Go方法参数和float64数组产生意外错误

Question

When compiling the following code...

package camera

type camera struct {
    position [3]float64
    viewWidth int
    viewHeight int
}

func (c camera) SwitchToCartesianThreeSpace(x, y int) [3]float64 { // LINE 9
    var x3 float64 = 0 // view is set to the origin
    var y3 float64 = float64(x) - (float64(c.viewWidth) / 2)
    var z3 float64 = float64(-y) + (float64(c.viewHeight) / 2)
    result := [3]float64{x3, y3, z3}                               // LINE 13
    return result
}

...the following errors occur.

camera/camera.go:9: undefined: x
camera/camera.go:9: undefined: y
camera/camera.go:11: undefined: x
camera/camera.go:12: undefined: y
camera/camera.go:13: cannot use x3 (type float64) as type [3]float64 in array element
camera/camera.go:13: cannot use y3 (type float64) as type [3]float64 in array element
camera/camera.go:13: cannot use z3 (type float64) as type [3]float64 in array element

I've written a fair amount of Go code so far and do not understand why the errors on line 9 or the errors on line 13 are occurring! Anyone able to explain?

Answer 1

Isolating in a playgroud, it compiles just fine, and has the expected output:

c := camera{}
res := c.SwitchToCartesianThreeSpace(2, 3)
// res is [0 2 -3]

You need to try with a camera.go including only that code, or check how the camera.go file fits in your current workspace.