initial commits

maxint.go

@@ -0,0 +1,3 @@
+package imgrow
+
+const intMax = int(^uint(0) >> 1)

minint.go

@@ -0,0 +1,3 @@
+package imgrow
+
+const intMin = -intMax - 1

scalexy.go

@@ -0,0 +1,8 @@
+package imgrow
+
+func scaleXY(scalar int, x int, y int) (int, int) {
+	x2 := x * scalar
+	y2 := y * scalar
+
+	return x2, y2
+}

scalexy_test.go

@@ -0,0 +1,86 @@
+package imgrow
+
+import (
+	"testing"
+)
+
+func TestScaleXY(t *testing.T) {
+
+	tests := []struct{
+		Scalar int
+		X int
+		Y int
+		ExpectedX int
+		ExpectedY int
+	}{
+		{
+			Scalar: -2,
+			X: 5,
+			Y: 7,
+			ExpectedX: -10,
+			ExpectedY: -14,
+		},
+		{
+			Scalar: -1,
+			X: 5,
+			Y: 7,
+			ExpectedX: -5,
+			ExpectedY: -7,
+		},
+		{
+			Scalar: 0,
+			X: 5,
+			Y: 7,
+			ExpectedX: 0,
+			ExpectedY: 0,
+		},
+		{
+			Scalar: 1,
+			X: 5,
+			Y: 7,
+			ExpectedX: 5,
+			ExpectedY: 7,
+		},
+		{
+			Scalar: 2,
+			X: 5,
+			Y: 7,
+			ExpectedX: 10,
+			ExpectedY: 14,
+		},
+		{
+			Scalar: 3,
+			X: 5,
+			Y: 7,
+			ExpectedX: 15,
+			ExpectedY: 21,
+		},
+
+
+
+
+		{
+			Scalar: 100,
+			X: -11,
+			Y: 13,
+			ExpectedX: -1100,
+			ExpectedY: 1300,
+		},
+	}
+
+	for testNumber, test := range tests {
+
+		actualX, actualY := scaleXY(test.Scalar, test.X, test.Y)
+		expectedX, expectedY := test.ExpectedX, test.ExpectedY
+
+		if expectedX != actualX || expectedY != actualY {
+			t.Errorf("For test #%d, the actual value is not what was expected.", testNumber)
+			t.Logf("EXPECTED (X,Y) = (%d, %d)", expectedX, expectedY)
+			t.Logf("ACTUAL (X,Y) = (%d, %d)", actualX, actualY)
+			t.Logf("SCALAR = %d", test.Scalar)
+			t.Logf("(X,Y) = (%d, %d)", test.X, test.Y)
+			continue
+		}
+
+	}
+}