Filled Rotated Ellipses

-=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- (c) WidthPadding Industries 1987 0\|34\|0 -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=-
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Andy_A	Created : 03 July 2011 System : Windows Language : Blitz Filled Rotated Ellipses Rotate an ellipse to any angle and fill it
Not terribly fast but acceptable, less than 1ms per ellipse on average. ; Title: Filled Rotated Ellipses ;Programmer: Andy Amaya ; Date: 2011.06.20 ;======================================================= ;FillTriangle by Tom Toad ;https://www.blitzmax.com/codearcs/codearcs.php?code=1200 ;======================================================= AppTitle "Filled Rotated Ellipses" Global sw = 800 : sh = 600 Graphics sw, sh, 32, 2 ClsColor 255,222,173 numOvals = 30 While MouseHit(1) = 0 Cls LockBuffer() st = MilliSecs() For i = 1 To numOvals Color Rand(0,255),Rand(0,255),Rand(0,255) ovalWide = Rand(20,300) ovalHigh = ovalWide/2 ovalCentX = Rand(ovalWide/2,sw-ovalWide/2) ovalCenty = Rand(ovalWide/2+20,sh-ovalWide/2-20) angle# = Rand(0.0,359.0) rEllipse(ovalCentX, ovalCentY,ovalWide/2,ovalHigh/2,30, angle, 1) Next et = MilliSecs()-st UnlockBuffer() Color 0,0,0 Text 5,5,"et: "+et Text sw/2,sh-15,"R-click for more ovals L-click to exit",True Flip WaitMouse() Wend End Function rEllipse(centerX%, centerY%, radius1#, radius2#, segments#, angle#, filled%=0) ;============================== Rotated Ellipse Function ============================== ; Parameters are: ; ; centerX, centerY coords locate center of ellipse to be plotted ; radius1 is width of ellipse along the X axis ; radius2 is height of ellipse along the Y axis ; segments is number of line segments used to draw the ellipse (minimum of 3) ; angle is number of degrees to rotate the ellipse (NOTE: 0 degrees = East) ; filled - default is 0 to draw an unfilled ellipse else draw a filled ellipse ; ; NOTE: This function is dependent on fillTriangle() function to perform the filling ; of rotated ellipses. ;====================================================================================== Local rca#, rsa#, incSize#, i#, ca#, sa#, x1%, y1%, x2%, y2% rca = Cos(angle) : rsa = Sin(angle) If segments < 3.0 Then segments = 3.0 incSize = 360.0/segments If angle = 0 Then x1 = radius1+centerX : y1 = centerY Else x1 = rcaradius1+centerX : y1 = rsaradius1+centerY End If ; Plot x1, y1 i = incSize While i <= 360.01 ca = Cos(i)radius1 : sa = Sin(i)radius2 If angle = 0.0 Then x2 = Int(ca + centerX) : y2 = Int(sa + centerY) Else x2 = Int(rcaca-rsasa +centerX) : y2 = Int(rsaca+rcasa +centerY) End If ;if mode is zero draw an unfilled ellipse If filled = 0 Then Line x1, y1, x2, y2 Else ;otherwise use the fillTriangle function to fill current arc segment fillTriangle(centerX, centerY, x1, y1, x2, y2) End If x1 = x2 : y1 = y2 i = i + incSize Wend End Function ;======================================================= ;FillTriangle by Tom Toad ;https://www.blitzmax.com/codearcs/codearcs.php?code=1200 ;======================================================= Function fillTriangle(x1#,y1#,x2#,y2#,x3#,y3#) Local slope1#,slope2#,slope3#,x#,y#,length# ;make sure the triangle coordinates are ordered so that x1 < x2 < x3 If x2 < x1 Then x = x2: y = y2: x2 = x1: y2 = y1: x1 = x: y1 = y If x3 < x1 Then x = x3: y = y3: x3 = x1: y3 = y1: x1 = x: y1 = y If x3 < x2 Then x = x3: y = y3: x3 = x2: y3 = y2: x2 = x: y2 = y If x1 <> x3 Then slope1 = (y3-y1)/(x3-x1) length = x2 - x1 ;draw the first half of the triangle If length <> 0 Then slope2 = (y2-y1)/(x2-x1) For x = 0 To length Line x+x1,xslope1+y1,x+x1,xslope2+y1 Next End If y = lengthslope1+y1 length = x3-x2 ;draw the second half If length <> 0 Then slope3 = (y3-y2)/(x3-x2) For x = 0 To length Line x+x2,xslope1+y,x+x2,x*slope3+y2 Next End If End Function --v

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Filled Rotated Ellipses

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