Code archives/Graphics/Fat Functions
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| Add thickness to Lines, Rects, Ovals, Stars, & Circles with these little functions. Rects and Ovals can be rotated through 360 degrees in near realtime (depending on size and thickness). Optimized for speed, and displays without annoying artifacts (holes in thick lines). Functions are commented and includes usage examples. Update: fatSuperEllipse function added. Very useful. | |||||
;This simple 2D demo shows examples of using lines of varying thickness to create graphic primitives.
;There are other methods to achieve the same results but other methods are usually plagued by 'banding'
; (artifacts caused by not filling in the thick line completely). These functions are free of 'banding' artifacts.
;The functions are:
; fatLine
; fatBox
; fatOval
; fatStar
; fatCircle
; fatSuperEllipse
;
;The fatBox and fatOval functions also allow full rotation through 360 degrees.
;Have commented the functions fairly well and each function has a description of the required parameters.
;
;I've tried to optimize all of the functions for speed, but some can be
;tweaked for better results by removing parameter checking and using LUT's.
;
;All of the functions except fatCircle are dependent on fatLine for line thickness, so if you want
;to use any of the other functions,don't forget to copy the fatLine function to
;your application as well. If you don't need the line thickness in the other functions,
;just replace all references to fatLine with Blitz's Line() function.
;
;fatLine written in Blitz+ by Andy Amaya 2003.06.23
;fatFunctions compiled 2003.10.02
;Update - fatSuperEllipse() function added 2003.10.06
;
;Feel free to use these routines as you see fit. Enjoy 8)
; ------> Press any key to cycle through the different examples
Const sw% = 800
Const sh% = 600
Const cx% = sw%/2
Const cy% = sh%/2
Graphics sw, sh, 16
SetBuffer BackBuffer()
SeedRnd MilliSecs()
fntArial=LoadFont("Arial",24,True,False,False)
SetFont fntArial
Cls
Gosub DrawFatLines
Gosub TrapKey
Gosub DrawFatBoxes
Gosub TrapKey
Gosub DrawFatCircles
Gosub TrapKey
Gosub DrawFatStars
Gosub DrawGlobe
Gosub TrapKey
Gosub DrawSuperEllipses
Gosub TrapKey
Gosub Swirly
End
.TrapKey
WaitKey
Return
.DrawFatLines
Cls
For i% = 1 To 360 Step 5
j% = Cos(i%) * cx% + cx%
k% = Sin(i%) * cy% + cy%
Color Rand(64,255),Rand(64,255),Rand(64,255)
;fatLine(x1%, y1%, x2%, y2%, penSize%) <-- shows syntax of function call
fatLine( cx%, cy%, j%, k%, Rand(1,25))
Next
Color 255,255,255
Text 0,0,"Randomly thick lines"
Flip
Return
.DrawFatBoxes
Cls
For i% = 0 To 14
Color Rand(64,255),Rand(64,255),Rand(64,255)
tcX% = Cos(i%*24) * 30 + cx%
tcY% = Sin(i%*24) * 30 + cy%
;fatBox( x%, y%, wide%, high%, penSize%, rotAngle%) <-- shows syntax of function call
fatBox(tcX%, tcY%, 160, 60, 3, i%*24)
fatBox(tcX%, tcY%, 170, 50, 3, i%*24)
fatBox(tcX%, tcY%, 180, 40, 3, i%*24)
fatBox(tcX%, tcY%, 190, 30, 3, i%*24)
fatBox(tcX%, tcY%, 200, 20, 3, i%*24)
fatBox(tcX%, tcY%, 210, 10, 3, i%*24)
Next
Color 255,255,255
Text 0,0,"Rotated rectangles"
Flip
Return
.DrawFatCircles
Cls
r% = 255: g% = 0 : b% = 0
y% = 5
pen% = 1
rad% = 5
While y% <= 620
Color r%, g%, b%
x% = 0
While x% <= 850
;fatCircle(centerX%, centerY%, rad%, penSize%) <-- shows syntax of function call
