 
 func (s ScanMode) HasEvenOffset() bool {
-	return s&32 == 32
+	return s&ScanModeEvenOffset == ScanModeEvenOffset
 }
 
 func (s ScanMode) HasJOffset() bool {
-	return s&64 == 64
+	return s&ScanModeJOffset == ScanModeJOffset
 }
 
 func (s ScanMode) HasOffsetPoints() bool {
-	return s&128 == 128
+	return s&ScanModeOffsetPoints == ScanModeOffsetPoints
 }
 
 // String returns a human readable description of the scan mode