Everything in Degrees instead of Radians

[bplus]

Would it make understanding graphics easier to follow, specially employing Sin, Cos and _Atan2?

Here I've converted Sin, Cos, _Atan2, DrawArc and ArrowTo to using Degree Units in the Call to the Sub and internalized all the radian conversions inside the Sub.

Here is main Demo:

Code: (Select All)

' OK let's be rid on the confusion caused by Radians
' by using User Defined Functions SinD and CosD that take Degrees 0 to 360 for whole circle,
' and having replaced _Atan2 by returning an angle in Degrees between 2 points: DAtan2(baseX, baseY, angleToX, angleToY)

_Title "Degrees for everything" 'b+ 2022-10-12
Screen _NewImage(800, 600, 32) ' standard screen size 800 wide, 600 height for quick QB64 Demos with full color potential (the 32)
_ScreenMove 250, 50

cx = _Width / 2 ' middle of the screen point  center x
cy = _Height / 2 ' center y
radius = 250 ' max is 300 for height 600
ArrowTo cx, cy, 0, radius - 3, &HFFFFFFFF
For degrees = 0 To 359 Step 10 ' go around a full circle in degrees in steps of 10 degrees

    ' calculate and draw points around the center of the screen
    x = cx + radius * CosD(degrees) ' use CosD for x dimensions
    y = cy + radius * SinD(degrees) ' use SinD for y dimensions
    Circle (x, y), 1 ' draw bigger points than single pixel

    ' labeling the degree angles before or after the point ?
    If x < cx Then Xoffset = -10 * Len(_Trim$(Str$(degrees))): YOffset = 0
    If x > cx Then Xoffset = 4 * Len(_Trim$(Str$(degrees))): YOffset = 0
    If x = cx Then
        Xoffset = -4 * Len(_Trim$(Str$(degrees)))
        If y > cy Then YOffset = 20 Else YOffset = -20
    End If
    _PrintString (x + Xoffset, y - 8 + YOffset), _Trim$(Str$(degrees))
Next

' save our compass dial to image
dial& = _NewImage(_Width, _Height, 32)
_PutImage , 0, dial& ' screen to dial image stored

' Getting use to seeing angles mouse makes to center of screen
Do
    Cls
    _PutImage , dial&, 0
    While _MouseInput: Wend ' this checks where mouse is right now!
    mx = _MouseX: my = _MouseY: mb1 = _MouseButton(1) ' left mouse down  ' saves mouse status to common variable names
    'lets's the angle in degrees the mouse is to the center of the screen
    dAngle = DAtan2(cx, cy, mx, my)
    Print "The mouse pointer is "; _Trim$(Str$(dAngle)); " Degrees from the screen center." ' then center point is first the mouse point is second
    ArrowTo cx, cy, dAngle, radius - 3, &HFFFFFF00
    drawArc cx, cy, 70, 0, dAngle, &HFFFFFF00
    _Display ' stop the blinking
    _Limit 60 ' only loop 60 times per second
Loop Until _KeyDown(27)


' use angles in degrees units instead of radians (converted inside sub)
Function CosD (degrees)
    ' Note this function uses whatever the default type is, better not be some Integer Type.
    CosD = Cos(_D2R(degrees))
End Function

' use angles in degrees units instead of radians (converted inside sub)
Function SinD (degrees)
    ' Note this function uses whatever the default type is, better not be some Integer Type.
    SinD = Sin(_D2R(degrees))
End Function

' use angles in degrees units instead of radians (converted inside sub)
Function DAtan2 (x1, y1, x2, y2) ' The angle in degrees a 2nd point (x2, y2)  makes to a first point (x1, y1)
    ' Note this function uses whatever the default type is, better not be some Integer Type.
    ' Delta means change between 1 measure and another for example x2 - x1
    deltaX = x2 - x1
    deltaY = y2 - y1
    '  To find the angle point(x2, y2) makes to (x1, y1) in Degrees
    ' Take DegreeAngle = DAtan2(y2 - y1, x2 - x1)
    rtn = _R2D(_Atan2(deltaY, deltaX))
    If rtn < 0 Then DAtan2 = rtn + 360 Else DAtan2 = rtn
End Function

' use angles in degrees units instead of radians (converted inside sub)
Sub ArrowTo (BaseX As Long, BaseY As Long, dAngle As Double, lngth As Long, colr As _Unsigned Long)
    Dim As Long x1, y1, x2, y2, x3, y3
    Dim As Double rAngle
    rAngle = _D2R(dAngle)
    x1 = BaseX + lngth * Cos(rAngle)
    y1 = BaseY + lngth * Sin(rAngle)
    x2 = BaseX + .8 * lngth * Cos(rAngle - _Pi(.05))
    y2 = BaseY + .8 * lngth * Sin(rAngle - _Pi(.05))
    x3 = BaseX + .8 * lngth * Cos(rAngle + _Pi(.05))
    y3 = BaseY + .8 * lngth * Sin(rAngle + _Pi(.05))
    Line (BaseX, BaseY)-(x1, y1), colr
    Line (x1, y1)-(x2, y2), colr
    Line (x1, y1)-(x3, y3), colr
End Sub

' use angles in degrees units instead of radians (converted inside sub)
Sub drawArc (xc, yc, radius, dStart, dMeasure, colr As _Unsigned Long)
    ' xc, yc Center for arc circle
    ' rStart is the Radian Start Angle, use _D2R for conversion from Degrees to Radians
    ' rMeasure is the measure of Arc in Radain units, use _D2R for conversion from Degrees to Radians
    ' Arc will start at rStart and go clockwise around for rMeasure Radians

    Dim rStart, rMeasure, rEnd, stepper, a, x, y
    rStart = _D2R(dStart)
    rMeasure = _D2R(dMeasure)
    rEnd = rStart + rMeasure
    stepper = 1 / radius ' the bigger the radius the smaller  the steps
    For a = rStart To rEnd Step stepper
        x = xc + radius * Cos(a)
        y = yc + radius * Sin(a)
        If a > rStart Then Line -(x, y), colr Else PSet (x, y), colr
    Next
End Sub