fatCircle( x%, y%, rad%, pen%)
x% = x% + rad% * 2 + pen%
Wend
pen% = pen% + 1
rad% = rad% + 2
y% = y% + rad% * 2 + pen
r% = r% - 18
g% = g% + 18
Wend
Color 255,255,255
Text 0,0,"Circles of varying thickness"
Flip
Return
.DrawFatStars
pen% = 1
While GetKey() = 0
For j = 30 To 70 Step 2
Cls
For i% = 1 To 5
outy% = i * j
inny% = outy%/2.6
If i% And 1 Then Color 255,96,0 Else Color 255,255,0
;fatStar(centerX%, centerY%, majorRadius%, minorRadius%, points%, penSize%, mode%) <-- shows syntax of function call
fatStar( cx%, cy%, outy%, inny%, 12, pen%, 0)
Next
Color 255,255,255
Text 0,0,"Variable sized stars"
Flip
Next
For j = 70 To 30 Step -2
Cls
For i% = 1 To 5
outy% = i * j
inny% = outy%/2.6
If i% And 1 Then Color 255,96,0 Else Color 255,255,0
;fatStar(centerX%, centerY%, majorRadius%, minorRadius%, points%, penSize%, mode%) <-- shows syntax of function call
fatStar( cx%, cy%, outy%, inny%, 12, pen%, 0)
Next
Color 255,255,255
Text 0,0,"Variable sized stars"
Flip
Next
For j = 30 To 70
Cls
For i% = 1 To 5
outy% = i * j
inny% = outy%/2.6
If i% And 1 Then Color 255,96,0 Else Color 255,255,0
;fatStar(centerX%, centerY%, majorRadius%, minorRadius%, points%, penSize%, mode%) <-- shows syntax of function call
fatStar( cx%, cy%, outy%, inny%, 5, pen%, 0)
Next
Color 255,255,255
Text 0,0,"Variable sized stars"
Flip
Next
For j = 70 To 30 Step -1
Cls
For i% = 1 To 5
outy% = i * j
inny% = outy%/2.6
If i% And 1 Then Color 255,96,0 Else Color 255,255,0
;fatStar(centerX%, centerY%, majorRadius%, minorRadius%, points%, penSize%, mode%) <-- shows syntax of function call
fatStar( cx%, cy%, outy%, inny%, 5, pen%, 0)
Next
Color 255,255,255
Text 0,0,"Variable sized stars"
Flip
Next
Wend
Return
.DrawGlobe
pen% = 2
globe = 225
globeStep = globe/15
counter = 0
toggle = 0
Cls
Flip
Cls
For rotate = 0 To 360 Step 15
t = 0
While t <= globe
penColor% = (penColor% + 1) Mod 3
Select penColor
Case 0: Color 0, 0, 255
Case 1: Color 0, 255, 0
Case 2: Color 255, 0, 0
End Select
u = globe-t
;fatOval(centerX%, centerY%, wide%, high%, penSize%, rotAngle%,interval%) <-- shows syntax of function call
fatOval( cx, cy, u, globe, pen%, rotate, 40)
counter = counter + 2
t = t + globeStep
Wend
Flip
Next
Color 255,255,255
Text 0,0,"Sphere made from rotated ovals"
Flip
Return
.Swirly
pen% = 2
toggle = 0
ClsColor 4,4,80
Cls
Repeat
;jiggle% = Rand(0,5) ;Jiggles center of whirlpool while spinning
For j% = 360 To 15 Step -15
Cls
iwx% = Rand(cx% - jiggle%, cx% + jiggle%)
iwy% = Rand(cy% - jiggle%, cy% + jiggle%)
For i% = 15 To 270 Step 15
toggle% = 1 - toggle%
If toggle Color 0,0,255 Else Color 16,16,192
;fatOval(centerX%, centerY%, wide%, high%, penSize%, rotAngle%,interval%) <-- shows syntax of function call
fatOval( iwx%, iwy%, i% Shl 1, i%, pen%, i%+j%, 24)
If GetKey() <> 0 Then flag% = 1: Exit
Next
Color 255 , 255 , 255
Text 0,0,"Whirlpool (rotating ovals)"
Flip
If flag% Then Exit
Next
If flag% Then Exit
Forever
Return
.DrawSuperEllipses
ClsColor 160,192,255
Cls
Color 96,96,96
For i% = 16 To 799 Step 16
Line(i%, 48, i%, 576)
Next
For i% = 48 To 576 Step 16
Line(0, i%, 799, i%)
Next
r% = 0: g% = 0: b% = 255
fpen# = 2
k% = 0
For j% = 32 To 795 Step 60
Color r%, g%, b%
; (show fatSuperEllipse() function syntax)
; fatSuperEllipse(centerX%, centerY%, wide%, high%, exponent#, levelOfDetail#, penSize%, rotAngle%)
fatSuperEllipse j%, 77, 24, 18, .4, 20.0, fpen#, k%
fatSuperEllipse j%, 134, 24, 18, .75, 20.0, fpen#, k%
fatSuperEllipse j%, 191, 24, 18, 1, 90.0, fpen#, k%
fatSuperEllipse j%, 248, 24, 24, 2, 72, fpen#, k%
fatSuperEllipse j%, 305, 24, 24, 2, 51.428571, fpen#, k%
fatSuperEllipse j%, 362, 24, 18, 2, 20.0, fpen#, k%
fatSuperEllipse j%, 420, 24, 18, 3, 20.0, fpen#, k%
fatSuperEllipse j%, 477, 24, 18, 5, 20.0, fpen#, k%
fatSuperEllipse j%, 534, 24, 18, 10, 15.0, fpen#, k%
k% = k% + 30
r% = r% + 21.25
b% = b% - 21.25
fpen# = fpen# + .3
Next
Color 0,0,128
For i% = 0 To 12
angle$ = Str$(i% * 30) + "°"
wid% = StringWidth(angle$)
Text (i * 61 - wid% + 42), 576,angle$
Next
msg$ = "All of these shapes created using just one function: fatSuperEllipse!"
wid% = StringWidth(msg$)
Text (800-wid%)/2,10,msg$
Flip
Return
;********************************** fatLine ******************************************
;** Parameters are: **
;** x1%, y1%, x2%, y2%, penSize% **
;** **
;** x1%, y1% are the coords of the line origin **
;** x2%, y2% are the coords of the line end point **
;** penSize% is the thickness of line to be drawn **
;** **
;** BRESLINE.PAS - A general line drawing procedure. **
;** By Mark Feldman **
;** **
;** Source: http://www.gamedev.net/reference/articles/article767.asp **
;** **
;** Adapted for Blitz+ fatLine function by Andy Amaya **
;** **
;*****************************************************************************************
Function fatLine(x1%, y1%, x2%, y2%, penSize%)
If penSize% < 1 Then Return False
If penSize% = 1 Then Line(x1%, y1%, x2%, y2%): Return
; penSize% is thickness to draw line
offset% = penSize% / 2 ;offset needed to place Oval correctly
; Calculate deltax and deltay for initialization
deltax% = Abs(x2% - x1%)
deltay% = Abs(y2% - y1%)
; Initialize all vars based on which is the independent variable
If deltax% >= deltay% Then
; x is the independent variable
numovals% = deltax% + 1
d% = (2 * deltay%) - deltax%
dinc1% = deltay% Shl 1
dinc2% = (deltay% - deltax%) Shl 1
xinc1% = 1
xinc2% = 1
yinc1% = 0
yinc2% = 1
Else
; y is the independent variable
numovals% = deltay% + 1
d% = (2 * deltax%) - deltay%
dinc1% = deltax% Shl 1
dinc2% = (deltax% - deltay%) Shl 1
xinc1% = 0
xinc2% = 1
yinc1% = 1
yinc2% = 1
End If
; Make sure x and y move in the right directions
If x1% > x2% Then
xinc1% = - xinc1%
xinc2% = - xinc2%
End If
If y1% > y2% Then
yinc1% = - yinc1%
yinc2% = - yinc2%
End If
; Start drawing at x%, y%
x% = x1% - offset%
y% = y1% - offset%
; Draw the filled ovals
For i% = 1 To numovals%
Oval x%, y%, penSize%, penSize%, 1
If d% < 0 Then
d% = d% + dinc1%
x% = x% + xinc1%
y% = y% + yinc1%
Else
d% = d% + dinc2%
x% = x% + xinc2%
y% = y% + yinc2%
End If
Next
End Function
;********************************** fatBox ******************************************
;** Parameters are: **
;** x%, y%, wide%, high%, penSize%, rotAngle% **
;** **
;** x%, y% are the coords of the upper left corner of the box to be plotted **
;** this function rotates box around the upper left corner (not center of box) **
;** wide% is the width of the box **
;** high% is the height of the box **
;** penSize% is the thickness of lines used to plot box **
;** rotAngle% is the rotation angle of the box to be plotted (0 to 360 typically) **
;** **
;*****************************************************************************************
Function fatBox(x%, y%, wide%, high%, penSize%, rotAngle%)
If rotAngle > 360 Then rotAngle = rotAngle Mod 360
;No rotation involved, so just draw a box
If rotAngle% = 0 Or rotAngle% = 360 Then
fatLine(x% , y% , x% + wide%, y% , penSize%)
fatLine(x% + wide%, y% , x% + wide%, y% + high%, penSize%)
fatLine(x% , y% + high%, x% + wide%, y% + high%, penSize%)
fatLine(x% , y% , x%, y% + high%, penSize%)
Else
;Make rotation calculations and draw rotated box
vtx% = rotAngle% + 90
cs% = Cos(vtx%) * high%
sn% = Sin(vtx%) * high%
x1% = Cos(rotAngle%)* wide% + x%
y1% = Sin(rotAngle%)* wide% + y%
fatLine(x%, y%, x1%, y1%, penSize%)
x2% = cs% + x1%
y2% = sn% + y1%
fatLine(x1%, y1%, x2%, y2%, penSize%)
x3% = cs% + x%
y3% = sn% + y%
fatLine(x%, y%, x3%, y3%, penSize%)
fatLine(x2%, y2%, x3%, y3%, penSize%)
End If
End Function
;********************************** fatOval ******************************************
;** Parameters are: **
;** centerX%, centerY%, wide%, high%, penSize%, rotAngle%, sides% **
;** **
;** centerX%, centerY% coords locate center of oval to be plotted **
;** wide% is the x-radius of the oval **
;** high% is the y-radius of the oval **
;** penSize% is the thickness of lines used to plot oval **
;** rotAngle% is the rotation angle of the oval to plot (0 to 359) **
;** sides% is the number of connected points on plotted oval **
;** **
;*****************************************************************************************
Function fatOval(centerX%, centerY%, wide%, high%, penSize%, rotAngle%, sides%)
;360 sides generates the smoothest oval, 3 sides generates a triangle
;interval# is the number of degrees between plotted points
interval# = Float(360 / sides%)
If interval# <= 0.0 Or interval# > 180.0 Then Return False
;Keep rotAngle between 0 and 359
rotAngle% = rotAngle% Mod 360
If penSize% < 1 Then Return False
;If rotation angle is 0 don't do extra calculations
If rotAngle% = 0 Then
x1% = wide% + centerX%
y1% = centerY%
;This While..Wend is same as For i# = interval# To 360.0 Step interval#)
i# = interval#
While i# <= 360.0
x2% = Cos(i#) * wide% + centerX%
y2% = Sin(i#) * high% + centerY%
fatLine(x1%, y1%, x2%, y2%, penSize%)
x1% = x2%
y1% = y2%
i# = i# + interval# ;(increment loop index, else you end up with a Repeat..Forever loop)
Wend
Else
;Make rotation calculations and draw oval
cs# = Cos(rotAngle%)
sn# = Sin(rotAngle%)
x1% = cs# * wide% + centerX%
y1% = sn# * wide% + centerY%
;This While..Wend is same as For i# = interval# To 360.0 Step interval#)
i# = interval#
While i# <= 360.0
rotX# = Cos(i#) * wide%
rotY# = Sin(i#) * high%
x2% = cs# * rotX# - sn# * rotY# + centerX%
y2% = sn# * rotX# + cs# * rotY# + centerY%
fatLine(x1%, y1%, x2%, y2%, penSize%)
x1% = x2%
y1% = y2%
i# = i# + interval# ;(increment loop index, else you end up with a Repeat..Forever loop)
Wend
End If
End Function
;********************************** fatStar ******************************************
;** Parameters are: **
;** centerX%, centerY%, majorRadius%, minorRadius%, points%, penSize%, mode% **
;** **
;** centerX%, centerY% coords locate center of star to be plotted **
;** majorRadius% is the size of 'convex' star points **
;** minorRadius% is the size of 'concave' star points **
;** points% is the number of ;convex; star points: 3 - 180 are valid number of points **
;** penSize% sets the thickness for lines that draw the star **
;** **
;*****************************************************************************************
Function fatStar(centerX%, centerY%, majorRadius%, minorRadius%, points%, penSize%, mode%)
;tell function to draw a star with 3 to 180 'convex' points, otherwise can't do - Return False
If points% < 3 Or points% > 180 Then Return False
;inc is number of star points times 2
;For example: a five point star has 5 ;convex; points + 5 ;concave; points
inc# = 360.0/(points * 2)
;initialize variables
;toggle keeps track of 'concave' And 'convex' radii
toggle% = 0
;calculate First x,y coords to start due north of center point
oldX% = centerX ;same as Cos(270)*majorRadius + centerX
oldY% = -majorRadius + centerY ;same as Sin(270)*majorRadius + centerY
;remember First x,y coords To close polyStar
firstX% = oldX%: firstY% = oldY%
;loop that draws the star
;next 3 lines are equivalent to: For i# = inc# To 360 - (inc#-1) Step inc
i# = 0
While i# <= 360 - (inc#-1)
i# = i# + inc#
;start first star point due north of center point
angle% = i# + 270
;scale back degrees to between 0 And 360
angle = angle Mod 360
;make toggle either 0 Or 1
toggle% = 1 - toggle%
;If toggle is 1 Then calculate a 'concave' point x,y pair
If toggle Then
;valid minorRadius values for stars are integers: 0 < minorRadius < majorRadius
newX% = Cos(angle) * minorRadius + centerX
newY% = Sin(angle) * minorRadius + centerY
;draw a line from last 'convex' point to new 'concave' point
fatLine(oldX, oldY, newX, newY, penSize)
;If mode = 1 Then draw lines from center of star to a 'concave' point
If mode% Then
fatLine(newX, newY, centerX, centerY, penSize)
End If
Else
;valid majorRadius values for stars are integers: 0 < minorRadius <= majorRadius
newX = Cos(angle) * majorRadius+ centerX
newY = Sin(angle) * majorRadius+ centerY
;draw a line from last 'concave' point to new 'convex' point
fatLine(oldX, oldY, newX, newY, penSize)
End If
;remember last x,y pair to use as start for the next line segment
oldX = newX
oldY = newY
Wend
;close the polyStar by drawing line from last 'concave' point to 1st 'convex' point
fatLine(oldX, oldY, firstX, firstY, penSize)
End Function
;********************************** fatCircle ******************************************
;** Parameters are: **
;** centerX%, centerY%, rad%, penSize% **
;** **
;** centerX%, centerY% coords locate center of circle to be plotted **
;** rad% is the radius of the circle **
;** penSize% is the line thickness used to draw circle **
;** **
;** Note: Bresenham's circle algorithm is smoother but is about 10 times slower **
;** **
;*****************************************************************************************
Function fatCircle(centerX%, centerY%, rad%, penSize%)
If penSize < 1 Or rad% < 1 Then Return False
If penSize% = 1 Then Oval centerX%-rad%, centerY%-rad%, rad% Shl 1, rad% Shl 1, 0: Return
offset% = penSize% Shr 1
For i% = 0 To 360
a% = Cos(i%) * rad% + centerX%
b% = Sin(i%) * rad% + centerY%
Oval a% - offset%, b% - offset%, penSize%, penSize%, 1
Next
End Function
;****************************** fatSuperEllipse *************************************
;** Parameters are: **
;** centerX%, centerY%, wide%, high%, exponent#, levelOfDetail, penSize%, rotAngle% **
;** **
;** centerX%, centerY% coords locate center of SuperEllipse to be plotted **
;** wide% is the x-radius of the SuperEllipse **
;** high% is the y-radius of the SuperEllipse **
;** exponent# determines the overall shape of the SuperEllipse (0.1 to 99 typical) **
;** levelOfDetail# - determines number of points plotted & connected with lines **
;** penSize% is the thickness of lines used to plot SuperEllipse ( 1 to 200 typical) **
;** rotAngle% is the rotation angle of the SuperEllipse plotted ( 0 to 360 typical) **
;** **
;** Sources: **
;** http://www.cs.colorado.edu/lizb/graphics.html **
;** http://astronomy.swin.edu.au/pbourke/surfaces/superellipse/ **
;** http://www.wikipedia.org/wiki/Super_ellipse **
;** **
;** Ported to Blitz+ by Andy Amaya 2003.10.06 **
;*****************************************************************************************
Function fatSuperEllipse (centerX%, centerY%, wide%, high%, exponent#, levelOfDetail#, penSize%, rotAngle%)
rotAngle% = rotAngle% Mod 360
;Make sure we don't get any divide by zero errors
If exponent# = 2.0 Or Exponent = 0.0 Then
power# = 0.0
Else
power# = 2.0/exponent#-1
End If
;If rotation angle is zero then don't do the extra calculations
If rotAngle% = 0 Then
theta# = 0.0
;determine the first x,y coords
x1% = wide% * 1.0^power# + centerX%
y1% = centerY%
;initialize theta (current angle) and loop variable
theta# = levelOfDetail#
limit# = 360.0 + levelOfDetail#
While theta# <= limit#
cosTheta# = Cos(theta#)
sinTheta# = Sin(theta#)
;calculate x,y coords using Super Ellipse formula
x2% = wide% * cosTheta# * Abs(cosTheta#)^power# + centerX%
y2% = high% * sinTheta# * Abs(sinTheta#)^power# + centerY%
;connect the 2 sets of coords calculated with a line
fatLine (x1%, y1%, x2%, y2%, penSize%)
;last coords are now first coords of line
x1% = x2%
y1% = y2%
;increment loop variable by amount indicated by "levelOfDetail"
theta# = theta# + levelOfDetail#
Wend
Else
;need to rotate SuperEllipse, so do the extra math
theta# = 0.0
cosTheta# = 1.0
sinTheta# = 0.0
;pre-calc Cos() and Sin() of rotation angle
cs# = Cos(rotAngle%)
sn# = Sin(rotAngle%)
;calculate the first rotated x,y coords
rotX# = wide% * 1.0^power#
rotY# = 0.0
x1% = cs# * rotX# - sn# * rotY# + centerX%
y1% = sn# * rotX# + cs# * rotY# + centerY%
;initialize theta (current angle) and loop variable
theta# = levelOfDetail#
limit# = 360.0 + levelOfDetail#
While theta# <= limit#
cosTheta# = Cos(theta#)
sinTheta# = Sin(theta#)
;calculate the next pair of rotated x,y coords
rotX# = cosTheta# * wide% * Abs(cosTheta#)^power#
rotY# = sinTheta# * high% * Abs(sinTheta#)^power#
x2% = cs# * rotX# - sn# * rotY# + centerX%
y2% = sn# * rotX# + cs# * rotY# + centerY%
;connect the 2 sets of coords calculated with a line
fatLine(x1%, y1%, x2%, y2%, penSize)
;last coords are now first coords of line
x1% = x2%
y1% = y2%
;increment loop variable by amount indicated by "levelOfDetail"
theta# = theta# + levelOfDetail#
Wend
End If
End Function |
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